New SP 800-56A compliant version of DH_compute_key().

[openssl.git] / crypto / dh / dh_key.c

diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index cb5abdcf47c4a18fd1d15d7d08d7c0f3801617f6..6c7a45726706de542aa6117a0011b82e9b8f798c 100644 (file)
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -56,11 +56,16 @@
  * [including the GNU Public Licence.]
  */
 
+#define OPENSSL_FIPSAPI
+
 #include <stdio.h>
 #include "cryptlib.h"
 #include <openssl/bn.h>
 #include <openssl/rand.h>
 #include <openssl/dh.h>
+#ifdef OPENSSL_FIPS
+#include <openssl/fips.h>
+#endif
 
 static int generate_key(DH *dh);
 static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
@@ -81,6 +86,21 @@ int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
        return dh->meth->compute_key(key, pub_key, dh);
        }
 
+int DH_compute_key_padded(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+       {
+       int rv, pad;
+       rv = dh->meth->compute_key(key, pub_key, dh);
+       if (rv <= 0)
+               return rv;
+       pad = BN_num_bytes(dh->p) - rv;
+       if (pad > 0)
+               {
+               memmove(key + pad, key, rv);
+               memset(key, 0, pad);
+               }
+       return rv + pad;
+       }
+
 static DH_METHOD dh_ossl = {
 "OpenSSL DH Method",
 generate_key,
@@ -107,6 +127,14 @@ static int generate_key(DH *dh)
        BN_MONT_CTX *mont=NULL;
        BIGNUM *pub_key=NULL,*priv_key=NULL;
 
+#ifdef OPENSSL_FIPS
+       if (FIPS_mode() && (BN_num_bits(dh->p) < OPENSSL_DH_FIPS_MIN_MODULUS_BITS))
+               {
+               DHerr(DH_F_GENERATE_KEY, DH_R_KEY_SIZE_TOO_SMALL);
+               return 0;
+               }
+#endif
+
        ctx = BN_CTX_new();
        if (ctx == NULL) goto err;
 
@@ -150,7 +178,7 @@ static int generate_key(DH *dh)
                        {
                        BN_init(&local_prk);
                        prk = &local_prk;
-                       BN_with_flags(prk, priv_key, BN_FLG_EXP_CONSTTIME);
+                       BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
                        }
                else
                        prk = priv_key;
@@ -173,7 +201,7 @@ err:
 
 static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
        {
-       BN_CTX *ctx;
+       BN_CTX *ctx=NULL;
        BN_MONT_CTX *mont=NULL;
        BIGNUM *tmp;
        int ret= -1;
@@ -185,6 +213,14 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
                goto err;
                }
 
+#ifdef OPENSSL_FIPS
+       if (FIPS_mode() && (BN_num_bits(dh->p) < OPENSSL_DH_FIPS_MIN_MODULUS_BITS))
+               {
+               DHerr(DH_F_COMPUTE_KEY, DH_R_KEY_SIZE_TOO_SMALL);
+               goto err;
+               }
+#endif
+
        ctx = BN_CTX_new();
        if (ctx == NULL) goto err;
        BN_CTX_start(ctx);
@@ -203,7 +239,7 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
                if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0)
                        {
                        /* XXX */
-                       BN_set_flags(dh->priv_key, BN_FLG_EXP_CONSTTIME);
+                       BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
                        }
                if (!mont)
                        goto err;
@@ -251,6 +287,9 @@ static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
 
 static int dh_init(DH *dh)
        {
+#ifdef OPENSSL_FIPS
+       FIPS_selftest_check();
+#endif
        dh->flags |= DH_FLAG_CACHE_MONT_P;
        return(1);
        }