cms_kari.c revision 312826 
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
66DECLARE_ASN1_ITEM(CMS_KeyAgreeRecipientInfo)
67DECLARE_ASN1_ITEM(CMS_RecipientEncryptedKey)
68DECLARE_ASN1_ITEM(CMS_OriginatorPublicKey)
69DECLARE_ASN1_ITEM(CMS_RecipientKeyIdentifier)
70
71/* Key Agreement Recipient Info (KARI) routines */
72
73int 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
91STACK_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
102int 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
144int 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
160int 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
194int 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
206int 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    if (pctx)
223        EVP_PKEY_CTX_free(pctx);
224    return 0;
225}
226
227EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
228{
229    if (ri->type == CMS_RECIPINFO_AGREE)
230        return &ri->d.kari->ctx;
231    return NULL;
232}
233
234/*
235 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
236 * or the encrypted CEK.
237 */
238
239static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
240                          const unsigned char *in, size_t inlen,
241                          CMS_KeyAgreeRecipientInfo *kari, int enc)
242{
243    /* Key encryption key */
244    unsigned char kek[EVP_MAX_KEY_LENGTH];
245    size_t keklen;
246    int rv = 0;
247    unsigned char *out = NULL;
248    int outlen;
249    keklen = EVP_CIPHER_CTX_key_length(&kari->ctx);
250    if (keklen > EVP_MAX_KEY_LENGTH)
251        return 0;
252    /* Derive KEK */
253    if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
254        goto err;
255    /* Set KEK in context */
256    if (!EVP_CipherInit_ex(&kari->ctx, NULL, NULL, kek, NULL, enc))
257        goto err;
258    /* obtain output length of ciphered key */
259    if (!EVP_CipherUpdate(&kari->ctx, NULL, &outlen, in, inlen))
260        goto err;
261    out = OPENSSL_malloc(outlen);
262    if (!out)
263        goto err;
264    if (!EVP_CipherUpdate(&kari->ctx, out, &outlen, in, inlen))
265        goto err;
266    *pout = out;
267    *poutlen = (size_t)outlen;
268    rv = 1;
269
270 err:
271    OPENSSL_cleanse(kek, keklen);
272    if (!rv && out)
273        OPENSSL_free(out);
274    EVP_CIPHER_CTX_cleanup(&kari->ctx);
275    EVP_PKEY_CTX_free(kari->pctx);
276    kari->pctx = NULL;
277    return rv;
278}
279
280int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
281                                   CMS_RecipientInfo *ri,
282                                   CMS_RecipientEncryptedKey *rek)
283{
284    int rv = 0;
285    unsigned char *enckey = NULL, *cek = NULL;
286    size_t enckeylen;
287    size_t ceklen;
288    CMS_EncryptedContentInfo *ec;
289    enckeylen = rek->encryptedKey->length;
290    enckey = rek->encryptedKey->data;
291    /* Setup all parameters to derive KEK */
292    if (!cms_env_asn1_ctrl(ri, 1))
293        goto err;
294    /* Attempt to decrypt CEK */
295    if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
296        goto err;
297    ec = cms->d.envelopedData->encryptedContentInfo;
298    if (ec->key) {
299        OPENSSL_cleanse(ec->key, ec->keylen);
300        OPENSSL_free(ec->key);
301    }
302    ec->key = cek;
303    ec->keylen = ceklen;
304    cek = NULL;
305    rv = 1;
306 err:
307    if (cek)
308        OPENSSL_free(cek);
309    return rv;
310}
311
312/* Create ephemeral key and initialise context based on it */
313static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
314                                         EVP_PKEY *pk)
315{
316    EVP_PKEY_CTX *pctx = NULL;
317    EVP_PKEY *ekey = NULL;
318    int rv = 0;
319    pctx = EVP_PKEY_CTX_new(pk, NULL);
320    if (!pctx)
321        goto err;
322    if (EVP_PKEY_keygen_init(pctx) <= 0)
323        goto err;
324    if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
325        goto err;
326    EVP_PKEY_CTX_free(pctx);
327    pctx = EVP_PKEY_CTX_new(ekey, NULL);
328    if (!pctx)
329        goto err;
330    if (EVP_PKEY_derive_init(pctx) <= 0)
331        goto err;
332    kari->pctx = pctx;
333    rv = 1;
334 err:
335    if (!rv && pctx)
336        EVP_PKEY_CTX_free(pctx);
337    if (ekey)
338        EVP_PKEY_free(ekey);
339    return rv;
340}
341
342/* Initialise a ktri based on passed certificate and key */
