2 * Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "internal/cryptlib.h"
11 #include <openssl/asn1t.h>
12 #include <openssl/pem.h>
13 #include <openssl/x509v3.h>
14 #include <openssl/err.h>
15 #include <openssl/cms.h>
16 #include <openssl/rand.h>
17 #include <openssl/aes.h>
19 #include "internal/asn1_int.h"
21 /* Key Agreement Recipient Info (KARI) routines */
23 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
25 ASN1_OCTET_STRING **pukm)
27 if (ri->type != CMS_RECIPINFO_AGREE) {
28 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
29 CMS_R_NOT_KEY_AGREEMENT);
33 *palg = ri->d.kari->keyEncryptionAlgorithm;
35 *pukm = ri->d.kari->ukm;
39 /* Retrieve recipient encrypted keys from a kari */
41 STACK_OF(CMS_RecipientEncryptedKey)
42 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
44 if (ri->type != CMS_RECIPINFO_AGREE) {
45 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
46 CMS_R_NOT_KEY_AGREEMENT);
49 return ri->d.kari->recipientEncryptedKeys;
52 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
54 ASN1_BIT_STRING **pubkey,
55 ASN1_OCTET_STRING **keyid,
59 CMS_OriginatorIdentifierOrKey *oik;
60 if (ri->type != CMS_RECIPINFO_AGREE) {
61 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
62 CMS_R_NOT_KEY_AGREEMENT);
65 oik = ri->d.kari->originator;
76 if (oik->type == CMS_OIK_ISSUER_SERIAL) {
78 *issuer = oik->d.issuerAndSerialNumber->issuer;
80 *sno = oik->d.issuerAndSerialNumber->serialNumber;
81 } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
83 *keyid = oik->d.subjectKeyIdentifier;
84 } else if (oik->type == CMS_OIK_PUBKEY) {
86 *pubalg = oik->d.originatorKey->algorithm;
88 *pubkey = oik->d.originatorKey->publicKey;
94 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
96 CMS_OriginatorIdentifierOrKey *oik;
97 if (ri->type != CMS_RECIPINFO_AGREE) {
98 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
99 CMS_R_NOT_KEY_AGREEMENT);
102 oik = ri->d.kari->originator;
103 if (oik->type == CMS_OIK_ISSUER_SERIAL)
104 return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
105 else if (oik->type == CMS_OIK_KEYIDENTIFIER)
106 return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
110 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
111 ASN1_OCTET_STRING **keyid,
112 ASN1_GENERALIZEDTIME **tm,
113 CMS_OtherKeyAttribute **other,
114 X509_NAME **issuer, ASN1_INTEGER **sno)
116 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
117 if (rid->type == CMS_REK_ISSUER_SERIAL) {
119 *issuer = rid->d.issuerAndSerialNumber->issuer;
121 *sno = rid->d.issuerAndSerialNumber->serialNumber;
128 } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
130 *keyid = rid->d.rKeyId->subjectKeyIdentifier;
132 *tm = rid->d.rKeyId->date;
134 *other = rid->d.rKeyId->other;
144 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
147 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
148 if (rid->type == CMS_REK_ISSUER_SERIAL)
149 return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
150 else if (rid->type == CMS_REK_KEYIDENTIFIER)
151 return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
156 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
159 CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
161 EVP_PKEY_CTX_free(kari->pctx);
165 pctx = EVP_PKEY_CTX_new(pk, NULL);
166 if (!pctx || !EVP_PKEY_derive_init(pctx))
171 EVP_PKEY_CTX_free(pctx);
175 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
177 if (ri->type == CMS_RECIPINFO_AGREE)
178 return ri->d.kari->ctx;
183 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
184 * or the encrypted CEK.
