add cofactor ECDH support from fips branch

[openssl.git] / crypto / ecdh / ech_ossl.c

diff --git a/crypto/ecdh/ech_ossl.c b/crypto/ecdh/ech_ossl.c
index b1c634b462876ee5e371f0a0694a3720991a1057..2656797449e7075cd910bd69deaf4c6c8012b3f5 100644 (file)
--- a/crypto/ecdh/ech_ossl.c
+++ b/crypto/ecdh/ech_ossl.c
@@ -67,13 +67,14 @@
  *
  */
 
+#define OPENSSL_FIPSAPI
 
 #include <string.h>
 #include <limits.h>
 
 #include "cryptlib.h"
 
-#include <openssl/ecdh.h>
+#include "ech_locl.h"
 #include <openssl/err.h>
 #include <openssl/sha.h>
 #include <openssl/obj_mac.h>
@@ -90,7 +91,7 @@ static ECDH_METHOD openssl_ecdh_meth = {
        NULL, /* init     */
        NULL, /* finish   */
 #endif
-       0,    /* flags    */
+       ECDH_FLAG_FIPS_METHOD,    /* flags    */
        NULL  /* app_data */
 };
 
@@ -112,10 +113,20 @@ static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
        BN_CTX *ctx;
        EC_POINT *tmp=NULL;
        BIGNUM *x=NULL, *y=NULL;
+       const BIGNUM *priv_key;
+       const EC_GROUP* group;
        int ret= -1;
        size_t buflen, len;
        unsigned char *buf=NULL;
 
+#ifdef OPENSSL_FIPS
+       if(FIPS_selftest_failed())
+               {
+               FIPSerr(FIPS_F_ECDH_COMPUTE_KEY,FIPS_R_FIPS_SELFTEST_FAILED);
+               return -1;
+               }
+#endif
+
        if (outlen > INT_MAX)
                {
                ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE); /* sort of, anyway */
@@ -127,42 +138,58 @@ static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
        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 (EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH)
+               {
+               if (!EC_GROUP_get_cofactor(group, x, ctx) ||
+                       !BN_mul(x, x, priv_key, ctx))
+                       {
+                       ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
+                       goto err;
+                       }
+               priv_key = x;
+               }
+
+       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;
                        }
                }
+#ifndef OPENSSL_NO_EC2M
        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;
                        }
                }
+#endif
 
-       buflen = (EC_GROUP_get_degree(ecdh->group) + 7)/8;
+       buflen = (EC_GROUP_get_degree(group) + 7)/8;
        len = BN_num_bytes(x);
        if (len > buflen)
                {
@@ -207,3 +234,15 @@ err:
        if (buf) OPENSSL_free(buf);
        return(ret);
        }
+
+#ifdef OPENSSL_FIPSCANISTER
+/* FIPS stanadlone version of ecdh_check: just return FIPS method */
+ECDH_DATA *fips_ecdh_check(EC_KEY *key)
+       {
+       static ECDH_DATA rv = {
+               0,0,0,
+               &openssl_ecdh_meth
+               };
+       return &rv;
+       }
+#endif