From 58d416351e6df1a41d415958ccdd8eb9c2173fed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 12 Jul 2021 19:03:09 +0200 Subject: [PATCH 01/20] tools/certs: Add print-cert-tbs-hash.sh MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a new helper print-cert-tbs-hash.sh to generate a TBSCertificate hash from a given certificate. This is useful to generate a blacklist key description used to forbid loading a specific certificate in a keyring, or to invalidate a certificate provided by a PKCS#7 file. This kind of hash formatting is required to populate the file pointed out by CONFIG_SYSTEM_BLACKLIST_HASH_LIST, but only the kernel code was available to understand how to effectively create such hash. Cc: David Howells Cc: David Woodhouse Cc: Eric Snowberg Signed-off-by: Mickaël Salaün Reviewed-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20210712170313.884724-2-mic@digikod.net Signed-off-by: Jarkko Sakkinen --- MAINTAINERS | 1 + tools/certs/print-cert-tbs-hash.sh | 91 ++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) create mode 100755 tools/certs/print-cert-tbs-hash.sh diff --git a/MAINTAINERS b/MAINTAINERS index f468864fd268..4f2a63b0ec3b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4576,6 +4576,7 @@ S: Maintained F: Documentation/admin-guide/module-signing.rst F: certs/ F: scripts/sign-file.c +F: tools/certs/ CFAG12864B LCD DRIVER M: Miguel Ojeda diff --git a/tools/certs/print-cert-tbs-hash.sh b/tools/certs/print-cert-tbs-hash.sh new file mode 100755 index 000000000000..c93df5387ec9 --- /dev/null +++ b/tools/certs/print-cert-tbs-hash.sh @@ -0,0 +1,91 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright © 2020, Microsoft Corporation. All rights reserved. +# +# Author: Mickaël Salaün +# +# Compute and print the To Be Signed (TBS) hash of a certificate. This is used +# as description of keys in the blacklist keyring to identify certificates. +# This output should be redirected, without newline, in a file (hash0.txt) and +# signed to create a PKCS#7 file (hash0.p7s). Both of these files can then be +# loaded in the kernel with. +# +# Exemple on a workstation: +# ./print-cert-tbs-hash.sh certificate-to-invalidate.pem > hash0.txt +# openssl smime -sign -in hash0.txt -inkey builtin-private-key.pem \ +# -signer builtin-certificate.pem -certfile certificate-chain.pem \ +# -noattr -binary -outform DER -out hash0.p7s +# +# Exemple on a managed system: +# keyctl padd blacklist "$(< hash0.txt)" %:.blacklist < hash0.p7s + +set -u -e -o pipefail + +CERT="${1:-}" +BASENAME="$(basename -- "${BASH_SOURCE[0]}")" + +if [ $# -ne 1 ] || [ ! -f "${CERT}" ]; then + echo "usage: ${BASENAME} " >&2 + exit 1 +fi + +# Checks that it is indeed a certificate (PEM or DER encoded) and exclude the +# optional PEM text header. +if ! PEM="$(openssl x509 -inform DER -in "${CERT}" 2>/dev/null || openssl x509 -in "${CERT}")"; then + echo "ERROR: Failed to parse certificate" >&2 + exit 1 +fi + +# TBSCertificate starts at the second entry. +# Cf. https://tools.ietf.org/html/rfc3280#section-4.1 +# +# Exemple of first lines printed by openssl asn1parse: +# 0:d=0 hl=4 l= 763 cons: SEQUENCE +# 4:d=1 hl=4 l= 483 cons: SEQUENCE +# 8:d=2 hl=2 l= 3 cons: cont [ 0 ] +# 10:d=3 hl=2 l= 1 prim: INTEGER :02 +# 13:d=2 hl=2 l= 20 prim: INTEGER :3CEB2CB8818D968AC00EEFE195F0DF9665328B7B +# 35:d=2 hl=2 l= 13 cons: SEQUENCE +# 37:d=3 hl=2 l= 9 prim: OBJECT :sha256WithRSAEncryption +RANGE_AND_DIGEST_RE=' +2s/^\s*\([0-9]\+\):d=\s*[0-9]\+\s\+hl=\s*[0-9]\+\s\+l=\s*\([0-9]\+\)\s\+cons:\s*SEQUENCE\s*$/\1 \2/p; +7s/^\s*[0-9]\+:d=\s*[0-9]\+\s\+hl=\s*[0-9]\+\s\+l=\s*[0-9]\+\s\+prim:\s*OBJECT\s*:\(.*\)$/\1/p; +' + +RANGE_AND_DIGEST=($(echo "${PEM}" | \ + openssl asn1parse -in - | \ + sed -n -e "${RANGE_AND_DIGEST_RE}")) + +if [ "${#RANGE_AND_DIGEST[@]}" != 3 ]; then + echo "ERROR: Failed to parse TBSCertificate." >&2 + exit 1 +fi + +OFFSET="${RANGE_AND_DIGEST[0]}" +END="$(( OFFSET + RANGE_AND_DIGEST[1] ))" +DIGEST="${RANGE_AND_DIGEST[2]}" + +# The signature hash algorithm is used by Linux to blacklist certificates. +# Cf. crypto/asymmetric_keys/x509_cert_parser.c:x509_note_pkey_algo() +DIGEST_MATCH="" +while read -r DIGEST_ITEM; do + if [ -z "${DIGEST_ITEM}" ]; then + break + fi + if echo "${DIGEST}" | grep -qiF "${DIGEST_ITEM}"; then + DIGEST_MATCH="${DIGEST_ITEM}" + break + fi +done < <(openssl list -digest-commands | tr ' ' '\n' | sort -ur) + +if [ -z "${DIGEST_MATCH}" ]; then + echo "ERROR: Unknown digest algorithm: ${DIGEST}" >&2 + exit 1 +fi + +echo "${PEM}" | \ + openssl x509 -in - -outform DER | \ + dd "bs=1" "skip=${OFFSET}" "count=${END}" "status=none" | \ + openssl dgst "-${DIGEST_MATCH}" - | \ + awk '{printf "tbs:" $2}' From 141e523914f72575915dd334fce3cef4fb0f1e91 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 12 Jul 2021 19:03:12 +0200 Subject: [PATCH 02/20] certs: Factor out the blacklist hash creation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Factor out the blacklist hash creation with the get_raw_hash() helper. This also centralize the "tbs" and "bin" prefixes and make them private, which help to manage them consistently. Cc: David Howells Cc: David S. Miller Cc: David Woodhouse Cc: Eric Snowberg Cc: Herbert Xu Cc: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210712170313.884724-5-mic@digikod.net Signed-off-by: Jarkko Sakkinen --- certs/blacklist.c | 76 ++++++++++++++----- crypto/asymmetric_keys/x509_public_key.c | 3 +- include/keys/system_keyring.h | 14 +++- .../platform_certs/keyring_handler.c | 26 +------ 4 files changed, 73 insertions(+), 46 deletions(-) diff --git a/certs/blacklist.c b/certs/blacklist.c index c9a435b15af4..1cdf309a5b08 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -83,11 +83,43 @@ static struct key_type key_type_blacklist = { .describe = blacklist_describe, }; +static char *get_raw_hash(const u8 *hash, size_t hash_len, + enum blacklist_hash_type hash_type) +{ + size_t type_len; + const char *type_prefix; + char *buffer, *p; + + switch (hash_type) { + case BLACKLIST_HASH_X509_TBS: + type_len = sizeof(tbs_prefix) - 1; + type_prefix = tbs_prefix; + break; + case BLACKLIST_HASH_BINARY: + type_len = sizeof(bin_prefix) - 1; + type_prefix = bin_prefix; + break; + default: + WARN_ON_ONCE(1); + return ERR_PTR(-EINVAL); + } + buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL); + if (!buffer) + return ERR_PTR(-ENOMEM); + p = memcpy(buffer, type_prefix, type_len); + p += type_len; + *p++ = ':'; + bin2hex(p, hash, hash_len); + p += hash_len * 2; + *p = '\0'; + return buffer; +} + /** - * mark_hash_blacklisted - Add a hash to the system blacklist + * mark_raw_hash_blacklisted - Add a hash to the system blacklist * @hash: The hash as a hex string with a type prefix (eg. "tbs:23aa429783") */ -int mark_hash_blacklisted(const char *hash) +static int mark_raw_hash_blacklisted(const char *hash) { key_ref_t key; @@ -107,29 +139,36 @@ int mark_hash_blacklisted(const char *hash) return 0; } +int mark_hash_blacklisted(const u8 *hash, size_t hash_len, + enum blacklist_hash_type hash_type) +{ + const char *buffer; + int err; + + buffer = get_raw_hash(hash, hash_len, hash_type); + if (IS_ERR(buffer)) + return PTR_ERR(buffer); + err = mark_raw_hash_blacklisted(buffer); + kfree(buffer); + return err; +} + /** * is_hash_blacklisted - Determine if a hash is blacklisted * @hash: The hash to be checked as a binary blob * @hash_len: The length of the binary hash - * @type: Type of hash + * @hash_type: Type of hash */ -int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type) +int is_hash_blacklisted(const u8 *hash, size_t hash_len, + enum blacklist_hash_type hash_type) { key_ref_t kref; - size_t type_len = strlen(type); - char *buffer, *p; + const char *buffer; int ret = 0; - buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL); - if (!buffer) - return -ENOMEM; - p = memcpy(buffer, type, type_len); - p += type_len; - *p++ = ':'; - bin2hex(p, hash, hash_len); - p += hash_len * 2; - *p = 0; - + buffer = get_raw_hash(hash, hash_len, hash_type); + if (IS_ERR(buffer)) + return PTR_ERR(buffer); kref = keyring_search(make_key_ref(blacklist_keyring, true), &key_type_blacklist, buffer, false); if (!IS_ERR(kref)) { @@ -144,7 +183,8 @@ EXPORT_SYMBOL_GPL(is_hash_blacklisted); int is_binary_blacklisted(const u8 *hash, size_t hash_len) { - if (is_hash_blacklisted(hash, hash_len, "bin") == -EKEYREJECTED) + if (is_hash_blacklisted(hash, hash_len, BLACKLIST_HASH_BINARY) == + -EKEYREJECTED) return -EPERM; return 0; @@ -217,7 +257,7 @@ static int __init blacklist_init(void) panic("Can't allocate system blacklist keyring\n"); for (bl = blacklist_hashes; *bl; bl++) - if (mark_hash_blacklisted(*bl) < 0) + if (mark_raw_hash_blacklisted(*bl) < 0) pr_err("- blacklisting failed\n"); return 0; } diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 91a4ad50dea2..77ed4e93ad56 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -69,7 +69,8 @@ int x509_get_sig_params(struct x509_certificate *cert) if (ret < 0) goto error_2; - ret = is_hash_blacklisted(sig->digest, sig->digest_size, "tbs"); + ret = is_hash_blacklisted(sig->digest, sig->digest_size, + BLACKLIST_HASH_X509_TBS); if (ret == -EKEYREJECTED) { pr_err("Cert %*phN is blacklisted\n", sig->digest_size, sig->digest); diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index 2419a735420f..91e080efb918 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -10,6 +10,13 @@ #include +enum blacklist_hash_type { + /* TBSCertificate hash */ + BLACKLIST_HASH_X509_TBS = 1, + /* Raw data hash */ + BLACKLIST_HASH_BINARY = 2, +}; + #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING extern int restrict_link_by_builtin_trusted(struct key *keyring, @@ -54,13 +61,14 @@ static inline void __init set_machine_trusted_keys(struct key *keyring) extern struct pkcs7_message *pkcs7; #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING -extern int mark_hash_blacklisted(const char *hash); +extern int mark_hash_blacklisted(const u8 *hash, size_t hash_len, + enum blacklist_hash_type hash_type); extern int is_hash_blacklisted(const u8 *hash, size_t hash_len, - const char *type); + enum blacklist_hash_type hash_type); extern int is_binary_blacklisted(const u8 *hash, size_t hash_len); #else static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len, - const char *type) + enum blacklist_hash_type hash_type) { return 0; } diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c index 1db4d3b4356d..a2464f3e66cc 100644 --- a/security/integrity/platform_certs/keyring_handler.c +++ b/security/integrity/platform_certs/keyring_handler.c @@ -16,35 +16,13 @@ static efi_guid_t efi_cert_x509_sha256_guid __initdata = EFI_CERT_X509_SHA256_GUID; static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID; -/* - * Blacklist a hash. - */ -static __init void uefi_blacklist_hash(const char *source, const void *data, - size_t len, const char *type, - size_t type_len) -{ - char *hash, *p; - - hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL); - if (!hash) - return; - p = memcpy(hash, type, type_len); - p += type_len; - bin2hex(p, data, len); - p += len * 2; - *p = 0; - - mark_hash_blacklisted(hash); - kfree(hash); -} - /* * Blacklist an X509 TBS hash. */ static __init void uefi_blacklist_x509_tbs(const char *source, const void *data, size_t len) { - uefi_blacklist_hash(source, data, len, "tbs:", 4); + mark_hash_blacklisted(data, len, BLACKLIST_HASH_X509_TBS); } /* @@ -53,7 +31,7 @@ static __init void uefi_blacklist_x509_tbs(const char *source, static __init void uefi_blacklist_binary(const char *source, const void *data, size_t len) { - uefi_blacklist_hash(source, data, len, "bin:", 4); + mark_hash_blacklisted(data, len, BLACKLIST_HASH_BINARY); } /* From bf21dc591bb5f17ba4b29b84d4866e0adc39f57f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 12 Jul 2021 19:03:11 +0200 Subject: [PATCH 03/20] certs: Make blacklist_vet_description() more strict MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Before exposing this new key type to user space, make sure that only meaningful blacklisted hashes are accepted. This is also checked for builtin blacklisted hashes, but a following commit make sure that the user will notice (at built time) and will fix the configuration if it already included errors. Check that a blacklist key description starts with a valid prefix and then a valid hexadecimal string. Cc: David Howells Cc: David Woodhouse Cc: Eric Snowberg Signed-off-by: Mickaël Salaün Reviewed-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20210712170313.884724-4-mic@digikod.net Signed-off-by: Jarkko Sakkinen --- certs/blacklist.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) diff --git a/certs/blacklist.c b/certs/blacklist.c index 1cdf309a5b08..b254c87ceb3a 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -19,6 +19,16 @@ #include "blacklist.h" #include "common.h" +/* + * According to crypto/asymmetric_keys/x509_cert_parser.c:x509_note_pkey_algo(), + * the size of the currently longest supported hash algorithm is 512 bits, + * which translates into 128 hex characters. + */ +#define MAX_HASH_LEN 128 + +static const char tbs_prefix[] = "tbs"; +static const char bin_prefix[] = "bin"; + static struct key *blacklist_keyring; #ifdef CONFIG_SYSTEM_REVOCATION_LIST @@ -32,24 +42,40 @@ extern __initconst const unsigned long revocation_certificate_list_size; */ static int blacklist_vet_description(const char *desc) { - int n = 0; + int i, prefix_len, tbs_step = 0, bin_step = 0; - if (*desc == ':') - return -EINVAL; - for (; *desc; desc++) - if (*desc == ':') - goto found_colon; + /* The following algorithm only works if prefix lengths match. */ + BUILD_BUG_ON(sizeof(tbs_prefix) != sizeof(bin_prefix)); + prefix_len = sizeof(tbs_prefix) - 1; + for (i = 0; *desc; desc++, i++) { + if (*desc == ':') { + if (tbs_step == prefix_len) + goto found_colon; + if (bin_step == prefix_len) + goto found_colon; + return -EINVAL; + } + if (i >= prefix_len) + return -EINVAL; + if (*desc == tbs_prefix[i]) + tbs_step++; + if (*desc == bin_prefix[i]) + bin_step++; + } return -EINVAL; found_colon: desc++; - for (; *desc; desc++) { + for (i = 0; *desc && i < MAX_HASH_LEN; desc++, i++) { if (!isxdigit(*desc) || isupper(*desc)) return -EINVAL; - n++; } + if (*desc) + /* The hash is greater than MAX_HASH_LEN. */ + return -ENOPKG; - if (n == 0 || n & 1) + /* Checks for an even number of hexadecimal characters. */ + if (i == 0 || i & 1) return -EINVAL; return 0; } From addf466389d9d78f255e8b15ac44ab4791029852 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 12 Jul 2021 19:03:10 +0200 Subject: [PATCH 04/20] certs: Check that builtin blacklist hashes are valid MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add and use a check-blacklist-hashes.awk script to make sure that the builtin blacklist hashes set with CONFIG_SYSTEM_BLACKLIST_HASH_LIST will effectively be taken into account as blacklisted hashes. This is useful to debug invalid hash formats, and it make sure that previous hashes which could have been loaded in the kernel, but silently ignored, are now noticed and deal with by the user at kernel build time. This also prevent stricter blacklist key description checking (provided by following commits) to failed for builtin hashes. Update CONFIG_SYSTEM_BLACKLIST_HASH_LIST help to explain the content of a hash string and how to generate certificate ones. Cc: David Howells Cc: David Woodhouse Cc: Eric Snowberg Cc: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210712170313.884724-3-mic@digikod.net Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- MAINTAINERS | 1 + certs/.gitignore | 1 + certs/Kconfig | 7 ++++-- certs/Makefile | 14 ++++++++++- scripts/check-blacklist-hashes.awk | 37 ++++++++++++++++++++++++++++++ 5 files changed, 57 insertions(+), 3 deletions(-) create mode 100755 scripts/check-blacklist-hashes.awk diff --git a/MAINTAINERS b/MAINTAINERS index 4f2a63b0ec3b..bf41a67635ec 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4575,6 +4575,7 @@ L: keyrings@vger.kernel.org S: Maintained F: Documentation/admin-guide/module-signing.rst F: certs/ +F: scripts/check-blacklist-hashes.awk F: scripts/sign-file.c F: tools/certs/ diff --git a/certs/.gitignore b/certs/.gitignore index 9e42fe3e02f5..56637aceaf81 100644 --- a/certs/.gitignore +++ b/certs/.gitignore @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only +/blacklist_hashes_checked /extract-cert /x509_certificate_list /x509_revocation_list diff --git a/certs/Kconfig b/certs/Kconfig index 73d1350c223a..4bd385b25084 100644 --- a/certs/Kconfig +++ b/certs/Kconfig @@ -104,8 +104,11 @@ config SYSTEM_BLACKLIST_HASH_LIST help If set, this option should be the filename of a list of hashes in the form "", "", ... . This will be included into a C - wrapper to incorporate the list into the kernel. Each should - be a string of hex digits. + wrapper to incorporate the list into the kernel. Each must be a + string starting with a prefix ("tbs" or "bin"), then a colon (":"), and + finally an even number of hexadecimal lowercase characters (up to 128). + Certificate hashes can be generated with + tools/certs/print-cert-tbs-hash.sh . config SYSTEM_REVOCATION_LIST bool "Provide system-wide ring of revocation certificates" diff --git a/certs/Makefile b/certs/Makefile index d8443cfb1c40..1d26ae36af20 100644 --- a/certs/Makefile +++ b/certs/Makefile @@ -7,6 +7,18 @@ obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o c obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),) +quiet_cmd_check_blacklist_hashes = CHECK $(patsubst "%",%,$(2)) + cmd_check_blacklist_hashes = $(AWK) -f $(srctree)/scripts/check-blacklist-hashes.awk $(2); touch $@ + +$(eval $(call config_filename,SYSTEM_BLACKLIST_HASH_LIST)) + +$(obj)/blacklist_hashes.o: $(obj)/blacklist_hashes_checked + +CFLAGS_blacklist_hashes.o += -I$(srctree) + +targets += blacklist_hashes_checked +$(obj)/blacklist_hashes_checked: $(SYSTEM_BLACKLIST_HASH_LIST_SRCPREFIX)$(SYSTEM_BLACKLIST_HASH_LIST_FILENAME) scripts/check-blacklist-hashes.awk FORCE + $(call if_changed,check_blacklist_hashes,$(SYSTEM_BLACKLIST_HASH_LIST_SRCPREFIX)$(CONFIG_SYSTEM_BLACKLIST_HASH_LIST)) obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o else obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o @@ -21,7 +33,7 @@ $(obj)/system_certificates.o: $(obj)/x509_certificate_list $(obj)/x509_certificate_list: $(CONFIG_SYSTEM_TRUSTED_KEYS) $(obj)/extract-cert FORCE $(call if_changed,extract_certs) -targets += x509_certificate_list +targets += x509_certificate_list blacklist_hashes_checked # If module signing is requested, say by allyesconfig, but a key has not been # supplied, then one will need to be generated to make sure the build does not diff --git a/scripts/check-blacklist-hashes.awk b/scripts/check-blacklist-hashes.awk new file mode 100755 index 000000000000..107c1d3204d4 --- /dev/null +++ b/scripts/check-blacklist-hashes.awk @@ -0,0 +1,37 @@ +#!/usr/bin/awk -f +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright © 2020, Microsoft Corporation. All rights reserved. +# +# Author: Mickaël Salaün +# +# Check that a CONFIG_SYSTEM_BLACKLIST_HASH_LIST file contains a valid array of +# hash strings. Such string must start with a prefix ("tbs" or "bin"), then a +# colon (":"), and finally an even number of hexadecimal lowercase characters +# (up to 128). + +BEGIN { + RS = "," +} +{ + if (!match($0, "^[ \t\n\r]*\"([^\"]*)\"[ \t\n\r]*$", part1)) { + print "Not a string (item " NR "):", $0; + exit 1; + } + if (!match(part1[1], "^(tbs|bin):(.*)$", part2)) { + print "Unknown prefix (item " NR "):", part1[1]; + exit 1; + } + if (!match(part2[2], "^([0-9a-f]+)$", part3)) { + print "Not a lowercase hexadecimal string (item " NR "):", part2[2]; + exit 1; + } + if (length(part3[1]) > 128) { + print "Hash string too long (item " NR "):", part3[1]; + exit 1; + } + if (length(part3[1]) % 2 == 1) { + print "Not an even number of hexadecimal characters (item " NR "):", part3[1]; + exit 1; + } +} From 6364d106e0417e00eb5f223d8a90287d1c421ce0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 12 Jul 2021 19:03:13 +0200 Subject: [PATCH 05/20] certs: Allow root user to append signed hashes to the blacklist keyring MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a kernel option SYSTEM_BLACKLIST_AUTH_UPDATE to enable the root user to dynamically add new keys to the blacklist keyring. This enables to invalidate new certificates, either from being loaded in a keyring, or from being trusted in a PKCS#7 certificate chain. This also enables to add new file hashes to be denied by the integrity infrastructure. Being able to untrust a certificate which could have normaly been trusted is a sensitive operation. This is why adding new hashes to the blacklist keyring is only allowed when these hashes are signed and vouched by the builtin trusted keyring. A blacklist hash is stored as a key description. The PKCS#7 signature of this description must be provided as the key payload. Marking a certificate as untrusted should be enforced while the system is running. It is then forbiden to remove such blacklist keys. Update blacklist keyring, blacklist key and revoked certificate access rights: * allows the root user to search for a specific blacklisted hash, which make sense because the descriptions are already viewable; * forbids key update (blacklist and asymmetric