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 */
32 const void *raw_serial;
33 unsigned raw_serial_size;
34 unsigned raw_issuer_size;
35 const void *raw_issuer;
39 * Free a signed information block.
41 static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
44 mpi_free(sinfo->sig.mpi[0]);
45 kfree(sinfo->sig.digest);
46 kfree(sinfo->signing_cert_id);
52 * pkcs7_free_message - Free a PKCS#7 message
53 * @pkcs7: The PKCS#7 message to free
55 void pkcs7_free_message(struct pkcs7_message *pkcs7)
57 struct x509_certificate *cert;
58 struct pkcs7_signed_info *sinfo;
61 while (pkcs7->certs) {
63 pkcs7->certs = cert->next;
64 x509_free_certificate(cert);
68 pkcs7->crl = cert->next;
69 x509_free_certificate(cert);
71 while (pkcs7->signed_infos) {
72 sinfo = pkcs7->signed_infos;
73 pkcs7->signed_infos = sinfo->next;
74 pkcs7_free_signed_info(sinfo);
79 EXPORT_SYMBOL_GPL(pkcs7_free_message);
82 * pkcs7_parse_message - Parse a PKCS#7 message
83 * @data: The raw binary ASN.1 encoded message to be parsed
84 * @datalen: The size of the encoded message
86 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
88 struct pkcs7_parse_context *ctx;
89 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
92 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
95 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
98 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
102 ctx->data = (unsigned long)data;
103 ctx->ppcerts = &ctx->certs;
104 ctx->ppsinfo = &ctx->msg->signed_infos;
106 /* Attempt to decode the signature */
107 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
118 struct x509_certificate *cert = ctx->certs;
119 ctx->certs = cert->next;
120 x509_free_certificate(cert);
122 pkcs7_free_signed_info(ctx->sinfo);
124 pkcs7_free_message(ctx->msg);
130 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
133 * pkcs7_get_content_data - Get access to the PKCS#7 content
134 * @pkcs7: The preparsed PKCS#7 message to access
135 * @_data: Place to return a pointer to the data
136 * @_data_len: Place to return the data length
137 * @want_wrapper: True if the ASN.1 object header should be included in the data
139 * Get access to the data content of the PKCS#7 message, including, optionally,
140 * the header of the ASN.1 object that contains it. Returns -ENODATA if the
141 * data object was missing from the message.
143 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
144 const void **_data, size_t *_data_len,
152 wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
153 *_data = pkcs7->data - wrapper;
154 *_data_len = pkcs7->data_len + wrapper;
157 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
160 * Note an OID when we find one for later processing when we know how
163 int pkcs7_note_OID(void *context, size_t hdrlen,
165 const void *value, size_t vlen)
167 struct pkcs7_parse_context *ctx = context;
169 ctx->last_oid = look_up_OID(value, vlen);
170 if (ctx->last_oid == OID__NR) {
172 sprint_oid(value, vlen, buffer, sizeof(buffer));
173 printk("PKCS7: Unknown OID: [%lu] %s\n",
174 (unsigned long)value - ctx->data, buffer);
180 * Note the digest algorithm for the signature.
182 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
184 const void *value, size_t vlen)
186 struct pkcs7_parse_context *ctx = context;
188 switch (ctx->last_oid) {
190 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD4;
193 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD5;
196 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA1;
199 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA256;
202 printk("Unsupported digest algo: %u\n", ctx->last_oid);
209 * Note the public key algorithm for the signature.
211 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
213 const void *value, size_t vlen)
215 struct pkcs7_parse_context *ctx = context;
217 switch (ctx->last_oid) {
218 case OID_rsaEncryption:
219 ctx->sinfo->sig.pkey_algo = PKEY_ALGO_RSA;
222 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
229 * We only support signed data [RFC2315 sec 9].
231 int pkcs7_check_content_type(void *context, size_t hdrlen,
233 const void *value, size_t vlen)
235 struct pkcs7_parse_context *ctx = context;
237 if (ctx->last_oid != OID_signed_data) {
238 pr_warn("Only support pkcs7_signedData type\n");
246 * Note the SignedData version
248 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
250 const void *value, size_t vlen)
257 version = *(const u8 *)value;
260 /* PKCS#7 SignedData [RFC2315 sec 9.1] */
269 pr_warn("Unsupported SignedData version\n");
274 * Note the SignerInfo version
276 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
278 const void *value, size_t vlen)
285 version = *(const u8 *)value;
288 /* PKCS#7 SignerInfo [RFC2315 sec 9.2] */
297 pr_warn("Unsupported SignerInfo version\n");
302 * Extract a certificate and store it in the context.