343
344int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip,
345                                EVP_PKEY *pk, unsigned int flags)
346{
347    CMS_KeyAgreeRecipientInfo *kari;
348    CMS_RecipientEncryptedKey *rek = NULL;
349
350    ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
351    if (!ri->d.kari)
352        return 0;
353    ri->type = CMS_RECIPINFO_AGREE;
354
355    kari = ri->d.kari;
356    kari->version = 3;
357
358    rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
359    if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
360        M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
361        return 0;
362    }
363
364    if (flags & CMS_USE_KEYID) {
365        rek->rid->type = CMS_REK_KEYIDENTIFIER;
366        rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
367        if (rek->rid->d.rKeyId == NULL)
368            return 0;
369        if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
370            return 0;
371    } else {
372        rek->rid->type = CMS_REK_ISSUER_SERIAL;
373        if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
374            return 0;
375    }
376
377    /* Create ephemeral key */
378    if (!cms_kari_create_ephemeral_key(kari, pk))
379        return 0;
380
381    CRYPTO_add(&pk->references, 1, CRYPTO_LOCK_EVP_PKEY);
382    rek->pkey = pk;
383    return 1;
384}
385
386static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
387                         const EVP_CIPHER *cipher)
388{
389    EVP_CIPHER_CTX *ctx = &kari->ctx;
390    const EVP_CIPHER *kekcipher;
391    int keylen = EVP_CIPHER_key_length(cipher);
392    /* If a suitable wrap algorithm is already set nothing to do */
393    kekcipher = EVP_CIPHER_CTX_cipher(ctx);
394
395    if (kekcipher) {
396        if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
397            return 0;
398        return 1;
399    }
400    /*
401     * Pick a cipher based on content encryption cipher. If it is DES3 use
402     * DES3 wrap otherwise use AES wrap similar to key size.
403     */
404#ifndef OPENSSL_NO_DES
405    if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
406        kekcipher = EVP_des_ede3_wrap();
407    else
408#endif
409    if (keylen <= 16)
410        kekcipher = EVP_aes_128_wrap();
411    else if (keylen <= 24)
412        kekcipher = EVP_aes_192_wrap();
413    else
414        kekcipher = EVP_aes_256_wrap();
415    return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
416}
417
418/* Encrypt content key in key agreement recipient info */
419
420int cms_RecipientInfo_kari_encrypt(CMS_ContentInfo *cms,
421                                   CMS_RecipientInfo *ri)
422{
423    CMS_KeyAgreeRecipientInfo *kari;
424    CMS_EncryptedContentInfo *ec;
425    CMS_RecipientEncryptedKey *rek;
426    STACK_OF(CMS_RecipientEncryptedKey) *reks;
427    int i;
428
429    if (ri->type != CMS_RECIPINFO_AGREE) {
430        CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
431        return 0;
432    }
433    kari = ri->d.kari;
434    reks = kari->recipientEncryptedKeys;
435    ec = cms->d.envelopedData->encryptedContentInfo;
436    /* Initialise wrap algorithm parameters */
437    if (!cms_wrap_init(kari, ec->cipher))
438        return 0;
439    /*
440     * If no orignator key set up initialise for ephemeral key the public key
441     * ASN1 structure will set the actual public key value.
442     */
443    if (kari->originator->type == -1) {
444        CMS_OriginatorIdentifierOrKey *oik = kari->originator;
445        oik->type = CMS_OIK_PUBKEY;
446        oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
447        if (!oik->d.originatorKey)
448            return 0;
449    }
450    /* Initialise KDF algorithm */
451    if (!cms_env_asn1_ctrl(ri, 0))
452        return 0;
453    /* For each rek, derive KEK, encrypt CEK */
454    for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
455        unsigned char *enckey;
456        size_t enckeylen;
457        rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
458        if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
459            return 0;
460        if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
461                            kari, 1))
462            return 0;
463        ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);
464    }
465
466    return 1;
467
468}
469