[PATCH 1/5] lib: crypto: add mscode_parser
AKASHI Takahiro
takahiro.akashi at linaro.org
Tue Jul 5 07:48:11 CEST 2022
In MS authenticode, pkcs7 should have data in its contentInfo field.
This data is tagged with SpcIndirectData type and, for a signed PE image,
provides a image's message digest as SpcPeImageData.
This parser is used in image authentication to parse the field and
retrieve a message digest.
Imported from linux v5.19-rc, crypto/asymmetric_keys/mscode*.
Checkpatch.pl generates tones of warnings, but those are not fixed
for the sake of maintainability (importing from another source).
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
include/crypto/mscode.h | 43 ++++++++++++
lib/crypto/Kconfig | 9 +++
lib/crypto/Makefile | 12 ++++
lib/crypto/mscode.asn1 | 28 ++++++++
lib/crypto/mscode_parser.c | 135 +++++++++++++++++++++++++++++++++++++
5 files changed, 227 insertions(+)
create mode 100644 include/crypto/mscode.h
create mode 100644 lib/crypto/mscode.asn1
create mode 100644 lib/crypto/mscode_parser.c
diff --git a/include/crypto/mscode.h b/include/crypto/mscode.h
new file mode 100644
index 000000000000..551058b96e60
--- /dev/null
+++ b/include/crypto/mscode.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* PE Binary parser bits
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#include <crypto/pkcs7.h>
+#ifndef __UBOOT__
+#include <crypto/hash_info.h>
+#endif
+
+struct pefile_context {
+#ifndef __UBOOT__
+ unsigned header_size;
+ unsigned image_checksum_offset;
+ unsigned cert_dirent_offset;
+ unsigned n_data_dirents;
+ unsigned n_sections;
+ unsigned certs_size;
+ unsigned sig_offset;
+ unsigned sig_len;
+ const struct section_header *secs;
+#endif
+
+ /* PKCS#7 MS Individual Code Signing content */
+ const void *digest; /* Digest */
+ unsigned digest_len; /* Digest length */
+ const char *digest_algo; /* Digest algorithm */
+};
+
+#ifndef __UBOOT__
+#define kenter(FMT, ...) \
+ pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#endif
+
+/*
+ * mscode_parser.c
+ */
+extern int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
+ size_t asn1hdrlen);
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 1c04a7ec5f48..c3f563b2e174 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -82,4 +82,13 @@ config PKCS7_MESSAGE_PARSER
config PKCS7_VERIFY
bool
+config MSCODE_PARSER
+ bool "MS authenticode parser"
+ select ASN1_DECODER
+ select ASN1_COMPILER
+ select OID_REGISTRY
+ help
+ This option provides support for parsing MicroSoft's Authenticode
+ in pkcs7 message.
+
endif # ASYMMETRIC_KEY_TYPE
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 6792b1d4f007..bec1bc95a658 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -55,3 +55,15 @@ obj-$(CONFIG_$(SPL_)PKCS7_VERIFY) += pkcs7_verify.o
$(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h
$(obj)/pkcs7.asn1.o: $(obj)/pkcs7.asn1.c $(obj)/pkcs7.asn1.h
+
+#
+# Signed PE binary-wrapped key handling
+#
+obj-$(CONFIG_$(SPL_)MSCODE_PARSER) += mscode.o
+
+mscode-y := \
+ mscode_parser.o \
+ mscode.asn1.o
+
+$(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h
+$(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h
diff --git a/lib/crypto/mscode.asn1 b/lib/crypto/mscode.asn1
new file mode 100644
index 000000000000..6d09ba48c41c
--- /dev/null
+++ b/lib/crypto/mscode.asn1
@@ -0,0 +1,28 @@
+--- Microsoft individual code signing data blob parser
+---
+--- Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+--- Written by David Howells (dhowells at redhat.com)
+---
+--- This program is free software; you can redistribute it and/or
+--- modify it under the terms of the GNU General Public Licence
+--- as published by the Free Software Foundation; either version
+--- 2 of the Licence, or (at your option) any later version.
