Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 4 | * All rights reserved |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 5 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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". |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 11 | * |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 12 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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: |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 38 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 39 | * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 40 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 41 | * Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to |
| 42 | * Computer Security. Prentice-Hall, 1989. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 43 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 44 | * Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill, |
| 45 | * 1994. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 46 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 47 | * R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications |
| 48 | * System and Method. US Patent 4,405,829, 1983. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 49 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 50 | * Hans Riesel: Prime Numbers and Computer Methods for Factorization. |
| 51 | * Birkhauser, 1994. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 52 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 53 | * The RSA Frequently Asked Questions document by RSA Data Security, |
| 54 | * Inc., 1995. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 55 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 56 | * RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as |
| 57 | * included below: |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 58 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 59 | * [gone - had to be deleted - what a pity] |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 60 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 61 | |
| 62 | #include "includes.h" |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 63 | RCSID("$OpenBSD: rsa.c,v 1.24 2001/12/27 18:22:16 markus Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 64 | |
| 65 | #include "rsa.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 66 | #include "log.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 67 | #include "xmalloc.h" |
| 68 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 69 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 70 | rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 71 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 72 | u_char *inbuf, *outbuf; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 73 | int len, ilen, olen; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 74 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 75 | if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) |
| 76 | fatal("rsa_public_encrypt() exponent too small or not odd"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 77 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 78 | olen = BN_num_bytes(key->n); |
| 79 | outbuf = xmalloc(olen); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 80 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 81 | ilen = BN_num_bytes(in); |
| 82 | inbuf = xmalloc(ilen); |
| 83 | BN_bn2bin(in, inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 84 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 85 | if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key, |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 86 | RSA_PKCS1_PADDING)) <= 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 87 | fatal("rsa_public_encrypt() failed"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 88 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 89 | BN_bin2bn(outbuf, len, out); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 90 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 91 | memset(outbuf, 0, olen); |
| 92 | memset(inbuf, 0, ilen); |
| 93 | xfree(outbuf); |
| 94 | xfree(inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 95 | } |
| 96 | |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 97 | int |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 98 | rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
| 99 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 100 | u_char *inbuf, *outbuf; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 101 | int len, ilen, olen; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 102 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 103 | olen = BN_num_bytes(key->n); |
| 104 | outbuf = xmalloc(olen); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 105 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 106 | ilen = BN_num_bytes(in); |
| 107 | inbuf = xmalloc(ilen); |
| 108 | BN_bn2bin(in, inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 109 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 110 | if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key, |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 111 | RSA_PKCS1_PADDING)) <= 0) { |
| 112 | error("rsa_private_decrypt() failed"); |
| 113 | } else { |
| 114 | BN_bin2bn(outbuf, len, out); |
| 115 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 116 | memset(outbuf, 0, olen); |
| 117 | memset(inbuf, 0, ilen); |
| 118 | xfree(outbuf); |
| 119 | xfree(inbuf); |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 120 | return len; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 121 | } |
Ben Lindstrom | d09fcf5 | 2001-03-29 00:29:54 +0000 | [diff] [blame] | 122 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 123 | /* calculate p-1 and q-1 */ |
Ben Lindstrom | d09fcf5 | 2001-03-29 00:29:54 +0000 | [diff] [blame] | 124 | void |
Ben Lindstrom | f7297dd | 2001-07-04 05:02:23 +0000 | [diff] [blame] | 125 | rsa_generate_additional_parameters(RSA *rsa) |
Ben Lindstrom | d09fcf5 | 2001-03-29 00:29:54 +0000 | [diff] [blame] | 126 | { |
| 127 | BIGNUM *aux; |
| 128 | BN_CTX *ctx; |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 129 | |
| 130 | if ((aux = BN_new()) == NULL) |
| 131 | fatal("rsa_generate_additional_parameters: BN_new failed"); |
| 132 | if ((ctx = BN_CTX_new()) == NULL) |
| 133 | fatal("rsa_generate_additional_parameters: BN_CTX_new failed"); |
Ben Lindstrom | d09fcf5 | 2001-03-29 00:29:54 +0000 | [diff] [blame] | 134 | |
| 135 | BN_sub(aux, rsa->q, BN_value_one()); |
| 136 | BN_mod(rsa->dmq1, rsa->d, aux, ctx); |
| 137 | |
| 138 | BN_sub(aux, rsa->p, BN_value_one()); |
| 139 | BN_mod(rsa->dmp1, rsa->d, aux, ctx); |
| 140 | |
| 141 | BN_clear_free(aux); |
| 142 | BN_CTX_free(ctx); |
| 143 | } |
| 144 | |