538 lines
13 KiB
C
538 lines
13 KiB
C
/* crypto/rsa/rsa_enc.c */
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/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
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* All rights reserved.
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*
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* This package is an SSL implementation written
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* by Eric Young (eay@cryptsoft.com).
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* The implementation was written so as to conform with Netscapes SSL.
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*
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* This library is free for commercial and non-commercial use as long as
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* the following conditions are aheared to. The following conditions
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* apply to all code found in this distribution, be it the RC4, RSA,
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation
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* included with this distribution is covered by the same copyright terms
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* except that the holder is Tim Hudson (tjh@cryptsoft.com).
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*
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* Copyright remains Eric Young's, and as such any Copyright notices in
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* the code are not to be removed.
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* If this package is used in a product, Eric Young should be given attribution
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* as the author of the parts of the library used.
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* This can be in the form of a textual message at program startup or
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* in documentation (online or textual) provided with the package.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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#include <stdio.h>
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#include "cryptlib.h"
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#include "bn.h"
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#include "rsa.h"
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#include "rand.h"
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#ifndef NOPROTO
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static int RSA_eay_public_encrypt(int flen, unsigned char *from,
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unsigned char *to, RSA *rsa,int padding);
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static int RSA_eay_private_encrypt(int flen, unsigned char *from,
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unsigned char *to, RSA *rsa,int padding);
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static int RSA_eay_public_decrypt(int flen, unsigned char *from,
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unsigned char *to, RSA *rsa,int padding);
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static int RSA_eay_private_decrypt(int flen, unsigned char *from,
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unsigned char *to, RSA *rsa,int padding);
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static int RSA_eay_mod_exp(BIGNUM *r0, BIGNUM *i, RSA *rsa);
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#else
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static int RSA_eay_public_encrypt();
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static int RSA_eay_private_encrypt();
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static int RSA_eay_public_decrypt();
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static int RSA_eay_private_decrypt();
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static int RSA_eay_mod_exp();
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#endif
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static RSA_METHOD rsa_pkcs1_eay_meth={
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"Eric Young's PKCS#1 RSA",
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RSA_eay_public_encrypt,
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RSA_eay_public_decrypt,
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RSA_eay_private_encrypt,
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RSA_eay_private_decrypt,
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RSA_eay_mod_exp,
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BN_mod_exp,
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NULL,
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NULL,
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};
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RSA_METHOD *RSA_PKCS1_SSLeay()
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{
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return(&rsa_pkcs1_eay_meth);
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}
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static int RSA_eay_public_encrypt(flen, from, to, rsa, padding)
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int flen;
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unsigned char *from;
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unsigned char *to;
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RSA *rsa;
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int padding;
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{
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BIGNUM *f=NULL,*ret=NULL;
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int i,j,k,num=0,r= -1;
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unsigned char *p;
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unsigned char *buf=NULL;
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BN_CTX *ctx=NULL;
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if ( (padding != RSA_PKCS1_PADDING) &&
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(padding != RSA_SSLV23_PADDING))
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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ctx=BN_CTX_new();
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if (ctx == NULL) goto err;
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num=BN_num_bytes(rsa->n);
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if (flen > (num-11))
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
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goto err;
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}
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buf=(unsigned char *)Malloc(num);
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if (buf == NULL)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
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goto err;
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}
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p=(unsigned char *)buf;
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*(p++)=0;
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*(p++)=2; /* Public Key BT (Block Type) */
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/* pad out with non-zero random data */
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j=num-3-flen;
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RAND_bytes(p,j);
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for (i=0; i<j; i++)
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{
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if (*p == '\0')
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do {
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RAND_bytes(p,1);
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} while (*p == '\0');
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p++;
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}
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if (padding == RSA_SSLV23_PADDING)
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memset(&(p[-8]),3,8);
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*(p++)='\0';
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memcpy(p,from,(unsigned int)flen);
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f=BN_new();
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ret=BN_new();
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if ((f == NULL) || (ret == NULL)) goto err;
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if (BN_bin2bn(buf,num,f) == NULL) goto err;
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if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err;
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/* put in leading 0 bytes if the number is less than the
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* length of the modulus */
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j=BN_num_bytes(ret);
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i=BN_bn2bin(ret,&(to[num-j]));
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for (k=0; k<(num-i); k++)
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to[k]=0;
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r=num;
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err:
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if (ctx != NULL) BN_CTX_free(ctx);
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if (f != NULL) BN_free(f);
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if (ret != NULL) BN_free(ret);
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if (buf != NULL)
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{
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memset(buf,0,num);
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Free(buf);
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}
