1 files changed, 61 insertions, 4 deletions

diff --git a/src/lib/libcrypto/dh/dh_key.c b/src/lib/libcrypto/dh/dh_key.c
index cede53bfc1..0c7eeaf260 100644
--- a/src/lib/libcrypto/dh/dh_key.c
+++ b/src/lib/libcrypto/dh/dh_key.c
@@ -62,8 +62,42 @@
 #include <openssl/rand.h>
 #include <openssl/dh.h>
 
+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;
@@ -103,7 +137,8 @@ int DH_generate_key(DH *dh)
                 }
         mont=(BN_MONT_CTX *)dh->method_mont_p;
 
-        if (!BN_mod_exp_mont(pub_key,dh->g,priv_key,dh->p,&ctx,mont)) goto err;
+        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;
@@ -118,7 +153,7 @@ err:
         return(ok);
         }
 
-int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
+static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
         {
         BN_CTX ctx;
         BN_MONT_CTX *mont;
@@ -126,7 +161,8 @@ int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
         int ret= -1;
 
         BN_CTX_init(&ctx);
-        tmp= &(ctx.bn[ctx.tos++]);
+        BN_CTX_start(&ctx);
+        tmp = BN_CTX_get(&ctx);
         
         if (dh->priv_key == NULL)
                 {
@@ -141,7 +177,7 @@ int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
                 }
 
         mont=(BN_MONT_CTX *)dh->method_mont_p;
-        if (!BN_mod_exp_mont(tmp,pub_key,dh->priv_key,dh->p,&ctx,mont))
+        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;
@@ -149,6 +185,27 @@ int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh)
 
         ret=BN_bn2bin(tmp,key);
 err:
+        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);
+}