1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2  * project 2006.
3  */
4 /* ====================================================================
5  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  *
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  *
19  * 3. All advertising materials mentioning features or use of this
20  *    software must display the following acknowledgment:
21  *    "This product includes software developed by the OpenSSL Project
22  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
23  *
24  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
25  *    endorse or promote products derived from this software without
26  *    prior written permission. For written permission, please contact
27  *    licensing@OpenSSL.org.
28  *
29  * 5. Products derived from this software may not be called "OpenSSL"
30  *    nor may "OpenSSL" appear in their names without prior written
31  *    permission of the OpenSSL Project.
32  *
33  * 6. Redistributions of any form whatsoever must retain the following
34  *    acknowledgment:
35  *    "This product includes software developed by the OpenSSL Project
36  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
37  *
38  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
39  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
41  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
42  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
47  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
49  * OF THE POSSIBILITY OF SUCH DAMAGE.
50  * ====================================================================
51  *
52  * This product includes cryptographic software written by Eric Young
53  * (eay@cryptsoft.com).  This product includes software written by Tim
54  * Hudson (tjh@cryptsoft.com). */
55 
56 #include <openssl/evp.h>
57 
58 #include <string.h>
59 
60 #include <openssl/bn.h>
61 #include <openssl/digest.h>
62 #include <openssl/ec.h>
63 #include <openssl/ec_key.h>
64 #include <openssl/ecdh.h>
65 #include <openssl/ecdsa.h>
66 #include <openssl/err.h>
67 #include <openssl/mem.h>
68 #include <openssl/nid.h>
69 
70 #include "internal.h"
71 #include "../fipsmodule/ec/internal.h"
72 #include "../internal.h"
73 
74 
75 typedef struct {
76   // message digest
77   const EVP_MD *md;
78   EC_GROUP *gen_group;
79 } EC_PKEY_CTX;
80 
81 
pkey_ec_init(EVP_PKEY_CTX * ctx)82 static int pkey_ec_init(EVP_PKEY_CTX *ctx) {
83   EC_PKEY_CTX *dctx;
84   dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX));
85   if (!dctx) {
86     return 0;
87   }
88   OPENSSL_memset(dctx, 0, sizeof(EC_PKEY_CTX));
89 
90   ctx->data = dctx;
91 
92   return 1;
93 }
94 
pkey_ec_copy(EVP_PKEY_CTX * dst,EVP_PKEY_CTX * src)95 static int pkey_ec_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) {
96   EC_PKEY_CTX *dctx, *sctx;
97   if (!pkey_ec_init(dst)) {
98     return 0;
99   }
100   sctx = src->data;
101   dctx = dst->data;
102 
103   dctx->md = sctx->md;
104 
105   return 1;
106 }
107 
pkey_ec_cleanup(EVP_PKEY_CTX * ctx)108 static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx) {
109   EC_PKEY_CTX *dctx = ctx->data;
110   if (!dctx) {
111     return;
112   }
113 
114   EC_GROUP_free(dctx->gen_group);
115   OPENSSL_free(dctx);
116 }
117 
pkey_ec_sign(EVP_PKEY_CTX * ctx,uint8_t * sig,size_t * siglen,const uint8_t * tbs,size_t tbslen)118 static int pkey_ec_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *siglen,
119                         const uint8_t *tbs, size_t tbslen) {
120   const EC_KEY *ec = ctx->pkey->pkey;
121   if (!sig) {
122     *siglen = ECDSA_size(ec);
123     return 1;
124   } else if (*siglen < (size_t)ECDSA_size(ec)) {
125     OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
126     return 0;
127   }
128 
129   unsigned int sltmp;
130   if (!ECDSA_sign(0, tbs, tbslen, sig, &sltmp, ec)) {
131     return 0;
132   }
133   *siglen = (size_t)sltmp;
134   return 1;
135 }
136 
pkey_ec_verify(EVP_PKEY_CTX * ctx,const uint8_t * sig,size_t siglen,const uint8_t * tbs,size_t tbslen)137 static int pkey_ec_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t siglen,
138                           const uint8_t *tbs, size_t tbslen) {
139   const EC_KEY *ec_key = ctx->pkey->pkey;
140   return ECDSA_verify(0, tbs, tbslen, sig, siglen, ec_key);
141 }
142 
pkey_ec_derive(EVP_PKEY_CTX * ctx,uint8_t * key,size_t * keylen)143 static int pkey_ec_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
144                           size_t *keylen) {
145   if (!ctx->pkey || !ctx->peerkey) {
146     OPENSSL_PUT_ERROR(EVP, EVP_R_KEYS_NOT_SET);
147     return 0;
148   }
149 
150   const EC_KEY *eckey = ctx->pkey->pkey;
151   if (!key) {
152     const EC_GROUP *group;
153     group = EC_KEY_get0_group(eckey);
154     *keylen = (EC_GROUP_get_degree(group) + 7) / 8;
155     return 1;
156   }
157 
158   const EC_KEY *eckey_peer = ctx->peerkey->pkey;
159   const EC_POINT *pubkey = EC_KEY_get0_public_key(eckey_peer);
160 
161   // NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is
162   // not an error, the result is truncated.
