mbedtls: add MSCode parser porting layer

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>

diff --git a/lib/mbedtls/Kconfig b/lib/mbedtls/Kconfig
index 189bb3186b601e30680d1abf6c2185abcc99a022..fd7263f9616744fb5ec79567fc584f2b533f1e60 100644 (file)
--- 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 128a29c512f97ead54c370132cf942f3d8adb30e..488b66402b36fbc788256ed7f5bf41e7c2fc1509 100644 (file)
--- 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 (file)
index 0000000..c3805c6
--- /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;
+}