/* crypto/rsa/rsa_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: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * 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 * 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 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * 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 deprecated versions (which are * compatibility wrappers using these functions) are in rsa_depr.c. * - Geoff */ #include <stdio.h> #include <time.h> #include "cryptlib.h" #include <openssl/bn.h> #include <openssl/rsa.h> static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb); /* NB: this wrapper would normally be placed in rsa_lib.c and the static * implementation would probably be in rsa_eay.c. Nonetheless, is kept here so * that we don't introduce a new linker dependency. Eg. any application that * wasn't previously linking object code related to key-generation won't have to * now just because key-generation is part of RSA_METHOD. */ int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) { if(rsa->meth->rsa_keygen) return rsa->meth->rsa_keygen(rsa, bits, e_value, cb); return rsa_builtin_keygen(rsa, bits, e_value, cb); } static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) { BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp; BIGNUM local_r0,local_d,local_p; BIGNUM *pr0,*d,*p; int bitsp,bitsq,ok= -1,n=0; BN_CTX *ctx=NULL; ctx=BN_CTX_new(); if (ctx == NULL) goto err; BN_CTX_start(ctx); r0 = BN_CTX_get(ctx); r1 = BN_CTX_get(ctx); r2 = BN_CTX_get(ctx); r3 = BN_CTX_get(ctx); if (r3 == NULL) goto err; bitsp=(bits+1)/2; bitsq=bits-bitsp; /* We need the RSA components non-NULL */ if(!rsa->n && ((rsa->n=BN_new()) == NULL)) goto err; if(!rsa->d && ((rsa->d=BN_new()) == NULL)) goto err; if(!rsa->e && ((rsa->e=BN_new()) == NULL)) goto err; if(!rsa->p && ((rsa->p=BN_new()) == NULL)) goto err; if(!rsa->q && ((rsa->q=BN_new()) == NULL)) goto err; if(!rsa->dmp1 && ((rsa->dmp1=BN_new()) == NULL)) goto err; if(!rsa->dmq1 && ((rsa->dmq1=BN_new()) == NULL)) goto err; if(!rsa->iqmp && ((rsa->iqmp=BN_new()) == NULL)) goto err; BN_copy(rsa->e, e_value); /* generate p and q */ for (;;) { if(!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb)) goto err; if (!BN_sub(r2,rsa->p,BN_value_one())) goto err; if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; if (BN_is_one(r1)) break; if(!BN_GENCB_call(cb, 2, n++)) goto err; } if(!BN_GENCB_call(cb, 3, 0)) goto err; for (;;) { /* When generating ridiculously small keys, we can get stuck * continually regenerating the same prime values. Check for * this and bail if it happens 3 times. */ unsigned int degenerate = 0; do { if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb)) goto err; } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3)); if(degenerate == 3) { ok = 0; /* we set our own err */ RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL); goto err; } if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; if (BN_is_one(r1)) break; if(!BN_GENCB_call(cb, 2, n++)) goto err; } if(!BN_GENCB_call(cb, 3, 1)) goto err; if (BN_cmp(rsa->p,rsa->q) < 0) { tmp=rsa->p; rsa->p=rsa->q; rsa->q=tmp; } /* calculate n */ if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err; /* calculate d */ if (!BN_sub(r1,rsa->p,BN_value_one())) goto err; /* p-1 */ if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; /* q-1 */ if (!BN_mul(r0,r1,r2,ctx)) goto err; /* (p-1)(q-1) */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { pr0 = &local_r0; BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); } else pr0 = r0; if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err; /* d */ /* set up d for correct BN_FLG_CONSTTIME flag */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { d = &local_d; BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); } else d = rsa->d; /* calculate d mod (p-1) */ if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err; /* calculate d mod (q-1) */ if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err; /* calculate inverse of q mod p */ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { p = &local_p; BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); } else p = rsa->p; if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err; ok=1; err: if (ok == -1) { RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN); ok=0; } if (ctx != NULL) { BN_CTX_end(ctx); BN_CTX_free(ctx); } return ok; }