crypto/asymmetric_keys/mscode_parser.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Parse a Microsoft Individual Code Signing blob
   3  *
   4  * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) "MSCODE: "fmt
   9 #include <linux/kernel.h>
  10 #include <linux/slab.h>
  11 #include <linux/err.h>
  12 #include <linux/oid_registry.h>
  13 #include <crypto/pkcs7.h>
  14 #include "verify_pefile.h"
  15 #include "mscode.asn1.h"
  16
  17 /*
  18  * Parse a Microsoft Individual Code Signing blob
  19  */
  20 int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
  21                  size_t asn1hdrlen)
  22 {
  23         struct pefile_context *ctx = _ctx;
  24
  25         content_data -= asn1hdrlen;
  26         data_len += asn1hdrlen;
  27         pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
  28                  content_data);
  29
  30         return asn1_ber_decoder(&mscode_decoder, ctx, content_data, data_len);
  31 }
  32
  33 /*
  34  * Check the content type OID
  35  */
  36 int mscode_note_content_type(void *context, size_t hdrlen,
  37                              unsigned char tag,
  38                              const void *value, size_t vlen)
  39 {
  40         enum OID oid;
  41
  42         oid = look_up_OID(value, vlen);
  43         if (oid == OID__NR) {
  44                 char buffer[50];
  45
  46                 sprint_oid(value, vlen, buffer, sizeof(buffer));
  47                 pr_err("Unknown OID: %s\n", buffer);
  48                 return -EBADMSG;
  49         }
  50
  51         /*
  52          * pesign utility had a bug where it was putting
  53          * OID_msIndividualSPKeyPurpose instead of OID_msPeImageDataObjId
  54          * So allow both OIDs.
  55          */
  56         if (oid != OID_msPeImageDataObjId &&
  57             oid != OID_msIndividualSPKeyPurpose) {
  58                 pr_err("Unexpected content type OID %u\n", oid);
  59                 return -EBADMSG;
  60         }
  61
  62         return 0;
  63 }
  64
  65 /*
  66  * Note the digest algorithm OID
  67  */
  68 int mscode_note_digest_algo(void *context, size_t hdrlen,
  69                             unsigned char tag,
  70                             const void *value, size_t vlen)
  71 {
  72         struct pefile_context *ctx = context;
  73         char buffer[50];
  74         enum OID oid;
  75
  76         oid = look_up_OID(value, vlen);
  77         switch (oid) {
  78         case OID_md4:
  79                 ctx->digest_algo = "md4";
  80                 break;
  81         case OID_md5:
  82                 ctx->digest_algo = "md5";
  83                 break;
  84         case OID_sha1:
  85                 ctx->digest_algo = "sha1";
  86                 break;
  87         case OID_sha256:
  88                 ctx->digest_algo = "sha256";
  89                 break;
  90         case OID_sha384:
  91                 ctx->digest_algo = "sha384";
  92                 break;
  93         case OID_sha512:
  94                 ctx->digest_algo = "sha512";
  95                 break;
  96         case OID_sha224:
  97                 ctx->digest_algo = "sha224";
  98                 break;
  99
 100         case OID__NR:
 101                 sprint_oid(value, vlen, buffer, sizeof(buffer));
 102                 pr_err("Unknown OID: %s\n", buffer);
 103                 return -EBADMSG;
 104
 105         default:
 106                 pr_err("Unsupported content type: %u\n", oid);
 107                 return -ENOPKG;
 108         }
 109
 110         return 0;
 111 }
 112
 113 /*
 114  * Note the digest we're guaranteeing with this certificate
 115  */
 116 int mscode_note_digest(void *context, size_t hdrlen,
 117                        unsigned char tag,
 118                        const void *value, size_t vlen)
 119 {
 120         struct pefile_context *ctx = context;
 121
 122         ctx->digest = kmemdup(value, vlen, GFP_KERNEL);
 123         if (!ctx->digest)
 124                 return -ENOMEM;
 125
 126         ctx->digest_len = vlen;
 127
 128         return 0;
 129 }