[openssh.git] / key.c

/*
 * Copyright (c) 2000 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Markus Friedl.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * read_bignum():
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 */

#include "includes.h"
#include "ssh.h"
#include <openssl/rsa.h>
#include <openssl/dsa.h>
#include <openssl/evp.h>
#include "xmalloc.h"
#include "key.h"

Key *
key_new(int type)
{
	Key *k;
	RSA *rsa;
	DSA *dsa;
	k = xmalloc(sizeof(*k));
	k->type = type;
	switch (k->type) {
	case KEY_RSA:
		rsa = RSA_new();
		rsa->n = BN_new();
		rsa->e = BN_new();
		k->rsa = rsa;
		break;
	case KEY_DSA:
		dsa = DSA_new();
		dsa->p = BN_new();
		dsa->q = BN_new();
		dsa->g = BN_new();
		dsa->pub_key = BN_new();
		k->dsa = dsa;
		break;
	case KEY_EMPTY:
		k->dsa = NULL;
		k->rsa = NULL;
		break;
	default:
		fatal("key_new: bad key type %d", k->type);
		break;
	}
	return k;
}
void
key_free(Key *k)
{
	switch (k->type) {
	case KEY_RSA:
		if (k->rsa != NULL)
			RSA_free(k->rsa);
		k->rsa = NULL;
		break;
	case KEY_DSA:
		if (k->dsa != NULL)
			DSA_free(k->dsa);
		k->dsa = NULL;
		break;
	default:
		fatal("key_free: bad key type %d", k->type);
		break;
	}
	xfree(k);
}
int
key_equal(Key *a, Key *b)
{
	if (a == NULL || b == NULL || a->type != b->type)
		return 0;
	switch (a->type) {
	case KEY_RSA:
		return a->rsa != NULL && b->rsa != NULL &&
		    BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
		    BN_cmp(a->rsa->n, b->rsa->n) == 0;
		break;
	case KEY_DSA:
		return a->dsa != NULL && b->dsa != NULL &&
		    BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
		    BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
		    BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
		    BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
		break;
	default:
		fatal("key_free: bad key type %d", a->type);
		break;
	}
	return 0;
}

#define FPRINT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"

/*
 * Generate key fingerprint in ascii format.
 * Based on ideas and code from Bjoern Groenvall <bg@sics.se>
 */
char *
key_fingerprint(Key *k)
{
	static char retval[80];
	unsigned char *buf = NULL;
	int len = 0;
	int nlen, elen, plen, qlen, glen, publen;

	switch (k->type) {
	case KEY_RSA:
		nlen = BN_num_bytes(k->rsa->n);
		elen = BN_num_bytes(k->rsa->e);
		len = nlen + elen;
		buf = xmalloc(len);
		BN_bn2bin(k->rsa->n, buf);
		BN_bn2bin(k->rsa->e, buf + nlen);
		break;
	case KEY_DSA:
		plen = BN_num_bytes(k->dsa->p);
		qlen = BN_num_bytes(k->dsa->q);
		glen = BN_num_bytes(k->dsa->g);
		publen = BN_num_bytes(k->dsa->pub_key);
		len = qlen + qlen + glen + publen;
		buf = xmalloc(len);
		BN_bn2bin(k->dsa->p, buf);
		BN_bn2bin(k->dsa->q, buf + plen);
		BN_bn2bin(k->dsa->g, buf + plen + qlen);
		BN_bn2bin(k->dsa->pub_key , buf + plen + qlen + glen);
		break;
	default:
		fatal("key_fingerprint: bad key type %d", k->type);
		break;
	}
	if (buf != NULL) {
		unsigned char d[16];
		EVP_MD_CTX md;
		EVP_DigestInit(&md, EVP_md5());
		EVP_DigestUpdate(&md, buf, len);
		EVP_DigestFinal(&md, d, NULL);
		snprintf(retval, sizeof(retval), FPRINT,
		    d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
		    d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
		memset(buf, 0, len);
		xfree(buf);
	}
	return retval;
}

