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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
2
3rsa.c
4
5Author: Tatu Ylonen <ylo@cs.hut.fi>
6
7Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 All rights reserved
9
10Created: Fri Mar 3 22:07:06 1995 ylo
11
12Description 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
35*/
36
37#include "includes.h"
Damien Millerda217a01999-11-09 10:35:52 +110038RCSID("$Id: rsa.c,v 1.3 1999/11/08 23:35:52 damien Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100039
40#include "rsa.h"
41#include "ssh.h"
42#include "xmalloc.h"
43
44int rsa_verbose = 1;
45
46int
47rsa_alive()
48{
49 RSA *key;
50
51 key = RSA_generate_key(32, 3, NULL, NULL);
52 if (key == NULL)
53 return (0);
54 RSA_free(key);
55 return (1);
56}
57
58/* Generates RSA public and private keys. This initializes the data
59 structures; they should be freed with rsa_clear_private_key and
60 rsa_clear_public_key. */
61
62void
63rsa_generate_key(RSA *prv, RSA *pub, unsigned int bits)
64{
65 RSA *key;
66
67 if (rsa_verbose) {
68 printf("Generating RSA keys: ");
69 fflush(stdout);
70 }
71
72 key = RSA_generate_key(bits, 35, NULL, NULL);
Damien Miller356a0b01999-11-08 15:30:59 +110073 if (key == NULL)
74 fatal("rsa_generate_key: key generation failed.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075
76 /* Copy public key parameters */
77 pub->n = BN_new();
78 BN_copy(pub->n, key->n);
79 pub->e = BN_new();
80 BN_copy(pub->e, key->e);
81
82 /* Copy private key parameters */
83 prv->n = BN_new();
84 BN_copy(prv->n, key->n);
85 prv->e = BN_new();
86 BN_copy(prv->e, key->e);
87 prv->d = BN_new();
88 BN_copy(prv->d, key->d);
89 prv->p = BN_new();
90 BN_copy(prv->p, key->p);
91 prv->q = BN_new();
92 BN_copy(prv->q, key->q);
93
94 prv->dmp1 = BN_new();
95 BN_copy(prv->dmp1, key->dmp1);
96
97 prv->dmq1 = BN_new();
98 BN_copy(prv->dmq1, key->dmq1);
99
100 prv->iqmp = BN_new();
101 BN_copy(prv->iqmp, key->iqmp);
102
103 RSA_free(key);
104
105 if (rsa_verbose)
106 printf("Key generation complete.\n");
107}
108
109void
110rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA* key)
111{
112 char *inbuf, *outbuf;
Damien Millerda217a01999-11-09 10:35:52 +1100113 int len, ilen, olen;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000114
115 if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e))
116 fatal("rsa_public_encrypt() exponent too small or not odd");
117
Damien Millerda217a01999-11-09 10:35:52 +1100118 olen = BN_num_bytes(key->n);
119 outbuf = xmalloc(olen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000120
Damien Millerda217a01999-11-09 10:35:52 +1100121 ilen = BN_num_bytes(in);
122 inbuf = xmalloc(ilen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000123 BN_bn2bin(in, inbuf);
124
Damien Millerda217a01999-11-09 10:35:52 +1100125 if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key,
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000126 RSA_PKCS1_PADDING)) <= 0)
127 fatal("rsa_public_encrypt() failed");
128
129 BN_bin2bn(outbuf, len, out);
130
Damien Millerda217a01999-11-09 10:35:52 +1100131 memset(outbuf, 0, olen);
132 memset(inbuf, 0, ilen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000133 xfree(outbuf);
134 xfree(inbuf);
135}
136
137void
138rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key)
139{
140 char *inbuf, *outbuf;
Damien Millerda217a01999-11-09 10:35:52 +1100141 int len, ilen, olen;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000142
Damien Millerda217a01999-11-09 10:35:52 +1100143 olen = BN_num_bytes(key->n);
144 outbuf = xmalloc(olen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000145
Damien Millerda217a01999-11-09 10:35:52 +1100146 ilen = BN_num_bytes(in);
147 inbuf = xmalloc(ilen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000148 BN_bn2bin(in, inbuf);
149
Damien Millerda217a01999-11-09 10:35:52 +1100150 if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key,
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000151 RSA_SSLV23_PADDING)) <= 0)
152 fatal("rsa_private_decrypt() failed");
153
154 BN_bin2bn(outbuf, len, out);
155
Damien Millerda217a01999-11-09 10:35:52 +1100156 memset(outbuf, 0, olen);
157 memset(inbuf, 0, ilen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000158 xfree(outbuf);
159 xfree(inbuf);
160}
161
162/* Set whether to output verbose messages during key generation. */
163
164void
165rsa_set_verbose(int verbose)
166{
167 rsa_verbose = verbose;
168}