+---
+
+MSCode ::= SEQUENCE {
+ type SEQUENCE {
+ contentType ContentType,
+ parameters ANY
+ },
+ content SEQUENCE {
+ digestAlgorithm DigestAlgorithmIdentifier,
+ digest OCTET STRING ({ mscode_note_digest })
+ }
+}
+
+ContentType ::= OBJECT IDENTIFIER ({ mscode_note_content_type })
+
+DigestAlgorithmIdentifier ::= SEQUENCE {
+ algorithm OBJECT IDENTIFIER ({ mscode_note_digest_algo }),
+ parameters ANY OPTIONAL
+}
diff --git a/lib/crypto/mscode_parser.c b/lib/crypto/mscode_parser.c
new file mode 100644
index 000000000000..90d5b37a6cf2
--- /dev/null
+++ b/lib/crypto/mscode_parser.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Parse a Microsoft Individual Code Signing blob
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#define pr_fmt(fmt) "MSCODE: "fmt
+#include <linux/kernel.h>
+#ifndef __UBOOT__
+#include <linux/slab.h>
+#endif
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include <crypto/pkcs7.h>
+#ifdef __UBOOT__
+#include <crypto/mscode.h>
+#else
+#include "verify_pefile.h"
+#endif
+#include "mscode.asn1.h"
+
+/*
+ * Parse a Microsoft Individual Code Signing blob
+ */
+int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
+ size_t asn1hdrlen)
+{
+ struct pefile_context *ctx = _ctx;
+
+ content_data -= asn1hdrlen;
+ data_len += asn1hdrlen;
+ pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
+ content_data);
+
+ return asn1_ber_decoder(&mscode_decoder, ctx, content_data, data_len);
+}
+
+/*
+ * Check the content type OID
+ */
+int mscode_note_content_type(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ enum OID oid;
+
+ oid = look_up_OID(value, vlen);
+ if (oid == OID__NR) {
+ char buffer[50];
+
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_err("Unknown OID: %s\n", buffer);
+ return -EBADMSG;
+ }
+
+ /*
+ * pesign utility had a bug where it was putting
+ * OID_msIndividualSPKeyPurpose instead of OID_msPeImageDataObjId
+ * So allow both OIDs.
+ */
+ if (oid != OID_msPeImageDataObjId &&
+ oid != OID_msIndividualSPKeyPurpose) {
+ pr_err("Unexpected content type OID %u\n", oid);
+ return -EBADMSG;
+ }
+
+ return 0;
+}
+
+/*
+ * Note the digest algorithm OID
+ */
+int mscode_note_digest_algo(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pefile_context *ctx = context;
+ char buffer[50];
+ enum OID oid;
+
+ oid = look_up_OID(value, vlen);
+ switch (oid) {
+ case OID_md4:
+ ctx->digest_algo = "md4";
+ break;
+ case OID_md5:
+ ctx->digest_algo = "md5";
+ break;
+ case OID_sha1:
+ ctx->digest_algo = "sha1";
+ break;
+ case OID_sha256:
+ ctx->digest_algo = "sha256";
+ break;
+ case OID_sha384:
+ ctx->digest_algo = "sha384";
+ break;
+ case OID_sha512:
+ ctx->digest_algo = "sha512";
+ break;
+ case OID_sha224:
+ ctx->digest_algo = "sha224";
+ break;
+
+ case OID__NR:
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_err("Unknown OID: %s\n", buffer);
+ return -EBADMSG;
+
+ default:
+ pr_err("Unsupported content type: %u\n", oid);
+ return -ENOPKG;
+ }
+
+ return 0;
+}
+
+/*
+ * Note the digest we're guaranteeing with this certificate
+ */
+int mscode_note_digest(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pefile_context *ctx = context;
+
+ ctx->digest = kmemdup(value, vlen, GFP_KERNEL);
+ if (!ctx->digest)
+ return -ENOMEM;
+
+ ctx->digest_len = vlen;
+
+ return 0;
+}
--
2.36.1
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