Add porting layer for PKCS7 parser on top of MbedTLS PKCS7 library. Introduce _LEGACY and _MBEDTLS kconfigs for PKCS7 parser legacy and MbedTLS implementations respectively.
Signed-off-by: Raymond Mao raymond.mao@linaro.org --- Changes in v2 - Move the porting layer to MbedTLS dir. - Fix EFI Capsule CI test failures. Changes in v3 - None. Changes in v4 - Introduce _LEGACY and _MBEDTLS kconfigs for PKCS7 parser legacy and MbedTLS implementations respectively. - Move common functions to helper. - Fix an unnecessary pointer casting. Changes in v5 - Refactored MbedTLS makefile. Changes in v6 - None. Changes in v7 - None. Changes in v8 - None
lib/mbedtls/Kconfig | 18 ++ lib/mbedtls/Makefile | 3 +- lib/mbedtls/pkcs7_parser.c | 506 +++++++++++++++++++++++++++++++++++++ 3 files changed, 526 insertions(+), 1 deletion(-) create mode 100644 lib/mbedtls/pkcs7_parser.c
diff --git a/lib/mbedtls/Kconfig b/lib/mbedtls/Kconfig index abdafd04e89..189bb3186b6 100644 --- a/lib/mbedtls/Kconfig +++ b/lib/mbedtls/Kconfig @@ -119,6 +119,7 @@ config LEGACY_CRYPTO_CERT select ASYMMETRIC_PUBLIC_KEY_LEGACY if \ ASYMMETRIC_PUBLIC_KEY_SUBTYPE select X509_CERTIFICATE_PARSER_LEGACY if X509_CERTIFICATE_PARSER + select PKCS7_MESSAGE_PARSER_LEGACY if PKCS7_MESSAGE_PARSER select SPL_ASYMMETRIC_PUBLIC_KEY_LEGACY if \ SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE help @@ -141,6 +142,14 @@ config X509_CERTIFICATE_PARSER_LEGACY This option chooses legacy certificate library for X509 certificate parser.
+config PKCS7_MESSAGE_PARSER_LEGACY + bool "PKCS#7 message parser with legacy certificate library" + depends on X509_CERTIFICATE_PARSER_LEGACY + select ASN1_DECODER_LEGACY + help + This option chooses legacy certificate library for PKCS7 message + parser. + if SPL
config SPL_ASYMMETRIC_PUBLIC_KEY_LEGACY @@ -293,6 +302,7 @@ config MBEDTLS_LIB_X509 select ASYMMETRIC_PUBLIC_KEY_MBEDTLS if \ ASYMMETRIC_PUBLIC_KEY_SUBTYPE select X509_CERTIFICATE_PARSER_MBEDTLS if X509_CERTIFICATE_PARSER + select PKCS7_MESSAGE_PARSER_MBEDTLS if PKCS7_MESSAGE_PARSER select SPL_ASYMMETRIC_PUBLIC_KEY_MBEDTLS if \ SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE help @@ -315,6 +325,14 @@ config X509_CERTIFICATE_PARSER_MBEDTLS This option chooses MbedTLS certificate library for X509 certificate parser.
