crypto/cms/cms_kari.c

   1 /* crypto/cms/cms_kari.c */
   2 /*
   3  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   4  * project.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 2013 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 <openssl/aes.h>
  63 #include "cms_lcl.h"
  64 #include "internal/asn1_int.h"
  65
  66 DECLARE_ASN1_ITEM(CMS_KeyAgreeRecipientInfo)
  67 DECLARE_ASN1_ITEM(CMS_RecipientEncryptedKey)
  68 DECLARE_ASN1_ITEM(CMS_OriginatorPublicKey)
  69 DECLARE_ASN1_ITEM(CMS_RecipientKeyIdentifier)
  70
  71 /* Key Agreement Recipient Info (KARI) routines */
  72
  73 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
  74                                     X509_ALGOR **palg,
  75                                     ASN1_OCTET_STRING **pukm)
  76 {
  77     if (ri->type != CMS_RECIPINFO_AGREE) {
  78         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
  79                CMS_R_NOT_KEY_AGREEMENT);
  80         return 0;
  81     }
  82     if (palg)
  83         *palg = ri->d.kari->keyEncryptionAlgorithm;
  84     if (pukm)
  85         *pukm = ri->d.kari->ukm;
  86     return 1;
  87 }
  88
  89 /* Retrieve recipient encrypted keys from a kari */
  90
  91 STACK_OF(CMS_RecipientEncryptedKey)
  92 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
  93 {
  94     if (ri->type != CMS_RECIPINFO_AGREE) {
  95         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
  96                CMS_R_NOT_KEY_AGREEMENT);
  97         return NULL;
  98     }
  99     return ri->d.kari->recipientEncryptedKeys;
 100 }
 101
 102 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
 103                                         X509_ALGOR **pubalg,
 104                                         ASN1_BIT_STRING **pubkey,
 105                                         ASN1_OCTET_STRING **keyid,
 106                                         X509_NAME **issuer,
 107                                         ASN1_INTEGER **sno)
 108 {
 109     CMS_OriginatorIdentifierOrKey *oik;
 110     if (ri->type != CMS_RECIPINFO_AGREE) {
 111         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
 112                CMS_R_NOT_KEY_AGREEMENT);
 113         return 0;
 114     }
 115     oik = ri->d.kari->originator;
 116     if (issuer)
 117         *issuer = NULL;
 118     if (sno)
 119         *sno = NULL;
 120     if (keyid)
 121         *keyid = NULL;
 122     if (pubalg)
 123         *pubalg = NULL;
 124     if (pubkey)
 125         *pubkey = NULL;
 126     if (oik->type == CMS_OIK_ISSUER_SERIAL) {
 127         if (issuer)
 128             *issuer = oik->d.issuerAndSerialNumber->issuer;
 129         if (sno)
 130             *sno = oik->d.issuerAndSerialNumber->serialNumber;
 131     } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
 132         if (keyid)
 133             *keyid = oik->d.subjectKeyIdentifier;
 134     } else if (oik->type == CMS_OIK_PUBKEY) {
 135         if (pubalg)
 136             *pubalg = oik->d.originatorKey->algorithm;
 137         if (pubkey)
 138             *pubkey = oik->d.originatorKey->publicKey;
 139     } else
 140         return 0;
 141     return 1;
 142 }
 143
 144 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
 145 {
 146     CMS_OriginatorIdentifierOrKey *oik;
 147     if (ri->type != CMS_RECIPINFO_AGREE) {
 148         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
 149                CMS_R_NOT_KEY_AGREEMENT);
 150         return -2;
 151     }
 152     oik = ri->d.kari->originator;
 153     if (oik->type == CMS_OIK_ISSUER_SERIAL)
 154         return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
 155     else if (oik->type == CMS_OIK_KEYIDENTIFIER)
 156         return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
 157     return -1;
 158 }
 159
 160 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
 161                                       ASN1_OCTET_STRING **keyid,
 162                                       ASN1_GENERALIZEDTIME **tm,
 163                                       CMS_OtherKeyAttribute **other,
 164                                       X509_NAME **issuer, ASN1_INTEGER **sno)
 165 {
 166     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 167     if (rid->type == CMS_REK_ISSUER_SERIAL) {
 168         if (issuer)
 169             *issuer = rid->d.issuerAndSerialNumber->issuer;
 170         if (sno)
 171             *sno = rid->d.issuerAndSerialNumber->serialNumber;
 172         if (keyid)
 173             *keyid = NULL;
 174         if (tm)
 175             *tm = NULL;
 176         if (other)
 177             *other = NULL;
 178     } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
 179         if (keyid)
 180             *keyid = rid->d.rKeyId->subjectKeyIdentifier;
