diff options
Diffstat (limited to 'crypto/rsa/rsa_enc.c')
| -rw-r--r-- | crypto/rsa/rsa_enc.c | 538 |
1 files changed, 538 insertions, 0 deletions
diff --git a/crypto/rsa/rsa_enc.c b/crypto/rsa/rsa_enc.c new file mode 100644 index 0000000000..c4a4ad5a60 --- /dev/null +++ b/crypto/rsa/rsa_enc.c @@ -0,0 +1,538 @@ +/* crypto/rsa/rsa_enc.c */ +/* Copyright (C) 1995-1997 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 "cryptlib.h" +#include "bn.h" +#include "rsa.h" +#include "rand.h" + +#ifndef NOPROTO +static int RSA_eay_public_encrypt(int flen, unsigned char *from, + unsigned char *to, RSA *rsa,int padding); +static int RSA_eay_private_encrypt(int flen, unsigned char *from, + unsigned char *to, RSA *rsa,int padding); +static int RSA_eay_public_decrypt(int flen, unsigned char *from, + unsigned char *to, RSA *rsa,int padding); +static int RSA_eay_private_decrypt(int flen, unsigned char *from, + unsigned char *to, RSA *rsa,int padding); +static int RSA_eay_mod_exp(BIGNUM *r0, BIGNUM *i, RSA *rsa); +#else +static int RSA_eay_public_encrypt(); +static int RSA_eay_private_encrypt(); +static int RSA_eay_public_decrypt(); +static int RSA_eay_private_decrypt(); +static int RSA_eay_mod_exp(); +#endif + +static RSA_METHOD rsa_pkcs1_eay_meth={ + "Eric Young's PKCS#1 RSA", + RSA_eay_public_encrypt, + RSA_eay_public_decrypt, + RSA_eay_private_encrypt, + RSA_eay_private_decrypt, + RSA_eay_mod_exp, + BN_mod_exp, + NULL, + NULL, + }; + +RSA_METHOD *RSA_PKCS1_SSLeay() + { + return(&rsa_pkcs1_eay_meth); + } + +static int RSA_eay_public_encrypt(flen, from, to, rsa, padding) +int flen; +unsigned char *from; +unsigned char *to; +RSA *rsa; +int padding; + { + BIGNUM *f=NULL,*ret=NULL; + int i,j,k,num=0,r= -1; + unsigned char *p; + unsigned char *buf=NULL; + BN_CTX *ctx=NULL; + + if ( (padding != RSA_PKCS1_PADDING) && + (padding != RSA_SSLV23_PADDING)) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); + goto err; + } + + ctx=BN_CTX_new(); + if (ctx == NULL) goto err; + + num=BN_num_bytes(rsa->n); + if (flen > (num-11)) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + goto err; + } + + buf=(unsigned char *)Malloc(num); + if (buf == NULL) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE); + goto err; + } + p=(unsigned char *)buf; + + *(p++)=0; + *(p++)=2; /* Public Key BT (Block Type) */ + + /* pad out with non-zero random data */ + j=num-3-flen; + + RAND_bytes(p,j); + for (i=0; i<j; i++) + { + if (*p == '\0') + do { + RAND_bytes(p,1); + } while (*p == '\0'); + p++; + } + + if (padding == RSA_SSLV23_PADDING) + memset(&(p[-8]),3,8); + + *(p++)='\0'; + + memcpy(p,from,(unsigned int)flen); + + f=BN_new(); + ret=BN_new(); + if ((f == NULL) || (ret == NULL)) goto err; + + if (BN_bin2bn(buf,num,f) == NULL) goto err; + if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err; + + /* put in leading 0 bytes if the number is less than the + * length of the modulus */ + j=BN_num_bytes(ret); + i=BN_bn2bin(ret,&(to[num-j])); + for (k=0; k<(num-i); k++) + to[k]=0; + + r=num; +err: + if (ctx != NULL) BN_CTX_free(ctx); + if (f != NULL) BN_free(f); + if (ret != NULL) BN_free(ret); + if (buf != NULL) + { + memset(buf,0,num); + Free(buf); + } + return(r); + } + +static int RSA_eay_private_encrypt(flen, from, to, rsa, padding) +int flen; +unsigned char *from; +unsigned char *to; +RSA *rsa; +int padding; + { + BIGNUM *f=NULL,*ret=NULL; + int i,j,k,num=0,r= -1; + unsigned char *p; + unsigned char *buf=NULL; + BN_CTX *ctx=NULL; + + if (padding != RSA_PKCS1_PADDING) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); + goto err; + } + + ctx=BN_CTX_new(); + if (ctx == NULL) goto err; + + num=BN_num_bytes(rsa->n); + if (flen > (num-11)) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + goto err; + } + buf=(unsigned char *)Malloc(num); + if (buf == NULL) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); + goto err; + } + p=buf; + + *(p++)=0; + *(p++)=1; /* Private Key BT (Block Type) */ + + /* padd out with 0xff data */ + j=num-3-flen; + for (i=0; i<j; i++) + *(p++)=0xff; + *(p++)='\0'; + memcpy(p,from,(unsigned int)flen); + ret=BN_new(); + f=BN_new(); + if ((ret == NULL) || (f == NULL)) goto err; + if (BN_bin2bn(buf,num,f) == NULL) goto err; + if ( (rsa->p != NULL) && + (rsa->q != NULL) && + (rsa->dmp1 != NULL) && + (rsa->dmq1 != NULL) && + (rsa->iqmp != NULL)) + { if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; } + else + { if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; } + + p=buf; + BN_bn2bin(ret,p); + + /* put in leading 0 bytes if the number is less than the + * length of the modulus */ + j=BN_num_bytes(ret); + i=BN_bn2bin(ret,&(to[num-j])); + for (k=0; k<(num-i); k++) + to[k]=0; + + r=num; +err: + if (ctx != NULL) BN_CTX_free(ctx); + if (ret != NULL) BN_free(ret); + if (f != NULL) BN_free(f); + if (buf != NULL) + { + memset(buf,0,num); + Free(buf); + } + return(r); + } + +static int RSA_eay_private_decrypt(flen, from, to, rsa,padding) +int flen; +unsigned char *from; +unsigned char *to; +RSA *rsa; +int padding; + { + BIGNUM *f=NULL,*ret=NULL; + int i,j,num=0,r= -1; + unsigned char *p; + unsigned char *buf=NULL; + BN_CTX *ctx=NULL; + + if ((padding != RSA_PKCS1_PADDING) && (padding != RSA_SSLV23_PADDING)) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); + goto err; + } + + ctx=BN_CTX_new(); + if (ctx == NULL) goto err; + + num=BN_num_bytes(rsa->n); + + buf=(unsigned char *)Malloc(num); + if (buf == NULL) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); + goto err; + } + + /* This check was for equallity but PGP does evil things + * and chops off the top '0' bytes */ + if (flen > num) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); + goto err; + } + + /* make data into a big number */ + ret=BN_new(); + f=BN_new(); + if ((ret == NULL) || (f == NULL)) goto err; + if (BN_bin2bn(from,(int)flen,f) == NULL) goto err; + /* do the decrypt */ + if ( (rsa->p != NULL) && + (rsa->q != NULL) && + (rsa->dmp1 != NULL) && + (rsa->dmq1 != NULL) && + (rsa->iqmp != NULL)) + { if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; } + else + { if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; } + + p=buf; + BN_bn2bin(ret,p); + + /* BT must be 02 */ + if (*(p++) != 02) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_02); + goto err; + } + + /* scan over padding data */ + j=num-2; /* one for type and one for the prepended 0. */ + for (i=0; i<j; i++) + if (*(p++) == 0) break; + + if (i == j) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING); + goto err; + } + + if (i < 8) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT); + goto err; + } + +#undef RSA_DEBUG +#ifdef RSA_DEBUG + { + int z; + unsigned char *q; + q= &(p[-9]); + fprintf(stderr,"\n"); + for (z=0; z<8; z++) fprintf(stderr,"%02X",q[z]); + fprintf(stderr,"\n"); + } +#endif + + if (padding == RSA_SSLV23_PADDING) + { + int z; + unsigned char *q; + + /* -9 because we have jumped the '\0' */ + q= &(p[-9]); + for (z=0; z<8; z++) + { + if (*(q++) != 0x03) + break; + } + if (z == 8) + { + RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_SSLV3_ROLLBACK_ATTACK); + goto err; + } + } + + /* skip over the '\0' */ + i++; + j-=i; + + /* output data */ + memcpy(to,p,(unsigned int)j); + r=j; +err: + if (ctx != NULL) BN_CTX_free(ctx); + if (f != NULL) BN_free(f); + if (ret != NULL) BN_free(ret); + if (buf != NULL) + { + memset(buf,0,num); + Free(buf); + } + return(r); + } + +static int RSA_eay_public_decrypt(flen, from, to, rsa, padding) +int flen; +unsigned char *from; +unsigned char *to; +RSA *rsa; +int padding; + { + BIGNUM *f=NULL,*ret=NULL; + int i,j,num=0,r= -1; + unsigned char *p; + unsigned char *buf=NULL; + BN_CTX *ctx=NULL; + + if (padding != RSA_PKCS1_PADDING) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); + goto err; + } + + ctx=BN_CTX_new(); + if (ctx == NULL) goto err; + + num=BN_num_bytes(rsa->n); + buf=(unsigned char *)Malloc(num); + if (buf == NULL) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE); + goto err; + } + + /* This check was for equallity but PGP does evil things + * and chops off the top '0' bytes */ + if (flen > num) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); + goto err; + } + + /* make data into a big number */ + f=BN_new(); + ret=BN_new(); + if ((f == NULL) || (ret == NULL)) goto err; + + if (BN_bin2bn(from,flen,f) == NULL) goto err; + /* do the decrypt */ + if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err; + + p=buf; + i=BN_bn2bin(ret,p); + + /* BT must be 01 */ + if (*(p++) != 01) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_01); + goto err; + } + + /* scan over padding data */ + j=num-2; /* one for type and one for the prepended 0. */ + for (i=0; i<j; i++) + { + if (*p != 0xff) /* should decrypt to 0xff */ + { + if (*p == 0) + { p++; break; } + else { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_FIXED_HEADER_DECRYPT); + goto err; + } + } + p++; + } + if (i == j) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING); + goto err; + } + if (i < 8) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT); + goto err; + } + + /* skip over the '\0' */ + i++; + j-=i; + + /* output data */ + memcpy(to,p,(unsigned int)j); + r=j; +err: + if (ctx != NULL) BN_CTX_free(ctx); + if (f != NULL) BN_free(f); + if (ret != NULL) BN_free(ret); + if (buf != NULL) + { + memset(buf,0,num); + Free(buf); + } + return(r); + } + +static int RSA_eay_mod_exp(r0, I, rsa) +BIGNUM *r0; +BIGNUM *I; +RSA *rsa; + { + BIGNUM *r1=NULL,*m1=NULL; + int ret=0; + BN_CTX *ctx; + + if ((ctx=BN_CTX_new()) == NULL) goto err; + m1=BN_new(); + r1=BN_new(); + 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); + } + + |