linux/crypto/asymmetric_keys/mscode_parser.c

134 lines
2.9 KiB
C

/* 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(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;
}