blob: a4c9136fd00ade97f259780c699950bfb34ea5c7 [file] [log] [blame]
/* Copyright (c) 2019, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/evp.h>
#include <openssl/curve25519.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "internal.h"
// X25519 has no parameters to copy.
static int pkey_x25519_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) { return 1; }
static int pkey_x25519_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
X25519_KEY *key = OPENSSL_malloc(sizeof(X25519_KEY));
if (key == NULL) {
return 0;
}
evp_pkey_set_method(pkey, &x25519_asn1_meth);
X25519_keypair(key->pub, key->priv);
key->has_private = 1;
OPENSSL_free(pkey->pkey);
pkey->pkey = key;
return 1;
}
static int pkey_x25519_derive(EVP_PKEY_CTX *ctx, uint8_t *out,
size_t *out_len) {
if (ctx->pkey == NULL || ctx->peerkey == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_KEYS_NOT_SET);
return 0;
}
const X25519_KEY *our_key = ctx->pkey->pkey;
const X25519_KEY *peer_key = ctx->peerkey->pkey;
if (our_key == NULL || peer_key == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_KEYS_NOT_SET);
return 0;
}
if (!our_key->has_private) {
OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
return 0;
}
if (out != NULL) {
if (*out_len < 32) {
OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
return 0;
}
if (!X25519(out, our_key->priv, peer_key->pub)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_PEER_KEY);
return 0;
}
}
*out_len = 32;
return 1;
}
static int pkey_x25519_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) {
switch (type) {
case EVP_PKEY_CTRL_PEER_KEY:
// |EVP_PKEY_derive_set_peer| requires the key implement this command,
// even if it is a no-op.
return 1;
default:
OPENSSL_PUT_ERROR(EVP, EVP_R_COMMAND_NOT_SUPPORTED);
return 0;
}
}
const EVP_PKEY_METHOD x25519_pkey_meth = {
EVP_PKEY_X25519,
NULL /* init */,
pkey_x25519_copy,
NULL /* cleanup */,
pkey_x25519_keygen,
NULL /* sign */,
NULL /* sign_message */,
NULL /* verify */,
NULL /* verify_message */,
NULL /* verify_recover */,
NULL /* encrypt */,
NULL /* decrypt */,
pkey_x25519_derive,
NULL /* paramgen */,
pkey_x25519_ctrl,
};