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return(r);
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}
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static int RSA_eay_private_encrypt(flen, from, to, rsa, padding)
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int flen;
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unsigned char *from;
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unsigned char *to;
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RSA *rsa;
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int padding;
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{
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BIGNUM *f=NULL,*ret=NULL;
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int i,j,k,num=0,r= -1;
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unsigned char *p;
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unsigned char *buf=NULL;
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BN_CTX *ctx=NULL;
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if (padding != RSA_PKCS1_PADDING)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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ctx=BN_CTX_new();
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if (ctx == NULL) goto err;
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num=BN_num_bytes(rsa->n);
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if (flen > (num-11))
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
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goto err;
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}
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buf=(unsigned char *)Malloc(num);
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if (buf == NULL)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
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goto err;
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}
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p=buf;
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*(p++)=0;
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*(p++)=1; /* Private Key BT (Block Type) */
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/* padd out with 0xff data */
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j=num-3-flen;
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for (i=0; i<j; i++)
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*(p++)=0xff;
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*(p++)='\0';
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memcpy(p,from,(unsigned int)flen);
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ret=BN_new();
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f=BN_new();
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if ((ret == NULL) || (f == NULL)) goto err;
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if (BN_bin2bn(buf,num,f) == NULL) goto err;
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if ( (rsa->p != NULL) &&
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(rsa->q != NULL) &&
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(rsa->dmp1 != NULL) &&
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(rsa->dmq1 != NULL) &&
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(rsa->iqmp != NULL))
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{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
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else
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{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }
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p=buf;
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BN_bn2bin(ret,p);
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/* put in leading 0 bytes if the number is less than the
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* length of the modulus */
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j=BN_num_bytes(ret);
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i=BN_bn2bin(ret,&(to[num-j]));
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for (k=0; k<(num-i); k++)
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to[k]=0;
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r=num;
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err:
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if (ctx != NULL) BN_CTX_free(ctx);
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if (ret != NULL) BN_free(ret);
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if (f != NULL) BN_free(f);
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if (buf != NULL)
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{
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memset(buf,0,num);
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Free(buf);
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}
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return(r);
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}
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static int RSA_eay_private_decrypt(flen, from, to, rsa,padding)
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int flen;
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unsigned char *from;
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unsigned char *to;
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RSA *rsa;
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int padding;
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{
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BIGNUM *f=NULL,*ret=NULL;
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int i,j,num=0,r= -1;
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unsigned char *p;
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unsigned char *buf=NULL;
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BN_CTX *ctx=NULL;
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if ((padding != RSA_PKCS1_PADDING) && (padding != RSA_SSLV23_PADDING))
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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ctx=BN_CTX_new();
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if (ctx == NULL) goto err;
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num=BN_num_bytes(rsa->n);
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buf=(unsigned char *)Malloc(num);
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if (buf == NULL)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
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goto err;
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}
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/* This check was for equallity but PGP does evil things
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* and chops off the top '0' bytes */
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if (flen > num)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
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goto err;
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}
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/* make data into a big number */
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ret=BN_new();
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f=BN_new();
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if ((ret == NULL) || (f == NULL)) goto err;
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if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
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/* do the decrypt */
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if ( (rsa->p != NULL) &&
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(rsa->q != NULL) &&
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(rsa->dmp1 != NULL) &&
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(rsa->dmq1 != NULL) &&
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(rsa->iqmp != NULL))
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{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
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else
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{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }
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p=buf;
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BN_bn2bin(ret,p);
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/* BT must be 02 */
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if (*(p++) != 02)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_02);
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goto err;
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}
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/* scan over padding data */
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j=num-2; /* one for type and one for the prepended 0. */
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for (i=0; i<j; i++)
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if (*(p++) == 0) break;
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if (i == j)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
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goto err;
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}
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if (i < 8)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
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goto err;
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}
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#undef RSA_DEBUG
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#ifdef RSA_DEBUG
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{
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int z;
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unsigned char *q;
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q= &(p[-9]);
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fprintf(stderr,"\n");
