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 "asn1_locl.h"
  65
  66 DECLARE_ASN1_ITEM(CMS_KeyAgreeRecipientInfo)
  67 DECLARE_ASN1_ITEM(CMS_RecipientEncryptedKey)
  68 DECLARE_ASN1_ITEM(CMS_OriginatorPublicKey)
  69
  70 /* Key Agreement Recipient Info (KARI) routines */
  71
  72 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
  73                                     X509_ALGOR **palg,
  74                                     ASN1_OCTET_STRING **pukm)
  75 {
  76     if (ri->type != CMS_RECIPINFO_AGREE) {
  77         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
  78                CMS_R_NOT_KEY_AGREEMENT);
  79         return 0;
  80     }
  81     if (palg)
  82         *palg = ri->d.kari->keyEncryptionAlgorithm;
  83     if (pukm)
  84         *pukm = ri->d.kari->ukm;
  85     return 1;
  86 }
  87
  88 /* Retrieve recipient encrypted keys from a kari */
  89
  90 STACK_OF(CMS_RecipientEncryptedKey)
  91 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
  92 {
  93     if (ri->type != CMS_RECIPINFO_AGREE) {
  94         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
  95                CMS_R_NOT_KEY_AGREEMENT);
  96         return NULL;
  97     }
  98     return ri->d.kari->recipientEncryptedKeys;
  99 }
 100
 101 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
 102                                         X509_ALGOR **pubalg,
 103                                         ASN1_BIT_STRING **pubkey,
 104                                         ASN1_OCTET_STRING **keyid,
 105                                         X509_NAME **issuer,
 106                                         ASN1_INTEGER **sno)
 107 {
 108     CMS_OriginatorIdentifierOrKey *oik;
 109     if (ri->type != CMS_RECIPINFO_AGREE) {
 110         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
 111                CMS_R_NOT_KEY_AGREEMENT);
 112         return 0;
 113     }
 114     oik = ri->d.kari->originator;
 115     if (issuer)
 116         *issuer = NULL;
 117     if (sno)
 118         *sno = NULL;
 119     if (keyid)
 120         *keyid = NULL;
 121     if (pubalg)
 122         *pubalg = NULL;
 123     if (pubkey)
 124         *pubkey = NULL;
 125     if (oik->type == CMS_OIK_ISSUER_SERIAL) {
 126         if (issuer)
 127             *issuer = oik->d.issuerAndSerialNumber->issuer;
 128         if (sno)
 129             *sno = oik->d.issuerAndSerialNumber->serialNumber;
 130     } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
 131         if (keyid)
 132             *keyid = oik->d.subjectKeyIdentifier;
 133     } else if (oik->type == CMS_OIK_PUBKEY) {
 134         if (pubalg)
 135             *pubalg = oik->d.originatorKey->algorithm;
 136         if (pubkey)
 137             *pubkey = oik->d.originatorKey->publicKey;
 138     } else
 139         return 0;
 140     return 1;
 141 }
 142
 143 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
 144 {
 145     CMS_OriginatorIdentifierOrKey *oik;
 146     if (ri->type != CMS_RECIPINFO_AGREE) {
 147         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
 148                CMS_R_NOT_KEY_AGREEMENT);
 149         return -2;
 150     }
 151     oik = ri->d.kari->originator;
 152     if (oik->type == CMS_OIK_ISSUER_SERIAL)
 153         return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
 154     else if (oik->type == CMS_OIK_KEYIDENTIFIER)
 155         return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
 156     return -1;
 157 }
 158
 159 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
 160                                       ASN1_OCTET_STRING **keyid,
 161                                       ASN1_GENERALIZEDTIME **tm,
 162                                       CMS_OtherKeyAttribute **other,
 163                                       X509_NAME **issuer, ASN1_INTEGER **sno)
 164 {
 165     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 166     if (rid->type == CMS_REK_ISSUER_SERIAL) {
 167         if (issuer)
 168             *issuer = rid->d.issuerAndSerialNumber->issuer;
 169         if (sno)
 170             *sno = rid->d.issuerAndSerialNumber->serialNumber;
 171         if (keyid)
 172             *keyid = NULL;
 173         if (tm)
 174             *tm = NULL;
 175         if (other)
 176             *other = NULL;
 177     } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
 178         if (keyid)
 179             *keyid = rid->d.rKeyId->subjectKeyIdentifier;
 180         if (tm)
 181             *tm = rid->d.rKeyId->date;
 182         if (other)
 183             *other = rid->d.rKeyId->other;
 184         if (issuer)
 185             *issuer = NULL;
 186         if (sno)
 187             *sno = NULL;
 188     } else
 189         return 0;
 190     return 1;
 191 }
 192
 193 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
 194                                        X509 *cert)
 195 {
 196     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 197     if (rid->type == CMS_REK_ISSUER_SERIAL)
 198         return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
 199     else if (rid->type == CMS_REK_KEYIDENTIFIER)
 200         return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
 201     else
 202         return -1;
 203 }
 204
 205 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
 206 {
 207     EVP_PKEY_CTX *pctx;
 208     CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
 209     if (kari->pctx) {
 210         EVP_PKEY_CTX_free(kari->pctx);
 211         kari->pctx = NULL;
 212     }
 213     if (!pk)
 214         return 1;
 215     pctx = EVP_PKEY_CTX_new(pk, NULL);
 216     if (!pctx || !EVP_PKEY_derive_init(pctx))
 217         goto err;
 218     kari->pctx = pctx;
 219     return 1;
 220  err:
 221     if (pctx)
 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     if (ec->key) {
 298         OPENSSL_cleanse(ec->key, ec->keylen);
 299         OPENSSL_free(ec->key);
 300     }
 301     ec->key = cek;
 302     ec->keylen = ceklen;
 303     cek = NULL;
 304     rv = 1;
 305  err:
 306     if (cek)
 307         OPENSSL_free(cek);
 308     return rv;
 309 }
 310
 311 /* Create ephemeral key and initialise context based on it */
 312 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
 313                                          EVP_PKEY *pk)
 314 {
 315     EVP_PKEY_CTX *pctx = NULL;
 316     EVP_PKEY *ekey = NULL;
 317     int rv = 0;
 318     pctx = EVP_PKEY_CTX_new(pk, NULL);
 319     if (!pctx)
 320         goto err;
 321     if (EVP_PKEY_keygen_init(pctx) <= 0)
 322         goto err;
 323     if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
 324         goto err;
 325     EVP_PKEY_CTX_free(pctx);
 326     pctx = EVP_PKEY_CTX_new(ekey, NULL);
 327     if (!pctx)
 328         goto err;
 329     if (EVP_PKEY_derive_init(pctx) <= 0)
 330         goto err;
 331     kari->pctx = pctx;
 332     rv = 1;
 333  err:
 334     if (!rv && pctx)
 335         EVP_PKEY_CTX_free(pctx);
 336     if (ekey)
 337         EVP_PKEY_free(ekey);
 338     return rv;
 339 }
 340
 341 /* Initialise a ktri based on passed certificate and key */
 342
 343 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
 344                                 EVP_PKEY *pk, unsigned int flags)
 345 {
 346     CMS_KeyAgreeRecipientInfo *kari;
 347     CMS_RecipientEncryptedKey *rek = NULL;
 348
 349     ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
 350     if (!ri->d.kari)
 351         return 0;
 352     ri->type = CMS_RECIPINFO_AGREE;
 353
 354     kari = ri->d.kari;
 355     kari->version = 3;
 356
 357     rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
 358     if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
 359         M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
 360         return 0;
 361     }
 362
 363     if (flags & CMS_USE_KEYID) {
 364         rek->rid->type = CMS_REK_KEYIDENTIFIER;
 365         if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
 366             return 0;
 367     } else {
 368         rek->rid->type = CMS_REK_ISSUER_SERIAL;
 369         if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
 370             return 0;
 371     }
 372
 373     /* Create ephemeral key */
 374     if (!cms_kari_create_ephemeral_key(kari, pk))
 375         return 0;
 376
 377     CRYPTO_add(&pk->references, 1, CRYPTO_LOCK_EVP_PKEY);
 378     rek->pkey = pk;
 379     return 1;
 380 }
 381
 382 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
 383                          const EVP_CIPHER *cipher)
 384 {
 385     EVP_CIPHER_CTX *ctx = &kari->ctx;
 386     const EVP_CIPHER *kekcipher;
 387     int keylen = EVP_CIPHER_key_length(cipher);
 388     /* If a suitable wrap algorithm is already set nothing to do */
 389     kekcipher = EVP_CIPHER_CTX_cipher(ctx);
 390
 391     if (kekcipher) {
 392         if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
 393             return 0;
 394         return 1;
 395     }
 396     /*
 397      * Pick a cipher based on content encryption cipher. If it is DES3 use
 398      * DES3 wrap otherwise use AES wrap similar to key size.
 399      */
 400     if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
 401         kekcipher = EVP_des_ede3_wrap();
 402     else if (keylen <= 16)
 403         kekcipher = EVP_aes_128_wrap();
 404     else if (keylen <= 24)
 405         kekcipher = EVP_aes_192_wrap();
 406     else
 407         kekcipher = EVP_aes_256_wrap();
 408     return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
 409 }
 410
 411 /* Encrypt content key in key agreement recipient info */
 412
 413 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
 414                                    CMS_RecipientInfo *ri)
 415 {
 416     CMS_KeyAgreeRecipientInfo *kari;
 417     CMS_EncryptedContentInfo *ec;
 418     CMS_RecipientEncryptedKey *rek;
 419     STACK_OF(CMS_RecipientEncryptedKey) *reks;
 420     int i;
 421
 422     if (ri->type != CMS_RECIPINFO_AGREE) {
 423         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
 424         return 0;
 425     }
 426     kari = ri->d.kari;
 427     reks = kari->recipientEncryptedKeys;
 428     ec = cms->d.envelopedData->encryptedContentInfo;
 429     /* Initialise wrap algorithm parameters */
 430     if (!cms_wrap_init(kari, ec->cipher))
 431         return 0;
 432     /*
 433      * If no orignator key set up initialise for ephemeral key the public key
 434      * ASN1 structure will set the actual public key value.
 435      */
 436     if (kari->originator->type == -1) {
 437         CMS_OriginatorIdentifierOrKey *oik = kari->originator;
 438         oik->type = CMS_OIK_PUBKEY;
 439         oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
 440         if (!oik->d.originatorKey)
 441             return 0;
 442     }
 443     /* Initialise KDF algorithm */
 444     if (!cms_env_asn1_ctrl(ri, 0))
 445         return 0;
 446     /* For each rek, derive KEK, encrypt CEK */
 447     for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
 448         unsigned char *enckey;
 449         size_t enckeylen;
 450         rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
 451         if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
 452             return 0;
 453         if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
 454                             kari, 1))
 455             return 0;
 456         ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);
 457     }
 458
 459     return 1;
 460
 461 }