From patchwork Fri Jan 14 00:29:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12713246 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50DDBC433EF for ; Fri, 14 Jan 2022 00:30:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238423AbiANAax (ORCPT ); Thu, 13 Jan 2022 19:30:53 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:40034 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230491AbiANAaw (ORCPT ); Thu, 13 Jan 2022 19:30:52 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4F24161D50; Fri, 14 Jan 2022 00:30:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CBC9C36AEF; Fri, 14 Jan 2022 00:30:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642120251; bh=31ObngJIWRlK96KNN1SCehwf7gev5VKl+XnN67ihKiY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pt7yE0iVvBipSScUJ96hfSjYvqCvkagbShfokre5nz43pdtdnR+HQ8QP5MZyU+kTI aHjwD0n87S2Pq3jsVS9o2Wx5gI1QrpHlNpSKjV4f0wnKBaeVG0oNKnIKfKmQQClasN OTybyqzbMbG3fClmNwWkLmOqfTYx+UxPq64nFtjDPRt5Iala+0vGiMQ1TI1XirFcDr 00vYtBi4F1odQkzgQ+bbUdFYJrQl2vAEFQ087MUEeHE9r69QeV6aACCsr9vNPjbWZV LEDV47zxAkzW8iW0svEC/mJNHeamgA6YZIgv6XbaIGkNWTI7y9SgOxKIUAZvC+lYRz Qpvjurj5GMipw== From: Eric Biggers To: keyrings@vger.kernel.org, David Howells , Jarkko Sakkinen Cc: linux-crypto@vger.kernel.org Subject: [PATCH 1/4] KEYS: x509: clearly distinguish between key and signature algorithms Date: Thu, 13 Jan 2022 16:29:17 -0800 Message-Id: <20220114002920.103858-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220114002920.103858-1-ebiggers@kernel.org> References: <20220114002920.103858-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org From: Eric Biggers An X.509 certificate has two, potentially different public key algorithms: the one used by the certificate's key, and the one that was used to sign the certificate. Some of the naming made it unclear which algorithm was meant. Rename things appropriately: - x509_note_pkey_algo() => x509_note_sig_algo() - algo_oid => sig_algo Signed-off-by: Eric Biggers Acked-by: Jarkko Sakkinen --- crypto/asymmetric_keys/x509.asn1 | 2 +- crypto/asymmetric_keys/x509_cert_parser.c | 32 +++++++++++++---------- 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/crypto/asymmetric_keys/x509.asn1 b/crypto/asymmetric_keys/x509.asn1 index 5c9f4e4a5231..92d59c32f96a 100644 --- a/crypto/asymmetric_keys/x509.asn1 +++ b/crypto/asymmetric_keys/x509.asn1 @@ -7,7 +7,7 @@ Certificate ::= SEQUENCE { TBSCertificate ::= SEQUENCE { version [ 0 ] Version DEFAULT, serialNumber CertificateSerialNumber ({ x509_note_serial }), - signature AlgorithmIdentifier ({ x509_note_pkey_algo }), + signature AlgorithmIdentifier ({ x509_note_sig_algo }), issuer Name ({ x509_note_issuer }), validity Validity, subject Name ({ x509_note_subject }), diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index 083405eb80c3..aec2396a7f7e 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -24,9 +24,9 @@ struct x509_parse_context { size_t key_size; /* Size of key data */ const void *params; /* Key parameters */ size_t params_size; /* Size of key parameters */ - enum OID key_algo; /* Public key algorithm */ + enum OID key_algo; /* Algorithm used by the cert's key */ enum OID last_oid; /* Last OID encountered */ - enum OID algo_oid; /* Algorithm OID */ + enum OID sig_algo; /* Algorithm used to sign the cert */ unsigned char nr_mpi; /* Number of MPIs stored */ u8 o_size; /* Size of organizationName (O) */ u8 cn_size; /* Size of commonName (CN) */ @@ -187,11 +187,10 @@ int x509_note_tbs_certificate(void *context, size_t hdrlen, } /* - * Record the public key algorithm + * Record the algorithm that was used to sign this certificate. */ -int x509_note_pkey_algo(void *context, size_t hdrlen, - unsigned char tag, - const void *value, size_t vlen) +int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) { struct x509_parse_context *ctx = context; @@ -263,22 +262,22 @@ int x509_note_pkey_algo(void *context, size_t hdrlen, rsa_pkcs1: ctx->cert->sig->pkey_algo = "rsa"; ctx->cert->sig->encoding = "pkcs1"; - ctx->algo_oid = ctx->last_oid; + ctx->sig_algo = ctx->last_oid; return 0; ecrdsa: ctx->cert->sig->pkey_algo = "ecrdsa"; ctx->cert->sig->encoding = "raw"; - ctx->algo_oid = ctx->last_oid; + ctx->sig_algo = ctx->last_oid; return 0; sm2: ctx->cert->sig->pkey_algo = "sm2"; ctx->cert->sig->encoding = "raw"; - ctx->algo_oid = ctx->last_oid; + ctx->sig_algo = ctx->last_oid; return 0; ecdsa: ctx->cert->sig->pkey_algo = "ecdsa"; ctx->cert->sig->encoding = "x962"; - ctx->algo_oid = ctx->last_oid; + ctx->sig_algo = ctx->last_oid; return 0; } @@ -291,11 +290,16 @@ int x509_note_signature(void *context, size_t hdrlen, { struct x509_parse_context *ctx = context; - pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen); + pr_debug("Signature: alg=%u, size=%zu\n", ctx->last_oid, vlen); - if (ctx->last_oid != ctx->algo_oid) { - pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n", - ctx->algo_oid, ctx->last_oid); + /* + * In X.509 certificates, the signature's algorithm is stored in two + * places: inside the TBSCertificate (the data that is signed), and + * alongside the signature. These *must* match. + */ + if (ctx->last_oid != ctx->sig_algo) { + pr_warn("signatureAlgorithm (%u) differs from tbsCertificate.signature (%u)\n", + ctx->last_oid, ctx->sig_algo); return -EINVAL; }