3 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #define pr_fmt(fmt) "PKCS7: "fmt
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/oid_registry.h>
18 #include "public_key.h"
19 #include "pkcs7_parser.h"
20 #include "pkcs7-asn1.h"
22 struct pkcs7_parse_context {
23 struct pkcs7_message *msg; /* Message being constructed */
24 struct pkcs7_signed_info *sinfo; /* SignedInfo being constructed */
25 struct pkcs7_signed_info **ppsinfo;
26 struct x509_certificate *certs; /* Certificate cache */
27 struct x509_certificate **ppcerts;
28 unsigned long data; /* Start of data */
29 enum OID last_oid; /* Last OID encountered */
35 * pkcs7_free_message - Free a PKCS#7 message
36 * @pkcs7: The PKCS#7 message to free
38 void pkcs7_free_message(struct pkcs7_message *pkcs7)
40 struct x509_certificate *cert;
41 struct pkcs7_signed_info *sinfo;
44 while (pkcs7->certs) {
46 pkcs7->certs = cert->next;
47 x509_free_certificate(cert);
51 pkcs7->crl = cert->next;
52 x509_free_certificate(cert);
54 while (pkcs7->signed_infos) {
55 sinfo = pkcs7->signed_infos;
56 pkcs7->signed_infos = sinfo->next;
57 mpi_free(sinfo->sig.mpi[0]);
58 kfree(sinfo->sig.digest);
64 EXPORT_SYMBOL_GPL(pkcs7_free_message);
67 * pkcs7_parse_message - Parse a PKCS#7 message
68 * @data: The raw binary ASN.1 encoded message to be parsed
69 * @datalen: The size of the encoded message
71 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
73 struct pkcs7_parse_context *ctx;
74 struct pkcs7_message *msg;
78 msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
81 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
84 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
89 ctx->data = (unsigned long)data;
90 ctx->ppcerts = &ctx->certs;
91 ctx->ppsinfo = &ctx->msg->signed_infos;
93 /* Attempt to decode the signature */
94 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
99 struct x509_certificate *cert = ctx->certs;
100 ctx->certs = cert->next;
101 x509_free_certificate(cert);
103 mpi_free(ctx->sinfo->sig.mpi[0]);
104 kfree(ctx->sinfo->sig.digest);
110 mpi_free(ctx->sinfo->sig.mpi[0]);
111 kfree(ctx->sinfo->sig.digest);
116 pkcs7_free_message(msg);
120 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
123 * pkcs7_get_content_data - Get access to the PKCS#7 content
124 * @pkcs7: The preparsed PKCS#7 message to access
125 * @_data: Place to return a pointer to the data
126 * @_data_len: Place to return the data length
127 * @want_wrapper: True if the ASN.1 object header should be included in the data
129 * Get access to the data content of the PKCS#7 message, including, optionally,
130 * the header of the ASN.1 object that contains it. Returns -ENODATA if the
131 * data object was missing from the message.
133 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
134 const void **_data, size_t *_data_len,
142 wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
143 *_data = pkcs7->data - wrapper;
144 *_data_len = pkcs7->data_len + wrapper;
147 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
150 * Note an OID when we find one for later processing when we know how
153 int pkcs7_note_OID(void *context, size_t hdrlen,
155 const void *value, size_t vlen)
157 struct pkcs7_parse_context *ctx = context;
159 ctx->last_oid = look_up_OID(value, vlen);
160 if (ctx->last_oid == OID__NR) {
162 sprint_oid(value, vlen, buffer, sizeof(buffer));
163 printk("PKCS7: Unknown OID: [%lu] %s\n",
164 (unsigned long)value - ctx->data, buffer);
170 * Note the digest algorithm for the signature.
172 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
174 const void *value, size_t vlen)
176 struct pkcs7_parse_context *ctx = context;
178 switch (ctx->last_oid) {
180 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD4;
183 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD5;
186 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA1;
189 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA256;
192 printk("Unsupported digest algo: %u\n", ctx->last_oid);
199 * Note the public key algorithm for the signature.