/*
 * Reads a multiple-precision integer in decimal from the buffer, and advances
 * the pointer.  The integer must already be initialized.  This function is
 * permitted to modify the buffer.  This leaves *cpp to point just beyond the
 * last processed (and maybe modified) character.  Note that this may modify
 * the buffer containing the number.
 */
int
read_bignum(char **cpp, BIGNUM * value)
{
	char *cp = *cpp;
	int old;

	/* Skip any leading whitespace. */
	for (; *cp == ' ' || *cp == '\t'; cp++)
		;

	/* Check that it begins with a decimal digit. */
	if (*cp < '0' || *cp > '9')
		return 0;

	/* Save starting position. */
	*cpp = cp;

	/* Move forward until all decimal digits skipped. */
	for (; *cp >= '0' && *cp <= '9'; cp++)
		;

	/* Save the old terminating character, and replace it by \0. */
	old = *cp;
	*cp = 0;

	/* Parse the number. */
	if (BN_dec2bn(&value, *cpp) == 0)
		return 0;

	/* Restore old terminating character. */
	*cp = old;

	/* Move beyond the number and return success. */
	*cpp = cp;
	return 1;
}
int
write_bignum(FILE *f, BIGNUM *num)
{
	char *buf = BN_bn2dec(num);
	if (buf == NULL) {
		error("write_bignum: BN_bn2dec() failed");
		return 0;
	}
	fprintf(f, " %s", buf);
	free(buf);
	return 1;
}
int
key_read(Key *ret, unsigned int bits, char **cpp)
{
	switch(ret->type) {
	case KEY_RSA:
		if (bits == 0)
			return 0;
		/* Get public exponent, public modulus. */
		if (!read_bignum(cpp, ret->rsa->e))
			return 0;
		if (!read_bignum(cpp, ret->rsa->n))
			return 0;
		break;
	case KEY_DSA:
		if (bits != 0)
			return 0;
		if (!read_bignum(cpp, ret->dsa->p))
			return 0;
		if (!read_bignum(cpp, ret->dsa->q))
			return 0;
		if (!read_bignum(cpp, ret->dsa->g))
			return 0;
		if (!read_bignum(cpp, ret->dsa->pub_key))
			return 0;
		break;
	default:
		fatal("bad key type: %d", ret->type);
		break;
	}
	return 1;
}
int
key_write(Key *key, FILE *f)
{
	int success = 0;
	unsigned int bits = 0;