+config PKCS7_MESSAGE_PARSER_MBEDTLS + bool "PKCS#7 message parser with MbedTLS certificate library" + depends on X509_CERTIFICATE_PARSER_MBEDTLS + select ASN1_DECODER_MBEDTLS + help + This option chooses MbedTLS certificate library for PKCS7 message + parser. + if SPL
config SPL_ASYMMETRIC_PUBLIC_KEY_MBEDTLS diff --git a/lib/mbedtls/Makefile b/lib/mbedtls/Makefile index 29653323279..128a29c512f 100644 --- a/lib/mbedtls/Makefile +++ b/lib/mbedtls/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_$(SPL_)ASYMMETRIC_PUBLIC_KEY_MBEDTLS) += \ public_key.o obj-$(CONFIG_$(SPL_)X509_CERTIFICATE_PARSER_MBEDTLS) += \ x509_cert_parser.o +obj-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER_MBEDTLS) += pkcs7_parser.o
# MbedTLS crypto library obj-$(CONFIG_MBEDTLS_LIB) += mbedtls_lib_crypto.o @@ -49,5 +50,5 @@ mbedtls_lib_x509-$(CONFIG_$(SPL_)ASYMMETRIC_PUBLIC_KEY_MBEDTLS) += \ mbedtls_lib_x509-$(CONFIG_$(SPL_)X509_CERTIFICATE_PARSER_MBEDTLS) += \ $(MBEDTLS_LIB_DIR)/x509_crl.o \ $(MBEDTLS_LIB_DIR)/x509_crt.o -mbedtls_lib_x509-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER) += \ +mbedtls_lib_x509-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER_MBEDTLS) += \ $(MBEDTLS_LIB_DIR)/pkcs7.o diff --git a/lib/mbedtls/pkcs7_parser.c b/lib/mbedtls/pkcs7_parser.c new file mode 100644 index 00000000000..69ca784858e --- /dev/null +++ b/lib/mbedtls/pkcs7_parser.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PKCS#7 parser using MbedTLS PKCS#7 library + * + * Copyright (c) 2024 Linaro Limited + * Author: Raymond Mao raymond.mao@linaro.org + */ + +#include <log.h> +#include <linux/kernel.h> +#include <linux/err.h> +#include <crypto/public_key.h> +#include <crypto/pkcs7_parser.h> + +static void pkcs7_free_mbedtls_ctx(struct pkcs7_mbedtls_ctx *ctx) +{ + if (ctx) { + kfree(ctx->content_data); + kfree(ctx); + } +} + +static void pkcs7_free_sinfo_mbedtls_ctx(struct pkcs7_sinfo_mbedtls_ctx *ctx) +{ + if (ctx) { + kfree(ctx->authattrs_data); + kfree(ctx->content_data_digest); + kfree(ctx); + } +} + +/* + * Parse Authenticate Attributes + * TODO: Shall we consider to integrate decoding of authenticate attribute into + * MbedTLS library? + * + * There are two kinds of structure for the Authenticate Attributes being used + * in U-Boot. + * + * Type 1 - contains in a PE/COFF EFI image: + * + * [C.P.0] { + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.3 (OID_contentType) + * U.P.SET { + * U.P.OBJECTIDENTIFIER 1.3.6.1.4.1.311.2.1.4 (OID_msIndirectData) + * } + * } + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.5 (OID_signingTime) + * U.P.SET { + * U.P.UTCTime '<siging_time>' + * } + * } + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.4 (OID_messageDigest) + * U.P.SET { + * U.P.OCTETSTRING <digest> + * } + * } + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.15 (OID_smimeCapabilites) + * U.P.SET { + * U.P.SEQUENCE { + * <...> + * } + * } + * } + * } + * + * Type 2 - contains in an EFI Capsule: + * + * [C.P.0] { + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.3 (OID_contentType) + * U.P.SET { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.7.1 (OID_data) + * } + * } + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.5 (OID_signingTime) + * U.P.SET { + * U.P.UTCTime '<siging_time>' + * } + * } + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.2.840.113549.1.9.4 (OID_messageDigest) + * U.P.SET { + * U.P.OCTETSTRING <digest> + * } + * } + *} + * + * Note: + * They have different Content Type (OID_msIndirectData or