ones); * restricts kernel rights on the blacklist keyring to align with the root user rights. See help in tools/certs/print-cert-tbs-hash.sh . Cc: David Howells Cc: David Woodhouse Cc: Eric Snowberg Cc: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210712170313.884724-6-mic@digikod.net Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- certs/Kconfig | 10 +++++ certs/blacklist.c | 96 ++++++++++++++++++++++++++++++++++++----------- 2 files changed, 85 insertions(+), 21 deletions(-) diff --git a/certs/Kconfig b/certs/Kconfig index 4bd385b25084..476755703cf8 100644 --- a/certs/Kconfig +++ b/certs/Kconfig @@ -127,4 +127,14 @@ config SYSTEM_REVOCATION_KEYS containing X.509 certificates to be included in the default blacklist keyring. +config SYSTEM_BLACKLIST_AUTH_UPDATE + bool "Allow root to add signed blacklist keys" + depends on SYSTEM_BLACKLIST_KEYRING + depends on SYSTEM_DATA_VERIFICATION + help + If set, provide the ability to load new blacklist keys at run time if + they are signed and vouched by a certificate from the builtin trusted + keyring. The PKCS#7 signature of the description is set in the key + payload. Blacklist keys cannot be removed. + endmenu diff --git a/certs/blacklist.c b/certs/blacklist.c index b254c87ceb3a..486ce0dd8e9c 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include "blacklist.h" #include "common.h" @@ -26,6 +27,9 @@ */ #define MAX_HASH_LEN 128 +#define BLACKLIST_KEY_PERM (KEY_POS_SEARCH | KEY_POS_VIEW | \ + KEY_USR_SEARCH | KEY_USR_VIEW) + static const char tbs_prefix[] = "tbs"; static const char bin_prefix[] = "bin"; @@ -80,19 +84,51 @@ found_colon: return 0; } -/* - * The hash to be blacklisted is expected to be in the description. There will - * be no payload. - */ -static int blacklist_preparse(struct key_preparsed_payload *prep) +static int blacklist_key_instantiate(struct key *key, + struct key_preparsed_payload *prep) { - if (prep->datalen > 0) - return -EINVAL; - return 0; +#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE + int err; +#endif + + /* Sets safe default permissions for keys loaded by user space. */ + key->perm = BLACKLIST_KEY_PERM; + + /* + * Skips the authentication step for builtin hashes, they are not + * signed but still trusted. + */ + if (key->flags & (1 << KEY_FLAG_BUILTIN)) + goto out; + +#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE + /* + * Verifies the description's PKCS#7 signature against the builtin + * trusted keyring. + */ + err = verify_pkcs7_signature(key->description, + strlen(key->description), prep->data, prep->datalen, + NULL, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); + if (err) + return err; +#else + /* + * It should not be possible to come here because the keyring doesn't + * have KEY_USR_WRITE and the only other way to call this function is + * for builtin hashes. + */ + WARN_ON_ONCE(1); + return -EPERM; +#endif + +out: + return generic_key_instantiate(key, prep); } -static void blacklist_free_preparse(struct key_preparsed_payload *prep) +static int blacklist_key_update(struct key *key, + struct key_preparsed_payload *prep) { + return -EPERM; } static void blacklist_describe(const struct key *key, struct seq_file *m) @@ -103,9 +139,8 @@ static void blacklist_describe(const struct key *key, struct seq_file *m) static struct key_type key_type_blacklist = { .name = "blacklist", .vet_description = blacklist_vet_description, - .preparse = blacklist_preparse, - .free_preparse = blacklist_free_preparse, - .instantiate = generic_key_instantiate, + .instantiate = blacklist_key_instantiate, + .update = blacklist_key_update, .describe = blacklist_describe, }; @@ -154,8 +189,7 @@ static int mark_raw_hash_blacklisted(const char *hash) hash, NULL, 0, - ((KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW), + BLACKLIST_KEY_PERM, KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_BUILT_IN); if (IS_ERR(key)) { @@ -232,8 +266,10 @@ int add_key_to_revocation_list(const char *data, size_t size) NULL, data, size, - ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW), - KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_BUILT_IN); + KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH + | KEY_USR_VIEW, + KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_BUILT_IN + | KEY_ALLOC_BYPASS_RESTRICTION); if (IS_ERR(key)) { pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key)); @@ -260,25 +296,43 @@ int is_key_on_revocation_list(struct pkcs7_message *pkcs7) } #endif +static int restrict_link_for_blacklist(struct key *dest_keyring, + const struct key_type *type, const union key_payload *payload, + struct key *restrict_key) +{ + if (type == &key_type_blacklist) + return 0; + return -EOPNOTSUPP; +} + /* * Initialise the blacklist */ static int __init blacklist_init(void) { const char *const *bl; + struct key_restriction *restriction; if (register_key_type(&key_type_blacklist) < 0) panic("Can't allocate system blacklist key type\n"); + restriction = kzalloc(sizeof(*restriction), GFP_KERNEL); + if (!restriction) + panic("Can't allocate blacklist keyring restriction\n"); + restriction->check = restrict_link_for_blacklist; + blacklist_keyring = keyring_alloc(".blacklist", GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, current_cred(), - (KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW | KEY_USR_READ | - KEY_USR_SEARCH, - KEY_ALLOC_NOT_IN_QUOTA | + KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | + KEY_POS_WRITE | + KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH +#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE + | KEY_USR_WRITE +#endif + , KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_SET_KEEP, - NULL, NULL); + restriction, NULL); if (IS_ERR(blacklist_keyring)) panic("Can't allocate system blacklist keyring\n"); From 4d99750106adbaecee587232f2589f65170d5ce4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Tue, 22 Mar 2022 12:13:23 +0100 Subject: [PATCH 06/20] certs: Explain the rationale to call panic() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The blacklist_init() function calls panic() for memory allocation errors. This change documents the reason why we don't return -ENODEV. Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@digikod.net Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@iki.fi Suggested-by: Paul Moore Reviewed-by: Paul Moore Reviewed-by: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Signed-off-by: Jarkko Sakkinen --- certs/blacklist.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/certs/blacklist.c b/certs/blacklist.c index 486ce0dd8e9c..25094ea73600 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -307,6 +307,15 @@ static int restrict_link_for_blacklist(struct key *dest_keyring, /* * Initialise the blacklist + * + * The blacklist_init() function is registered as an initcall via + * device_initcall(). As a result if the blacklist_init() function fails for + * any reason the kernel continues to execute. While cleanly returning -ENODEV + * could be acceptable for some non-critical kernel parts, if the blacklist + * keyring fails to load it defeats the certificate/key based deny list for + * signed modules. If a critical piece of security functionality that users + * expect to be present fails to initialize, panic()ing is likely the right + * thing to do. */ static int __init blacklist_init(void) { From 80b8a39777a9161d77608ac702c7eeafce5ddce7 Mon Sep 17 00:00:00 2001 From: Haowen Bai Date: Fri, 18 Mar 2022 11:35:25 +0800 Subject: [PATCH 07/20] tpm/tpm_ftpm_tee: Return true/false (not 1/0) from bool functions Return boolean values ("true" or "false") instead of 1 or 0 from bool functions. Signed-off-by: Haowen Bai Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_ftpm_tee.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c index 6e3235565a4d..5c233423c56f 100644 --- a/drivers/char/tpm/tpm_ftpm_tee.c +++ b/drivers/char/tpm/tpm_ftpm_tee.c @@ -177,7 +177,7 @@ static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip) static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status) { - return 0; + return false; } static const struct tpm_class_ops ftpm_tee_tpm_ops = { From d0dc1a7100f19121f6e7450f9cdda11926aa3838 Mon Sep 17 00:00:00 2001 From: Xiu Jianfeng Date: Fri, 18 Mar 2022 14:02:01 +0800 Subject: [PATCH 08/20] tpm: ibmvtpm: Correct the return value in tpm_ibmvtpm_probe() Currently it returns zero when CRQ response timed out, it should return an error code instead. Fixes: d8d74ea3c002 ("tpm: ibmvtpm: Wait for buffer to be set before proceeding") Signed-off-by: Xiu Jianfeng Reviewed-by: Stefan Berger Acked-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_ibmvtpm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 3af4c07a9342..d3989b257f42 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -681,6 +681,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, if (!wait_event_timeout(ibmvtpm->crq_queue.wq, ibmvtpm->rtce_buf != NULL, HZ)) { + rc = -ENODEV; dev_err(dev, "CRQ response timed out\n"); goto init_irq_cleanup; } From 6422cbd3c52deb1d53a0e60c271f34d882ca8a9d Mon Sep 17 00:00:00 2001 From: Johannes Holland Date: Mon, 21 Mar 2022 10:09:24 +0100 Subject: [PATCH 09/20] tpm: Remove read16/read32/write32 calls from tpm_tis_phy_ops Only tpm_tis and tpm_tis_synquacer have a dedicated way to access multiple bytes at once, every other driver will just fall back to read_bytes/write_bytes. Therefore, remove the read16/read32/write32 calls and move their logic to read_bytes/write_bytes. Suggested-by: Jarkko Sakkinen Signed-off-by: Johannes Holland Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis.c | 65 ++++++++---------- drivers/char/tpm/tpm_tis_core.h | 58 ++++++++++++---- drivers/char/tpm/tpm_tis_spi.h | 4 -- drivers/char/tpm/tpm_tis_spi_cr50.c | 7 +- drivers/char/tpm/tpm_tis_spi_main.c | 45 +------------ drivers/char/tpm/tpm_tis_synquacer.c | 98 +++++++++++----------------- 6 files changed, 117 insertions(+), 160 deletions(-) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index d3f2e5364c27..bcff6429e0b4 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -153,50 +153,46 @@ static int check_acpi_tpm2(struct device *dev) #endif static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, - u8 *result) + u8 *result, enum tpm_tis_io_mode io_mode) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); + __le16 result_le16; + __le32 result_le32; - while (len--) - *result++ = ioread8(phy->iobase + addr); + switch (io_mode) { + case TPM_TIS_PHYS_8: + while (len--) + *result++ = ioread8(phy->iobase + addr); + break; + case TPM_TIS_PHYS_16: + result_le16 = cpu_to_le16(ioread16(phy->iobase + addr)); + memcpy(result, &result_le16, sizeof(u16)); + break; + case