	if (key->type == KEY_RSA && key->rsa != NULL) {
		/* size of modulus 'n' */
		bits = BN_num_bits(key->rsa->n);
		fprintf(f, "%u", bits);
		if (write_bignum(f, key->rsa->e) &&
		    write_bignum(f, key->rsa->n)) {
			success = 1;
		} else {
			error("key_write: failed for RSA key");
		}
	} else if (key->type == KEY_DSA && key->dsa != NULL) {
		/* bits == 0 means DSA key */
		bits = 0;
		fprintf(f, "%u", bits);
		if (write_bignum(f, key->dsa->p) &&
		    write_bignum(f, key->dsa->q) &&
		    write_bignum(f, key->dsa->g) &&
		    write_bignum(f, key->dsa->pub_key)) {
			success = 1;
		} else {
			error("key_write: failed for DSA key");
		}
	}
	return success;
}
Commit	Line	Data
4fe2af09	1	/*
	2	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	* 3. All advertising materials mentioning features or use of this software
	13	* must display the following acknowledgement:
	14	* This product includes software developed by Markus Friedl.
	15	* 4. The name of the author may not be used to endorse or promote products
	16	* derived from this software without specific prior written permission.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	28	*/
	29	/*
	30	* read_bignum():
	31	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	32	*/
	33
	34	#include "includes.h"
35484284	35	#include "ssh.h"
4fe2af09	36	#include <openssl/rsa.h>
	37	#include <openssl/dsa.h>
	38	#include <openssl/evp.h>
4fe2af09	39	#include "xmalloc.h"
	40	#include "key.h"
	41
	42	Key *
	43	key_new(int type)
	44	{
	45	Key *k;
	46	RSA *rsa;
	47	DSA *dsa;
	48	k = xmalloc(sizeof(*k));
	49	k->type = type;
	50	switch (k->type) {
	51	case KEY_RSA:
	52	rsa = RSA_new();
	53	rsa->n = BN_new();
	54	rsa->e = BN_new();
	55	k->rsa = rsa;
	56	break;
	57	case KEY_DSA:
	58	dsa = DSA_new();
	59	dsa->p = BN_new();
	60	dsa->q = BN_new();
	61	dsa->g = BN_new();
	62	dsa->pub_key = BN_new();
	63	k->dsa = dsa;
	64	break;
	65	case KEY_EMPTY:
	66	k->dsa = NULL;
	67	k->rsa = NULL;
	68	break;
	69	default:
	70	fatal("key_new: bad key type %d", k->type);
	71	break;
	72	}
	73	return k;
	74	}
	75	void
	76	key_free(Key *k)
	77	{
	78	switch (k->type) {
	79	case KEY_RSA:
	80	if (k->rsa != NULL)
	81	RSA_free(k->rsa);
	82	k->rsa = NULL;
	83	break;
	84	case KEY_DSA:
	85	if (k->dsa != NULL)
	86	DSA_free(k->dsa);
	87	k->dsa = NULL;
	88	break;
	89	default:
	90	fatal("key_free: bad key type %d", k->type);
	91	break;
	92	}
	93	xfree(k);
	94	}
	95	int
	96	key_equal(Key a, Key b)
	97	{
	98	if (a == NULL \|\| b == NULL \|\| a->type != b->type)
	99	return 0;
	100	switch (a->type) {
	101	case KEY_RSA:
	102	return a->rsa != NULL && b->rsa != NULL &&
103	BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
104	BN_cmp(a->rsa->n, b->rsa->n) == 0;
105	break;
106	case KEY_DSA:
107	return a->dsa != NULL && b->dsa != NULL &&
108	BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
109	BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
110	BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
111	BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
112	break;
113	default:
114	fatal("key_free: bad key type %d", a->type);
115	break;
116	}
117	return 0;
118	}
119
120	#define FPRINT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
121
122	/*
123	* Generate key fingerprint in ascii format.
124	* Based on ideas and code from Bjoern Groenvall <bg@sics.se>
125	*/
126	char *
127	key_fingerprint(Key *k)
128	{
129	static char retval[80];
130	unsigned char *buf = NULL;
131	int len = 0;
132	int nlen, elen, plen, qlen, glen, publen;
133
134	switch (k->type) {
135	case KEY_RSA:
136	nlen = BN_num_bytes(k->rsa->n);
137	elen = BN_num_bytes(k->rsa->e);
138	len = nlen + elen;
139	buf = xmalloc(len);
140	BN_bn2bin(k->rsa->n, buf);
141	BN_bn2bin(k->rsa->e, buf + nlen);
142	break;
143	case KEY_DSA:
144	plen = BN_num_bytes(k->dsa->p);
145	qlen = BN_num_bytes(k->dsa->q);
146	glen = BN_num_bytes(k->dsa->g);
147	publen = BN_num_bytes(k->dsa->pub_key);
148	len = qlen + qlen + glen + publen;
149	buf = xmalloc(len);
150	BN_bn2bin(k->dsa->p, buf);
151	BN_bn2bin(k->dsa->q, buf + plen);
152	BN_bn2bin(k->dsa->g, buf + plen + qlen);
153	BN_bn2bin(k->dsa->pub_key , buf + plen + qlen + glen);
154	break;
155	default:
156	fatal("key_fingerprint: bad key type %d", k->type);
157	break;
158	}
159	if (buf != NULL) {
160	unsigned char d[16];
161	EVP_MD_CTX md;
162	EVP_DigestInit(&md, EVP_md5());
163	EVP_DigestUpdate(&md, buf, len);
164	EVP_DigestFinal(&md, d, NULL);
165	snprintf(retval, sizeof(retval), FPRINT,
166	d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
167	d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
168	memset(buf, 0, len);
169	xfree(buf);
170	}
171	return retval;
172	}
173
174	/*
175	* Reads a multiple-precision integer in decimal from the buffer, and advances
176	* the pointer. The integer must already be initialized. This function is
177	* permitted to modify the buffer. This leaves *cpp to point just beyond the
178	* last processed (and maybe modified) character. Note that this may modify
179	* the buffer containing the number.
180	*/
181	int
182	read_bignum(char *cpp, BIGNUM value)
183	{
184	char cp = cpp;
185	int old;
186
187	/* Skip any leading whitespace. */
188	for (; cp == ' ' \|\| cp == '\t'; cp++)
189	;
190
191	/* Check that it begins with a decimal digit. */
192	if (cp < '0' \|\| cp > '9')
193	return 0;
194
195	/* Save starting position. */
196	*cpp = cp;
197
198	/* Move forward until all decimal digits skipped. */
199	for (; cp >= '0' && cp <= '9'; cp++)
200	;
201
202	/* Save the old terminating character, and replace it by \0. */
203	old = *cp;
204	*cp = 0;
205
206	/* Parse the number. */
207	if (BN_dec2bn(&value, *cpp) == 0)
208	return 0;
209
210	/* Restore old terminating character. */
211	*cp = old;
212
213	/* Move beyond the number and return success. */
214	*cpp = cp;
215	return 1;
216	}
217	int
218	write_bignum(FILE f, BIGNUM num)
219	{
220	char *buf = BN_bn2dec(num);
221	if (buf == NULL) {
222	error("write_bignum: BN_bn2dec() failed");
223	return 0;
224	}
225	fprintf(f, " %s", buf);
226	free(buf);
227	return 1;
228	}
229	int
230	key_read(Key ret, unsigned int bits, char *cpp)
231	{
232	switch(ret->type) {
233	case KEY_RSA:
234	if (bits == 0)
235	return 0;
236	/* Get public exponent, public modulus. */
237	if (!read_bignum(cpp, ret->rsa->e))
238	return 0;
239	if (!read_bignum(cpp, ret->rsa->n))
240	return 0;
241	break;
242	case KEY_DSA:
243	if (bits != 0)
244	return 0;
245	if (!read_bignum(cpp, ret->dsa->p))
246	return 0;
247	if (!read_bignum(cpp, ret->dsa->q))
248	return 0;
249	if (!read_bignum(cpp, ret->dsa->g))
250	return 0;
251	if (!read_bignum(cpp, ret->dsa->pub_key))
252	return 0;
253	break;
254	default:
255	fatal("bad key type: %d", ret->type);
256	break;
257	}
258	return 1;
259	}
260	int
261	key_write(Key key, FILE f)
262	{
263	int success = 0;
264	unsigned int bits = 0;
265
266	if (key->type == KEY_RSA && key->rsa != NULL) {
267	/* size of modulus 'n' */
268	bits = BN_num_bits(key->rsa->n);
269	fprintf(f, "%u", bits);
270	if (write_bignum(f, key->rsa->e) &&
271	write_bignum(f, key->rsa->n)) {
272	success = 1;
273	} else {
274	error("key_write: failed for RSA key");
275	}
276	} else if (key->type == KEY_DSA && key->dsa != NULL) {
277	/* bits == 0 means DSA key */
278	bits = 0;
279	fprintf(f, "%u", bits);
280	if (write_bignum(f, key->dsa->p) &&
281	write_bignum(f, key->dsa->q) &&
282	write_bignum(f, key->dsa->g) &&
283	write_bignum(f, key->dsa->pub_key)) {
284	success = 1;
285	} else {
286	error("key_write: failed for DSA key");
287	}
288	}
289	return success;
290	}