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Diffstat (limited to 'crypto/asymmetric_keys/mscode_parser.c')
-rw-r--r-- | crypto/asymmetric_keys/mscode_parser.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c new file mode 100644 index 000000000..83d2e9b38 --- /dev/null +++ b/crypto/asymmetric_keys/mscode_parser.c @@ -0,0 +1,133 @@ +/* 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; +} |