1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * As far as I am concerned, the code I have written for this software 7 * can be used freely for any purpose. Any derived versions of this 8 * software must be clearly marked as such, and if the derived work is 9 * incompatible with the protocol description in the RFC file, it must be 10 * called by a name other than "ssh" or "Secure Shell". 11 * 12 * 13 * Copyright (c) 1999 Niels Provos. All rights reserved. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 * 35 * 36 * Description of the RSA algorithm can be found e.g. from the following 37 * sources: 38 * 39 * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994. 40 * 41 * Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to 42 * Computer Security. Prentice-Hall, 1989. 43 * 44 * Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill, 45 * 1994. 46 * 47 * R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications 48 * System and Method. US Patent 4,405,829, 1983. 49 * 50 * Hans Riesel: Prime Numbers and Computer Methods for Factorization. 51 * Birkhauser, 1994. 52 * 53 * The RSA Frequently Asked Questions document by RSA Data Security, 54 * Inc., 1995. 55 * 56 * RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as 57 * included below: 58 * 59 * [gone - had to be deleted - what a pity] 60 */ 61 62 #include "includes.h" 63 RCSID("$OpenBSD: rsa.c,v 1.24 2001/12/27 18:22:16 markus Exp $"); 64 65 #pragma ident "%Z%%M% %I% %E% SMI" 66 67 #include "rsa.h" 68 #include "log.h" 69 #include "xmalloc.h" 70 71 void 72 rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key) 73 { 74 u_char *inbuf, *outbuf; 75 int len, ilen, olen; 76 77 if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) 78 fatal("rsa_public_encrypt() exponent too small or not odd"); 79 80 olen = BN_num_bytes(key->n); 81 outbuf = xmalloc(olen); 82 83 ilen = BN_num_bytes(in); 84 inbuf = xmalloc(ilen); 85 BN_bn2bin(in, inbuf); 86 87 if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key, 88 RSA_PKCS1_PADDING)) <= 0) 89 fatal("rsa_public_encrypt() failed"); 90 91 BN_bin2bn(outbuf, len, out); 92 93 memset(outbuf, 0, olen); 94 memset(inbuf, 0, ilen); 95 xfree(outbuf); 96 xfree(inbuf); 97 } 98 99 int 100 rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) 101 { 102 u_char *inbuf, *outbuf; 103 int len, ilen, olen; 104 105 olen = BN_num_bytes(key->n); 106 outbuf = xmalloc(olen); 107 108 ilen = BN_num_bytes(in); 109 inbuf = xmalloc(ilen); 110 BN_bn2bin(in, inbuf); 111 112 if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key, 113 RSA_PKCS1_PADDING)) <= 0) { 114 error("rsa_private_decrypt() failed"); 115 } else { 116 BN_bin2bn(outbuf, len, out); 117 } 118 memset(outbuf, 0, olen); 119 memset(inbuf, 0, ilen); 120 xfree(outbuf); 121 xfree(inbuf); 122 return len; 123 } 124 125 /* calculate p-1 and q-1 */ 126 void 127 rsa_generate_additional_parameters(RSA *rsa) 128 { 129 BIGNUM *aux; 130 BN_CTX *ctx; 131 132 if ((aux = BN_new()) == NULL) 133 fatal("rsa_generate_additional_parameters: BN_new failed"); 134 if ((ctx = BN_CTX_new()) == NULL) 135 fatal("rsa_generate_additional_parameters: BN_CTX_new failed"); 136 137 BN_sub(aux, rsa->q, BN_value_one()); 138 BN_mod(rsa->dmq1, rsa->d, aux, ctx); 139 140 BN_sub(aux, rsa->p, BN_value_one()); 141 BN_mod(rsa->dmp1, rsa->d, aux, ctx); 142 143 BN_clear_free(aux); 144 BN_CTX_free(ctx); 145 } 146 147