163   size_t outlen = *keylen;
164   int ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
165   if (ret < 0) {
166     return 0;
167   }
168   *keylen = ret;
169   return 1;
170 }
171 
pkey_ec_ctrl(EVP_PKEY_CTX * ctx,int type,int p1,void * p2)172 static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) {
173   EC_PKEY_CTX *dctx = ctx->data;
174 
175   switch (type) {
176     case EVP_PKEY_CTRL_MD: {
177       const EVP_MD *md = p2;
178       int md_type = EVP_MD_type(md);
179       if (md_type != NID_sha1 && md_type != NID_sha224 &&
180           md_type != NID_sha256 && md_type != NID_sha384 &&
181           md_type != NID_sha512) {
182         OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_DIGEST_TYPE);
183         return 0;
184       }
185       dctx->md = md;
186       return 1;
187     }
188 
189     case EVP_PKEY_CTRL_GET_MD:
190       *(const EVP_MD **)p2 = dctx->md;
191       return 1;
192 
193     case EVP_PKEY_CTRL_PEER_KEY:
194       // Default behaviour is OK
195       return 1;
196 
197     case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID: {
198       EC_GROUP *group = EC_GROUP_new_by_curve_name(p1);
199       if (group == NULL) {
200         return 0;
201       }
202       EC_GROUP_free(dctx->gen_group);
203       dctx->gen_group = group;
204       return 1;
205     }
206 
207     default:
208       OPENSSL_PUT_ERROR(EVP, EVP_R_COMMAND_NOT_SUPPORTED);
209       return 0;
210   }
211 }
212 
pkey_ec_keygen(EVP_PKEY_CTX * ctx,EVP_PKEY * pkey)213 static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
214   EC_PKEY_CTX *dctx = ctx->data;
215   const EC_GROUP *group = dctx->gen_group;
216   if (group == NULL) {
217     if (ctx->pkey == NULL) {
218       OPENSSL_PUT_ERROR(EVP, EVP_R_NO_PARAMETERS_SET);
219       return 0;
220     }
221     group = EC_KEY_get0_group(ctx->pkey->pkey);
222   }
223   EC_KEY *ec = EC_KEY_new();
224   if (ec == NULL ||
225       !EC_KEY_set_group(ec, group) ||
226       !EC_KEY_generate_key(ec)) {
227     EC_KEY_free(ec);
228     return 0;
229   }
230   EVP_PKEY_assign_EC_KEY(pkey, ec);
231   return 1;
232 }
233 
pkey_ec_paramgen(EVP_PKEY_CTX * ctx,EVP_PKEY * pkey)234 static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
235   EC_PKEY_CTX *dctx = ctx->data;
236   if (dctx->gen_group == NULL) {
237     OPENSSL_PUT_ERROR(EVP, EVP_R_NO_PARAMETERS_SET);
238     return 0;
239   }
240   EC_KEY *ec = EC_KEY_new();
241   if (ec == NULL ||
242       !EC_KEY_set_group(ec, dctx->gen_group)) {
243     EC_KEY_free(ec);
244     return 0;
245   }
246   EVP_PKEY_assign_EC_KEY(pkey, ec);
247   return 1;
248 }
249 
250 const EVP_PKEY_METHOD ec_pkey_meth = {
251     EVP_PKEY_EC,
252     pkey_ec_init,
253     pkey_ec_copy,
254     pkey_ec_cleanup,
255     pkey_ec_keygen,
256     pkey_ec_sign,
257     NULL /* sign_message */,
258     pkey_ec_verify,
259     NULL /* verify_message */,
260     NULL /* verify_recover */,
261     NULL /* encrypt */,
262     NULL /* decrypt */,
263     pkey_ec_derive,
264     pkey_ec_paramgen,
265     pkey_ec_ctrl,
266 };
267 
EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX * ctx,int nid)268 int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid) {
269   return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_EC, EVP_PKEY_OP_TYPE_GEN,
270                            EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID, nid, NULL);
271 }
272 
EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX * ctx,int encoding)273 int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int encoding) {
274   // BoringSSL only supports named curve syntax.
275   if (encoding != OPENSSL_EC_NAMED_CURVE) {
276     OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_PARAMETERS);
277     return 0;
278   }
279   return 1;
280 }
281