Allow ML-DSA module signing to be enabled. Note that OpenSSL's CMS_*() function suite does not, as of OpenSSL-3.6, support the use of CMS_NOATTR with ML-DSA, so the prohibition against using signedAttrs with module signing has to be removed. The selected digest then applies only to the algorithm used to calculate the digest stored in the messageDigest attribute. The OpenSSL development branch has patches applied that fix this[1], but it appears that that will only be available in OpenSSL-4.
[1] https://github.com/openssl/openssl/pull/28923 sign-file won't set CMS_NOATTR if openssl is earlier than v4, resulting in the use of signed attributes. The ML-DSA algorithm takes the raw data to be signed without regard to what digest algorithm is specified in the CMS message. The CMS specified digest algorithm is ignored unless signedAttrs are used; in such a case, only SHA512 is permitted. Signed-off-by: David Howells <[email protected]> cc: Eric Biggers <[email protected]> cc: Lukas Wunner <[email protected]> cc: Ignat Korchagin <[email protected]> cc: Stephan Mueller <[email protected]> cc: Herbert Xu <[email protected]> cc: [email protected] cc: [email protected] --- Documentation/admin-guide/module-signing.rst | 16 +++++---- certs/Kconfig | 30 +++++++++++++++++ certs/Makefile | 3 ++ crypto/asymmetric_keys/pkcs7_verify.c | 4 --- scripts/sign-file.c | 34 +++++++++++++++----- 5 files changed, 68 insertions(+), 19 deletions(-) diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst index a8667a777490..7f2f127dc76f 100644 --- a/Documentation/admin-guide/module-signing.rst +++ b/Documentation/admin-guide/module-signing.rst @@ -28,10 +28,12 @@ trusted userspace bits. This facility uses X.509 ITU-T standard certificates to encode the public keys involved. The signatures are not themselves encoded in any industrial standard -type. The built-in facility currently only supports the RSA & NIST P-384 ECDSA -public key signing standard (though it is pluggable and permits others to be -used). The possible hash algorithms that can be used are SHA-2 and SHA-3 of -sizes 256, 384, and 512 (the algorithm is selected by data in the signature). +type. The built-in facility currently only supports the RSA, NIST P-384 ECDSA +and NIST FIPS-204 ML-DSA public key signing standards (though it is pluggable +and permits others to be used). For RSA and ECDSA, the possible hash +algorithms that can be used are SHA-2 and SHA-3 of sizes 256, 384, and 512 (the +algorithm is selected by data in the signature); ML-DSA does its own hashing, +but is allowed to be used with a SHA512 hash for signed attributes. ========================== @@ -146,9 +148,9 @@ into vmlinux) using parameters in the:: file (which is also generated if it does not already exist). -One can select between RSA (``MODULE_SIG_KEY_TYPE_RSA``) and ECDSA -(``MODULE_SIG_KEY_TYPE_ECDSA``) to generate either RSA 4k or NIST -P-384 keypair. +One can select between RSA (``MODULE_SIG_KEY_TYPE_RSA``), ECDSA +(``MODULE_SIG_KEY_TYPE_ECDSA``) and ML-DSA (``MODULE_SIG_KEY_TYPE_MLDSA_*``) to +generate an RSA 4k, a NIST P-384 keypair or an ML-DSA 44, 65 or 87 keypair. It is strongly recommended that you provide your own x509.genkey file. diff --git a/certs/Kconfig b/certs/Kconfig index 78307dc25559..2b088ef58373 100644 --- a/certs/Kconfig +++ b/certs/Kconfig @@ -39,6 +39,36 @@ config MODULE_SIG_KEY_TYPE_ECDSA Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem, when falling back to building Linux 5.14 and older kernels. +config MODULE_SIG_KEY_TYPE_MLDSA_44 + bool "ML-DSA-44" + select CRYPTO_MLDSA + help + Use an ML-DSA-44 key (NIST FIPS 204) for module signing. ML-DSA + support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+. With + the latter, the entire module body will be signed; with the former, + signedAttrs will be used as it lacks support for CMS_NOATTR with + ML-DSA. + +config MODULE_SIG_KEY_TYPE_MLDSA_65 + bool "ML-DSA-65" + select CRYPTO_MLDSA + help + Use an ML-DSA-65 key (NIST FIPS 204) for module signing. ML-DSA + support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+. With + the latter, the entire module body will be signed; with the former, + signedAttrs will be used as it lacks support for CMS_NOATTR with + ML-DSA. + +config MODULE_SIG_KEY_TYPE_MLDSA_87 + bool "ML-DSA-87" + select CRYPTO_MLDSA + help + Use an ML-DSA-87 key (NIST FIPS 204) for module signing. ML-DSA + support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+. With + the latter, the entire module body will be signed; with the former, + signedAttrs will be used as it lacks support for CMS_NOATTR with + ML-DSA. + endchoice config SYSTEM_TRUSTED_KEYRING diff --git a/certs/Makefile b/certs/Makefile index f6fa4d8d75e0..3ee1960f9f4a 100644 --- a/certs/Makefile +++ b/certs/Makefile @@ -43,6 +43,9 @@ targets += x509_certificate_list ifeq ($(CONFIG_MODULE_SIG_KEY),certs/signing_key.pem) keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_curve:secp384r1 +keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_44) := -newkey ml-dsa-44 +keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_65) := -newkey ml-dsa-65 +keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_87) := -newkey ml-dsa-87 quiet_cmd_gen_key = GENKEY $@ cmd_gen_key = openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \ diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c index a5b2ed4d53fd..75d1d694dc7b 100644 --- a/crypto/asymmetric_keys/pkcs7_verify.c +++ b/crypto/asymmetric_keys/pkcs7_verify.c @@ -431,10 +431,6 @@ int pkcs7_verify(struct pkcs7_message *pkcs7, pr_warn("Invalid module sig (not pkcs7-data)\n"); return -EKEYREJECTED; } - if (pkcs7->have_authattrs) { - pr_warn("Invalid module sig (has authattrs)\n"); - return -EKEYREJECTED; - } break; case VERIFYING_FIRMWARE_SIGNATURE: if (pkcs7->data_type != OID_data) { diff --git a/scripts/sign-file.c b/scripts/sign-file.c index 7070245edfc1..547b97097230 100644 --- a/scripts/sign-file.c +++ b/scripts/sign-file.c @@ -315,18 +315,36 @@ int main(int argc, char **argv) ERR(!digest_algo, "EVP_get_digestbyname"); #ifndef USE_PKCS7 + + unsigned int flags = + CMS_NOCERTS | + CMS_PARTIAL | + CMS_BINARY | + CMS_DETACHED | + CMS_STREAM | + CMS_NOSMIMECAP | + CMS_NO_SIGNING_TIME | + use_keyid; + + if ((EVP_PKEY_is_a(private_key, "ML-DSA-44") || + EVP_PKEY_is_a(private_key, "ML-DSA-65") || + EVP_PKEY_is_a(private_key, "ML-DSA-87")) && + OPENSSL_VERSION_MAJOR < 4) { + /* ML-DSA + CMS_NOATTR is not supported in openssl-3.5 + * and before. + */ + use_signed_attrs = 0; + } + + flags |= use_signed_attrs; + /* Load the signature message from the digest buffer. */ - cms = CMS_sign(NULL, NULL, NULL, NULL, - CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | - CMS_DETACHED | CMS_STREAM); + cms = CMS_sign(NULL, NULL, NULL, NULL, flags); ERR(!cms, "CMS_sign"); - ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, - CMS_NOCERTS | CMS_BINARY | - CMS_NOSMIMECAP | use_keyid | - use_signed_attrs), + ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, flags), "CMS_add1_signer"); - ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) != 1, + ERR(CMS_final(cms, bm, NULL, flags) != 1, "CMS_final"); #else
