2 * Copyright 2006-2016 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
11 #include "internal/cryptlib.h"
12 #include <openssl/x509.h>
13 #include <openssl/ec.h>
14 #include <openssl/rand.h>
15 #include "internal/asn1_int.h"
16 #include "internal/evp_int.h"
19 #define X25519_KEYLEN 32
20 #define X25519_BITS 253
21 #define X25519_SECURITY_BITS 128
24 unsigned char pubkey[X25519_KEYLEN];
25 unsigned char *privkey;
34 /* Setup EVP_PKEY using public, private or generation */
35 static int ecx_key_op(EVP_PKEY *pkey, const X509_ALGOR *palg,
36 const unsigned char *p, int plen, ecx_key_op_t op)
40 if (op != X25519_KEYGEN) {
44 /* Algorithm parameters must be absent */
45 X509_ALGOR_get0(NULL, &ptype, NULL, palg);
46 if (ptype != V_ASN1_UNDEF) {
47 ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
52 if (p == NULL || plen != X25519_KEYLEN) {
53 ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
58 xkey = OPENSSL_zalloc(sizeof(*xkey));
60 ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
64 if (op == X25519_PUBLIC) {
65 memcpy(xkey->pubkey, p, plen);
67 xkey->privkey = OPENSSL_secure_malloc(X25519_KEYLEN);
68 if (xkey->privkey == NULL) {
69 ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
73 if (op == X25519_KEYGEN) {
74 if (RAND_bytes(xkey->privkey, X25519_KEYLEN) <= 0) {
75 OPENSSL_secure_free(xkey->privkey);
79 xkey->privkey[0] &= 248;
80 xkey->privkey[31] &= 127;
81 xkey->privkey[31] |= 64;
83 memcpy(xkey->privkey, p, X25519_KEYLEN);
85 X25519_public_from_private(xkey->pubkey, xkey->privkey);
88 EVP_PKEY_assign(pkey, NID_X25519, xkey);
92 static int ecx_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
94 const X25519_KEY *xkey = pkey->pkey.ptr;
98 ECerr(EC_F_ECX_PUB_ENCODE, EC_R_INVALID_KEY);
102 penc = OPENSSL_memdup(xkey->pubkey, X25519_KEYLEN);
104 ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
108 if (!X509_PUBKEY_set0_param(pk, OBJ_nid2obj(NID_X25519), V_ASN1_UNDEF,
109 NULL, penc, X25519_KEYLEN)) {
111 ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
117 static int ecx_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
119 const unsigned char *p;
123 if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
125 return ecx_key_op(pkey, palg, p, pklen, X25519_PUBLIC);
128 static int ecx_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
130 const X25519_KEY *akey = a->pkey.ptr;
131 const X25519_KEY *bkey = b->pkey.ptr;
133 if (akey == NULL || bkey == NULL)
135 return !CRYPTO_memcmp(akey->pubkey, bkey->pubkey, X25519_KEYLEN);
138 static int ecx_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
140 const unsigned char *p;
142 ASN1_OCTET_STRING *oct = NULL;
143 const X509_ALGOR *palg;
146 if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8))
149 oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
154 p = ASN1_STRING_get0_data(oct);
155 plen = ASN1_STRING_length(oct);
158 rv = ecx_key_op(pkey, palg, p, plen, X25519_PRIVATE);
159 ASN1_OCTET_STRING_free(oct);
163 static int ecx_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
165 const X25519_KEY *xkey = pkey->pkey.ptr;
166 ASN1_OCTET_STRING oct;
167 unsigned char *penc = NULL;
170 if (xkey == NULL || xkey->privkey == NULL) {
171 ECerr(EC_F_ECX_PRIV_ENCODE, EC_R_INVALID_PRIVATE_KEY);
175 oct.data = xkey->privkey;
176 oct.length = X25519_KEYLEN;
179 penclen = i2d_ASN1_OCTET_STRING(&oct, &penc);