 181         if (tm)
 182             *tm = rid->d.rKeyId->date;
 183         if (other)
 184             *other = rid->d.rKeyId->other;
 185         if (issuer)
 186             *issuer = NULL;
 187         if (sno)
 188             *sno = NULL;
 189     } else
 190         return 0;
 191     return 1;
 192 }
 193
 194 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
 195                                        X509 *cert)
 196 {
 197     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 198     if (rid->type == CMS_REK_ISSUER_SERIAL)
 199         return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
 200     else if (rid->type == CMS_REK_KEYIDENTIFIER)
 201         return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
 202     else
 203         return -1;
 204 }
 205
 206 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
 207 {
 208     EVP_PKEY_CTX *pctx;
 209     CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
 210     if (kari->pctx) {
 211         EVP_PKEY_CTX_free(kari->pctx);
 212         kari->pctx = NULL;
 213     }
 214     if (!pk)
 215         return 1;
 216     pctx = EVP_PKEY_CTX_new(pk, NULL);
 217     if (!pctx || !EVP_PKEY_derive_init(pctx))
 218         goto err;
 219     kari->pctx = pctx;
 220     return 1;
 221  err:
 222     EVP_PKEY_CTX_free(pctx);
 223     return 0;
 224 }
 225
 226 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
 227 {
 228     if (ri->type == CMS_RECIPINFO_AGREE)
 229         return &ri->d.kari->ctx;
 230     return NULL;
 231 }
 232
 233 /*
 234  * Derive KEK and decrypt/encrypt with it to produce either the original CEK
 235  * or the encrypted CEK.
 236  */
 237
 238 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
 239                           const unsigned char *in, size_t inlen,
 240                           CMS_KeyAgreeRecipientInfo *kari, int enc)
 241 {
 242     /* Key encryption key */
 243     unsigned char kek[EVP_MAX_KEY_LENGTH];
 244     size_t keklen;
 245     int rv = 0;
 246     unsigned char *out = NULL;
 247     int outlen;
 248     keklen = EVP_CIPHER_CTX_key_length(&kari->ctx);
 249     if (keklen > EVP_MAX_KEY_LENGTH)
 250         return 0;
 251     /* Derive KEK */
 252     if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
 253         goto err;
 254     /* Set KEK in context */
 255     if (!EVP_CipherInit_ex(&kari->ctx, NULL, NULL, kek, NULL, enc))
 256         goto err;
 257     /* obtain output length of ciphered key */
 258     if (!EVP_CipherUpdate(&kari->ctx, NULL, &outlen, in, inlen))
 259         goto err;
 260     out = OPENSSL_malloc(outlen);
 261     if (!out)
 262         goto err;
 263     if (!EVP_CipherUpdate(&kari->ctx, out, &outlen, in, inlen))
 264         goto err;
 265     *pout = out;
 266     *poutlen = (size_t)outlen;
 267     rv = 1;
 268
 269  err:
 270     OPENSSL_cleanse(kek, keklen);
 271     if (!rv && out)
 272         OPENSSL_free(out);
 273     EVP_CIPHER_CTX_cleanup(&kari->ctx);
 274     EVP_PKEY_CTX_free(kari->pctx);
 275     kari->pctx = NULL;
 276     return rv;
 277 }
 278
 279 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
 280                                    CMS_RecipientInfo *ri,
 281                                    CMS_RecipientEncryptedKey *rek)
 282 {
 283     int rv = 0;
 284     unsigned char *enckey = NULL, *cek = NULL;
 285     size_t enckeylen;
 286     size_t ceklen;
 287     CMS_EncryptedContentInfo *ec;
 288     enckeylen = rek->encryptedKey->length;
 289     enckey = rek->encryptedKey->data;
 290     /* Setup all parameters to derive KEK */
 291     if (!cms_env_asn1_ctrl(ri, 1))
 292         goto err;
 293     /* Attempt to decrypt CEK */
 294     if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
 295         goto err;
 296     ec = cms->d.envelopedData->encryptedContentInfo;
 297     OPENSSL_clear_free(ec->key, ec->keylen);
 298     ec->key = cek;
 299     ec->keylen = ceklen;
 300     cek = NULL;
 301     rv = 1;
 302  err:
 303     if (cek)
 304         OPENSSL_free(cek);
 305     return rv;
 306 }
 307
 308 /* Create ephemeral key and initialise context based on it */
 309 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
 310                                          EVP_PKEY *pk)
 311 {
 312     EVP_PKEY_CTX *pctx = NULL;
 313     EVP_PKEY *ekey = NULL;
 314     int rv = 0;
 315     pctx = EVP_PKEY_CTX_new(pk, NULL);
 316     if (!pctx)
 317         goto err;
 318     if (EVP_PKEY_keygen_init(pctx) <= 0)
 319         goto err;
 320     if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
 321         goto err;
 322     EVP_PKEY_CTX_free(pctx);
 323     pctx = EVP_PKEY_CTX_new(ekey, NULL);
 324     if (!pctx)
 325         goto err;
 326     if (EVP_PKEY_derive_init(pctx) <= 0)
 327         goto err;
