crypto/cms/cms_enc.c

   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
  66 DECLARE_ASN1_ITEM(CMS_EncryptedData)
  67
  68 /* Return BIO based on EncryptedContentInfo and key */
  69
  70 BIO *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_clear_free(ec->key, ec->keylen);
 168                 ec->key = tkey;
 169                 ec->keylen = tkeylen;
 170                 tkey = NULL;
 171                 ERR_clear_error();
 172             }
 173         }
 174     }
 175
 176     if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {
 177         CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
 178                CMS_R_CIPHER_INITIALISATION_ERROR);
 179         goto err;
 180     }
 181
 182     if (piv) {
 183         calg->parameter = ASN1_TYPE_new();
 184         if (!calg->parameter) {
 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     }
 194     ok = 1;
 195
 196  err:
 197     if (ec->key && !keep_key) {
 198         OPENSSL_clear_free(ec->key, ec->keylen);
 199         ec->key = NULL;
 200     }
 201     OPENSSL_clear_free(tkey, tkeylen);
 202     if (ok)
 203         return b;
 204     BIO_free(b);
 205     return NULL;
 206 }
 207
 208 int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,
 209                               const EVP_CIPHER *cipher,
 210                               const unsigned char *key, size_t keylen)
 211 {
 212     ec->cipher = cipher;
 213     if (key) {
 214         ec->key = OPENSSL_malloc(keylen);
 215         if (!ec->key)
 216             return 0;
 217         memcpy(ec->key, key, keylen);
 218     }
 219     ec->keylen = keylen;
 220     if (cipher)
 221         ec->contentType = OBJ_nid2obj(NID_pkcs7_data);
 222     return 1;
 223 }
 224
 225 int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,
 226                                const unsigned char *key, size_t keylen)
 227 {
 228     CMS_EncryptedContentInfo *ec;
 229     if (!key || !keylen) {
 230         CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY);
 231         return 0;
 232     }
 233     if (ciph) {
 234         cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);
 235         if (!cms->d.encryptedData) {
 236             CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, ERR_R_MALLOC_FAILURE);
 237             return 0;
 238         }
 239         cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);
 240         cms->d.encryptedData->version = 0;
 241     } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {
 242         CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NOT_ENCRYPTED_DATA);
 243         return 0;
 244     }
 245     ec = cms->d.encryptedData->encryptedContentInfo;
 246     return cms_EncryptedContent_init(ec, ciph, key, keylen);
 247 }
 248
 249 BIO *cms_EncryptedData_init_bio(CMS_ContentInfo *cms)
 250 {
 251     CMS_EncryptedData *enc = cms->d.encryptedData;
 252     if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)
 253         enc->version = 2;
 254     return cms_EncryptedContent_init_bio(enc->encryptedContentInfo);
 255 }