1 /*
2  * Copyright 2020-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (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
8  */
9 
10 #include <string.h>
11 #include <openssl/core_names.h>
12 #include <openssl/params.h>
13 #include <openssl/ec.h>
14 #include <openssl/rand.h>
15 #include <openssl/err.h>
16 #ifndef FIPS_MODULE
17 # include <openssl/x509.h>
18 #endif
19 #include "crypto/ecx.h"
20 #include "ecx_backend.h"
21 
22 /*
23  * The intention with the "backend" source file is to offer backend support
24  * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
25  * implementations alike.
26  */
27 
ossl_ecx_public_from_private(ECX_KEY * key)28 int ossl_ecx_public_from_private(ECX_KEY *key)
29 {
30     switch (key->type) {
31     case ECX_KEY_TYPE_X25519:
32         ossl_x25519_public_from_private(key->pubkey, key->privkey);
33         break;
34     case ECX_KEY_TYPE_ED25519:
35         if (!ossl_ed25519_public_from_private(key->libctx, key->pubkey,
36                                               key->privkey, key->propq)) {
37             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
38             return 0;
39         }
40         break;
41     case ECX_KEY_TYPE_X448:
42         ossl_x448_public_from_private(key->pubkey, key->privkey);
43         break;
44     case ECX_KEY_TYPE_ED448:
45         if (!ossl_ed448_public_from_private(key->libctx, key->pubkey,
46                                             key->privkey, key->propq)) {
47             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
48             return 0;
49         }
50         break;
51     }
52     return 1;
53 }
54 
ossl_ecx_key_fromdata(ECX_KEY * ecx,const OSSL_PARAM params[],int include_private)55 int ossl_ecx_key_fromdata(ECX_KEY *ecx, const OSSL_PARAM params[],
56                           int include_private)
57 {
58     size_t privkeylen = 0, pubkeylen = 0;
59     const OSSL_PARAM *param_priv_key = NULL, *param_pub_key;
60     unsigned char *pubkey;
61 
62     if (ecx == NULL)
63         return 0;
64 
65     param_pub_key = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
66     if (include_private)
67         param_priv_key =
68             OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
69 
70     if (param_pub_key == NULL && param_priv_key == NULL)
71         return 0;
72 
73     if (param_priv_key != NULL
74         && !OSSL_PARAM_get_octet_string(param_priv_key,
75                                         (void **)&ecx->privkey, ecx->keylen,
76                                         &privkeylen))
77         return 0;
78 
79     pubkey = ecx->pubkey;
80     if (param_pub_key != NULL
81         && !OSSL_PARAM_get_octet_string(param_pub_key,
82                                         (void **)&pubkey,
83                                          sizeof(ecx->pubkey), &pubkeylen))
84         return 0;
85 
86     if ((param_pub_key != NULL && pubkeylen != ecx->keylen)
87         || (param_priv_key != NULL && privkeylen != ecx->keylen))
88         return 0;
89 
90     if (param_pub_key == NULL && !ossl_ecx_public_from_private(ecx))
91         return 0;
92 
93     ecx->haspubkey = 1;
94 
95     return 1;
96 }
97 
ossl_ecx_key_dup(const ECX_KEY * key,int selection)98 ECX_KEY *ossl_ecx_key_dup(const ECX_KEY *key, int selection)
99 {
100     ECX_KEY *ret = OPENSSL_zalloc(sizeof(*ret));
101 
102     if (ret == NULL) {
103         ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
104         return NULL;
105     }
106 
107     ret->lock = CRYPTO_THREAD_lock_new();
108     if (ret->lock == NULL) {
109         OPENSSL_free(ret);
110         return NULL;
111     }
112 
113     ret->libctx = key->libctx;
114     ret->haspubkey = key->haspubkey;
115     ret->keylen = key->keylen;
116     ret->type = key->type;
117     ret->references = 1;
118 
119     if (key->propq != NULL) {
120         ret->propq = OPENSSL_strdup(key->propq);
121         if (ret->propq == NULL)
122             goto err;
123     }
124 
125     if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
126         memcpy(ret->pubkey, key->pubkey, sizeof(ret->pubkey));
127 
128     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
129         && key->privkey != NULL) {