OID_data). + * OID_smimeCapabilites only exists in a PE/COFF EFI image. + */ +static int authattrs_parse(struct pkcs7_message *msg, void *aa, size_t aa_len, + struct pkcs7_signed_info *sinfo) +{ + unsigned char *p = aa; + unsigned char *end = (unsigned char *)aa + aa_len; + size_t len = 0; + int ret; + unsigned char *inner_p; + size_t seq_len = 0; + + ret = mbedtls_asn1_get_tag(&p, end, &seq_len, + MBEDTLS_ASN1_CONTEXT_SPECIFIC | + MBEDTLS_ASN1_CONSTRUCTED); + if (ret) + return ret; + + while (!mbedtls_asn1_get_tag(&p, end, &seq_len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE)) { + inner_p = p; + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_OID); + if (ret) + return ret; + + if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_PKCS9_CONTENTTYPE, inner_p, len)) { + inner_p += len; + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SET); + if (ret) + return ret; + + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_OID); + if (ret) + return ret; + + /* + * We should only support 1.2.840.113549.1.7.1 (OID_data) + * for PKCS7 DATA that is used in EFI Capsule and + * 1.3.6.1.4.1.311.2.1.4 (OID_msIndirectData) for + * MicroSoft Authentication Code that is used in EFI + * Secure Boot. + */ + if (MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_MICROSOFT_INDIRECTDATA, + inner_p, len) && + MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_PKCS7_DATA, + inner_p, len)) + return -EINVAL; + + if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set)) + return -EINVAL; + } else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_PKCS9_MESSAGEDIGEST, inner_p, + len)) { + inner_p += len; + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SET); + if (ret) + return ret; + + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_OCTET_STRING); + if (ret) + return ret; + + sinfo->msgdigest = inner_p; + sinfo->msgdigest_len = len; + + if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set)) + return -EINVAL; + } else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_PKCS9_SIGNINGTIME, inner_p, + len)) { + mbedtls_x509_time st; + + inner_p += len; + ret = mbedtls_asn1_get_tag(&inner_p, p + seq_len, &len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SET); + if (ret) + return ret; + + ret = mbedtls_x509_get_time(&inner_p, p + seq_len, &st); + if (ret) + return ret; + sinfo->signing_time = x509_get_timestamp(&st); + + if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set)) + return -EINVAL; + } else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_PKCS9_SMIMECAP, inner_p, + len)) { + if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set)) + return -EINVAL; + + if (msg->data_type != OID_msIndirectData && + msg->data_type != OID_data) + return -EINVAL; + } else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_MICROSOFT_SPOPUSINFO, inner_p, + len)) { + if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) + return -EINVAL; + } else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_MICROSOFT_STATETYPE, inner_p, + len)) { + if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set)) + return -EINVAL; + } + + p += seq_len; + } + + if (ret && ret != MBEDTLS_ERR_ASN1_OUT_OF_DATA) + return ret; + + msg->have_authattrs = true; + + /* + * Skip the leading tag byte (MBEDTLS_ASN1_CONTEXT_SPECIFIC | + * MBEDTLS_ASN1_CONSTRUCTED) to satisfy pkcs7_digest() when calculating + * the digest of authattrs. + */ + sinfo->authattrs = aa + 1; + sinfo->authattrs_len = aa_len - 1; + + return 0; +} + +static int x509_populate_content_data(struct