Mike Lockwood | 1305e95 | 2011-12-07 08:17:59 -0800 | [diff] [blame] | 1 | /* $OpenBSD: rsa.c,v 1.29 2006/11/06 21:25:28 markus Exp $ */ |
| 2 | /* |
| 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
| 6 | * |
| 7 | * As far as I am concerned, the code I have written for this software |
| 8 | * can be used freely for any purpose. Any derived versions of this |
| 9 | * software must be clearly marked as such, and if the derived work is |
| 10 | * incompatible with the protocol description in the RFC file, it must be |
| 11 | * called by a name other than "ssh" or "Secure Shell". |
| 12 | * |
| 13 | * |
| 14 | * Copyright (c) 1999 Niels Provos. All rights reserved. |
| 15 | * |
| 16 | * Redistribution and use in source and binary forms, with or without |
| 17 | * modification, are permitted provided that the following conditions |
| 18 | * are met: |
| 19 | * 1. Redistributions of source code must retain the above copyright |
| 20 | * notice, this list of conditions and the following disclaimer. |
| 21 | * 2. Redistributions in binary form must reproduce the above copyright |
| 22 | * notice, this list of conditions and the following disclaimer in the |
| 23 | * documentation and/or other materials provided with the distribution. |
| 24 | * |
| 25 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 26 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 27 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 28 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 29 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 30 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 31 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 32 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 33 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 34 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 35 | * |
| 36 | * |
| 37 | * Description of the RSA algorithm can be found e.g. from the following |
| 38 | * sources: |
| 39 | * |
| 40 | * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994. |
| 41 | * |
| 42 | * Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to |
| 43 | * Computer Security. Prentice-Hall, 1989. |
| 44 | * |
| 45 | * Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill, |
| 46 | * 1994. |
| 47 | * |
| 48 | * R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications |
| 49 | * System and Method. US Patent 4,405,829, 1983. |
| 50 | * |
| 51 | * Hans Riesel: Prime Numbers and Computer Methods for Factorization. |
| 52 | * Birkhauser, 1994. |
| 53 | * |
| 54 | * The RSA Frequently Asked Questions document by RSA Data Security, |
| 55 | * Inc., 1995. |
| 56 | * |
| 57 | * RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as |
| 58 | * included below: |
| 59 | * |
| 60 | * [gone - had to be deleted - what a pity] |
| 61 | */ |
| 62 | |
| 63 | #include "includes.h" |
| 64 | |
| 65 | #include <sys/types.h> |
| 66 | |
| 67 | #include <stdarg.h> |
| 68 | #include <string.h> |
| 69 | |
| 70 | #include "xmalloc.h" |
| 71 | #include "rsa.h" |
| 72 | #include "log.h" |
| 73 | |
| 74 | void |
| 75 | rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
| 76 | { |
| 77 | u_char *inbuf, *outbuf; |
| 78 | int len, ilen, olen; |
| 79 | |
| 80 | if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) |
| 81 | fatal("rsa_public_encrypt() exponent too small or not odd"); |
| 82 | |
| 83 | olen = BN_num_bytes(key->n); |
| 84 | outbuf = xmalloc(olen); |
| 85 | |
| 86 | ilen = BN_num_bytes(in); |
| 87 | inbuf = xmalloc(ilen); |
| 88 | BN_bn2bin(in, inbuf); |
| 89 | |
| 90 | if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key, |
| 91 | RSA_PKCS1_PADDING)) <= 0) |
| 92 | fatal("rsa_public_encrypt() failed"); |
| 93 | |
| 94 | if (BN_bin2bn(outbuf, len, out) == NULL) |
| 95 | fatal("rsa_public_encrypt: BN_bin2bn failed"); |
| 96 | |
| 97 | memset(outbuf, 0, olen); |
| 98 | memset(inbuf, 0, ilen); |
| 99 | xfree(outbuf); |
| 100 | xfree(inbuf); |
| 101 | } |
| 102 | |
| 103 | int |
| 104 | rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
| 105 | { |
| 106 | u_char *inbuf, *outbuf; |
| 107 | int len, ilen, olen; |
| 108 | |
| 109 | olen = BN_num_bytes(key->n); |
| 110 | outbuf = xmalloc(olen); |
| 111 | |
| 112 | ilen = BN_num_bytes(in); |
| 113 | inbuf = xmalloc(ilen); |
| 114 | BN_bn2bin(in, inbuf); |
| 115 | |
| 116 | if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key, |
| 117 | RSA_PKCS1_PADDING)) <= 0) { |
| 118 | error("rsa_private_decrypt() failed"); |
| 119 | } else { |
| 120 | if (BN_bin2bn(outbuf, len, out) == NULL) |
| 121 | fatal("rsa_private_decrypt: BN_bin2bn failed"); |
| 122 | } |
| 123 | memset(outbuf, 0, olen); |
| 124 | memset(inbuf, 0, ilen); |
| 125 | xfree(outbuf); |
| 126 | xfree(inbuf); |
| 127 | return len; |
| 128 | } |
| 129 | |
| 130 | /* calculate p-1 and q-1 */ |
| 131 | void |
| 132 | rsa_generate_additional_parameters(RSA *rsa) |
| 133 | { |
| 134 | BIGNUM *aux; |
| 135 | BN_CTX *ctx; |
| 136 | |
| 137 | if ((aux = BN_new()) == NULL) |
| 138 | fatal("rsa_generate_additional_parameters: BN_new failed"); |
| 139 | if ((ctx = BN_CTX_new()) == NULL) |
| 140 | fatal("rsa_generate_additional_parameters: BN_CTX_new failed"); |
| 141 | |
| 142 | if ((BN_sub(aux, rsa->q, BN_value_one()) == 0) || |
| 143 | (BN_mod(rsa->dmq1, rsa->d, aux, ctx) == 0) || |
| 144 | (BN_sub(aux, rsa->p, BN_value_one()) == 0) || |
| 145 | (BN_mod(rsa->dmp1, rsa->d, aux, ctx) == 0)) |
| 146 | fatal("rsa_generate_additional_parameters: BN_sub/mod failed"); |
| 147 | |
| 148 | BN_clear_free(aux); |
| 149 | BN_CTX_free(ctx); |
| 150 | } |
| 151 | |