304 int pkcs7_extract_cert(void *context, size_t hdrlen,
306 const void *value, size_t vlen)
308 struct pkcs7_parse_context *ctx = context;
309 struct x509_certificate *x509;
311 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
312 pr_debug("Cert began with tag %02x at %lu\n",
313 tag, (unsigned long)ctx - ctx->data);
317 /* We have to correct for the header so that the X.509 parser can start
318 * from the beginning. Note that since X.509 stipulates DER, there
319 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
325 if (((u8*)value)[1] == 0x80)
326 vlen += 2; /* Indefinite length - there should be an EOC */
328 x509 = x509_cert_parse(value, vlen);
330 return PTR_ERR(x509);
332 x509->index = ++ctx->x509_index;
333 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
334 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
336 *ctx->ppcerts = x509;
337 ctx->ppcerts = &x509->next;
342 * Save the certificate list
344 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
346 const void *value, size_t vlen)
348 struct pkcs7_parse_context *ctx = context;
350 pr_devel("Got cert list (%02x)\n", tag);
352 *ctx->ppcerts = ctx->msg->certs;
353 ctx->msg->certs = ctx->certs;
355 ctx->ppcerts = &ctx->certs;
360 * Extract the data from the message and store that and its content type OID in
363 int pkcs7_note_data(void *context, size_t hdrlen,
365 const void *value, size_t vlen)
367 struct pkcs7_parse_context *ctx = context;
369 pr_debug("Got data\n");
371 ctx->msg->data = value;
372 ctx->msg->data_len = vlen;
373 ctx->msg->data_hdrlen = hdrlen;
374 ctx->msg->data_type = ctx->last_oid;
379 * Parse authenticated attributes
381 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
383 const void *value, size_t vlen)
385 struct pkcs7_parse_context *ctx = context;
387 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
389 switch (ctx->last_oid) {
390 case OID_messageDigest:
393 ctx->sinfo->msgdigest = value;
394 ctx->sinfo->msgdigest_len = vlen;
402 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
404 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
406 const void *value, size_t vlen)
408 struct pkcs7_parse_context *ctx = context;
410 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
411 ctx->sinfo->authattrs = value - (hdrlen - 1);
412 ctx->sinfo->authattrs_len = vlen + (hdrlen - 1);
417 * Note the issuing certificate serial number
419 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
421 const void *value, size_t vlen)
423 struct pkcs7_parse_context *ctx = context;
424 ctx->raw_serial = value;
425 ctx->raw_serial_size = vlen;
430 * Note the issuer's name
432 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
434 const void *value, size_t vlen)
436 struct pkcs7_parse_context *ctx = context;
437 ctx->raw_issuer = value;
438 ctx->raw_issuer_size = vlen;
443 * Note the signature data
445 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
447 const void *value, size_t vlen)
449 struct pkcs7_parse_context *ctx = context;
452 BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
454 mpi = mpi_read_raw_data(value, vlen);
458 ctx->sinfo->sig.mpi[0] = mpi;
459 ctx->sinfo->sig.nr_mpi = 1;
464 * Note a signature information block
466 int pkcs7_note_signed_info(void *context, size_t hdrlen,
468 const void *value, size_t vlen)
470 struct pkcs7_parse_context *ctx = context;
471 struct pkcs7_signed_info *sinfo = ctx->sinfo;
472 struct asymmetric_key_id *kid;
474 /* Generate cert issuer + serial number key ID */
475 kid = asymmetric_key_generate_id(ctx->raw_serial,
476 ctx->raw_serial_size,
478 ctx->raw_issuer_size);
482 sinfo->signing_cert_id = kid;
483 sinfo->index = ++ctx->sinfo_index;
484 *ctx->ppsinfo = sinfo;
485 ctx->ppsinfo = &sinfo->next;
486 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);