pkcs7_message *msg, + mbedtls_pkcs7 *pkcs7_ctx) +{ + struct pkcs7_mbedtls_ctx *mctx; + + if (!pkcs7_ctx->content_data.data || + !pkcs7_ctx->content_data.data_len) + return 0; + + mctx = kzalloc(sizeof(*mctx), GFP_KERNEL); + if (!mctx) + return -ENOMEM; + + mctx->content_data = kmemdup(pkcs7_ctx->content_data.data, + pkcs7_ctx->content_data.data_len, + GFP_KERNEL); + if (!mctx->content_data) { + pkcs7_free_mbedtls_ctx(mctx); + return -ENOMEM; + } + + msg->data = mctx->content_data; + msg->data_len = pkcs7_ctx->content_data.data_len; + msg->data_hdrlen = pkcs7_ctx->content_data.data_hdrlen; + msg->data_type = pkcs7_ctx->content_data.data_type; + + msg->mbedtls_ctx = mctx; + return 0; +} + +static int x509_populate_sinfo(struct pkcs7_message *msg, + mbedtls_pkcs7_signer_info *mb_sinfo, + struct pkcs7_signed_info **sinfo) +{ + struct pkcs7_signed_info *signed_info; + struct public_key_signature *s; + mbedtls_md_type_t md_alg; + struct pkcs7_sinfo_mbedtls_ctx *mctx; + int ret; + + signed_info = kzalloc(sizeof(*signed_info), GFP_KERNEL); + if (!signed_info) + return -ENOMEM; + + s = kzalloc(sizeof(*s), GFP_KERNEL); + if (!s) { + ret = -ENOMEM; + goto out_no_sig; + } + + mctx = kzalloc(sizeof(*mctx), GFP_KERNEL); + if (!mctx) { + ret = -ENOMEM; + goto out_no_mctx; + } + + /* + * Hash algorithm: + * + * alg_identifier = digestAlgorithm (DigestAlgorithmIdentifier) + * MbedTLS internally checks this field to ensure + * it is the same as digest_alg_identifiers. + * sig_alg_identifier = digestEncryptionAlgorithm + * (DigestEncryptionAlgorithmIdentifier) + * MbedTLS just saves this field without any actions. + * See function pkcs7_get_signer_info() for reference. + * + * Public key algorithm: + * No information related to public key algorithm under MbedTLS signer + * info. Assume that we are using RSA. + */ + ret = mbedtls_oid_get_md_alg(&mb_sinfo->alg_identifier, &md_alg); + if (ret) + goto out_err_sinfo; + s->pkey_algo = "rsa"; + + /* Translate the hash algorithm */ + switch (md_alg) { + case MBEDTLS_MD_SHA1: + s->hash_algo = "sha1"; + s->digest_size = SHA1_SUM_LEN; + break; + case MBEDTLS_MD_SHA256: + s->hash_algo = "sha256"; + s->digest_size = SHA256_SUM_LEN; + break; + case MBEDTLS_MD_SHA384: + s->hash_algo = "sha384"; + s->digest_size = SHA384_SUM_LEN; + break; + case MBEDTLS_MD_SHA512: + s->hash_algo = "sha512"; + s->digest_size = SHA512_SUM_LEN; + break; + /* Unsupported algo */ + case MBEDTLS_MD_MD5: + case MBEDTLS_MD_SHA224: + default: + ret = -EINVAL; + goto out_err_sinfo; + } + + /* + * auth_ids holds AuthorityKeyIdentifier, aka akid + * auth_ids[0]: + * [PKCS#7 or CMS ver 1] - generated from "Issuer + Serial number" + * [CMS ver 3] - generated from skid (subjectKeyId) + * auth_ids[1]: generated from skid (subjectKeyId) + * + * Assume that we are using PKCS#7 (msg->version=1), + * not CMS ver 3 (msg->version=3). + */ + s->auth_ids[0] = asymmetric_key_generate_id(mb_sinfo->serial.p, + mb_sinfo->serial.len, + mb_sinfo->issuer_raw.p, + mb_sinfo->issuer_raw.len); + if (!s->auth_ids[0]) { + ret = -ENOMEM; + goto out_err_sinfo; + } + + /* skip s->auth_ids[1], no subjectKeyId in MbedTLS signer info ctx */ + + /* + * Encoding can be pkcs1 or raw, but only pkcs1 is supported. + * Set the encoding explicitly to pkcs1. + */ + s->encoding = "pkcs1"; + + /* Copy the signature data */ + s->s = kmemdup(mb_sinfo->sig.p, mb_sinfo->sig.len, GFP_KERNEL); + if (!s->s) { + ret = -ENOMEM; + goto out_err_sinfo; + } + s->s_size = mb_sinfo->sig.len; + signed_info->sig = s; + + /* Save the Authenticate Attributes data if exists */ + if (!mb_sinfo->authattrs.data || !mb_sinfo->authattrs.data_len) + goto no_authattrs; + + mctx->authattrs_data = kmemdup(mb_sinfo->authattrs.data, + mb_sinfo->authattrs.data_len, + GFP_KERNEL); + if (!mctx->authattrs_data) { + ret = -ENOMEM; + goto out_err_sinfo; + } + signed_info->mbedtls_ctx = mctx; + + /* If authattrs exists, decode it and parse msgdigest from it */ + ret = authattrs_parse(msg, mctx->authattrs_data, + mb_sinfo->authattrs.data_len, + signed_info); + if (ret) + goto out_err_sinfo; + +no_authattrs: + *sinfo = signed_info; + return 0; + +out_err_sinfo: + pkcs7_free_sinfo_mbedtls_ctx(mctx); +out_no_mctx: + public_key_signature_free(s); +out_no_sig: + kfree(signed_info); + return ret; +} + +/* + * Free a signed information block. + */ +static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo) +{ + if (sinfo) { + public_key_signature_free(sinfo->sig); + pkcs7_free_sinfo_mbedtls_ctx(sinfo->mbedtls_ctx); + kfree(sinfo); + } +} + +/** + * pkcs7_free_message - Free a PKCS#7 message + * @pkcs7: The PKCS#7 message to free + */ +void pkcs7_free_message(struct pkcs7_message *pkcs7) +{ + struct x509_certificate *cert; + struct pkcs7_signed_info *sinfo; + + if (pkcs7) { + while (pkcs7->certs) { + cert = pkcs7->certs; + pkcs7->certs = cert->next; + x509_free_certificate(cert); + } + while (pkcs7->crl) { + cert = pkcs7->crl; + pkcs7->crl = cert->next; + x509_free_certificate(cert); + } + while (pkcs7->signed_infos) { + sinfo = pkcs7->signed_infos; + pkcs7->signed_infos = sinfo->next; + pkcs7_free_signed_info(sinfo); + } + pkcs7_free_mbedtls_ctx(pkcs7->mbedtls_ctx); + kfree(pkcs7); + } +} + +struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen) +{ + int i; + int ret; + mbedtls_pkcs7 pkcs7_ctx; + mbedtls_pkcs7_signer_info *mb_sinfos; + mbedtls_x509_crt *mb_certs; + struct pkcs7_message *msg; + struct x509_certificate **cert; + struct pkcs7_signed_info **sinfos; + + msg = kzalloc(sizeof(*msg), GFP_KERNEL); + if (!msg) { + ret = -ENOMEM; + goto out_no_msg; + } + + /* Parse the DER encoded PKCS#7 message using MbedTLS */ + mbedtls_pkcs7_init(&pkcs7_ctx); + ret = mbedtls_pkcs7_parse_der(&pkcs7_ctx, data, datalen); + /* Check if it is a PKCS#7 message with signed data */ + if (ret != MBEDTLS_PKCS7_SIGNED_DATA) + goto parse_fail; + + /* Assume that we are using PKCS#7, not CMS ver 3 */ + msg->version = 1; /* 1 for [PKCS#7 or CMS ver 1] */ + + /* Populate the certs to msg->certs */ + for (i = 0, cert = &msg->certs, mb_certs = &pkcs7_ctx.signed_data.certs; + i < pkcs7_ctx.signed_data.no_of_certs && mb_certs; + i++, cert = &(*cert)->next, mb_certs = mb_certs->next) { + ret = x509_populate_cert(mb_certs, cert); + if (ret) + goto parse_fail; + + (*cert)->index = i + 1; + } + + /* + * Skip populating crl, that is not currently in-use. + */ + + /* Populate content data */ + ret = x509_populate_content_data(msg, &pkcs7_ctx); + if (ret) + goto parse_fail; + + /* Populate signed info to msg->signed_infos */ + for (i = 0, sinfos = &msg->signed_infos, + mb_sinfos = &pkcs7_ctx.signed_data.signers; + i < pkcs7_ctx.signed_data.no_of_signers && mb_sinfos; + i++, sinfos = &(*sinfos)->next, mb_sinfos = mb_sinfos->next) { + ret = x509_populate_sinfo(msg, mb_sinfos, sinfos); + if (ret) + goto parse_fail; + + (*sinfos)->index = i + 1; + } + + mbedtls_pkcs7_free(&pkcs7_ctx); + return msg; + +parse_fail: + mbedtls_pkcs7_free(&pkcs7_ctx); + pkcs7_free_message(msg); +out_no_msg: + msg = ERR_PTR(ret); + return msg; +}