 328     kari->pctx = pctx;
 329     rv = 1;
 330  err:
 331     if (!rv)
 332         EVP_PKEY_CTX_free(pctx);
 333     EVP_PKEY_free(ekey);
 334     return rv;
 335 }
 336
 337 /* Initialise a ktri based on passed certificate and key */
 338
 339 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
 340                                 EVP_PKEY *pk, unsigned int flags)
 341 {
 342     CMS_KeyAgreeRecipientInfo *kari;
 343     CMS_RecipientEncryptedKey *rek = NULL;
 344
 345     ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
 346     if (!ri->d.kari)
 347         return 0;
 348     ri->type = CMS_RECIPINFO_AGREE;
 349
 350     kari = ri->d.kari;
 351     kari->version = 3;
 352
 353     rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
 354     if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
 355         M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
 356         return 0;
 357     }
 358
 359     if (flags & CMS_USE_KEYID) {
 360         rek->rid->type = CMS_REK_KEYIDENTIFIER;
 361         rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
 362         if (rek->rid->d.rKeyId == NULL)
 363             return 0;
 364         if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
 365             return 0;
 366     } else {
 367         rek->rid->type = CMS_REK_ISSUER_SERIAL;
 368         if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
 369             return 0;
 370     }
 371
 372     /* Create ephemeral key */
 373     if (!cms_kari_create_ephemeral_key(kari, pk))
 374         return 0;
 375
 376     CRYPTO_add(&pk->references, 1, CRYPTO_LOCK_EVP_PKEY);
 377     rek->pkey = pk;
 378     return 1;
 379 }
 380
 381 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
 382                          const EVP_CIPHER *cipher)
 383 {
 384     EVP_CIPHER_CTX *ctx = &kari->ctx;
 385     const EVP_CIPHER *kekcipher;
 386     int keylen = EVP_CIPHER_key_length(cipher);
 387     /* If a suitable wrap algorithm is already set nothing to do */
 388     kekcipher = EVP_CIPHER_CTX_cipher(ctx);
 389
 390     if (kekcipher) {
 391         if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
 392             return 0;
 393         return 1;
 394     }
 395     /*
 396      * Pick a cipher based on content encryption cipher. If it is DES3 use
 397      * DES3 wrap otherwise use AES wrap similar to key size.
 398      */
 399     if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
 400         kekcipher = EVP_des_ede3_wrap();
 401     else if (keylen <= 16)
 402         kekcipher = EVP_aes_128_wrap();
 403     else if (keylen <= 24)
 404         kekcipher = EVP_aes_192_wrap();
 405     else
 406         kekcipher = EVP_aes_256_wrap();
 407     return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
 408 }
 409
 410 /* Encrypt content key in key agreement recipient info */
 411
 412 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
 413                                    CMS_RecipientInfo *ri)
 414 {
 415     CMS_KeyAgreeRecipientInfo *kari;
 416     CMS_EncryptedContentInfo *ec;
 417     CMS_RecipientEncryptedKey *rek;
 418     STACK_OF(CMS_RecipientEncryptedKey) *reks;
 419     int i;
 420
 421     if (ri->type != CMS_RECIPINFO_AGREE) {
 422         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
 423         return 0;
 424     }
 425     kari = ri->d.kari;
 426     reks = kari->recipientEncryptedKeys;
 427     ec = cms->d.envelopedData->encryptedContentInfo;
 428     /* Initialise wrap algorithm parameters */
 429     if (!cms_wrap_init(kari, ec->cipher))
 430         return 0;
 431     /*
 432      * If no orignator key set up initialise for ephemeral key the public key
 433      * ASN1 structure will set the actual public key value.
 434      */
 435     if (kari->originator->type == -1) {
 436         CMS_OriginatorIdentifierOrKey *oik = kari->originator;
 437         oik->type = CMS_OIK_PUBKEY;
 438         oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
 439         if (!oik->d.originatorKey)
 440             return 0;
 441     }
 442     /* Initialise KDF algorithm */
 443     if (!cms_env_asn1_ctrl(ri, 0))
 444         return 0;
 445     /* For each rek, derive KEK, encrypt CEK */
 446     for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
 447         unsigned char *enckey;
 448         size_t enckeylen;
 449         rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
 450         if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
 451             return 0;
 452         if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
 453                             kari, 1))
 454             return 0;
 455         ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);
 456     }
 457
 458     return 1;
 459
 460 }