* The ECC Code is licensed pursuant to the OpenSSL open source
* license provided below.
*
- * In addition, Sun covenants to all licensees who provide a reciprocal
- * covenant with respect to their own patents if any, not to sue under
- * current and future patent claims necessarily infringed by the making,
- * using, practicing, selling, offering for sale and/or otherwise
- * disposing of the ECC Code as delivered hereunder (or portions thereof),
- * provided that such covenant shall not apply:
- * 1) for code that a licensee deletes from the ECC Code;
- * 2) separates from the ECC Code; or
- * 3) for infringements caused by:
- * i) the modification of the ECC Code or
- * ii) the combination of the ECC Code with other software or
- * devices where such combination causes the infringement.
- *
* The ECDH software is originally written by Douglas Stebila of
* Sun Microsystems Laboratories.
*
*/
/* ====================================================================
- * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
*/
-#include "ecdh.h"
+#include <string.h>
+#include <limits.h>
+
+#include "cryptlib.h"
+
+#include "ech_locl.h"
#include <openssl/err.h>
#include <openssl/sha.h>
#include <openssl/obj_mac.h>
+#include <openssl/bn.h>
-static int ecdh_compute_key(unsigned char *key, const EC_POINT *pub_key, EC_KEY *ecdh);
+static int ecdh_compute_key(void *out, size_t len, const EC_POINT *pub_key,
+ EC_KEY *ecdh,
+ void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen));
static ECDH_METHOD openssl_ecdh_meth = {
"OpenSSL ECDH method",
/* This implementation is based on the following primitives in the IEEE 1363 standard:
* - ECKAS-DH1
* - ECSVDP-DH
- * - KDF1 with SHA-1
+ * Finally an optional KDF is applied.
*/
-static int ecdh_compute_key(unsigned char *key, const EC_POINT *pub_key, EC_KEY *ecdh)
+static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
+ EC_KEY *ecdh,
+ void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
{
BN_CTX *ctx;
EC_POINT *tmp=NULL;
BIGNUM *x=NULL, *y=NULL;
- int ret= -1, len;
+ const BIGNUM *priv_key;
+ const EC_GROUP* group;
+ int ret= -1;
+ size_t buflen, len;
unsigned char *buf=NULL;
+ if (outlen > INT_MAX)
+ {
+ ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE); /* sort of, anyway */
+ return -1;
+ }
+
if ((ctx = BN_CTX_new()) == NULL) goto err;
BN_CTX_start(ctx);
x = BN_CTX_get(ctx);
y = BN_CTX_get(ctx);
- if (ecdh->priv_key == NULL)
+ priv_key = EC_KEY_get0_private_key(ecdh);
+ if (priv_key == NULL)
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_NO_PRIVATE_VALUE);
goto err;
}
- if ((tmp=EC_POINT_new(ecdh->group)) == NULL)
+ group = EC_KEY_get0_group(ecdh);
+ if ((tmp=EC_POINT_new(group)) == NULL)
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
goto err;
}
- if (!EC_POINT_mul(ecdh->group, tmp, NULL, pub_key, ecdh->priv_key, ctx))
+ if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx))
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
goto err;
}
- if (EC_METHOD_get_field_type(EC_GROUP_method_of(ecdh->group)) == NID_X9_62_prime_field)
+ if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
{
- if (!EC_POINT_get_affine_coordinates_GFp(ecdh->group, tmp, x, y, ctx))
+ if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y, ctx))
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
goto err;
}
else
{
- if (!EC_POINT_get_affine_coordinates_GF2m(ecdh->group, tmp, x, y, ctx))
+ if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y, ctx))
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
goto err;
}
}
- if ((buf = (unsigned char *)OPENSSL_malloc(sizeof(unsigned char) * BN_num_bytes(x))) == NULL)
+ buflen = (EC_GROUP_get_degree(group) + 7)/8;
+ len = BN_num_bytes(x);
+ if (len > buflen)
+ {
+ ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ if ((buf = OPENSSL_malloc(buflen)) == NULL)
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
goto err;
}
- if ((len = BN_bn2bin(x,buf)) <= 0)
+ memset(buf, 0, buflen - len);
+ if (len != (size_t)BN_bn2bin(x, buf + buflen - len))
{
ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_BN_LIB);
goto err;
}
- if ((SHA1(buf, len, key) == NULL))
+ if (KDF != 0)
{
- ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_SHA1_DIGEST_FAILED);
- goto err;
+ if (KDF(buf, buflen, out, &outlen) == NULL)
+ {
+ ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_KDF_FAILED);
+ goto err;
+ }
+ ret = outlen;
+ }
+ else
+ {
+ /* no KDF, just copy as much as we can */
+ if (outlen > buflen)
+ outlen = buflen;
+ memcpy(out, buf, outlen);
+ ret = outlen;
}
- ret = 20;
-
err:
if (tmp) EC_POINT_free(tmp);
if (ctx) BN_CTX_end(ctx);