TPM_TIS_PHYS_32: + result_le32 = cpu_to_le32(ioread32(phy->iobase + addr)); + memcpy(result, &result_le32, sizeof(u32)); + break; + } return 0; } static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, - const u8 *value) + const u8 *value, enum tpm_tis_io_mode io_mode) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - while (len--) - iowrite8(*value++, phy->iobase + addr); - - return 0; -} - -static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result) -{ - struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - - *result = ioread16(phy->iobase + addr); - - return 0; -} - -static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result) -{ - struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - - *result = ioread32(phy->iobase + addr); - - return 0; -} - -static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value) -{ - struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - - iowrite32(value, phy->iobase + addr); + switch (io_mode) { + case TPM_TIS_PHYS_8: + while (len--) + iowrite8(*value++, phy->iobase + addr); + break; + case TPM_TIS_PHYS_16: + return -EINVAL; + case TPM_TIS_PHYS_32: + iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase + addr); + break; + } return 0; } @@ -204,9 +200,6 @@ static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value) static const struct tpm_tis_phy_ops tpm_tcg = { .read_bytes = tpm_tcg_read_bytes, .write_bytes = tpm_tcg_write_bytes, - .read16 = tpm_tcg_read16, - .read32 = tpm_tcg_read32, - .write32 = tpm_tcg_write32, }; static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info) diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 3be24f221e32..6c203f36b8a1 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -104,54 +104,88 @@ struct tpm_tis_data { unsigned int timeout_max; /* usecs */ }; +/* + * IO modes to indicate how many bytes should be read/written at once in the + * tpm_tis_phy_ops read_bytes/write_bytes calls. Use TPM_TIS_PHYS_8 to + * receive/transmit byte-wise, TPM_TIS_PHYS_16 for two bytes etc. + */ +enum tpm_tis_io_mode { + TPM_TIS_PHYS_8, + TPM_TIS_PHYS_16, + TPM_TIS_PHYS_32, +}; + struct tpm_tis_phy_ops { + /* data is passed in little endian */ int (*read_bytes)(struct tpm_tis_data *data, u32 addr, u16 len, - u8 *result); + u8 *result, enum tpm_tis_io_mode mode); int (*write_bytes)(struct tpm_tis_data *data, u32 addr, u16 len, - const u8 *value); - int (*read16)(struct tpm_tis_data *data, u32 addr, u16 *result); - int (*read32)(struct tpm_tis_data *data, u32 addr, u32 *result); - int (*write32)(struct tpm_tis_data *data, u32 addr, u32 src); + const u8 *value, enum tpm_tis_io_mode mode); }; static inline int tpm_tis_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, u8 *result) { - return data->phy_ops->read_bytes(data, addr, len, result); + return data->phy_ops->read_bytes(data, addr, len, result, + TPM_TIS_PHYS_8); } static inline int tpm_tis_read8(struct tpm_tis_data *data, u32 addr, u8 *result) { - return data->phy_ops->read_bytes(data, addr, 1, result); + return data->phy_ops->read_bytes(data, addr, 1, result, TPM_TIS_PHYS_8); } static inline int tpm_tis_read16(struct tpm_tis_data *data, u32 addr, u16 *result) { - return data->phy_ops->read16(data, addr, result); + __le16 result_le; + int rc; + + rc = data->phy_ops->read_bytes(data, addr, sizeof(u16), + (u8 *)&result_le, TPM_TIS_PHYS_16); + if (!rc) + *result = le16_to_cpu(result_le); + + return rc; } static inline int tpm_tis_read32(struct tpm_tis_data *data, u32 addr, u32 *result) { - return data->phy_ops->read32(data, addr, result); + __le32 result_le; + int rc; + + rc = data->phy_ops->read_bytes(data, addr, sizeof(u32), + (u8 *)&result_le, TPM_TIS_PHYS_32); + if (!rc) + *result = le32_to_cpu(result_le); + + return rc; } static inline int tpm_tis_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, const u8 *value) { - return data->phy_ops->write_bytes(data, addr, len, value); + return data->phy_ops->write_bytes(data, addr, len, value, + TPM_TIS_PHYS_8); } static inline int tpm_tis_write8(struct tpm_tis_data *data, u32 addr, u8 value) { - return data->phy_ops->write_bytes(data, addr, 1, &value); + return data->phy_ops->write_bytes(data, addr, 1, &value, + TPM_TIS_PHYS_8); } static inline int tpm_tis_write32(struct tpm_tis_data *data, u32 addr, u32 value) { - return data->phy_ops->write32(data, addr, value); + __le32 value_le; + int rc; + + value_le = cpu_to_le32(value); + rc = data->phy_ops->write_bytes(data, addr, sizeof(u32), + (u8 *)&value_le, TPM_TIS_PHYS_32); + return rc; } static inline bool is_bsw(void) diff --git a/drivers/char/tpm/tpm_tis_spi.h b/drivers/char/tpm/tpm_tis_spi.h index bba73979c368..d0f66f6f1931 100644 --- a/drivers/char/tpm/tpm_tis_spi.h +++ b/drivers/char/tpm/tpm_tis_spi.h @@ -31,10 +31,6 @@ extern int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, extern int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, u8 *in, const u8 *out); -extern int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result); -extern int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result); -extern int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value); - #ifdef CONFIG_TCG_TIS_SPI_CR50 extern int cr50_spi_probe(struct spi_device *spi); #else diff --git a/drivers/char/tpm/tpm_tis_spi_cr50.c b/drivers/char/tpm/tpm_tis_spi_cr50.c index 7bf123d3c537..f4937280e940 100644 --- a/drivers/char/tpm/tpm_tis_spi_cr50.c +++ b/drivers/char/tpm/tpm_tis_spi_cr50.c @@ -222,13 +222,13 @@ static int tpm_tis_spi_cr50_transfer(struct tpm_tis_data *data, u32 addr, u16 le } static int tpm_tis_spi_cr50_read_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, u8 *result) + u16 len, u8 *result, enum tpm_tis_io_mode io_mode) { return tpm_tis_spi_cr50_transfer(data, addr, len, result, NULL); } static int tpm_tis_spi_cr50_write_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, const u8 *value) + u16 len, const u8 *value, enum tpm_tis_io_mode io_mode) { return tpm_tis_spi_cr50_transfer(data, addr, len, NULL, value); } @@ -236,9 +236,6 @@ static int tpm_tis_spi_cr50_write_bytes(struct tpm_tis_data *data, u32 addr, static const struct tpm_tis_phy_ops tpm_spi_cr50_phy_ops = { .read_bytes = tpm_tis_spi_cr50_read_bytes, .write_bytes = tpm_tis_spi_cr50_write_bytes, - .read16 = tpm_tis_spi_read16, - .read32 = tpm_tis_spi_read32, - .write32 = tpm_tis_spi_write32, }; static void cr50_print_fw_version(struct tpm_tis_data *data) diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c index 184396b3af50..a0963a3e92bd 100644 --- a/drivers/char/tpm/tpm_tis_spi_main.c +++ b/drivers/char/tpm/tpm_tis_spi_main.c @@ -141,55 +141,17 @@ exit: } static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, u8 *result) + u16 len, u8 *result, enum tpm_tis_io_mode io_mode) { return tpm_tis_spi_transfer(data, addr, len, result, NULL); } static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, const u8 *value) + u16 len, const u8 *value, enum tpm_tis_io_mode io_mode) { return tpm_tis_spi_transfer(data, addr, len, NULL, value); } -int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result) -{ - __le16 result_le; - int rc; - - rc = data->phy_ops->read_bytes(data, addr, sizeof(u16), - (u8 *)&result_le); - if (!rc) - *result = le16_to_cpu(result_le); - - return rc; -} - -int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result) -{ - __le32 result_le; - int rc; - - rc = data->phy_ops->read_bytes(data, addr, sizeof(u32), - (u8 *)&result_le); - if (!rc) - *result = le32_to_cpu(result_le); - - return rc; -} - -int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value) -{ - __le32 value_le; - int rc; - - value_le = cpu_to_le32(value); - rc = data->phy_ops->write_bytes(data, addr, sizeof(u32), - (u8 *)&value_le); - - return rc; -} - int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, int irq, const struct tpm_tis_phy_ops *phy_ops) { @@ -205,9 +167,6 @@ int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, static const struct tpm_tis_phy_ops tpm_spi_phy_ops = { .read_bytes = tpm_tis_spi_read_bytes, .write_bytes = tpm_tis_spi_write_bytes, - .read16 = tpm_tis_spi_read16, - .read32 = tpm_tis_spi_read32, - .write32 = tpm_tis_spi_write32, }; static int tpm_tis_spi_probe(struct spi_device *dev) diff --git a/drivers/char/tpm/tpm_tis_synquacer.c b/drivers/char/tpm/tpm_tis_synquacer.c index e47bdd272704..679196c61401 100644 --- a/drivers/char/tpm/tpm_tis_synquacer.c +++ b/drivers/char/tpm/tpm_tis_synquacer.c @@ -35,72 +35,53 @@ static inline struct tpm_tis_synquacer_phy *to_tpm_tis_tcg_phy(struct tpm_tis_da } static int tpm_tis_synquacer_read_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, u8 *result) + u16 len, u8 *result, + enum tpm_tis_io_mode io_mode) { struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data); - - while (len--) - *result++ = ioread8(phy->iobase + addr); + switch (io_mode) { + case TPM_TIS_PHYS_8: + while (len--) + *result++ = ioread8(phy->iobase + addr); + break; + case TPM_TIS_PHYS_16: + result[1] = ioread8(phy->iobase + addr + 1); + result[0] = ioread8(phy->iobase + addr); + break; + case TPM_TIS_PHYS_32: + result[3] = ioread8(phy->iobase + addr + 3); + result[2] = ioread8(phy->iobase + addr + 2); + result[1] = ioread8(phy->iobase + addr + 1); + result[0] = ioread8(phy->iobase + addr); + break; + } return 0; } static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr, - u16 len, const u8 *value) + u16 len, const u8 *value, + enum tpm_tis_io_mode io_mode) { struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data); - - while (len--) - iowrite8(*value++, phy->iobase + addr); - - return 0; -} - -static int tpm_tis_synquacer_read16_bw(struct tpm_tis_data *data, - u32 addr, u16 *result) -{ - struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data); - - /* - * Due to the limitation of SPI controller on SynQuacer, - * 16/32 bits access must be done in byte-wise and descending order. - */ - *result = (ioread8(phy->iobase + addr + 1) << 8) | - (ioread8(phy->iobase + addr)); - - return 0; -} - -static int tpm_tis_synquacer_read32_bw(struct tpm_tis_data *data, - u32 addr, u32 *result) -{ - struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data); - - /* - * Due to the limitation of SPI controller on SynQuacer, - * 16/32 bits access must be done in byte-wise and descending order. - */ - *result = (ioread8(phy->iobase + addr + 3) << 24) | - (ioread8(phy->iobase + addr + 2) << 16) | - (ioread8(phy->iobase + addr + 1) << 8) | - (ioread8(phy->iobase + addr)); - - return 0; -} - -static int tpm_tis_synquacer_write32_bw(struct tpm_tis_data *data, - u32 addr, u32 value) -{ - struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data); - - /* - * Due to