WolfSSL
/
wolfssl
mirror of https://github.com/wolfSSL/wolfssl.git
1
0
Fork 0
Code Issues Releases Wiki Activity
wolfssl/wolfcrypt/src/curve25519.c

409 lines
11 KiB
C
Raw Blame History

/* curve25519.c
*
* Copyright (C) 2006-2015 wolfSSL Inc.
*
* This file is part of wolfSSL. (formerly known as CyaSSL)
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/* Based On Daniel J Bernstein's curve25519 Public Domain ref10 work. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <wolfssl/wolfcrypt/settings.h>
#ifdef HAVE_CURVE25519
#include <wolfssl/wolfcrypt/curve25519.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#ifdef NO_INLINE
#include <wolfssl/wolfcrypt/misc.h>
#else
#include <wolfcrypt/src/misc.c>
#endif
const curve25519_set_type curve25519_sets[] = {
{
32,
"CURVE25519",
}
};
int wc_curve25519_make_key(WC_RNG* rng, int keysize, curve25519_key* key)
{
unsigned char basepoint[CURVE25519_KEYSIZE] = {9};
int ret;
if (key == NULL || rng == NULL)
return BAD_FUNC_ARG;
/* currently only a key size of 32 bytes is used */
if (keysize != CURVE25519_KEYSIZE)
return ECC_BAD_ARG_E;
/* random number for private key */
ret = wc_RNG_GenerateBlock(rng, key->k.point, keysize);
if (ret != 0)
return ret;
/* Clamp the private key */
key->k.point[0] &= 248;
key->k.point[CURVE25519_KEYSIZE-1] &= 63; /* same &=127 because |=64 after */
key->k.point[CURVE25519_KEYSIZE-1] |= 64;
/* compute public key */
ret = curve25519(key->p.point, key->k.point, basepoint);
if (ret != 0) {
ForceZero(key->k.point, keysize);
ForceZero(key->p.point, keysize);
return ret;
}
return ret;
}
#ifdef HAVE_CURVE25519_SHARED_SECRET
int wc_curve25519_shared_secret(curve25519_key* private_key,
curve25519_key* public_key,
byte* out, word32* outlen)
{
return wc_curve25519_shared_secret_ex(private_key, public_key,
out, outlen, EC25519_BIG_ENDIAN);
}
int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
curve25519_key* public_key,
byte* out, word32* outlen, int endian)
{
unsigned char o[CURVE25519_KEYSIZE];
int ret = 0;
/* sanity check */
if (private_key == NULL || public_key == NULL ||
out == NULL || outlen == NULL || *outlen < CURVE25519_KEYSIZE)
return BAD_FUNC_ARG;
/* avoid implementation fingerprinting */
if (public_key->p.point[CURVE25519_KEYSIZE-1] > 0x7F)
return ECC_BAD_ARG_E;
ret = curve25519(o, private_key->k.point, public_key->p.point);
if (ret != 0) {
ForceZero(o, CURVE25519_KEYSIZE);
return ret;
}
if (endian == EC25519_BIG_ENDIAN) {
int i;
/* put shared secret key in Big Endian format */
for (i = 0; i < CURVE25519_KEYSIZE; i++)
out[i] = o[CURVE25519_KEYSIZE - i -1];
}
else /* put shared secret key in Little Endian format */
XMEMCPY(out, o, CURVE25519_KEYSIZE);
*outlen = CURVE25519_KEYSIZE;
ForceZero(o, sizeof(o));
return ret;
}
#endif /* HAVE_CURVE25519_SHARED_SECRET */
#ifdef HAVE_CURVE25519_KEY_EXPORT
/* export curve25519 public key (Big endian)
* return 0 on success */
int wc_curve25519_export_public(curve25519_key* key, byte* out, word32* outLen)
{
return wc_curve25519_export_public_ex(key, out, outLen, EC25519_BIG_ENDIAN);
}
/* export curve25519 public key (Big or Little endian)
* return 0 on success */
int wc_curve25519_export_public_ex(curve25519_key* key, byte* out,
word32* outLen, int endian)
{
word32 keySz;
if (key == NULL || out == NULL || outLen == NULL)
return BAD_FUNC_ARG;
/* check size of outgoing key */
keySz = wc_curve25519_size(key);
/* check and set outgoing key size */
if (*outLen < keySz) {
*outLen = keySz;
return ECC_BAD_ARG_E;
}
*outLen = keySz;
if (endian == EC25519_BIG_ENDIAN) {
int i;
/* read keys in Big Endian format */
for (i = 0; i < CURVE25519_KEYSIZE; i++)
out[i] = key->p.point[CURVE25519_KEYSIZE - i - 1];
}
else
XMEMCPY(out, key->p.point, keySz);
return 0;
}
#endif /* HAVE_CURVE25519_KEY_EXPORT */
#ifdef HAVE_CURVE25519_KEY_IMPORT
/* import curve25519 public key (Big endian)
* return 0 on success */
int wc_curve25519_import_public(const byte* in, word32 inLen,
curve25519_key* key)
{
return wc_curve25519_import_public_ex(in, inLen, key, EC25519_BIG_ENDIAN);
}
/* import curve25519 public key (Big or Little endian)
* return 0 on success */
int wc_curve25519_import_public_ex(const byte* in, word32 inLen,
curve25519_key* key, int endian)
{
word32 keySz;
/* sanity check */
if (key == NULL || in == NULL)
return BAD_FUNC_ARG;
/* check size of incoming keys */
keySz = wc_curve25519_size(key);
if (inLen != keySz)
return ECC_BAD_ARG_E;
if (endian == EC25519_BIG_ENDIAN) {
int i;
/* read keys in Big Endian format */
for (i = 0; i < CURVE25519_KEYSIZE; i++)
