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 | * |
| 3 | * rsa.c |
| 4 | * |
| 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 6 | * |
| 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | * All rights reserved |
| 9 | * |
| 10 | * Created: Fri Mar 3 22:07:06 1995 ylo |
| 11 | * |
| 12 | * Description of the RSA algorithm can be found e.g. from the following sources: |
| 13 | * |
| 14 | * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994. |
| 15 | * |
| 16 | * Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to |
| 17 | * Computer Security. Prentice-Hall, 1989. |
| 18 | * |
| 19 | * Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill, |
| 20 | * 1994. |
| 21 | * |
| 22 | * R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications |
| 23 | * System and Method. US Patent 4,405,829, 1983. |
| 24 | * |
| 25 | * Hans Riesel: Prime Numbers and Computer Methods for Factorization. |
| 26 | * Birkhauser, 1994. |
| 27 | * |
| 28 | * The RSA Frequently Asked Questions document by RSA Data Security, Inc., 1995. |
| 29 | * |
| 30 | * RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as included |
| 31 | * below: |
| 32 | * |
| 33 | * [gone - had to be deleted - what a pity] |
| 34 | * |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 35 | */ |
| 36 | |
| 37 | #include "includes.h" |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 38 | RCSID("$Id: rsa.c,v 1.5 1999/11/25 00:54:59 damien Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 39 | |
| 40 | #include "rsa.h" |
| 41 | #include "ssh.h" |
| 42 | #include "xmalloc.h" |
| 43 | |
| 44 | int rsa_verbose = 1; |
| 45 | |
| 46 | int |
| 47 | rsa_alive() |
| 48 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 49 | RSA *key; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 50 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 51 | key = RSA_generate_key(32, 3, NULL, NULL); |
| 52 | if (key == NULL) |
| 53 | return (0); |
| 54 | RSA_free(key); |
| 55 | return (1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 56 | } |
| 57 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 58 | /* |
| 59 | * Generates RSA public and private keys. This initializes the data |
| 60 | * structures; they should be freed with rsa_clear_private_key and |
| 61 | * rsa_clear_public_key. |
| 62 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 63 | |
| 64 | void |
| 65 | rsa_generate_key(RSA *prv, RSA *pub, unsigned int bits) |
| 66 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 67 | RSA *key; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 68 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 69 | if (rsa_verbose) { |
| 70 | printf("Generating RSA keys: "); |
| 71 | fflush(stdout); |
| 72 | } |
| 73 | key = RSA_generate_key(bits, 35, NULL, NULL); |
| 74 | if (key == NULL) |
| 75 | fatal("rsa_generate_key: key generation failed."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 76 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 77 | /* Copy public key parameters */ |
| 78 | pub->n = BN_new(); |
| 79 | BN_copy(pub->n, key->n); |
| 80 | pub->e = BN_new(); |
| 81 | BN_copy(pub->e, key->e); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 82 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 83 | /* Copy private key parameters */ |
| 84 | prv->n = BN_new(); |
| 85 | BN_copy(prv->n, key->n); |
| 86 | prv->e = BN_new(); |
| 87 | BN_copy(prv->e, key->e); |
| 88 | prv->d = BN_new(); |
| 89 | BN_copy(prv->d, key->d); |
| 90 | prv->p = BN_new(); |
| 91 | BN_copy(prv->p, key->p); |
| 92 | prv->q = BN_new(); |
| 93 | BN_copy(prv->q, key->q); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 94 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 95 | prv->dmp1 = BN_new(); |
| 96 | BN_copy(prv->dmp1, key->dmp1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 97 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 98 | prv->dmq1 = BN_new(); |
| 99 | BN_copy(prv->dmq1, key->dmq1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 100 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 101 | prv->iqmp = BN_new(); |
| 102 | BN_copy(prv->iqmp, key->iqmp); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 103 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 104 | RSA_free(key); |
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 | if (rsa_verbose) |
| 107 | printf("Key generation complete.\n"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 108 | } |
| 109 | |
| 110 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 111 | rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 112 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 113 | char *inbuf, *outbuf; |
| 114 | int len, ilen, olen; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 115 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 116 | if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) |
| 117 | fatal("rsa_public_encrypt() exponent too small or not odd"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 118 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 119 | olen = BN_num_bytes(key->n); |
| 120 | outbuf = xmalloc(olen); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 121 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 122 | ilen = BN_num_bytes(in); |
| 123 | inbuf = xmalloc(ilen); |
| 124 | BN_bn2bin(in, inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 125 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 126 | if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key, |
| 127 | RSA_PKCS1_PADDING)) <= 0) |
| 128 | fatal("rsa_public_encrypt() failed"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 129 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 130 | BN_bin2bn(outbuf, len, out); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 131 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 132 | memset(outbuf, 0, olen); |
| 133 | memset(inbuf, 0, ilen); |
| 134 | xfree(outbuf); |
| 135 | xfree(inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 136 | } |
| 137 | |
| 138 | void |
| 139 | rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) |
| 140 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 141 | char *inbuf, *outbuf; |
| 142 | int len, ilen, olen; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 143 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 144 | olen = BN_num_bytes(key->n); |
| 145 | outbuf = xmalloc(olen); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 146 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 147 | ilen = BN_num_bytes(in); |
| 148 | inbuf = xmalloc(ilen); |
| 149 | BN_bn2bin(in, inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 150 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 151 | if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key, |
| 152 | RSA_SSLV23_PADDING)) <= 0) |
| 153 | fatal("rsa_private_decrypt() failed"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 154 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 155 | BN_bin2bn(outbuf, len, out); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 156 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 157 | memset(outbuf, 0, olen); |
| 158 | memset(inbuf, 0, ilen); |
| 159 | xfree(outbuf); |
| 160 | xfree(inbuf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 161 | } |
| 162 | |
| 163 | /* Set whether to output verbose messages during key generation. */ |
| 164 | |
| 165 | void |
| 166 | rsa_set_verbose(int verbose) |
| 167 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 168 | rsa_verbose = verbose; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 169 | } |