the limitation of SPI controller on SynQuacer, - * 16/32 bits access must be done in byte-wise and descending order. - */ - iowrite8(value >> 24, phy->iobase + addr + 3); - iowrite8(value >> 16, phy->iobase + addr + 2); - iowrite8(value >> 8, phy->iobase + addr + 1); - iowrite8(value, phy->iobase + addr); + switch (io_mode) { + case TPM_TIS_PHYS_8: + while (len--) + iowrite8(*value++, phy->iobase + addr); + break; + case TPM_TIS_PHYS_16: + return -EINVAL; + case TPM_TIS_PHYS_32: + /* + * Due to the limitation of SPI controller on SynQuacer, + * 16/32 bits access must be done in byte-wise and descending order. + */ + iowrite8(value[3], phy->iobase + addr + 3); + iowrite8(value[2], phy->iobase + addr + 2); + iowrite8(value[1], phy->iobase + addr + 1); + iowrite8(value[0], phy->iobase + addr); + break; + } return 0; } @@ -108,9 +89,6 @@ static int tpm_tis_synquacer_write32_bw(struct tpm_tis_data *data, static const struct tpm_tis_phy_ops tpm_tcg_bw = { .read_bytes = tpm_tis_synquacer_read_bytes, .write_bytes = tpm_tis_synquacer_write_bytes, - .read16 = tpm_tis_synquacer_read16_bw, - .read32 = tpm_tis_synquacer_read32_bw, - .write32 = tpm_tis_synquacer_write32_bw, }; static int tpm_tis_synquacer_init(struct device *dev, From 9c438fdef8906fe9c025e0106cef6fe491728790 Mon Sep 17 00:00:00 2001 From: "Jes B. Klinke" Date: Tue, 19 Apr 2022 16:37:57 -0700 Subject: [PATCH 10/20] tpm: cr50: Add new device/vendor ID 0x504a6666 Accept one additional numerical value of DID:VID for next generation Google TPM with new firmware, to be used in future Chromebooks. The TPM with the new firmware has the code name TI50, and is going to use the same interfaces. Signed-off-by: Jes B. Klinke Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_i2c_cr50.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c index f6c0affbb456..4ddb8ff3a856 100644 --- a/drivers/char/tpm/tpm_tis_i2c_cr50.c +++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c @@ -31,6 +31,7 @@ #define TPM_CR50_TIMEOUT_SHORT_MS 2 /* Short timeout during transactions */ #define TPM_CR50_TIMEOUT_NOIRQ_MS 20 /* Timeout for TPM ready without IRQ */ #define TPM_CR50_I2C_DID_VID 0x00281ae0L /* Device and vendor ID reg value */ +#define TPM_TI50_I2C_DID_VID 0x504a6666L /* Device and vendor ID reg value */ #define TPM_CR50_I2C_MAX_RETRIES 3 /* Max retries due to I2C errors */ #define TPM_CR50_I2C_RETRY_DELAY_LO 55 /* Min usecs between retries on I2C */ #define TPM_CR50_I2C_RETRY_DELAY_HI 65 /* Max usecs between retries on I2C */ @@ -742,15 +743,15 @@ static int tpm_cr50_i2c_probe(struct i2c_client *client) } vendor = le32_to_cpup((__le32 *)buf); - if (vendor != TPM_CR50_I2C_DID_VID) { + if (vendor != TPM_CR50_I2C_DID_VID && vendor != TPM_TI50_I2C_DID_VID) { dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor); tpm_cr50_release_locality(chip, true); return -ENODEV; } - dev_info(dev, "cr50 TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n", + dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n", + vendor == TPM_TI50_I2C_DID_VID ? "ti50" : "cr50", client->addr, client->irq, vendor >> 16); - return tpm_chip_register(chip); } From e0687fe958f763f1790f22ed5483025b7624e744 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Tue, 26 Apr 2022 10:06:02 +0200 Subject: [PATCH 11/20] char: tpm: cr50_i2c: Suppress duplicated error message in .remove() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Returning an error value in an i2c remove callback results in an error message being emitted by the i2c core, but otherwise it doesn't make a difference. The device goes away anyhow and the devm cleanups are called. As tpm_cr50_i2c_remove() emits an error message already and the additional error message by the i2c core doesn't add any useful information, change the return value to zero to suppress this error message. Note that if i2c_clientdata is NULL, there is something really fishy. Assuming no memory corruption happened (then all bets are lost anyhow), tpm_cr50_i2c_remove() is only called after tpm_cr50_i2c_probe() returned successfully. So there was a tpm chip registered before and after tpm_cr50_i2c_remove() its privdata is freed but the associated character device isn't removed. If after that happened userspace accesses the character device it's likely that the freed memory is accessed. For that reason the warning message is made a bit more frightening. Signed-off-by: Uwe Kleine-König Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_i2c_cr50.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c index 4ddb8ff3a856..974479a1ec5a 100644 --- a/drivers/char/tpm/tpm_tis_i2c_cr50.c +++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c @@ -769,8 +769,8 @@ static int tpm_cr50_i2c_remove(struct i2c_client *client) struct device *dev = &client->dev; if (!chip) { - dev_err(dev, "Could not get client data at remove\n"); - return -ENODEV; + dev_crit(dev, "Could not get client data at remove, memory corruption ahead\n"); + return 0; } tpm_chip_unregister(chip); From e57b2523bd37e6434f4e64c7a685e3715ad21e9a Mon Sep 17 00:00:00 2001 From: Stefan Mahnke-Hartmann Date: Fri, 13 May 2022 15:41:51 +0200 Subject: [PATCH 12/20] tpm: Fix buffer access in tpm2_get_tpm_pt() Under certain conditions uninitialized memory will be accessed. As described by TCG Trusted Platform Module Library Specification, rev. 1.59 (Part 3: Commands), if a TPM2_GetCapability is received, requesting a capability, the TPM in field upgrade mode may return a zero length list. Check the property count in tpm2_get_tpm_pt(). Fixes: 2ab3241161b3 ("tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf") Cc: stable@vger.kernel.org Signed-off-by: Stefan Mahnke-Hartmann Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm2-cmd.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 4704fa553098..04a3e23a4afc 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -400,7 +400,16 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, if (!rc) { out = (struct tpm2_get_cap_out *) &buf.data[TPM_HEADER_SIZE]; - *value = be32_to_cpu(out->value); + /* + * To prevent failing boot up of some systems, Infineon TPM2.0 + * returns SUCCESS on TPM2_Startup in field upgrade mode. Also + * the TPM2_Getcapability command returns a zero length list + * in field upgrade mode. + */ + if (be32_to_cpu(out->property_cnt) > 0) + *value = be32_to_cpu(out->value); + else + rc = -ENODATA; } tpm_buf_destroy(&buf); return rc; From af402ee3c045b0cbd10b7e66d2431304ac9e69bb Mon Sep 17 00:00:00 2001 From: Stefan Mahnke-Hartmann Date: Fri, 13 May 2022 15:41:53 +0200 Subject: [PATCH 13/20] tpm: Add field upgrade mode support for Infineon TPM2 modules TPM2_GetCapability with a capability that has the property type value of TPM_PT_TOTAL_COMMANDS returns a zero length list, when an Infineon TPM2 is in field upgrade mode. Since an Infineon TPM2.0 in field upgrade mode returns RC_SUCCESS on TPM2_Startup, the field upgrade mode has to be detected by TPM2_GetCapability. Signed-off-by: Stefan Mahnke-Hartmann Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm2-cmd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 04a3e23a4afc..c1eb5d223839 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -754,7 +754,11 @@ int tpm2_auto_startup(struct tpm_chip *chip) rc = tpm2_get_cc_attrs_tbl(chip); out: - if (rc == TPM2_RC_UPGRADE) { + /* + * Infineon TPM in field upgrade mode will return no data for the number + * of supported commands. + */ + if (rc == TPM2_RC_UPGRADE || rc == -ENODATA) { dev_info(&chip->dev, "TPM in field upgrade mode, requires firmware upgrade\n"); chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE; rc = 0; From be07858fbf8115fc74528292c2ee8775fe49116f Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:56:59 +0200 Subject: [PATCH 14/20] KEYS: trusted: allow use of TEE as backend without TCG_TPM support With recent rework, trusted keys are no longer limited to TPM as trust source. The Kconfig symbol is unchanged however leading to a few issues: - TCG_TPM is required, even if only TEE is to be used - Enabling TCG_TPM, but excluding it from available trusted sources is not possible - TEE=m && TRUSTED_KEYS=y will lead to TEE support being silently dropped, which is not the best user experience Remedy these issues by introducing two new boolean Kconfig symbols: TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate dependencies. Any new code depending on the TPM trusted key backend in particular or symbols exported by it will now need to explicitly state that it depends on TRUSTED_KEYS && TRUSTED_KEYS_TPM The latter to ensure the dependency is built and the former to ensure it's reachable for module builds. There are no such users yet. Reviewed-by: Sumit Garg Reviewed-by: Jarkko Sakkinen Reviewed-by: Pankaj Gupta Tested-by: Pankaj Gupta Tested-by: Andreas Rammhold Tested-by: Tim Harvey Tested-by: Michael Walle # on ls1028a (non-E and E) Tested-by: John Ernberg # iMX8QXP Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- security/keys/Kconfig | 18 ++++++-------- security/keys/trusted-keys/Kconfig | 29 +++++++++++++++++++++++ security/keys/trusted-keys/Makefile | 8 +++---- security/keys/trusted-keys/trusted_core.c | 4 ++-- 4 files changed, 42 insertions(+), 17 deletions(-) create mode 100644 security/keys/trusted-keys/Kconfig diff --git a/security/keys/Kconfig b/security/keys/Kconfig index 0e30b361e1c1..abb03a1b2a5c 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -70,23 +70,19 @@ config BIG_KEYS config TRUSTED_KEYS tristate "TRUSTED KEYS" - depends on KEYS && TCG_TPM - select CRYPTO - select CRYPTO_HMAC - select CRYPTO_SHA1 - select CRYPTO_HASH_INFO - select ASN1_ENCODER - select OID_REGISTRY - select ASN1 + depends on KEYS help This option provides support for creating, sealing, and unsealing keys in the kernel. Trusted keys are random number symmetric keys, - generated and RSA-sealed by the TPM. The TPM only unseals the keys, - if the boot PCRs and other criteria match. Userspace will only ever - see encrypted blobs. + generated and sealed by a trust source selected at kernel boot-time. + Userspace will only ever see encrypted blobs. If you are unsure as to whether this is required, answer N. +if TRUSTED_KEYS +source "security/keys/trusted-keys/Kconfig" +endif + config ENCRYPTED_KEYS tristate "ENCRYPTED KEYS" depends on KEYS diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig new file mode 100644 index 000000000000..fc4abd581abb --- /dev/null +++ b/security/keys/trusted-keys/Kconfig @@ -0,0 +1,29 @@ +config TRUSTED_KEYS_TPM + bool "TPM-based trusted keys" + depends on TCG_TPM >= TRUSTED_KEYS + default y + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_HASH_INFO + select ASN1_ENCODER + select OID_REGISTRY + select ASN1 + help + Enable use of the Trusted Platform Module (TPM) as trusted key + backend. Trusted keys are random number symmetric keys, + which will be generated and RSA-sealed by the TPM. + The TPM only unseals the keys, if the boot PCRs and other + criteria match. + +config TRUSTED_KEYS_TEE + bool "TEE-based trusted keys" + depends on TEE >= TRUSTED_KEYS + default y + help + Enable use of the Trusted Execution Environment (TEE) as trusted + key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE +comment "No trust source selected!" +endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index feb8b6c3cc79..2e2371eae4d5 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -5,10 +5,10 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o trusted-y += trusted_core.o -trusted-y += trusted_tpm1.