181 ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
185 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X25519), 0,
186 V_ASN1_UNDEF, NULL, penc, penclen)) {
187 OPENSSL_clear_free(penc, penclen);
188 ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
195 static int ecx_size(const EVP_PKEY *pkey)
197 return X25519_KEYLEN;
200 static int ecx_bits(const EVP_PKEY *pkey)
205 static int ecx_security_bits(const EVP_PKEY *pkey)
207 return X25519_SECURITY_BITS;
210 static void ecx_free(EVP_PKEY *pkey)
212 X25519_KEY *xkey = pkey->pkey.ptr;
215 OPENSSL_secure_free(xkey->privkey);
219 /* "parameters" are always equal */
220 static int ecx_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
225 static int ecx_key_print(BIO *bp, const EVP_PKEY *pkey, int indent,
226 ASN1_PCTX *ctx, ecx_key_op_t op)
228 const X25519_KEY *xkey = pkey->pkey.ptr;
230 if (op == X25519_PRIVATE) {
231 if (xkey == NULL || xkey->privkey == NULL) {
232 if (BIO_printf(bp, "%*s<INVALID PRIVATE KEY>\n", indent, "") <= 0)
236 if (BIO_printf(bp, "%*sX25519 Private-Key:\n", indent, "") <= 0)
238 if (BIO_printf(bp, "%*spriv:\n", indent, "") <= 0)
240 if (ASN1_buf_print(bp, xkey->privkey, X25519_KEYLEN, indent + 4) == 0)
244 if (BIO_printf(bp, "%*s<INVALID PUBLIC KEY>\n", indent, "") <= 0)
248 if (BIO_printf(bp, "%*sX25519 Public-Key:\n", indent, "") <= 0)
251 if (BIO_printf(bp, "%*spub:\n", indent, "") <= 0)
253 if (ASN1_buf_print(bp, xkey->pubkey, X25519_KEYLEN, indent + 4) == 0)
258 static int ecx_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
261 return ecx_key_print(bp, pkey, indent, ctx, X25519_PRIVATE);
264 static int ecx_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
267 return ecx_key_print(bp, pkey, indent, ctx, X25519_PUBLIC);
270 static int ecx_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
274 case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
275 return ecx_key_op(pkey, NULL, arg2, arg1, X25519_PUBLIC);
277 case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
278 if (pkey->pkey.ptr != NULL) {
279 const X25519_KEY *xkey = pkey->pkey.ptr;
280 unsigned char **ppt = arg2;
281 *ppt = OPENSSL_memdup(xkey->pubkey, X25519_KEYLEN);
283 return X25519_KEYLEN;
287 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
288 *(int *)arg2 = NID_sha256;
297 const EVP_PKEY_ASN1_METHOD ecx25519_asn1_meth = {
302 "OpenSSL X25519 algorithm",
327 static int pkey_ecx_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
329 return ecx_key_op(pkey, NULL, NULL, 0, X25519_KEYGEN);
332 static int pkey_ecx_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
335 const X25519_KEY *pkey, *peerkey;
337 if (ctx->pkey == NULL || ctx->peerkey == NULL) {
338 ECerr(EC_F_PKEY_ECX_DERIVE, EC_R_KEYS_NOT_SET);
341 pkey = ctx->pkey->pkey.ptr;
342 peerkey = ctx->peerkey->pkey.ptr;
343 if (pkey == NULL || pkey->privkey == NULL) {
344 ECerr(EC_F_PKEY_ECX_DERIVE, EC_R_INVALID_PRIVATE_KEY);
347 if (peerkey == NULL) {
348 ECerr(EC_F_PKEY_ECX_DERIVE, EC_R_INVALID_PEER_KEY);
351 *keylen = X25519_KEYLEN;
352 if (key != NULL && X25519(key, pkey->privkey, peerkey->pubkey) == 0)
357 static int pkey_ecx_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
359 /* Only need to handle peer key for derivation */
360 if (type == EVP_PKEY_CTRL_PEER_KEY)
365 const EVP_PKEY_METHOD ecx25519_pkey_meth = {
369 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,