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for (z=0; z<8; z++) fprintf(stderr,"%02X",q[z]);
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fprintf(stderr,"\n");
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}
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#endif
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if (padding == RSA_SSLV23_PADDING)
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{
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int z;
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unsigned char *q;
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/* -9 because we have jumped the '\0' */
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q= &(p[-9]);
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for (z=0; z<8; z++)
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{
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if (*(q++) != 0x03)
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break;
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}
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if (z == 8)
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{
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RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_SSLV3_ROLLBACK_ATTACK);
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goto err;
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}
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}
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/* skip over the '\0' */
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i++;
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j-=i;
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/* output data */
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memcpy(to,p,(unsigned int)j);
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r=j;
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err:
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if (ctx != NULL) BN_CTX_free(ctx);
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if (f != NULL) BN_free(f);
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if (ret != NULL) BN_free(ret);
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if (buf != NULL)
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{
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memset(buf,0,num);
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Free(buf);
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}
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return(r);
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}
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static int RSA_eay_public_decrypt(flen, from, to, rsa, padding)
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int flen;
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unsigned char *from;
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unsigned char *to;
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RSA *rsa;
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int padding;
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{
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BIGNUM *f=NULL,*ret=NULL;
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int i,j,num=0,r= -1;
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unsigned char *p;
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unsigned char *buf=NULL;
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BN_CTX *ctx=NULL;
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if (padding != RSA_PKCS1_PADDING)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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ctx=BN_CTX_new();
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if (ctx == NULL) goto err;
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num=BN_num_bytes(rsa->n);
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buf=(unsigned char *)Malloc(num);
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if (buf == NULL)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
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goto err;
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}
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/* This check was for equallity but PGP does evil things
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* and chops off the top '0' bytes */
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if (flen > num)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
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goto err;
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}
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/* make data into a big number */
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f=BN_new();
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ret=BN_new();
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if ((f == NULL) || (ret == NULL)) goto err;
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if (BN_bin2bn(from,flen,f) == NULL) goto err;
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/* do the decrypt */
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if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err;
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p=buf;
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i=BN_bn2bin(ret,p);
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/* BT must be 01 */
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if (*(p++) != 01)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_01);
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goto err;
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}
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/* scan over padding data */
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j=num-2; /* one for type and one for the prepended 0. */
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for (i=0; i<j; i++)
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{
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if (*p != 0xff) /* should decrypt to 0xff */
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{
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if (*p == 0)
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{ p++; break; }
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else {
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_FIXED_HEADER_DECRYPT);
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goto err;
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}
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}
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p++;
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}
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if (i == j)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
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goto err;
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}
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if (i < 8)
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{
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RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
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goto err;
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}
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/* skip over the '\0' */
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i++;
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j-=i;
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/* output data */
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memcpy(to,p,(unsigned int)j);
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r=j;
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err:
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if (ctx != NULL) BN_CTX_free(ctx);
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if (f != NULL) BN_free(f);
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if (ret != NULL) BN_free(ret);
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if (buf != NULL)
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{
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memset(buf,0,num);
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Free(buf);
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}
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return(r);
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}
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static int RSA_eay_mod_exp(r0, I, rsa)
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BIGNUM *r0;
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BIGNUM *I;
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RSA *rsa;
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{
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BIGNUM *r1=NULL,*m1=NULL;
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int ret=0;
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BN_CTX *ctx;
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if ((ctx=BN_CTX_new()) == NULL) goto err;
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m1=BN_new();
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r1=BN_new();
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|
if ((m1 == NULL) || (r1 == NULL)) goto err;
|
|
|
|
if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
|
|
if (!rsa->meth->bn_mod_exp(m1,r1,rsa->dmq1,rsa->q,ctx)) goto err;
|
|
|
|
if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
|
|
if (!rsa->meth->bn_mod_exp(r0,r1,rsa->dmp1,rsa->p,ctx)) goto err;
|
|
|
|
if (!BN_add(r1,r0,rsa->p)) goto err;
|
|
if (!BN_sub(r0,r1,m1)) goto err;
|
|
|
|
if (!BN_mul(r1,r0,rsa->iqmp)) goto err;
|
|
if (!BN_mod(r0,r1,rsa->p,ctx)) goto err;
|
|
if (!BN_mul(r1,r0,rsa->q)) goto err;
|
|
if (!BN_add(r0,r1,m1)) goto err;
|
|
|
|
ret=1;
|
|
err:
|
|
if (m1 != NULL) BN_free(m1);
|
|
if (r1 != NULL) BN_free(r1);
|
|
BN_CTX_free(ctx);
|
|
return(ret);
|
|
}
|
|
|
|
|