New functions BN_CTX_start(), BN_CTX_get(), BN_CTX_end() to access
[openssl.git] / crypto / dh / dh_key.c
index 12f47c4..0c7eeaf 100644 (file)
@@ -1,5 +1,5 @@
 /* crypto/dh/dh_key.c */
-/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
  * This package is an SSL implementation written
 
 #include <stdio.h>
 #include "cryptlib.h"
-#include "bn.h"
-#include "rand.h"
-#include "dh.h"
+#include <openssl/bn.h>
+#include <openssl/rand.h>
+#include <openssl/dh.h>
 
-int DH_generate_key(dh)
-DH *dh;
+static int generate_key(DH *dh);
+static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
+static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+                       const BIGNUM *m, BN_CTX *ctx,
+                       BN_MONT_CTX *m_ctx);
+static int dh_init(DH *dh);
+static int dh_finish(DH *dh);
+
+int DH_generate_key(DH *dh)
+       {
+       return dh->meth->generate_key(dh);
+       }
+
+int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
+       {
+       return dh->meth->compute_key(key, pub_key, dh);
+       }
+
+static DH_METHOD dh_ossl = {
+"OpenSSL DH Method",
+generate_key,
+compute_key,
+dh_bn_mod_exp,
+dh_init,
+dh_finish,
+0,
+NULL
+};
+
+DH_METHOD *DH_OpenSSL(void)
+{
+       return &dh_ossl;
+}
+
+static int generate_key(DH *dh)
        {
        int ok=0;
        unsigned int i;
-       BN_CTX *ctx=NULL;
+       BN_CTX ctx;
+       BN_MONT_CTX *mont;
        BIGNUM *pub_key=NULL,*priv_key=NULL;
 
-       ctx=BN_CTX_new();
-       if (ctx == NULL) goto err;
+       BN_CTX_init(&ctx);
 
        if (dh->priv_key == NULL)
                {
@@ -96,7 +129,16 @@ DH *dh;
        else
                pub_key=dh->pub_key;
 
-       if (!BN_mod_exp(pub_key,dh->g,priv_key,dh->p,ctx)) goto err;
+       if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
+               {
+               if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
+                       if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
+                               dh->p,&ctx)) goto err;
+               }
+       mont=(BN_MONT_CTX *)dh->method_mont_p;
+
+       if (!dh->meth->bn_mod_exp(dh, pub_key,dh->g,priv_key,dh->p,&ctx,mont))
+                                                               goto err;
                
        dh->pub_key=pub_key;
        dh->priv_key=priv_key;
@@ -107,29 +149,35 @@ err:
 
        if ((pub_key != NULL)  && (dh->pub_key == NULL))  BN_free(pub_key);
        if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key);
-       if (ctx != NULL) BN_CTX_free(ctx);
+       BN_CTX_free(&ctx);
        return(ok);
        }
 
-int DH_compute_key(key,pub_key,dh)
-unsigned char *key;
-BIGNUM *pub_key;
-DH *dh;
+static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
        {
-       BN_CTX *ctx;
+       BN_CTX ctx;
+       BN_MONT_CTX *mont;
        BIGNUM *tmp;
        int ret= -1;
 
-       ctx=BN_CTX_new();
-       if (ctx == NULL) goto err;
-       tmp=ctx->bn[ctx->tos++];
+       BN_CTX_init(&ctx);
+       BN_CTX_start(&ctx);
+       tmp = BN_CTX_get(&ctx);
        
        if (dh->priv_key == NULL)
                {
                DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE);
                goto err;
                }
-       if (!BN_mod_exp(tmp,pub_key,dh->priv_key,dh->p,ctx))
+       if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P))
+               {
+               if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
+                       if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p,
+                               dh->p,&ctx)) goto err;
+               }
+
+       mont=(BN_MONT_CTX *)dh->method_mont_p;
+       if (!dh->meth->bn_mod_exp(dh, tmp,pub_key,dh->priv_key,dh->p,&ctx,mont))
                {
                DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB);
                goto err;
@@ -137,6 +185,27 @@ DH *dh;
 
        ret=BN_bn2bin(tmp,key);
 err:
-       if (ctx != NULL) BN_CTX_free(ctx);
+       BN_CTX_end(&ctx);
+       BN_CTX_free(&ctx);
        return(ret);
        }
+
+static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+                       const BIGNUM *m, BN_CTX *ctx,
+                       BN_MONT_CTX *m_ctx)
+{
+       return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+}
+
+static int dh_init(DH *dh)
+{
+       dh->flags |= DH_FLAG_CACHE_MONT_P;
+       return(1);
+}
+
+static int dh_finish(DH *dh)
+{
+       if(dh->method_mont_p)
+               BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p);
+       return(1);
+}