crypto/cms/cms_kari.c

   1 /*
   2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2013 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  */
  53
  54 #include "internal/cryptlib.h"
  55 #include <openssl/asn1t.h>
  56 #include <openssl/pem.h>
  57 #include <openssl/x509v3.h>
  58 #include <openssl/err.h>
  59 #include <openssl/cms.h>
  60 #include <openssl/rand.h>
  61 #include <openssl/aes.h>
  62 #include "cms_lcl.h"
  63 #include "internal/asn1_int.h"
  64
  65 /* Key Agreement Recipient Info (KARI) routines */
  66
  67 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
  68                                     X509_ALGOR **palg,
  69                                     ASN1_OCTET_STRING **pukm)
  70 {
  71     if (ri->type != CMS_RECIPINFO_AGREE) {
  72         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
  73                CMS_R_NOT_KEY_AGREEMENT);
  74         return 0;
  75     }
  76     if (palg)
  77         *palg = ri->d.kari->keyEncryptionAlgorithm;
  78     if (pukm)
  79         *pukm = ri->d.kari->ukm;
  80     return 1;
  81 }
  82
  83 /* Retrieve recipient encrypted keys from a kari */
  84
  85 STACK_OF(CMS_RecipientEncryptedKey)
  86 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
  87 {
  88     if (ri->type != CMS_RECIPINFO_AGREE) {
  89         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
  90                CMS_R_NOT_KEY_AGREEMENT);
  91         return NULL;
  92     }
  93     return ri->d.kari->recipientEncryptedKeys;
  94 }
  95
  96 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
  97                                         X509_ALGOR **pubalg,
  98                                         ASN1_BIT_STRING **pubkey,
  99                                         ASN1_OCTET_STRING **keyid,
 100                                         X509_NAME **issuer,
 101                                         ASN1_INTEGER **sno)
 102 {
 103     CMS_OriginatorIdentifierOrKey *oik;
 104     if (ri->type != CMS_RECIPINFO_AGREE) {
 105         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
 106                CMS_R_NOT_KEY_AGREEMENT);
 107         return 0;
 108     }
 109     oik = ri->d.kari->originator;
 110     if (issuer)
 111         *issuer = NULL;
 112     if (sno)
 113         *sno = NULL;
 114     if (keyid)
 115         *keyid = NULL;
 116     if (pubalg)
 117         *pubalg = NULL;
 118     if (pubkey)
 119         *pubkey = NULL;
 120     if (oik->type == CMS_OIK_ISSUER_SERIAL) {
 121         if (issuer)
 122             *issuer = oik->d.issuerAndSerialNumber->issuer;
 123         if (sno)
 124             *sno = oik->d.issuerAndSerialNumber->serialNumber;
 125     } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
 126         if (keyid)
 127             *keyid = oik->d.subjectKeyIdentifier;
 128     } else if (oik->type == CMS_OIK_PUBKEY) {
 129         if (pubalg)
 130             *pubalg = oik->d.originatorKey->algorithm;
 131         if (pubkey)
 132             *pubkey = oik->d.originatorKey->publicKey;
 133     } else
 134         return 0;
 135     return 1;
 136 }
 137
 138 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
 139 {
 140     CMS_OriginatorIdentifierOrKey *oik;
 141     if (ri->type != CMS_RECIPINFO_AGREE) {
 142         CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
 143                CMS_R_NOT_KEY_AGREEMENT);
 144         return -2;
 145     }
 146     oik = ri->d.kari->originator;
 147     if (oik->type == CMS_OIK_ISSUER_SERIAL)
 148         return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
 149     else if (oik->type == CMS_OIK_KEYIDENTIFIER)
 150         return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
 151     return -1;
 152 }
 153
 154 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
 155                                       ASN1_OCTET_STRING **keyid,
 156                                       ASN1_GENERALIZEDTIME **tm,
