X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fdh%2Fdh_gen.c;h=5c96dacdba0a0e1831e1b56456126cb6a45c3285;hp=32237e8b95e8d18d42734c03713dfdaa4a58692e;hb=0aeddcfa61250a6c474c4f8b3533772a63192f1b;hpb=ec577822f95a8bca0023c5c77cef1a4916822d4a diff --git a/crypto/dh/dh_gen.c b/crypto/dh/dh_gen.c index 32237e8b95..5c96dacdba 100644 --- a/crypto/dh/dh_gen.c +++ b/crypto/dh/dh_gen.c @@ -1,25 +1,24 @@ -/* 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: @@ -34,10 +33,10 @@ * 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 @@ -49,19 +48,36 @@ * 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 -#include "cryptlib.h" +#include "internal/cryptlib.h" #include -#include +#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 @@ -72,76 +88,91 @@ * 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 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)(P_I_I_P), char *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; +}