key->p.point[i] = in[CURVE25519_KEYSIZE - i - 1];
}
else
XMEMCPY(key->p.point, in, inLen);
key->dp = &curve25519_sets[0];
return 0;
}
#endif /* HAVE_CURVE25519_KEY_IMPORT */
#ifdef HAVE_CURVE25519_KEY_EXPORT
/* export curve25519 private key only raw (Big endian)
* outLen is in/out size
* return 0 on success */
int wc_curve25519_export_private_raw(curve25519_key* key, byte* out,
word32* outLen)
{
return wc_curve25519_export_private_raw_ex(key, out, outLen,
EC25519_BIG_ENDIAN);
}
/* export curve25519 private key only raw (Big or Little endian)
* outLen is in/out size
* return 0 on success */
int wc_curve25519_export_private_raw_ex(curve25519_key* key, byte* out,
word32* outLen, int endian)
{
word32 keySz;
/* sanity check */
if (key == NULL || out == NULL || outLen == NULL)
return BAD_FUNC_ARG;
/* check size of outgoing buffer */
keySz = wc_curve25519_size(key);
if (*outLen < keySz) {
*outLen = keySz;
return ECC_BAD_ARG_E;
}
*outLen = keySz;
if (endian == EC25519_BIG_ENDIAN) {
int i;
/* put the key in Big Endian format */
for (i = 0; i < CURVE25519_KEYSIZE; i++)
out[i] = key->k.point[CURVE25519_KEYSIZE - i - 1];
}
else
XMEMCPY(out, key->k.point, keySz);
return 0;
}
/* curve25519 key pair export (Big or Little endian)
* return 0 on success */
int wc_curve25519_export_key_raw(curve25519_key* key,
byte* priv, word32 *privSz,
byte* pub, word32 *pubSz)
{
return wc_curve25519_export_key_raw_ex(key, priv, privSz,
pub, pubSz, EC25519_BIG_ENDIAN);
}
/* curve25519 key pair export (Big or Little endian)
* return 0 on success */
int wc_curve25519_export_key_raw_ex(curve25519_key* key,
byte* priv, word32 *privSz,
byte* pub, word32 *pubSz,
int endian)
{
int ret;
/* export private part */
ret = wc_curve25519_export_private_raw_ex(key, priv, privSz, endian);
if (ret != 0)
return ret;
/* export public part */
return wc_curve25519_export_public_ex(key, pub, pubSz, endian);
}
#endif /* HAVE_CURVE25519_KEY_EXPORT */
#ifdef HAVE_CURVE25519_KEY_IMPORT
/* curve25519 private key import (Big endian)
* Public key to match private key needs to be imported too
* return 0 on success */
int wc_curve25519_import_private_raw(const byte* priv, word32 privSz,
const byte* pub, word32 pubSz,
curve25519_key* key)
{
return wc_curve25519_import_private_raw_ex(priv, privSz, pub, pubSz,
key, EC25519_BIG_ENDIAN);
}
/* curve25519 private key import (Big or Little endian)
* Public key to match private key needs to be imported too
* return 0 on success */
int wc_curve25519_import_private_raw_ex(const byte* priv, word32 privSz,
const byte* pub, word32 pubSz,
curve25519_key* key, int endian)
{
int ret;
/* import private part */
ret = wc_curve25519_import_private_ex(priv, privSz, key, endian);
if (ret != 0)
return ret;
/* import public part */
return wc_curve25519_import_public_ex(pub, pubSz, key, endian);
}
/* curve25519 private key import only. (Big endian)
* return 0 on success */
int wc_curve25519_import_private(const byte* priv, word32 privSz,
curve25519_key* key)
{
return wc_curve25519_import_private_ex(priv, privSz,
key, EC25519_BIG_ENDIAN);
}
/* curve25519 private key import only. (Big or Little endian)
* return 0 on success */
int wc_curve25519_import_private_ex(const byte* priv, word32 privSz,
curve25519_key* key, int endian)
{
/* sanity check */
if (key == NULL || priv == NULL)
return BAD_FUNC_ARG;
/* check size of incoming keys */
if ((int)privSz != wc_curve25519_size(key))
return ECC_BAD_ARG_E;
if (endian == EC25519_BIG_ENDIAN) {
int i;
/* read the key in Big Endian format */
for (i = 0; i < CURVE25519_KEYSIZE; i++)
key->k.point[i] = priv[CURVE25519_KEYSIZE - i - 1];
}
else
XMEMCPY(key->k.point, priv, privSz);
key->dp = &curve25519_sets[0];
/* Clamp the key */
key->k.point[0] &= 248;
key->k.point[privSz-1] &= 63; /* same &=127 because |=64 after */
key->k.point[privSz-1] |= 64;
return 0;
}
#endif /* HAVE_CURVE25519_KEY_IMPORT */
int wc_curve25519_init(curve25519_key* key)
{
if (key == NULL)
return BAD_FUNC_ARG;
/* currently the format for curve25519 */
key->dp = &curve25519_sets[0];
XMEMSET(key->k.point, 0, key->dp->size);
XMEMSET(key->p.point, 0, key->dp->size);
return 0;
}
/* Clean the memory of a key */
void wc_curve25519_free(curve25519_key* key)
{
if (key == NULL)
return;
key->dp = NULL;
ForceZero(key->p.point, sizeof(key->p.point));
ForceZero(key->k.point, sizeof(key->k.point));
}
/* get key size */
int wc_curve25519_size(curve25519_key* key)
{
if (key == NULL)
return 0;
return key->dp->size;
}
#endif /*HAVE_CURVE25519*/
Reference in New Issue View Git Blame Copy Permalink