187 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
188 const unsigned char *in, size_t inlen,
189 CMS_KeyAgreeRecipientInfo *kari, int enc)
191 /* Key encryption key */
192 unsigned char kek[EVP_MAX_KEY_LENGTH];
195 unsigned char *out = NULL;
197 keklen = EVP_CIPHER_CTX_key_length(kari->ctx);
198 if (keklen > EVP_MAX_KEY_LENGTH)
201 if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
203 /* Set KEK in context */
204 if (!EVP_CipherInit_ex(kari->ctx, NULL, NULL, kek, NULL, enc))
206 /* obtain output length of ciphered key */
207 if (!EVP_CipherUpdate(kari->ctx, NULL, &outlen, in, inlen))
209 out = OPENSSL_malloc(outlen);
212 if (!EVP_CipherUpdate(kari->ctx, out, &outlen, in, inlen))
215 *poutlen = (size_t)outlen;
219 OPENSSL_cleanse(kek, keklen);
222 EVP_CIPHER_CTX_reset(kari->ctx);
223 /* FIXME: WHY IS kari->pctx freed here? /RL */
224 EVP_PKEY_CTX_free(kari->pctx);
229 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
230 CMS_RecipientInfo *ri,
231 CMS_RecipientEncryptedKey *rek)
234 unsigned char *enckey = NULL, *cek = NULL;
237 CMS_EncryptedContentInfo *ec;
238 enckeylen = rek->encryptedKey->length;
239 enckey = rek->encryptedKey->data;
240 /* Setup all parameters to derive KEK */
241 if (!cms_env_asn1_ctrl(ri, 1))
243 /* Attempt to decrypt CEK */
244 if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
246 ec = cms->d.envelopedData->encryptedContentInfo;
247 OPENSSL_clear_free(ec->key, ec->keylen);
257 /* Create ephemeral key and initialise context based on it */
258 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
261 EVP_PKEY_CTX *pctx = NULL;
262 EVP_PKEY *ekey = NULL;
264 pctx = EVP_PKEY_CTX_new(pk, NULL);
267 if (EVP_PKEY_keygen_init(pctx) <= 0)
269 if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
271 EVP_PKEY_CTX_free(pctx);
272 pctx = EVP_PKEY_CTX_new(ekey, NULL);
275 if (EVP_PKEY_derive_init(pctx) <= 0)
281 EVP_PKEY_CTX_free(pctx);
286 /* Initialise a ktri based on passed certificate and key */
288 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
289 EVP_PKEY *pk, unsigned int flags)
291 CMS_KeyAgreeRecipientInfo *kari;
292 CMS_RecipientEncryptedKey *rek = NULL;
294 ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
297 ri->type = CMS_RECIPINFO_AGREE;
302 rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
303 if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
304 M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
308 if (flags & CMS_USE_KEYID) {
309 rek->rid->type = CMS_REK_KEYIDENTIFIER;
310 rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
311 if (rek->rid->d.rKeyId == NULL)
313 if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
316 rek->rid->type = CMS_REK_ISSUER_SERIAL;
317 if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
321 /* Create ephemeral key */
322 if (!cms_kari_create_ephemeral_key(kari, pk))
330 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
331 const EVP_CIPHER *cipher)
333 EVP_CIPHER_CTX *ctx = kari->ctx;
334 const EVP_CIPHER *kekcipher;
335 int keylen = EVP_CIPHER_key_length(cipher);
336 /* If a suitable wrap algorithm is already set nothing to do */
337 kekcipher = EVP_CIPHER_CTX_cipher(ctx);
340 if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
345 * Pick a cipher based on content encryption cipher. If it is DES3 use
346 * DES3 wrap otherwise use AES wrap similar to key size.
348 #ifndef OPENSSL_NO_DES
349 if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
350 kekcipher = EVP_des_ede3_wrap();
354 kekcipher = EVP_aes_128_wrap();
355 else if (keylen <= 24)
356 kekcipher = EVP_aes_192_wrap();
358 kekcipher = EVP_aes_256_wrap();
359 return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
362 /* Encrypt content key in key agreement recipient info */
364 int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
365 CMS_RecipientInfo *ri)
367 CMS_KeyAgreeRecipientInfo *kari;
368 CMS_EncryptedContentInfo *ec;
369 CMS_RecipientEncryptedKey *rek;
370 STACK_OF(CMS_RecipientEncryptedKey) *reks;
373 if (ri->type != CMS_RECIPINFO_AGREE) {
374 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
378 reks = kari->recipientEncryptedKeys;
379 ec = cms->d.envelopedData->encryptedContentInfo;
380 /* Initialise wrap algorithm parameters */
381 if (!cms_wrap_init(kari, ec->cipher))
384 * If no originator key set up initialise for ephemeral key the public key
385 * ASN1 structure will set the actual public key value.
387 if (kari->originator->type == -1) {
388 CMS_OriginatorIdentifierOrKey *oik = kari->originator;
389 oik->type = CMS_OIK_PUBKEY;
390 oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
391 if (!oik->d.originatorKey)
394 /* Initialise KDF algorithm */
395 if (!cms_env_asn1_ctrl(ri, 0))
397 /* For each rek, derive KEK, encrypt CEK */
398 for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
399 unsigned char *enckey;
401 rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
402 if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
404 if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
407 ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);