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h -trusted-y += trusted_tpm2.o -trusted-y += tpm2key.asn1.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o -trusted-$(CONFIG_TEE) += trusted_tee.o +trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index 9b9d3ef79cbe..7cdbd16aed30 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0); MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); static const struct trusted_key_source trusted_key_sources[] = { -#if IS_REACHABLE(CONFIG_TCG_TPM) +#if defined(CONFIG_TRUSTED_KEYS_TPM) { "tpm", &trusted_key_tpm_ops }, #endif -#if IS_REACHABLE(CONFIG_TEE) +#if defined(CONFIG_TRUSTED_KEYS_TEE) { "tee", &trusted_key_tee_ops }, #endif }; From fcd7c26901c83681532c6daac599e53d4df11738 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:00 +0200 Subject: [PATCH 15/20] KEYS: trusted: allow use of kernel RNG for key material The two existing trusted key sources don't make use of the kernel RNG, but instead let the hardware doing the sealing/unsealing also generate the random key material. However, both users and future backends may want to place less trust into the quality of the trust source's random number generator and instead reuse the kernel entropy pool, which can be seeded from multiple entropy sources. Make this possible by adding a new trusted.rng parameter, that will force use of the kernel RNG. In its absence, it's up to the trust source to decide, which random numbers to use, maintaining the existing behavior. Suggested-by: Jarkko Sakkinen Acked-by: Sumit Garg Acked-by: Pankaj Gupta Reviewed-by: David Gstir Reviewed-by: Pankaj Gupta Reviewed-by: Jarkko Sakkinen Tested-by: Pankaj Gupta Tested-by: Michael Walle # on ls1028a (non-E and E) Tested-by: John Ernberg # iMX8QXP Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- .../admin-guide/kernel-parameters.txt | 10 ++++++ .../security/keys/trusted-encrypted.rst | 20 ++++++----- include/keys/trusted-type.h | 2 +- security/keys/trusted-keys/trusted_core.c | 35 ++++++++++++++++++- 4 files changed, 57 insertions(+), 10 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3f1cc5e317ed..4deed1908a75 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5963,6 +5963,16 @@ first trust source as a backend which is initialized successfully during iteration. + trusted.rng= [KEYS] + Format: + The RNG used to generate key material for trusted keys. + Can be one of: + - "kernel" + - the same value as trusted.source: "tpm" or "tee" + - "default" + If not specified, "default" is used. In this case, + the RNG's choice is left to each individual trust source. + tsc= Disable clocksource stability checks for TSC. Format: [x86] reliable: mark tsc clocksource as reliable, this diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index f614dad7de12..2fe6fd1a2bbd 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -87,22 +87,26 @@ Key Generation Trusted Keys ------------ -New keys are created from random numbers generated in the trust source. They -are encrypted/decrypted using a child key in the storage key hierarchy. -Encryption and decryption of the child key must be protected by a strong -access control policy within the trust source. +New keys are created from random numbers. They are encrypted/decrypted using +a child key in the storage key hierarchy. Encryption and decryption of the +child key must be protected by a strong access control policy within the +trust source. The random number generator in use differs according to the +selected trust source: - * TPM (hardware device) based RNG + * TPM: hardware device based RNG - Strength of random numbers may vary from one device manufacturer to - another. + Keys are generated within the TPM. Strength of random numbers may vary + from one device manufacturer to another. - * TEE (OP-TEE based on Arm TrustZone) based RNG + * TEE: OP-TEE based on Arm TrustZone based RNG RNG is customizable as per platform needs. It can either be direct output from platform specific hardware RNG or a software based Fortuna CSPRNG which can be seeded via multiple entropy sources. +Users may override this by specifying ``trusted.rng=kernel`` on the kernel +command-line to override the used RNG with the kernel's random number pool. + Encrypted Keys -------------- diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index d89fa2579ac0..4eb64548a74f 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -64,7 +64,7 @@ struct trusted_key_ops { /* Unseal a key. */ int (*unseal)(struct trusted_key_payload *p, char *datablob); - /* Get a randomized key. */ + /* Optional: Get a randomized key. */ int (*get_random)(unsigned char *key, size_t key_len); /* Exit key interface. */ diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index 7cdbd16aed30..9235fb7d0ec9 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -16,12 +16,17 @@ #include #include #include +#include #include #include #include #include #include +static char *trusted_rng = "default"; +module_param_named(rng, trusted_rng, charp, 0); +MODULE_PARM_DESC(rng, "Select trusted key RNG"); + static char *trusted_key_source; module_param_named(source, trusted_key_source, charp, 0); MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); @@ -312,8 +317,14 @@ struct key_type key_type_trusted = { }; EXPORT_SYMBOL_GPL(key_type_trusted); +static int kernel_get_random(unsigned char *key, size_t key_len) +{ + return get_random_bytes_wait(key, key_len) ?: key_len; +} + static int __init init_trusted(void) { + int (*get_random)(unsigned char *key, size_t key_len); int i, ret = 0; for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) { @@ -322,6 +333,28 @@ static int __init init_trusted(void) strlen(trusted_key_sources[i].name))) continue; + /* + * We always support trusted.rng="kernel" and "default" as + * well as trusted.rng=$trusted.source if the trust source + * defines its own get_random callback. + */ + get_random = trusted_key_sources[i].ops->get_random; + if (trusted_rng && strcmp(trusted_rng, "default")) { + if (!strcmp(trusted_rng, "kernel")) { + get_random = kernel_get_random; + } else if (strcmp(trusted_rng, trusted_key_sources[i].name) || + !get_random) { + pr_warn("Unsupported RNG. Supported: kernel"); + if (get_random) + pr_cont(", %s", trusted_key_sources[i].name); + pr_cont(", default\n"); + return -EINVAL; + } + } + + if (!get_random) + get_random = kernel_get_random; + static_call_update(trusted_key_init, trusted_key_sources[i].ops->init); static_call_update(trusted_key_seal, @@ -329,7 +362,7 @@ static int __init init_trusted(void) static_call_update(trusted_key_unseal, trusted_key_sources[i].ops->unseal); static_call_update(trusted_key_get_random, - trusted_key_sources[i].ops->get_random); + get_random); static_call_update(trusted_key_exit, trusted_key_sources[i].ops->exit); migratable = trusted_key_sources[i].ops->migratable; From 7a0e7d5265f58eab5983f6560817d4fe9943743b Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:01 +0200 Subject: [PATCH 16/20] crypto: caam - determine whether CAAM supports blob encap/decap Depending on SoC variant, a CAAM may be available, but with some futures fused out. The LS1028A (non-E) SoC is one such SoC and while it indicates BLOB support, BLOB operations will ultimately fail, because there is no AES support. Add a new blob_present member to reflect whether both BLOB support and the AES support it depends on is available. These will be used in a follow-up commit to allow blob driver initialization to error out on SoCs without the necessary hardware support instead of failing at runtime with a cryptic caam_jr 8020000.jr: 20000b0f: CCB: desc idx 11: : Invalid CHA selected. Co-developed-by: Michael Walle Signed-off-by: Michael Walle Tested-by: Michael Walle # on ls1028a (non-E and E) Signed-off-by: Ahmad Fatoum Reviewed-by: Pankaj Gupta Signed-off-by: Jarkko Sakkinen --- drivers/crypto/caam/ctrl.c | 17 +++++++++++++++-- drivers/crypto/caam/intern.h | 1 + drivers/crypto/caam/regs.h | 4 +++- 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index ca0361b2dbb0..38c4d88a9d03 100644 --- a/drivers/crypto/caam/ctrl.c +++ b/drivers/crypto/caam/ctrl.c @@ -820,12 +820,25 @@ static int caam_probe(struct platform_device *pdev) return -ENOMEM; } - if (ctrlpriv->era < 10) + comp_params = rd_reg32(&ctrl->perfmon.comp_parms_ls); + ctrlpriv->blob_present = !!