-/* crypto/dh/dh_gen.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
- *
+ *
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
+ *
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
- *
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
+ * 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
+ *
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
- *
+ *
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [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 "internal/cryptlib.h"
#include <openssl/bn.h>
-#include <openssl/dh.h>
+#include "dh_locl.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
* 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.
*/
+/*
+ * 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 *t1, *t2;
+ int g, ok = -1;
+ BN_CTX *ctx = NULL;
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ 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;
-DH *DH_generate_parameters(int prime_len, int generator,
- void (*callback)(int,int,void *), void *cb_arg)
- {
- BIGNUM *p=NULL,*t1,*t2;
- DH *ret=NULL;
- int g,ok= -1;
- BN_CTX *ctx=NULL;
+ if (generator <= 1) {
+ DHerr(DH_F_DH_BUILTIN_GENPARAMS, DH_R_BAD_GENERATOR);
+ goto err;
+ }
+ if (generator == DH_GENERATOR_2) {
+ if (!BN_set_word(t1, 24))
+ goto err;
+ if (!BN_set_word(t2, 11))
+ goto err;
+ g = 2;
+ } else if (generator == DH_GENERATOR_5) {
+ 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;
+ }
- ret=DH_new();
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- t1= &(ctx->bn[0]);
- t2= &(ctx->bn[1]);
- ctx->tos=2;
-
- if (generator == DH_GENERATOR_2)
- {
- BN_set_word(t1,24);
- BN_set_word(t2,11);
- g=2;
- }
-#ifdef undef /* does not work for strong primes */
- else if (generator == DH_GENERATOR_3)
- {
- BN_set_word(t1,12);
- BN_set_word(t2,5);
- g=3;
- }
-#endif
- else if (generator == DH_GENERATOR_5)
- {
- BN_set_word(t1,10);
- BN_set_word(t2,3);
- /* BN_set_word(t3,7); just have to miss
- * out on these ones :-( */
- g=5;
- }
- else
- g=generator;
-
- p=BN_generate_prime(NULL,prime_len,1,t1,t2,callback,cb_arg);
- if (p == NULL) goto err;
- if (callback != NULL) callback(3,0,cb_arg);
- ret->p=p;
- ret->g=BN_new();
- 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);
- ok=0;
- }
+ 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_BUILTIN_GENPARAMS, ERR_R_BN_LIB);
+ ok = 0;
+ }
- if (ctx != NULL) BN_CTX_free(ctx);
- if (!ok && (ret != NULL))
- {
- DH_free(ret);
- ret=NULL;
- }
- return(ret);
- }
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ return ok;
+}
projects / openssl.git / blobdiff