rsa_lib.c

/* crypto/rsa/rsa_lib.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.]
 */

#include <stdio.h>
#include <openssl/crypto.h>
#include "cryptlib.h"
#include <openssl/lhash.h>
#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/rand.h>
#ifndef OPENSSL_NO_ENGINE
#include <openssl/engine.h>
#endif

const char *RSA_version="RSA" OPENSSL_VERSION_PTEXT;

static const RSA_METHOD *default_RSA_meth=NULL;

RSA *RSA_new(void)
	{
	RSA *r=RSA_new_method(NULL);

	return r;
	}

void RSA_set_default_method(const RSA_METHOD *meth)
	{
	default_RSA_meth = meth;
	}

const RSA_METHOD *RSA_get_default_method(void)
	{
	if (default_RSA_meth == NULL)
		{
#ifdef RSA_NULL
		default_RSA_meth=RSA_null_method();
#else
#if 0 /* was: #ifdef RSAref */
		default_RSA_meth=RSA_PKCS1_RSAref();
#else
		default_RSA_meth=RSA_PKCS1_SSLeay();
#endif
#endif
		}

	return default_RSA_meth;
	}

const RSA_METHOD *RSA_get_method(const RSA *rsa)
	{
	return rsa->meth;
	}

int RSA_set_method(RSA *rsa, const RSA_METHOD *meth)
	{
	/* NB: The caller is specifically setting a method, so it's not up to us
	 * to deal with which ENGINE it comes from. */
	const RSA_METHOD *mtmp;
	mtmp = rsa->meth;
	if (mtmp->finish) mtmp->finish(rsa);
#ifndef OPENSSL_NO_ENGINE
	if (rsa->engine)
		{
		ENGINE_finish(rsa->engine);
		rsa->engine = NULL;
		}
#endif
	rsa->meth = meth;
	if (meth->init) meth->init(rsa);
	return 1;
	}

RSA *RSA_new_method(ENGINE *engine)
	{
	RSA *ret;

	ret=(RSA *)OPENSSL_malloc(sizeof(RSA));
	if (ret == NULL)
		{
		RSAerr(RSA_F_RSA_NEW_METHOD,ERR_R_MALLOC_FAILURE);
		return NULL;
		}

	ret->meth = RSA_get_default_method();
#ifndef OPENSSL_NO_ENGINE
	if (engine)
		{
		if (!ENGINE_init(engine))
			{
			RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
			OPENSSL_free(ret);
			return NULL;
			}
		ret->engine = engine;
		}
	else
		ret->engine = ENGINE_get_default_RSA();
	if(ret->engine)
		{
		ret->meth = ENGINE_get_RSA(ret->engine);
		if(!ret->meth)
			{
			RSAerr(RSA_F_RSA_NEW_METHOD,
				ERR_R_ENGINE_LIB);
			ENGINE_finish(ret->engine);
			OPENSSL_free(ret);
			return NULL;
			}
		}
#endif

	ret->pad=0;
	ret->version=0;
	ret->n=NULL;
	ret->e=NULL;
	ret->d=NULL;
	ret->p=NULL;
	ret->q=NULL;
	ret->dmp1=NULL;
	ret->dmq1=NULL;
	ret->iqmp=NULL;
	ret->references=1;
	ret->_method_mod_n=NULL;
	ret->_method_mod_p=NULL;
	ret->_method_mod_q=NULL;
	ret->blinding=NULL;
	ret->mt_blinding=NULL;
	ret->bignum_data=NULL;
	ret->flags=ret->meth->flags;
	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data);
	if ((ret->meth->init != NULL) && !ret->meth->init(ret))
		{
#ifndef OPENSSL_NO_ENGINE
		if (ret->engine)
			ENGINE_finish(ret->engine);
#endif
		CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data);
		OPENSSL_free(ret);
		ret=NULL;
		}
	return(ret);
	}

void RSA_free(RSA *r)
	{
	int i;

	if (r == NULL) return;

	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_RSA);
#ifdef REF_PRINT
	REF_PRINT("RSA",r);
#endif
	if (i > 0) return;
#ifdef REF_CHECK
	if (i < 0)
		{
		fprintf(stderr,"RSA_free, bad reference count\n");
		abort();
		}
#endif

	if (r->meth->finish)
		r->meth->finish(r);
#ifndef OPENSSL_NO_ENGINE
	if (r->engine)
		ENGINE_finish(r->engine);
#endif

	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, r, &r->ex_data);

	if (r->n != NULL) BN_clear_free(r->n);
	if (r->e != NULL) BN_clear_free(r->e);
	if (r->d != NULL) BN_clear_free(r->d);
	if (r->p != NULL) BN_clear_free(r->p);
	if (r->q != NULL) BN_clear_free(r->q);
	if (r->dmp1 != NULL) BN_clear_free(r->dmp1);
	if (r->dmq1 != NULL) BN_clear_free(r->dmq1);
	if (r->iqmp != NULL) BN_clear_free(r->iqmp);
	if (r->blinding != NULL) BN_BLINDING_free(r->blinding);
	if (r->mt_blinding != NULL) BN_BLINDING_free(r->mt_blinding);
	if (r->bignum_data != NULL) OPENSSL_free_locked(r->bignum_data);
	OPENSSL_free(r);
	}