(comp_params & CTPR_LS_BLOB); + + /* + * Some SoCs like the LS1028A (non-E) indicate CTPR_LS_BLOB support, + * but fail when actually using it due to missing AES support, so + * check both here. + */ + if (ctrlpriv->era < 10) { rng_vid = (rd_reg32(&ctrl->perfmon.cha_id_ls) & CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; - else + ctrlpriv->blob_present = ctrlpriv->blob_present && + (rd_reg32(&ctrl->perfmon.cha_num_ls) & CHA_ID_LS_AES_MASK); + } else { rng_vid = (rd_reg32(&ctrl->vreg.rng) & CHA_VER_VID_MASK) >> CHA_VER_VID_SHIFT; + ctrlpriv->blob_present = ctrlpriv->blob_present && + (rd_reg32(&ctrl->vreg.aesa) & CHA_VER_MISC_AES_NUM_MASK); + } /* * If SEC has RNG version >= 4 and RNG state handle has not been diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h index 7d45b21bd55a..e92210e2ab76 100644 --- a/drivers/crypto/caam/intern.h +++ b/drivers/crypto/caam/intern.h @@ -92,6 +92,7 @@ struct caam_drv_private { */ u8 total_jobrs; /* Total Job Rings in device */ u8 qi_present; /* Nonzero if QI present in device */ + u8 blob_present; /* Nonzero if BLOB support present in device */ u8 mc_en; /* Nonzero if MC f/w is active */ int secvio_irq; /* Security violation interrupt number */ int virt_en; /* Virtualization enabled in CAAM */ diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h index 3738625c0250..66d6dad841bb 100644 --- a/drivers/crypto/caam/regs.h +++ b/drivers/crypto/caam/regs.h @@ -320,7 +320,8 @@ struct version_regs { #define CHA_VER_VID_MASK (0xffull << CHA_VER_VID_SHIFT) /* CHA Miscellaneous Information - AESA_MISC specific */ -#define CHA_VER_MISC_AES_GCM BIT(1 + CHA_VER_MISC_SHIFT) +#define CHA_VER_MISC_AES_NUM_MASK GENMASK(7, 0) +#define CHA_VER_MISC_AES_GCM BIT(1 + CHA_VER_MISC_SHIFT) /* CHA Miscellaneous Information - PKHA_MISC specific */ #define CHA_VER_MISC_PKHA_NO_CRYPT BIT(7 + CHA_VER_MISC_SHIFT) @@ -414,6 +415,7 @@ struct caam_perfmon { #define CTPR_MS_PG_SZ_MASK 0x10 #define CTPR_MS_PG_SZ_SHIFT 4 u32 comp_parms_ms; /* CTPR - Compile Parameters Register */ +#define CTPR_LS_BLOB BIT(1) u32 comp_parms_ls; /* CTPR - Compile Parameters Register */ u64 rsvd1[2]; From 007c3ff11f38d83cc95b0f402e432cbf484e3c31 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:02 +0200 Subject: [PATCH 17/20] crypto: caam - add in-kernel interface for blob generator The NXP Cryptographic Acceleration and Assurance Module (CAAM) can be used to protect user-defined data across system reboot: - When the system is fused and boots into secure state, the master key is a unique never-disclosed device-specific key - random key is encrypted by key derived from master key - data is encrypted using the random key - encrypted data and its encrypted random key are stored alongside - This blob can now be safely stored in non-volatile memory On next power-on: - blob is loaded into CAAM - CAAM writes decrypted data either into memory or key register Add functions to realize encrypting and decrypting into memory alongside the CAAM driver. They will be used in a later commit as a source for the trusted key seal/unseal mechanism. Reviewed-by: David Gstir Reviewed-by: Pankaj Gupta Tested-by: Tim Harvey Tested-by: Matthias Schiffer Tested-by: Pankaj Gupta Tested-by: Michael Walle # on ls1028a (non-E and E) Tested-by: John Ernberg # iMX8QXP Signed-off-by: Steffen Trumtrar Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- drivers/crypto/caam/Kconfig | 3 + drivers/crypto/caam/Makefile | 1 + drivers/crypto/caam/blob_gen.c | 182 +++++++++++++++++++++++++++++++++ include/soc/fsl/caam-blob.h | 103 +++++++++++++++++++ 4 files changed, 289 insertions(+) create mode 100644 drivers/crypto/caam/blob_gen.c create mode 100644 include/soc/fsl/caam-blob.h diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig index 84ea7cba5ee5..ea9f8b1ae981 100644 --- a/drivers/crypto/caam/Kconfig +++ b/drivers/crypto/caam/Kconfig @@ -151,6 +151,9 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API Selecting this will register the SEC4 hardware rng to the hw_random API for supplying the kernel entropy pool. +config CRYPTO_DEV_FSL_CAAM_BLOB_GEN + bool + endif # CRYPTO_DEV_FSL_CAAM_JR endif # CRYPTO_DEV_FSL_CAAM diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile index 3570286eb9ce..25f7ae5a4642 100644 --- a/drivers/crypto/caam/Makefile +++ b/drivers/crypto/caam/Makefile @@ -21,6 +21,7 @@ caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o +caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o ifneq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),) diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c new file mode 100644 index 000000000000..6345c7269eb0 --- /dev/null +++ b/drivers/crypto/caam/blob_gen.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 Pengutronix, Steffen Trumtrar + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#define pr_fmt(fmt) "caam blob_gen: " fmt + +#include +#include + +#include "compat.h" +#include "desc_constr.h" +#include "desc.h" +#include "error.h" +#include "intern.h" +#include "jr.h" +#include "regs.h" + +#define CAAM_BLOB_DESC_BYTES_MAX \ + /* Command to initialize & stating length of descriptor */ \ + (CAAM_CMD_SZ + \ + /* Command to append the key-modifier + key-modifier data */ \ + CAAM_CMD_SZ + CAAM_BLOB_KEYMOD_LENGTH + \ + /* Command to include input key + pointer to the input key */ \ + CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \ + /* Command to include output key + pointer to the output key */ \ + CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \ + /* Command describing the operation to perform */ \ + CAAM_CMD_SZ) + +struct caam_blob_priv { + struct device jrdev; +}; + +struct caam_blob_job_result { + int err; + struct completion completion; +}; + +static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context) +{ + struct caam_blob_job_result *res = context; + int ecode = 0; + + dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err); + + if (err) + ecode = caam_jr_strstatus(dev, err); + + res->err = ecode; + + /* + * Upon completion, desc points to a buffer containing a CAAM job + * descriptor which encapsulates data into an externally-storable + * blob. + */ + complete(&res->completion); +} + +int caam_process_blob(struct caam_blob_priv *priv, + struct caam_blob_info *info, bool encap) +{ + struct caam_blob_job_result testres; + struct device *jrdev = &priv->jrdev; + dma_addr_t dma_in, dma_out; + int op = OP_PCLID_BLOB; + size_t output_len; + u32 *desc; + int ret; + + if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH) + return -EINVAL; + + if (encap) { + op |= OP_TYPE_ENCAP_PROTOCOL; + output_len = info->input_len + CAAM_BLOB_OVERHEAD; + } else { + op |= OP_TYPE_DECAP_PROTOCOL; + output_len = info->input_len - CAAM_BLOB_OVERHEAD; + } + + desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL | GFP_DMA); + if (!desc) + return -ENOMEM; + + dma_in = dma_map_single(jrdev, info->input, info->input_len, + DMA_TO_DEVICE); + if (dma_mapping_error(jrdev, dma_in)) { + dev_err(jrdev, "unable to map input DMA buffer\n"); + ret = -ENOMEM; + goto out_free; + } + + dma_out = dma_map_single(jrdev, info->output, output_len, + DMA_FROM_DEVICE); + if (dma_mapping_error(jrdev, dma_out)) { + dev_err(jrdev, "unable to map output DMA buffer\n"); + ret = -ENOMEM; + goto out_unmap_in; + } + + /* + * A data blob is encrypted using a blob key (BK); a random number. + * The BK is used as an AES-CCM key. The initial block (B0) and the + * initial counter (Ctr0) are generated automatically and stored in + * Class 1 Context DWords 0+1+2+3. The random BK is stored in the + * Class 1 Key Register. Operation Mode is set to AES-CCM. + */ + + init_job_desc(desc, 0); + append_key_as_imm(desc, info->key_mod, info->key_mod_len, + info->key_mod_len, CLASS_2 | KEY_DEST_CLASS_REG); + append_seq_in_ptr_intlen(desc, dma_in, info->input_len, 0); + append_seq_out_ptr_intlen(desc, dma_out, output_len, 0); + append_operation(desc, op); + + print_hex_dump_debug("data@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, info->input, + info->input_len, false); + print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, desc, + desc_bytes(desc), false); + + testres.err = 0; + init_completion(&testres.completion); + + ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres); + if (ret == -EINPROGRESS) { + wait_for_completion(&testres.completion); + ret = testres.err; + print_hex_dump_debug("output@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, info->output, + output_len, false); + } + + if (ret == 0) + info->output_len = output_len; + + dma_unmap_single(jrdev, dma_out, output_len, DMA_FROM_DEVICE); +out_unmap_in: + dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE); +out_free: + kfree(desc); + + return ret; +} +EXPORT_SYMBOL(caam_process_blob); + +struct caam_blob_priv *caam_blob_gen_init(void) +{ + struct caam_drv_private *ctrlpriv; + struct device *jrdev; + + /* + * caam_blob_gen_init() may expectedly fail with -ENODEV, e.g. when + * CAAM driver didn't probe or when SoC lacks BLOB support. An + * error would be harsh in this case, so we stick to info level. + */ + + jrdev = caam_jr_alloc(); + if (IS_ERR(jrdev)) { + pr_info("job ring requested, but none currently available\n"); + return ERR_PTR(-ENODEV); + } + + ctrlpriv = dev_get_drvdata(jrdev->parent); + if (!ctrlpriv->blob_present) { + dev_info(jrdev, "no hardware blob generation support\n"); + caam_jr_free(jrdev); + return ERR_PTR(-ENODEV); + } + + return container_of(jrdev, struct caam_blob_priv, jrdev); +} +EXPORT_SYMBOL(caam_blob_gen_init); + +void caam_blob_gen_exit(struct caam_blob_priv *priv) +{ + caam_jr_free(&priv->jrdev); +} +EXPORT_SYMBOL(caam_blob_gen_exit); diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h new file mode 100644 index 000000000000..937cac52f36d --- /dev/null +++ b/include/soc/fsl/caam-blob.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Pengutronix, Ahmad Fatoum + */ + +#ifndef __CAAM_BLOB_GEN +#define __CAAM_BLOB_GEN + +#include +#include + +#define CAAM_BLOB_KEYMOD_LENGTH 16 +#define CAAM_BLOB_OVERHEAD (32 + 16) +#define CAAM_BLOB_MAX_LEN 4096 + +struct caam_blob_priv; + +/** + * struct caam_blob_info - information for CAAM blobbing + * @input: pointer to input buffer (must be DMAable) + * @input_len: length of @input buffer in bytes. + * @output: pointer to output buffer (must be DMAable) + * @output_len: length of @output buffer in bytes. + * @key_mod: key modifier + * @key_mod_len: length of @key_mod in bytes. + * May not exceed %CAAM_BLOB_KEYMOD_LENGTH + */ +struct caam_blob_info { + void *input; + size_t input_len; + + void *output; + size_t output_len; + + const void *key_mod; + size_t key_mod_len; +}; + +/** + * caam_blob_gen_init - initialize blob generation + * Return: pointer to new &struct caam_blob_priv instance on success + * and ``ERR_PTR(-ENODEV)`` if CAAM has no hardware blobbing support + * or no job ring could be allocated. + */ +struct caam_blob_priv *caam_blob_gen_init(void); + +/** + * caam_blob_gen_exit - free blob generation resources + * @priv: instance returned by caam_blob_gen_init() + */ +void caam_blob_gen_exit(struct caam_blob_priv *priv); + +/** + * caam_process_blob - encapsulate or decapsulate blob + * @priv: instance returned by caam_blob_gen_init() + * @info: pointer to blobbing info describing key, blob and + * key modifier buffers. + * @encap: true for encapsulation, false for decapsulation + * + * Return: %0 and sets ``info->output_len`` on success and a negative + * error code otherwise. + */ +int caam_process_blob(struct caam_blob_priv *priv, + struct caam_blob_info *info, bool encap); + +/** + * caam_encap_blob - encapsulate blob + * @priv: instance returned by caam_blob_gen_init() + * @info: pointer to blobbing info describing input key, + * output blob and key modifier buffers. + * + * Return: %0 and sets ``info->output_len`` on success and + * a negative error code otherwise. + */ +static inline int caam_encap_blob(struct caam_blob_priv *priv, + struct caam_blob_info *info) +{ + if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD) + return -EINVAL; + + return caam_process_blob(priv, info, true); +} + +/** + * caam_decap_blob - decapsulate blob + * @priv: instance returned by caam_blob_gen_init() + * @info: pointer to blobbing info describing output key, + * input blob and key modifier buffers. + * + * Return: %0 and sets ``info->output_len`` on success and + * a negative error code otherwise. + */ +static inline int caam_decap_blob(struct caam_blob_priv *priv, + struct caam_blob_info *info) +{ + if (info->input_len < CAAM_BLOB_OVERHEAD || + info->output_len < info->input_len - CAAM_BLOB_OVERHEAD) + return -EINVAL; + + return caam_process_blob(priv, info, false); +} + +#endif From e9c5048c2de1913d0bcd589bc1487810c2e24bc1 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:03 +0200 Subject: [PATCH 18/20] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core built into many newer i.MX and QorIQ SoCs by NXP. The CAAM does crypto acceleration, hardware number generation and has a blob mechanism for encapsulation/decapsulation of sensitive material. This blob mechanism depends on a device specific random 256-bit One Time Programmable Master Key that is fused in each SoC at manufacturing time. This key is unreadable and can only be used by the CAAM for AES encryption/decryption of user data. This makes it a suitable backend (source) for kernel trusted keys. Previous commits generalized trusted keys to support multiple backends and added an API to access the CAAM blob mechanism. Based on these, provide the necessary glue to use the CAAM for trusted keys. Reviewed-by: David Gstir Reviewed-by: Pankaj Gupta Reviewed-by: Jarkko Sakkinen Tested-by: Tim Harvey Tested-by: Matthias Schiffer Tested-by: Pankaj Gupta Tested-by: Michael Walle # on ls1028a (non-E and E) Tested-by: John Ernberg # iMX8QXP Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- .../admin-guide/kernel-parameters.txt | 1 + include/keys/trusted_caam.h | 11 +++ security/keys/trusted-keys/Kconfig | 11 ++- security/keys/trusted-keys/Makefile | 2 + security/keys/trusted-keys/trusted_caam.c | 80 +++++++++++++++++++ security/keys/trusted-keys/trusted_core.c | 6 +- 6 files changed, 109 insertions(+), 2 deletions(-) create mode 100644 include/keys/trusted_caam.h create mode 100644 security/keys/trusted-keys/trusted_caam.c diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 4deed1908a75..9afb7046ce97 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5958,6 +5958,7 @@ sources: - "tpm" - "tee" + - "caam" If not specified then it defaults to iterating through the trust source list starting with TPM and assigns the first trust source as a backend which is initialized diff --git a/include/keys/trusted_caam.h b/include/keys/trusted_caam.h new file mode 100644 index 000000000000..73fe2f32f65e --- /dev/null +++ b/include/keys/trusted_caam.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#ifndef __CAAM_TRUSTED_KEY_H +#define __CAAM_TRUSTED_KEY_H + +extern struct trusted_key_ops trusted_key_caam_ops; + +#endif diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig index fc4abd581abb..dbfdd8536468 100644 --- a/security/keys/trusted-keys/Kconfig +++ b/security/keys/trusted-keys/Kconfig @@ -24,6 +24,15 @@ config TRUSTED_KEYS_TEE Enable use of the Trusted Execution Environment (TEE) as trusted key backend. -if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE +config TRUSTED_KEYS_CAAM + bool "CAAM-based trusted keys" + depends on CRYPTO_DEV_FSL_CAAM_JR >= TRUSTED_KEYS + select CRYPTO_DEV_FSL_CAAM_BLOB_GEN + default y + help + Enable use of NXP's Cryptographic Accelerator and Assurance Module + (CAAM) as trusted key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE && !TRUSTED_KEYS_CAAM comment "No trust source selected!" endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 2e2371eae4d5..735aa0bc08ef 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -12,3 +12,5 @@ trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o + +trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o diff --git a/security/keys/trusted-keys/trusted_caam.c b/security/keys/trusted-keys/trusted_caam.c new file mode 100644 index 000000000000..e3415c520c0a --- /dev/null +++ b/security/keys/trusted-keys/trusted_caam.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#include +#include +#include +#include +#include + +static struct caam_blob_priv *blobifier; + +#define KEYMOD "SECURE_KEY" + +static_assert(MAX_KEY_SIZE + CAAM_BLOB_OVERHEAD <= CAAM_BLOB_MAX_LEN); +static_assert(MAX_BLOB_SIZE <= CAAM_BLOB_MAX_LEN); + +static int trusted_caam_seal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct caam_blob_info info = { + .input = p->key, .input_len = p->key_len, + .output = p->blob, .output_len = MAX_BLOB_SIZE, + .key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1, + }; + + ret = caam_encap_blob(blobifier, &info); + if (ret) + return ret; + + p->blob_len = info.output_len; + return 0; +} + +static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob) +{ + int ret; + struct caam_blob_info info = { + .input = p->blob, .input_len = p->blob_len, + .output = p->key, .output_len = MAX_KEY_SIZE, + .key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1, + }; + + ret = caam_decap_blob(blobifier, &info); + if (ret) + return ret; + + p->key_len = info.output_len; + return 0; +} + +static int trusted_caam_init(void) +{ + int ret; + + blobifier = caam_blob_gen_init(); + if (IS_ERR(blobifier)) + return PTR_ERR(blobifier); + + ret = register_key_type(&key_type_trusted); + if (ret) + caam_blob_gen_exit(blobifier); + + return ret; +} + +static void trusted_caam_exit(void) +{ + unregister_key_type(&key_type_trusted); + caam_blob_gen_exit(blobifier); +} + +struct trusted_key_ops trusted_key_caam_ops = { + .migratable = 0, /* non-migratable */ + .init = trusted_caam_init, + .seal = trusted_caam_seal, + .unseal = trusted_caam_unseal, + .exit = trusted_caam_exit, +}; diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index 9235fb7d0ec9..c6fc50d67214 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -29,7 +30,7 @@ MODULE_PARM_DESC(rng, "Select trusted key RNG"); static char *trusted_key_source; module_param_named(source, trusted_key_source, charp, 0); -MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); +MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee or caam)"); static const struct trusted_key_source trusted_key_sources[] = { #if defined(CONFIG_TRUSTED_KEYS_TPM) @@ -38,6 +39,9 @@ static const struct trusted_key_source trusted_key_sources[] = { #if defined(CONFIG_TRUSTED_KEYS_TEE) { "tee", &trusted_key_tee_ops }, #endif +#if defined(CONFIG_TRUSTED_KEYS_CAAM) + { "caam", &trusted_key_caam_ops }, +#endif }; DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init); From 5002426e426166f57e1636b936666b275e6b3d2f Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:04 +0200 Subject: [PATCH 19/20] doc: trusted-encrypted: describe new CAAM trust source Update documentation for trusted key use with the Cryptographic Acceleration and Assurance Module (CAAM), an IP on NXP SoCs. Reviewed-by: Pankaj Gupta Reviewed-by: Jarkko Sakkinen Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- .../security/keys/trusted-encrypted.rst | 40 ++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index 2fe6fd1a2bbd..0bfb4c339748 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -35,6 +35,13 @@ safe. Rooted to Hardware Unique Key (HUK) which is generally burnt in on-chip fuses and is accessible to TEE only. + (3) CAAM (Cryptographic Acceleration and Assurance Module: IP on NXP SoCs) + + When High Assurance Boot (HAB) is enabled and the CAAM is in secure + mode, trust is rooted to the OTPMK, a never-disclosed 256-bit key + randomly generated and fused into each SoC at manufacturing time. + Otherwise, a common fixed test key is used instead. + * Execution isolation (1) TPM @@ -46,6 +53,10 @@ safe. Customizable set of operations running in isolated execution environment verified via Secure/Trusted boot process. + (3) CAAM + + Fixed set of operations running in isolated execution environment. + * Optional binding to platform integrity state (1) TPM @@ -63,6 +74,11 @@ safe. Relies on Secure/Trusted boot process for platform integrity. It can be extended with TEE based measured boot process. + (3) CAAM + + Relies on the High Assurance Boot (HAB) mechanism of NXP SoCs + for platform integrity. + * Interfaces and APIs (1) TPM @@ -74,10 +90,13 @@ safe. TEEs have well-documented, standardized client interface and APIs. For more details refer to ``Documentation/staging/tee.rst``. + (3) CAAM + + Interface is specific to silicon vendor. * Threat model - The strength and appropriateness of a particular TPM or TEE for a given + The strength and appropriateness of a particular trust source for a given purpose must be assessed when using them to protect security-relevant data. @@ -104,6 +123,12 @@ selected trust source: from platform specific hardware RNG or a software based Fortuna CSPRNG which can be seeded via multiple entropy sources. + * CAAM: Kernel RNG + + The normal kernel random number generator is used. To seed it from the + CAAM HWRNG, enable CRYPTO_DEV_FSL_CAAM_RNG_API and ensure the device + is probed. + Users may override this by specifying ``trusted.rng=kernel`` on the kernel command-line to override the used RNG with the kernel's random number pool. @@ -193,6 +218,19 @@ Usage:: specific to TEE device implementation. The key length for new keys is always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). +Trusted Keys usage: CAAM +------------------------ + +Usage:: + + keyctl add trusted name "new keylen" ring + keyctl add trusted name "load hex_blob" ring + keyctl print keyid + +"keyctl print" returns an ASCII hex copy of the sealed key, which is in a +CAAM-specific format. The key length for new keys is always in bytes. +Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). + Encrypted Keys usage -------------------- From 7f3113e3b9f7207f0bd57b5fdae1a1b9c8215e08 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:05 +0200 Subject: [PATCH 20/20] MAINTAINERS: add KEYS-TRUSTED-CAAM Create a maintainer entry for CAAM trusted keys in the Linux keyring. Reviewed-by: Pankaj Gupta Acked-by: Jarkko Sakkinen Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- MAINTAINERS | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index bf41a67635ec..982894375bb4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10860,6 +10860,15 @@ S: Supported F: include/keys/trusted_tee.h F: security/keys/trusted-keys/trusted_tee.c +KEYS-TRUSTED-CAAM +M: Ahmad Fatoum +R: Pengutronix Kernel Team +L: linux-integrity@vger.kernel.org +L: keyrings@vger.kernel.org +S: Maintained +F: include/keys/trusted_caam.h +F: security/keys/trusted-keys/trusted_caam.c + KEYS/KEYRINGS M: David Howells M: Jarkko Sakkinen