 157                                       CMS_OtherKeyAttribute **other,
 158                                       X509_NAME **issuer, ASN1_INTEGER **sno)
 159 {
 160     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 161     if (rid->type == CMS_REK_ISSUER_SERIAL) {
 162         if (issuer)
 163             *issuer = rid->d.issuerAndSerialNumber->issuer;
 164         if (sno)
 165             *sno = rid->d.issuerAndSerialNumber->serialNumber;
 166         if (keyid)
 167             *keyid = NULL;
 168         if (tm)
 169             *tm = NULL;
 170         if (other)
 171             *other = NULL;
 172     } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
 173         if (keyid)
 174             *keyid = rid->d.rKeyId->subjectKeyIdentifier;
 175         if (tm)
 176             *tm = rid->d.rKeyId->date;
 177         if (other)
 178             *other = rid->d.rKeyId->other;
 179         if (issuer)
 180             *issuer = NULL;
 181         if (sno)
 182             *sno = NULL;
 183     } else
 184         return 0;
 185     return 1;
 186 }
 187
 188 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
 189                                        X509 *cert)
 190 {
 191     CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
 192     if (rid->type == CMS_REK_ISSUER_SERIAL)
 193         return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
 194     else if (rid->type == CMS_REK_KEYIDENTIFIER)
 195         return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
 196     else
 197         return -1;
 198 }
 199
 200 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
 201 {
 202     EVP_PKEY_CTX *pctx;
 203     CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
 204
 205     EVP_PKEY_CTX_free(kari->pctx);
 206     kari->pctx = NULL;
 207     if (!pk)
 208         return 1;
 209     pctx = EVP_PKEY_CTX_new(pk, NULL);
 210     if (!pctx || !EVP_PKEY_derive_init(pctx))
 211         goto err;
 212     kari->pctx = pctx;
 213     return 1;
 214  err:
 215     EVP_PKEY_CTX_free(pctx);
 216     return 0;
 217 }
 218
 219 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
 220 {
 221     if (ri->type == CMS_RECIPINFO_AGREE)
 222         return ri->d.kari->ctx;
 223     return NULL;
 224 }
 225
 226 /*
 227  * Derive KEK and decrypt/encrypt with it to produce either the original CEK
 228  * or the encrypted CEK.
 229  */
 230
 231 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
 232                           const unsigned char *in, size_t inlen,
 233                           CMS_KeyAgreeRecipientInfo *kari, int enc)
 234 {
 235     /* Key encryption key */
 236     unsigned char kek[EVP_MAX_KEY_LENGTH];
 237     size_t keklen;
 238     int rv = 0;
 239     unsigned char *out = NULL;
 240     int outlen;
 241     keklen = EVP_CIPHER_CTX_key_length(kari->ctx);
 242     if (keklen > EVP_MAX_KEY_LENGTH)
 243         return 0;
 244     /* Derive KEK */
 245     if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
 246         goto err;
 247     /* Set KEK in context */
 248     if (!EVP_CipherInit_ex(kari->ctx, NULL, NULL, kek, NULL, enc))
 249         goto err;
 250     /* obtain output length of ciphered key */
 251     if (!EVP_CipherUpdate(kari->ctx, NULL, &outlen, in, inlen))
 252         goto err;
 253     out = OPENSSL_malloc(outlen);
 254     if (out == NULL)
 255         goto err;
 256     if (!EVP_CipherUpdate(kari->ctx, out, &outlen, in, inlen))
 257         goto err;
 258     *pout = out;
 259     *poutlen = (size_t)outlen;
 260     rv = 1;
 261
 262  err:
 263     OPENSSL_cleanse(kek, keklen);
 264     if (!rv)
 265         OPENSSL_free(out);
 266     EVP_CIPHER_CTX_reset(kari->ctx);
 267     /* FIXME: WHY IS kari->pctx freed here?  /RL */
 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     EVP_PKEY_up_ref(pk);
 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 }