201 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
203 const void *value, size_t vlen)
205 struct pkcs7_parse_context *ctx = context;
207 switch (ctx->last_oid) {
208 case OID_rsaEncryption:
209 ctx->sinfo->sig.pkey_algo = PKEY_ALGO_RSA;
212 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
219 * Extract a certificate and store it in the context.
221 int pkcs7_extract_cert(void *context, size_t hdrlen,
223 const void *value, size_t vlen)
225 struct pkcs7_parse_context *ctx = context;
226 struct x509_certificate *x509;
228 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
229 pr_debug("Cert began with tag %02x at %lu\n",
230 tag, (unsigned long)ctx - ctx->data);
234 /* We have to correct for the header so that the X.509 parser can start
235 * from the beginning. Note that since X.509 stipulates DER, there
236 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
242 if (((u8*)value)[1] == 0x80)
243 vlen += 2; /* Indefinite length - there should be an EOC */
245 x509 = x509_cert_parse(value, vlen);
247 return PTR_ERR(x509);
249 pr_debug("Got cert for %s\n", x509->subject);
250 pr_debug("- fingerprint %s\n", x509->fingerprint);
252 x509->index = ++ctx->x509_index;
253 *ctx->ppcerts = x509;
254 ctx->ppcerts = &x509->next;
259 * Save the certificate list
261 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
263 const void *value, size_t vlen)
265 struct pkcs7_parse_context *ctx = context;
267 pr_devel("Got cert list (%02x)\n", tag);
269 *ctx->ppcerts = ctx->msg->certs;
270 ctx->msg->certs = ctx->certs;
272 ctx->ppcerts = &ctx->certs;
277 * Extract the data from the message and store that and its content type OID in
280 int pkcs7_note_data(void *context, size_t hdrlen,
282 const void *value, size_t vlen)
284 struct pkcs7_parse_context *ctx = context;
286 pr_debug("Got data\n");
288 ctx->msg->data = value;
289 ctx->msg->data_len = vlen;
290 ctx->msg->data_hdrlen = hdrlen;
291 ctx->msg->data_type = ctx->last_oid;
296 * Parse authenticated attributes
298 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
300 const void *value, size_t vlen)
302 struct pkcs7_parse_context *ctx = context;
304 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
306 switch (ctx->last_oid) {
307 case OID_messageDigest:
310 ctx->sinfo->msgdigest = value;
311 ctx->sinfo->msgdigest_len = vlen;
319 * Note the set of auth attributes for digestion purposes [RFC2315 9.3]
321 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
323 const void *value, size_t vlen)
325 struct pkcs7_parse_context *ctx = context;
327 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
328 ctx->sinfo->authattrs = value - (hdrlen - 1);
329 ctx->sinfo->authattrs_len = vlen + (hdrlen - 1);
334 * Note the issuing certificate serial number
336 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
338 const void *value, size_t vlen)
340 struct pkcs7_parse_context *ctx = context;
341 ctx->sinfo->raw_serial = value;
342 ctx->sinfo->raw_serial_size = vlen;
347 * Note the issuer's name
349 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
351 const void *value, size_t vlen)
353 struct pkcs7_parse_context *ctx = context;
354 ctx->sinfo->raw_issuer = value;
355 ctx->sinfo->raw_issuer_size = vlen;
360 * Note the signature data
362 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
364 const void *value, size_t vlen)
366 struct pkcs7_parse_context *ctx = context;
369 BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
371 mpi = mpi_read_raw_data(value, vlen);
375 ctx->sinfo->sig.mpi[0] = mpi;
376 ctx->sinfo->sig.nr_mpi = 1;
381 * Note a signature information block
383 int pkcs7_note_signed_info(void *context, size_t hdrlen,
385 const void *value, size_t vlen)
387 struct pkcs7_parse_context *ctx = context;
389 ctx->sinfo->index = ++ctx->sinfo_index;
390 *ctx->ppsinfo = ctx->sinfo;
391 ctx->ppsinfo = &ctx->sinfo->next;
392 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);