crypto/asymmetric_keys/mscode_parser.c

   1 /* Parse a Microsoft Individual Code Signing blob
   2  *
   3  * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) "MSCODE: "fmt
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/err.h>
  16 #include <linux/oid_registry.h>
  17 #include <crypto/pkcs7.h>
  18 #include "verify_pefile.h"
  19 #include "mscode-asn1.h"
  20
  21 /*
  22  * Parse a Microsoft Individual Code Signing blob
  23  */
  24 int mscode_parse(struct pefile_context *ctx)
  25 {
  26         const void *content_data;
  27         size_t data_len;
  28         int ret;
  29
  30         ret = pkcs7_get_content_data(ctx->pkcs7, &content_data, &data_len, 1);
  31
  32         if (ret) {
  33                 pr_debug("PKCS#7 message does not contain data\n");
  34                 return ret;
  35         }
  36
  37         pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
  38                  content_data);
  39
  40         return asn1_ber_decoder(&mscode_decoder, ctx, content_data, data_len);
  41 }
  42
  43 /*
  44  * Check the content type OID
  45  */
  46 int mscode_note_content_type(void *context, size_t hdrlen,
  47                              unsigned char tag,
  48                              const void *value, size_t vlen)
  49 {
  50         enum OID oid;
  51
  52         oid = look_up_OID(value, vlen);
  53         if (oid == OID__NR) {
  54                 char buffer[50];
  55
  56                 sprint_oid(value, vlen, buffer, sizeof(buffer));
  57                 pr_err("Unknown OID: %s\n", buffer);
  58                 return -EBADMSG;
  59         }
  60
  61         /*
  62          * pesign utility had a bug where it was putting
  63          * OID_msIndividualSPKeyPurpose instead of OID_msPeImageDataObjId
  64          * So allow both OIDs.
  65          */
  66         if (oid != OID_msPeImageDataObjId &&
  67             oid != OID_msIndividualSPKeyPurpose) {
  68                 pr_err("Unexpected content type OID %u\n", oid);
  69                 return -EBADMSG;
  70         }
  71
  72         return 0;
  73 }
  74
  75 /*
  76  * Note the digest algorithm OID
  77  */
  78 int mscode_note_digest_algo(void *context, size_t hdrlen,
  79                             unsigned char tag,
  80                             const void *value, size_t vlen)
  81 {
  82         struct pefile_context *ctx = context;
  83         char buffer[50];
  84         enum OID oid;
  85
  86         oid = look_up_OID(value, vlen);
  87         switch (oid) {
  88         case OID_md4:
  89                 ctx->digest_algo = HASH_ALGO_MD4;
  90                 break;
  91         case OID_md5:
  92                 ctx->digest_algo = HASH_ALGO_MD5;
  93                 break;
  94         case OID_sha1:
  95                 ctx->digest_algo = HASH_ALGO_SHA1;
  96                 break;
  97         case OID_sha256:
  98                 ctx->digest_algo = HASH_ALGO_SHA256;
  99                 break;
 100         case OID_sha384:
 101                 ctx->digest_algo = HASH_ALGO_SHA384;
 102                 break;
 103         case OID_sha512:
 104                 ctx->digest_algo = HASH_ALGO_SHA512;
 105                 break;
 106         case OID_sha224:
 107                 ctx->digest_algo = HASH_ALGO_SHA224;
 108                 break;
 109
 110         case OID__NR:
 111                 sprint_oid(value, vlen, buffer, sizeof(buffer));
 112                 pr_err("Unknown OID: %s\n", buffer);
 113                 return -EBADMSG;
 114
 115         default:
 116                 pr_err("Unsupported content type: %u\n", oid);
 117                 return -ENOPKG;
 118         }
 119
 120         return 0;
 121 }
 122
 123 /*
 124  * Note the digest we're guaranteeing with this certificate
 125  */
 126 int mscode_note_digest(void *context, size_t hdrlen,
 127                        unsigned char tag,
 128                        const void *value, size_t vlen)
 129 {
 130         struct pefile_context *ctx = context;
 131
 132         ctx->digest = value;
 133         ctx->digest_len = vlen;
 134         return 0;
 135 }