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 * Free a signed information block.
37 static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
40 mpi_free(sinfo->sig.mpi[0]);
41 kfree(sinfo->sig.digest);
47 * pkcs7_free_message - Free a PKCS#7 message
48 * @pkcs7: The PKCS#7 message to free
50 void pkcs7_free_message(struct pkcs7_message *pkcs7)
52 struct x509_certificate *cert;
53 struct pkcs7_signed_info *sinfo;
56 while (pkcs7->certs) {
58 pkcs7->certs = cert->next;
59 x509_free_certificate(cert);
63 pkcs7->crl = cert->next;
64 x509_free_certificate(cert);
66 while (pkcs7->signed_infos) {
67 sinfo = pkcs7->signed_infos;
68 pkcs7->signed_infos = sinfo->next;
69 pkcs7_free_signed_info(sinfo);
74 EXPORT_SYMBOL_GPL(pkcs7_free_message);
77 * pkcs7_parse_message - Parse a PKCS#7 message
78 * @data: The raw binary ASN.1 encoded message to be parsed
79 * @datalen: The size of the encoded message
81 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
83 struct pkcs7_parse_context *ctx;
84 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
87 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
90 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
93 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
97 ctx->data = (unsigned long)data;
98 ctx->ppcerts = &ctx->certs;
99 ctx->ppsinfo = &ctx->msg->signed_infos;
101 /* Attempt to decode the signature */
102 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
113 struct x509_certificate *cert = ctx->certs;
114 ctx->certs = cert->next;
115 x509_free_certificate(cert);
117 pkcs7_free_signed_info(ctx->sinfo);
119 pkcs7_free_message(ctx->msg);
125 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
128 * pkcs7_get_content_data - Get access to the PKCS#7 content
129 * @pkcs7: The preparsed PKCS#7 message to access
130 * @_data: Place to return a pointer to the data
131 * @_data_len: Place to return the data length
132 * @want_wrapper: True if the ASN.1 object header should be included in the data
134 * Get access to the data content of the PKCS#7 message, including, optionally,
135 * the header of the ASN.1 object that contains it. Returns -ENODATA if the
136 * data object was missing from the message.
138 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
139 const void **_data, size_t *_data_len,
147 wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
148 *_data = pkcs7->data - wrapper;
149 *_data_len = pkcs7->data_len + wrapper;
152 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
155 * Note an OID when we find one for later processing when we know how
158 int pkcs7_note_OID(void *context, size_t hdrlen,
160 const void *value, size_t vlen)
162 struct pkcs7_parse_context *ctx = context;
164 ctx->last_oid = look_up_OID(value, vlen);
165 if (ctx->last_oid == OID__NR) {
167 sprint_oid(value, vlen, buffer, sizeof(buffer));
168 printk("PKCS7: Unknown OID: [%lu] %s\n",
169 (unsigned long)value - ctx->data, buffer);
175 * Note the digest algorithm for the signature.
177 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
179 const void *value, size_t vlen)
181 struct pkcs7_parse_context *ctx = context;
183 switch (ctx->last_oid) {
185 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD4;
188 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD5;
191 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA1;
194 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA256;
197 printk("Unsupported digest algo: %u\n", ctx->last_oid);
204 * Note the public key algorithm for the signature.
206 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
208 const void *value, size_t vlen)
210 struct pkcs7_parse_context *ctx = context;
212 switch (ctx->last_oid) {
213 case OID_rsaEncryption:
214 ctx->sinfo->sig.pkey_algo = PKEY_ALGO_RSA;
217 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
224 * Extract a certificate and store it in the context.
226 int pkcs7_extract_cert(void *context, size_t hdrlen,
228 const void *value, size_t vlen)
230 struct pkcs7_parse_context *ctx = context;
231 struct x509_certificate *x509;
233 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
234 pr_debug("Cert began with tag %02x at %lu\n",
235 tag, (unsigned long)ctx - ctx->data);
239 /* We have to correct for the header so that the X.509 parser can start
240 * from the beginning. Note that since X.509 stipulates DER, there
241 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
247 if (((u8*)value)[1] == 0x80)
248 vlen += 2; /* Indefinite length - there should be an EOC */
250 x509 = x509_cert_parse(value, vlen);
252 return PTR_ERR(x509);
254 pr_debug("Got cert for %s\n", x509->subject);
255 pr_debug("- fingerprint %s\n", x509->fingerprint);
257 x509->index = ++ctx->x509_index;
258 *ctx->ppcerts = x509;
259 ctx->ppcerts = &x509->next;
264 * Save the certificate list
266 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
268 const void *value, size_t vlen)
270 struct pkcs7_parse_context *ctx = context;
272 pr_devel("Got cert list (%02x)\n", tag);
274 *ctx->ppcerts = ctx->msg->certs;
275 ctx->msg->certs = ctx->certs;
277 ctx->ppcerts = &ctx->certs;
282 * Extract the data from the message and store that and its content type OID in
285 int pkcs7_note_data(void *context, size_t hdrlen,
287 const void *value, size_t vlen)
289 struct pkcs7_parse_context *ctx = context;
291 pr_debug("Got data\n");
293 ctx->msg->data = value;
294 ctx->msg->data_len = vlen;
295 ctx->msg->data_hdrlen = hdrlen;
296 ctx->msg->data_type = ctx->last_oid;
301 * Parse authenticated attributes
303 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
305 const void *value, size_t vlen)
307 struct pkcs7_parse_context *ctx = context;
309 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
311 switch (ctx->last_oid) {
312 case OID_messageDigest:
315 ctx->sinfo->msgdigest = value;
316 ctx->sinfo->msgdigest_len = vlen;
324 * Note the set of auth attributes for digestion purposes [RFC2315 9.3]
326 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
328 const void *value, size_t vlen)
330 struct pkcs7_parse_context *ctx = context;
332 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
333 ctx->sinfo->authattrs = value - (hdrlen - 1);
334 ctx->sinfo->authattrs_len = vlen + (hdrlen - 1);
339 * Note the issuing certificate serial number
341 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
343 const void *value, size_t vlen)
345 struct pkcs7_parse_context *ctx = context;
346 ctx->sinfo->raw_serial = value;
347 ctx->sinfo->raw_serial_size = vlen;
352 * Note the issuer's name
354 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
356 const void *value, size_t vlen)
358 struct pkcs7_parse_context *ctx = context;
359 ctx->sinfo->raw_issuer = value;
360 ctx->sinfo->raw_issuer_size = vlen;
365 * Note the signature data
367 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
369 const void *value, size_t vlen)
371 struct pkcs7_parse_context *ctx = context;
374 BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
376 mpi = mpi_read_raw_data(value, vlen);
380 ctx->sinfo->sig.mpi[0] = mpi;
381 ctx->sinfo->sig.nr_mpi = 1;
386 * Note a signature information block
388 int pkcs7_note_signed_info(void *context, size_t hdrlen,
390 const void *value, size_t vlen)
392 struct pkcs7_parse_context *ctx = context;
394 ctx->sinfo->index = ++ctx->sinfo_index;
395 *ctx->ppsinfo = ctx->sinfo;
396 ctx->ppsinfo = &ctx->sinfo->next;
397 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);