Add porting layer for MSCode on top of MbedTLS ASN1 library. Introduce _MBEDTLS kconfigs for MSCode MbedTLS implementation.
Signed-off-by: Raymond Mao raymond.mao@linaro.org Acked-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- Changes in v2 - Move the porting layer to MbedTLS dir. Changes in v3 - None. Changes in v4 - Introduce _LEGACY and _MBEDTLS kconfigs for MSCode legacy and MbedTLS implementations respectively. - Fix a few code style. Changes in v5 - Correct kconfig dependence. - Refactored MbedTLS makefile. - Move mscode legacy kconfig to the next patch. Changes in v6 - None. Changes in v7 - None. Changes in v8 - None
lib/mbedtls/Kconfig | 9 +++ lib/mbedtls/Makefile | 1 + lib/mbedtls/mscode_parser.c | 123 ++++++++++++++++++++++++++++++++++++ 3 files changed, 133 insertions(+) create mode 100644 lib/mbedtls/mscode_parser.c
diff --git a/lib/mbedtls/Kconfig b/lib/mbedtls/Kconfig index 189bb3186b6..fd7263f9616 100644 --- a/lib/mbedtls/Kconfig +++ b/lib/mbedtls/Kconfig @@ -303,6 +303,7 @@ config MBEDTLS_LIB_X509 ASYMMETRIC_PUBLIC_KEY_SUBTYPE select X509_CERTIFICATE_PARSER_MBEDTLS if X509_CERTIFICATE_PARSER select PKCS7_MESSAGE_PARSER_MBEDTLS if PKCS7_MESSAGE_PARSER + select MSCODE_PARSER_MBEDTLS if MSCODE_PARSER select SPL_ASYMMETRIC_PUBLIC_KEY_MBEDTLS if \ SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE help @@ -333,6 +334,14 @@ config PKCS7_MESSAGE_PARSER_MBEDTLS This option chooses MbedTLS certificate library for PKCS7 message parser.
+config MSCODE_PARSER_MBEDTLS + bool "MS authenticode parser with MbedTLS certificate library" + depends on MBEDTLS_LIB_X509 && MSCODE_PARSER + select ASN1_DECODER_MBEDTLS + help + This option chooses MbedTLS certificate library for MS authenticode + parser. + if SPL
config SPL_ASYMMETRIC_PUBLIC_KEY_MBEDTLS diff --git a/lib/mbedtls/Makefile b/lib/mbedtls/Makefile index 128a29c512f..488b66402b3 100644 --- a/lib/mbedtls/Makefile +++ b/lib/mbedtls/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_$(SPL_)ASYMMETRIC_PUBLIC_KEY_MBEDTLS) += \ obj-$(CONFIG_$(SPL_)X509_CERTIFICATE_PARSER_MBEDTLS) += \ x509_cert_parser.o obj-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER_MBEDTLS) += pkcs7_parser.o +obj-$(CONFIG_$(SPL_)MSCODE_PARSER_MBEDTLS) += mscode_parser.o
# MbedTLS crypto library obj-$(CONFIG_MBEDTLS_LIB) += mbedtls_lib_crypto.o diff --git a/lib/mbedtls/mscode_parser.c b/lib/mbedtls/mscode_parser.c new file mode 100644 index 00000000000..c3805c6503c --- /dev/null +++ b/lib/mbedtls/mscode_parser.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * MSCode parser using MbedTLS ASN1 library + * + * Copyright (c) 2024 Linaro Limited + * Author: Raymond Mao raymond.mao@linaro.org + */ + +#include <linux/kernel.h> +#include <linux/err.h> +#include <crypto/pkcs7.h> +#include <crypto/mscode.h> + +/* + * Parse a Microsoft Individual Code Signing blob + * + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER 1.3.6.1.4.1.311.2.1.15 (SPC_PE_IMAGE_DATA_OBJID) + * U.P.SEQUENCE { + * U.P.BITSTRING NaN : 0 unused bit(s); + * [C.P.0] { + * [C.P.2] { + * [C.P.0] <arbitrary string> + * } + * } + * } + * } + * U.P.SEQUENCE { + * U.P.SEQUENCE { + * U.P.OBJECTIDENTIFIER <digest algorithm OID> + * U.P.NULL + * } + * U.P.OCTETSTRING <PE image digest> + * } + * + * @ctx: PE file context. + * @content_data: content data pointer. + * @data_len: content data length. + * @asn1hdrlen: ASN1 header length. + */ +int mscode_parse(void *ctx, const void *content_data, size_t data_len, + size_t asn1hdrlen) +{ + struct pefile_context *_ctx = ctx; + unsigned char *p = (unsigned char *)content_data; + unsigned char *end = (unsigned char *)content_data + data_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_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE); + if (ret) + return ret; + + inner_p = p; + ret = mbedtls_asn1_get_tag(&inner_p, inner_p + seq_len, &len, + MBEDTLS_ASN1_OID); + if (ret) + return ret; + + /* Sanity check on the PE Image Data OID (1.3.6.1.4.1.311.2.1.15) */ + if (MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_MICROSOFT_PEIMAGEDATA, inner_p, + len)) + return -EINVAL; + + p += seq_len; + ret = mbedtls_asn1_get_tag(&p, end, &seq_len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE); + if (ret) + return ret; + + ret = mbedtls_asn1_get_tag(&p, p + seq_len, &seq_len, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE); + if (ret) + return ret; + + inner_p = p; + + /* + * Check if the inner sequence contains a supported hash + * algorithm OID + */ + ret = mbedtls_asn1_get_tag(&inner_p, inner_p + seq_len, &len, + MBEDTLS_ASN1_OID); + if (ret) + return ret; + + if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_MD5, inner_p, len)) + _ctx->digest_algo = "md5"; + else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_SHA1, inner_p, + len)) + _ctx->digest_algo = "sha1"; + else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_SHA224, inner_p, + len)) + _ctx->digest_algo = "sha224"; + else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_SHA256, inner_p, + len)) + _ctx->digest_algo = "sha256"; + else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_SHA384, inner_p, + len)) + _ctx->digest_algo = "sha384"; + else if (!MBEDTLS_OID_CMP_RAW(MBEDTLS_OID_DIGEST_ALG_SHA512, inner_p, + len)) + _ctx->digest_algo = "sha512"; + + if (!_ctx->digest_algo) + return -EINVAL; + + p += seq_len; + ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); + if (ret) + return ret; + + _ctx->digest = p; + _ctx->digest_len = len; + + return 0; +}