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