130         if (ossl_ecx_key_allocate_privkey(ret) == NULL)
131             goto err;
132         memcpy(ret->privkey, key->privkey, ret->keylen);
133     }
134 
135     return ret;
136 
137 err:
138     ossl_ecx_key_free(ret);
139     ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
140     return NULL;
141 }
142 
143 #ifndef FIPS_MODULE
ossl_ecx_key_op(const X509_ALGOR * palg,const unsigned char * p,int plen,int id,ecx_key_op_t op,OSSL_LIB_CTX * libctx,const char * propq)144 ECX_KEY *ossl_ecx_key_op(const X509_ALGOR *palg,
145                          const unsigned char *p, int plen,
146                          int id, ecx_key_op_t op,
147                          OSSL_LIB_CTX *libctx, const char *propq)
148 {
149     ECX_KEY *key = NULL;
150     unsigned char *privkey, *pubkey;
151 
152     if (op != KEY_OP_KEYGEN) {
153         if (palg != NULL) {
154             int ptype;
155 
156             /* Algorithm parameters must be absent */
157             X509_ALGOR_get0(NULL, &ptype, NULL, palg);
158             if (ptype != V_ASN1_UNDEF) {
159                 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
160                 return 0;
161             }
162             if (id == EVP_PKEY_NONE)
163                 id = OBJ_obj2nid(palg->algorithm);
164             else if (id != OBJ_obj2nid(palg->algorithm)) {
165                 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
166                 return 0;
167             }
168         }
169 
170         if (p == NULL || id == EVP_PKEY_NONE || plen != KEYLENID(id)) {
171             ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
172             return 0;
173         }
174     }
175 
176     key = ossl_ecx_key_new(libctx, KEYNID2TYPE(id), 1, propq);
177     if (key == NULL) {
178         ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
179         return 0;
180     }
181     pubkey = key->pubkey;
182 
183     if (op == KEY_OP_PUBLIC) {
184         memcpy(pubkey, p, plen);
185     } else {
186         privkey = ossl_ecx_key_allocate_privkey(key);
187         if (privkey == NULL) {
188             ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
189             goto err;
190         }
191         if (op == KEY_OP_KEYGEN) {
192             if (id != EVP_PKEY_NONE) {
193                 if (RAND_priv_bytes_ex(libctx, privkey, KEYLENID(id), 0) <= 0)
194                     goto err;
195                 if (id == EVP_PKEY_X25519) {
196                     privkey[0] &= 248;
197                     privkey[X25519_KEYLEN - 1] &= 127;
198                     privkey[X25519_KEYLEN - 1] |= 64;
199                 } else if (id == EVP_PKEY_X448) {
200                     privkey[0] &= 252;
201                     privkey[X448_KEYLEN - 1] |= 128;
202                 }
203             }
204         } else {
205             memcpy(privkey, p, KEYLENID(id));
206         }
207         if (!ossl_ecx_public_from_private(key)) {
208             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
209             goto err;
210         }
211     }
212 
213     return key;
214  err:
215     ossl_ecx_key_free(key);
216     return NULL;
217 }
218 
ossl_ecx_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO * p8inf,OSSL_LIB_CTX * libctx,const char * propq)219 ECX_KEY *ossl_ecx_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
220                                  OSSL_LIB_CTX *libctx, const char *propq)
221 {
222     ECX_KEY *ecx = NULL;
223     const unsigned char *p;
224     int plen;
225     ASN1_OCTET_STRING *oct = NULL;
226     const X509_ALGOR *palg;
227 
228     if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8inf))
229         return 0;
230 
231     oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
232     if (oct == NULL) {
233         p = NULL;
234         plen = 0;
235     } else {
236         p = ASN1_STRING_get0_data(oct);
237         plen = ASN1_STRING_length(oct);
238     }
239 
240     /*
241      * EVP_PKEY_NONE means that ecx_key_op() has to figure out the key type
242      * on its own.
243      */
244     ecx = ossl_ecx_key_op(palg, p, plen, EVP_PKEY_NONE, KEY_OP_PRIVATE,
245                           libctx, propq);
246     ASN1_OCTET_STRING_free(oct);
247     return ecx;
248 }
249 #endif
250