cms_enc.c revision 306195 
1/* crypto/cms/cms_enc.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
4 * project.
5 */
6/* ====================================================================
7 * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 */
54
55#include "cryptlib.h"
56#include <openssl/asn1t.h>
57#include <openssl/pem.h>
58#include <openssl/x509v3.h>
59#include <openssl/err.h>
60#include <openssl/cms.h>
61#include <openssl/rand.h>
62#include "cms_lcl.h"
63
64/* CMS EncryptedData Utilities */
65
66DECLARE_ASN1_ITEM(CMS_EncryptedData)
67
68/* Return BIO based on EncryptedContentInfo and key */
69
70BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
71{
72    BIO *b;
73    EVP_CIPHER_CTX *ctx;
74    const EVP_CIPHER *ciph;
75    X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
76    unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
77    unsigned char *tkey = NULL;
78    size_t tkeylen = 0;
79
80    int ok = 0;
81
82    int enc, keep_key = 0;
83
84    enc = ec->cipher ? 1 : 0;
85
86    b = BIO_new(BIO_f_cipher());
87    if (!b) {
88        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
89        return NULL;
90    }
91
92    BIO_get_cipher_ctx(b, &ctx);
93
94    if (enc) {
95        ciph = ec->cipher;
96        /*
97         * If not keeping key set cipher to NULL so subsequent calls decrypt.
98         */
99        if (ec->key)
100            ec->cipher = NULL;
101    } else {
102        ciph = EVP_get_cipherbyobj(calg->algorithm);
103
104        if (!ciph) {
105            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, CMS_R_UNKNOWN_CIPHER);
106            goto err;
107        }
108    }
109
110    if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) {
111        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
112               CMS_R_CIPHER_INITIALISATION_ERROR);
113        goto err;
114    }
115
116    if (enc) {
117        int ivlen;
118        calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx));
119        /* Generate a random IV if we need one */
120        ivlen = EVP_CIPHER_CTX_iv_length(ctx);
121        if (ivlen > 0) {
122            if (RAND_bytes(iv, ivlen) <= 0)
123                goto err;
124            piv = iv;
125        }
126    } else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) {
127        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
128               CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
129        goto err;
130    }
131    tkeylen = EVP_CIPHER_CTX_key_length(ctx);
132    /* Generate random session key */
133    if (!enc || !ec->key) {
134        tkey = OPENSSL_malloc(tkeylen);
135        if (!tkey) {
136            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
137            goto err;
138        }
139        if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
140            goto err;
141    }
142
143    if (!ec->key) {
144        ec->key = tkey;
145        ec->keylen = tkeylen;
146        tkey = NULL;
147        if (enc)
148            keep_key = 1;
149        else
150            ERR_clear_error();
151
152    }
153
154    if (ec->keylen != tkeylen) {
155        /* If necessary set key length */
156        if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {
157            /*
158             * Only reveal failure if debugging so we don't leak information
159             * which may be useful in MMA.
160             */
161            if (enc || ec->debug) {
162                CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
163                       CMS_R_INVALID_KEY_LENGTH);
164                goto err;
165            } else {
166                /* Use random key */
167                OPENSSL_cleanse(ec->key, ec->keylen);
168                OPENSSL_free(ec->key);
169                ec->key = tkey;
170                ec->keylen = tkeylen;
171                tkey = NULL;
172                ERR_clear_error();
173            }
174        }
175    }
176
177    if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {
178        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
179               CMS_R_CIPHER_INITIALISATION_ERROR);
180        goto err;
181    }
182    if (enc) {
183        calg->parameter = ASN1_TYPE_new();
184        if (calg->parameter == NULL) {
185            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
186            goto err;
187        }
188        if (EVP_CIPHER_param_to_asn1(ctx, calg->parameter) <= 0) {
189            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
190                   CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
191            goto err;
192        }
193        /* If parameter type not set omit parameter */
194        if (calg->parameter->type == V_ASN1_UNDEF) {
195            ASN1_TYPE_free(calg->parameter);
196            calg->parameter = NULL;
197        }
198    }
199    ok = 1;
200
201 err:
202    if (ec->key && (!keep_key || !ok)) {
203        OPENSSL_cleanse(ec->key, ec->keylen);
204        OPENSSL_free(ec->key);
205        ec->key = NULL;
206    }
207    if (tkey) {
208        OPENSSL_cleanse(tkey, tkeylen);
209        OPENSSL_free(tkey);
210    }
211    if (ok)
212        return b;
213    BIO_free(b);
214    return NULL;
215}
216
217int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,
218                              const EVP_CIPHER *cipher,
219                              const unsigned char *key, size_t keylen)
220{
221    ec->cipher = cipher;
222    if (key) {
223        ec->key = OPENSSL_malloc(keylen);
224        if (!ec->key)
225            return 0;
226        memcpy(ec->key, key, keylen);
227    }
228    ec->keylen = keylen;
229    if (cipher)
230        ec->contentType = OBJ_nid2obj(NID_pkcs7_data);
231    return 1;
232}
233
234int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,
235                               const unsigned char *key, size_t keylen)
236{
237    CMS_EncryptedContentInfo *ec;
238    if (!key || !keylen) {
239        CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY);
240        return 0;
241    }
242    if (ciph) {
243        cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);
244        if (!cms->d.encryptedData) {
245            CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, ERR_R_MALLOC_FAILURE);
246            return 0;
247        }
248        cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);
249        cms->d.encryptedData->version = 0;
250    } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {
251        CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NOT_ENCRYPTED_DATA);
252        return 0;
253    }
254    ec = cms->d.encryptedData->encryptedContentInfo;
255    return cms_EncryptedContent_init(ec, ciph, key, keylen);
256}
257
258BIO *cms_EncryptedData_init_bio(CMS_ContentInfo *cms)
259{
260    CMS_EncryptedData *enc = cms->d.encryptedData;
261    if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)
262        enc->version = 2;
263    return cms_EncryptedContent_init_bio(enc->encryptedContentInfo);
264}
265