X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fdh%2Fdh_gen.c;h=1d3cbe8a8927bc398b47afd83faedca8f77de691;hp=ff4f18e1e05262bc9bb97c6881ed08570e475776;hb=1d97c8435171a7af575f73c526d79e1ef0ee5960;hpb=eda1f21f1af8b6f77327e7b37573af9c1ba73726

diff --git a/crypto/dh/dh_gen.c b/crypto/dh/dh_gen.c
index ff4f18e1e0..1d3cbe8a89 100644
--- a/crypto/dh/dh_gen.c
+++ b/crypto/dh/dh_gen.c
@@ -1,5 +1,5 @@
 /* crypto/dh/dh_gen.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
@@ -56,12 +56,29 @@
  * [including the GNU Public Licence.]
  */
 
+/* NB: These functions have been upgraded - the previous prototypes are in
+ * dh_depr.c as wrappers to these ones.
+ *  - Geoff
+ */
+
+
+
 #include <stdio.h>
 #include "cryptlib.h"
-#include "bn.h"
-#include "dh.h"
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+
+static int dh_builtin_genparams(DH *ret, int prime_len, int generator, BN_GENCB *cb);
+
+int DH_generate_parameters_ex(DH *ret, int prime_len, int generator, BN_GENCB *cb)
+	{
+	if(ret->meth->generate_params)
+		return ret->meth->generate_params(ret, prime_len, generator, cb);
+	return dh_builtin_genparams(ret, prime_len, generator, cb);
+	}
 
-/* We generate DH parameters as follows
+/*-
+ * We generate DH parameters as follows
  * find a prime q which is prime_len/2 bits long.
  * p=(2*q)+1 or (p-1)/2 = q
  * For this case, g is a generator if
@@ -72,78 +89,90 @@
  * Having said all that,
  * there is another special case method for the generators 2, 3 and 5.
  * for 2, p mod 24 == 11
- * for 3, p mod 12 == 5  <<<<< does not work for strong primes.
+ * for 3, p mod 12 == 5  <<<<< does not work for safe primes.
  * for 5, p mod 10 == 3 or 7
  *
  * Thanks to Phil Karn <karn@qualcomm.com> for the pointers about the
  * special generators and for answering some of my questions.
  *
  * I've implemented the second simple method :-).
- * Since DH should be using a strong prime (both p and q are prime),
+ * Since DH should be using a safe prime (both p and q are prime),
  * this generator function can take a very very long time to run.
  */
-
-DH *DH_generate_parameters(prime_len,generator,callback)
-int prime_len;
-int generator;
-void (*callback)(P_I_I);
+/* Actually there is no reason to insist that 'generator' be a generator.
+ * It's just as OK (and in some sense better) to use a generator of the
+ * order-q subgroup.
+ */
+static int dh_builtin_genparams(DH *ret, int prime_len, int generator, BN_GENCB *cb)
 	{
-	BIGNUM *p=NULL,*t1,*t2;
-	DH *ret=NULL;
+	BIGNUM *t1,*t2;
 	int g,ok= -1;
 	BN_CTX *ctx=NULL;
 
-	ret=DH_new();
 	ctx=BN_CTX_new();
 	if (ctx == NULL) goto err;
-	t1=ctx->bn[0];
-	t2=ctx->bn[1];
-	ctx->tos=2;
+	BN_CTX_start(ctx);
+	t1 = BN_CTX_get(ctx);
+	t2 = BN_CTX_get(ctx);
+	if (t1 == NULL || t2 == NULL) goto err;
+
+	/* Make sure 'ret' has the necessary elements */
+	if(!ret->p && ((ret->p = BN_new()) == NULL)) goto err;
+	if(!ret->g && ((ret->g = BN_new()) == NULL)) goto err;
 	
+	if (generator <= 1)
+		{
+		DHerr(DH_F_DH_BUILTIN_GENPARAMS, DH_R_BAD_GENERATOR);
+		goto err;
+		}
 	if (generator == DH_GENERATOR_2)
 		{
-		BN_set_word(t1,24);
-		BN_set_word(t2,11);
+		if (!BN_set_word(t1,24)) goto err;
+		if (!BN_set_word(t2,11)) goto err;
 		g=2;
 		}
-#ifdef undef  /* does not work for strong primes */
+#if 0 /* does not work for safe primes */
 	else if (generator == DH_GENERATOR_3)
 		{
-		BN_set_word(t1,12);
-		BN_set_word(t2,5);
+		if (!BN_set_word(t1,12)) goto err;
+		if (!BN_set_word(t2,5)) goto err;
 		g=3;
 		}
 #endif
 	else if (generator == DH_GENERATOR_5)
 		{
-		BN_set_word(t1,10);
-		BN_set_word(t2,3);
+		if (!BN_set_word(t1,10)) goto err;
+		if (!BN_set_word(t2,3)) goto err;
 		/* BN_set_word(t3,7); just have to miss
 		 * out on these ones :-( */
 		g=5;
 		}
 	else
+		{
+		/* in the general case, don't worry if 'generator' is a
+		 * generator or not: since we are using safe primes,
+		 * it will generate either an order-q or an order-2q group,
+		 * which both is OK */
+		if (!BN_set_word(t1,2)) goto err;
+		if (!BN_set_word(t2,1)) goto err;
 		g=generator;
+		}
 	
-	p=BN_generate_prime(prime_len,1,t1,t2,callback);
-	if (p == NULL) goto err;
-	if (callback != NULL) callback(3,0);
-	ret->p=p;
-	ret->g=BN_new();
+	if(!BN_generate_prime_ex(ret->p,prime_len,1,t1,t2,cb)) goto err;
+	if(!BN_GENCB_call(cb, 3, 0)) goto err;
 	if (!BN_set_word(ret->g,g)) goto err;
 	ok=1;
 err:
 	if (ok == -1)
 		{
-		DHerr(DH_F_DH_GENERATE_PARAMETERS,ERR_R_BN_LIB);
+		DHerr(DH_F_DH_BUILTIN_GENPARAMS,ERR_R_BN_LIB);
 		ok=0;
 		}
 
-	if (ctx != NULL) BN_CTX_free(ctx);
-	if (!ok && (ret != NULL))
+	if (ctx != NULL)
 		{
-		DH_free(ret);
-		ret=NULL;
+		BN_CTX_end(ctx);
+		BN_CTX_free(ctx);
 		}
-	return(ret);
+	return ok;
 	}