int RSA_up_ref(RSA *r)
	{
	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_RSA);
#ifdef REF_PRINT
	REF_PRINT("RSA",r);
#endif
#ifdef REF_CHECK
	if (i < 2)
		{
		fprintf(stderr, "RSA_up_ref, bad reference count\n");
		abort();
		}
#endif
	return ((i > 1) ? 1 : 0);
	}

int RSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
        {
	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_RSA, argl, argp,
				new_func, dup_func, free_func);
        }

int RSA_set_ex_data(RSA *r, int idx, void *arg)
	{
	return(CRYPTO_set_ex_data(&r->ex_data,idx,arg));
	}

void *RSA_get_ex_data(const RSA *r, int idx)
	{
	return(CRYPTO_get_ex_data(&r->ex_data,idx));
	}

int RSA_size(const RSA *r)
	{
	return(BN_num_bytes(r->n));
	}

int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
	     RSA *rsa, int padding)
	{
	return(rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));
	}

int RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
	     RSA *rsa, int padding)
	{
	return(rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));
	}

int RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
	     RSA *rsa, int padding)
	{
	return(rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));
	}

int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
	     RSA *rsa, int padding)
	{
	return(rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));
	}

int RSA_flags(const RSA *r)
	{
	return((r == NULL)?0:r->meth->flags);
	}

void RSA_blinding_off(RSA *rsa)
	{
	if (rsa->blinding != NULL)
		{
		BN_BLINDING_free(rsa->blinding);
		rsa->blinding=NULL;
		}
	rsa->flags &= ~RSA_FLAG_BLINDING;
	rsa->flags |= RSA_FLAG_NO_BLINDING;
	}

int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
	{
	int ret=0;

	if (rsa->blinding != NULL)
		RSA_blinding_off(rsa);

	rsa->blinding = RSA_setup_blinding(rsa, ctx);
	if (rsa->blinding == NULL)
		goto err;

	rsa->flags |= RSA_FLAG_BLINDING;
	rsa->flags &= ~RSA_FLAG_NO_BLINDING;
	ret=1;
err:
	return(ret);
	}

static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
	const BIGNUM *q, BN_CTX *ctx)
{
	BIGNUM *ret = NULL, *r0, *r1, *r2;

	if (d == NULL || p == NULL || q == NULL)
		return NULL;

	BN_CTX_start(ctx);
	r0 = BN_CTX_get(ctx);
	r1 = BN_CTX_get(ctx);
	r2 = BN_CTX_get(ctx);
	if (r2 == NULL)
		goto err;

	if (!BN_sub(r1, p, BN_value_one())) goto err;
	if (!BN_sub(r2, q, BN_value_one())) goto err;
	if (!BN_mul(r0, r1, r2, ctx)) goto err;

	ret = BN_mod_inverse(NULL, d, r0, ctx);
err:
	BN_CTX_end(ctx);
	return ret;
}

BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
{
	BIGNUM *e;
	BN_CTX *ctx;
	BN_BLINDING *ret = NULL;

	if (in_ctx == NULL)
		{
		if ((ctx = BN_CTX_new()) == NULL) return 0;
		}
	else
		ctx = in_ctx;

	BN_CTX_start(ctx);
	e  = BN_CTX_get(ctx);
	if (e == NULL)
		{
		RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
		goto err;
		}

	if (rsa->e == NULL)
		{
		e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
		if (e == NULL)
			{
			RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
			goto err;
			}
		}
	else
		e = rsa->e;

	
	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
		{
		/* if PRNG is not properly seeded, resort to secret
		 * exponent as unpredictable seed */
		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);
		}

	ret = BN_BLINDING_create_param(NULL, e, rsa->n, ctx,
			rsa->meth->bn_mod_exp, rsa->_method_mod_n);
	BN_BLINDING_set_thread_id(ret, CRYPTO_thread_id());
err:
	BN_CTX_end(ctx);
	if (in_ctx == NULL)
		BN_CTX_free(ctx);

	return ret;
}

int RSA_memory_lock(RSA *r)
	{
	int i,j,k,off;
	char *p;
	BIGNUM *bn,**t[6],*b;
	BN_ULONG *ul;

	if (r->d == NULL) return(1);
	t[0]= &r->d;
	t[1]= &r->p;
	t[2]= &r->q;
	t[3]= &r->dmp1;
	t[4]= &r->dmq1;
	t[5]= &r->iqmp;
	k=sizeof(BIGNUM)*6;
	off=k/sizeof(BN_ULONG)+1;
	j=1;
	for (i=0; i<6; i++)
		j+= (*t[i])->top;
	if ((p=OPENSSL_malloc_locked((off+j)*sizeof(BN_ULONG))) == NULL)
		{
		RSAerr(RSA_F_RSA_MEMORY_LOCK,ERR_R_MALLOC_FAILURE);
		return(0);
		}
	bn=(BIGNUM *)p;
	ul=(BN_ULONG *)&(p[off]);
	for (i=0; i<6; i++)
		{
		b= *(t[i]);
		*(t[i])= &(bn[i]);
		memcpy((char *)&(bn[i]),(char *)b,sizeof(BIGNUM));
		bn[i].flags=BN_FLG_STATIC_DATA;
		bn[i].d=ul;
		memcpy((char *)ul,b->d,sizeof(BN_ULONG)*b->top);
		ul+=b->top;
		BN_clear_free(b);
		}
	
	/* I should fix this so it can still be done */
	r->flags&= ~(RSA_FLAG_CACHE_PRIVATE|RSA_FLAG_CACHE_PUBLIC);

	r->bignum_data=p;
	return(1);
	}