1 files changed, 126 insertions, 0 deletions

diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
new file mode 100644
index 000000000000..214a992123cd
--- /dev/null
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -0,0 +1,126 @@
+/* Parse a Microsoft Individual Code Signing blob
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@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.
+ */
+
+#define pr_fmt(fmt) "MSCODE: "fmt
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include <crypto/pkcs7.h>
+#include "verify_pefile.h"
+#include "mscode-asn1.h"
+
+/*
+ * Parse a Microsoft Individual Code Signing blob
+ */
+int mscode_parse(struct pefile_context *ctx)
+{
+        const void *content_data;
+        size_t data_len;
+        int ret;
+
+        ret = pkcs7_get_content_data(ctx->pkcs7, &content_data, &data_len, 1);
+
+        if (ret) {
+                pr_debug("PKCS#7 message does not contain data\n");
+                return ret;
+        }
+
+        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 = HASH_ALGO_MD4;
+                break;
+        case OID_md5:
+                ctx->digest_algo = HASH_ALGO_MD5;
+                break;
+        case OID_sha1:
+                ctx->digest_algo = HASH_ALGO_SHA1;
+                break;
+        case OID_sha256:
+                ctx->digest_algo = HASH_ALGO_SHA256;
+                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 = value;
+        ctx->digest_len = vlen;
+        return 0;
+}