[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"
#include "dsa.h"
#include "uuencode.h"

RCSID("$OpenBSD: key.c,v 1.9 2000/06/22 23:55:00 djm Exp $");

#define SSH_DSS "ssh-dss"

Key *
key_new(int type)
{
	Key *k;
	RSA *rsa;
	DSA *dsa;
	k = xmalloc(sizeof(*k));
	k->type = type;
	k->dsa = NULL;
	k->rsa = NULL;
	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:
		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_equal: bad key type %d", a->type);
		break;
	}
	return 0;
}

/*
 * 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[(EVP_MAX_MD_SIZE+1)*3];
	unsigned char *blob = NULL;
	int len = 0;
	int nlen, elen;

	switch (k->type) {
	case KEY_RSA:
		nlen = BN_num_bytes(k->rsa->n);
		elen = BN_num_bytes(k->rsa->e);
		len = nlen + elen;
		blob = xmalloc(len);
		BN_bn2bin(k->rsa->n, blob);
		BN_bn2bin(k->rsa->e, blob + nlen);
		break;
	case KEY_DSA:
		dsa_make_key_blob(k, &blob, &len);
		break;
	default:
		fatal("key_fingerprint: bad key type %d", k->type);
		break;
	}
	retval[0] = '\0';

	if (blob != NULL) {
		int i;
		unsigned char digest[EVP_MAX_MD_SIZE];
		EVP_MD *md = EVP_md5();
		EVP_MD_CTX ctx;
		EVP_DigestInit(&ctx, md);
		EVP_DigestUpdate(&ctx, blob, len);
		EVP_DigestFinal(&ctx, digest, NULL);
		for(i = 0; i < md->md_size; i++) {
			char hex[4];
			snprintf(hex, sizeof(hex), "%02x:", digest[i]);
			strlcat(retval, hex, sizeof(retval));
		}
		retval[strlen(retval) - 1] = '\0';
		memset(blob, 0, len);
		xfree(blob);
	}
	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;
}
unsigned int
key_read(Key *ret, char **cpp)
{
	Key *k;
	unsigned int bits = 0;
	char *cp;
	int len, n;
	unsigned char *blob;

	cp = *cpp;

	switch(ret->type) {
	case KEY_RSA:
		/* Get number of bits. */
		if (*cp < '0' || *cp > '9')
			return 0;	/* Bad bit count... */
		for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
			bits = 10 * bits + *cp - '0';
		if (bits == 0)
			return 0;
		*cpp = cp;
		/* 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 (strncmp(cp, SSH_DSS " ", 7) != 0)
			return 0;
		cp += 7;
		len = 2*strlen(cp);
		blob = xmalloc(len);
		n = uudecode(cp, blob, len);
		if (n < 0) {
			error("key_read: uudecode %s failed", cp);
			return 0;
		}
		k = dsa_key_from_blob(blob, n);
		if (k == NULL) {
			error("key_read: dsa_key_from_blob %s failed", cp);
			return 0;
		}
		xfree(blob);
		if (ret->dsa != NULL)
			DSA_free(ret->dsa);
		ret->dsa = k->dsa;
		k->dsa = NULL;
		key_free(k);
		bits = BN_num_bits(ret->dsa->p);
		/* advance cp: skip whitespace and data */
		while (*cp == ' ' || *cp == '\t')
			cp++;
		while (*cp != '\0' && *cp != ' ' && *cp != '\t')
			cp++;
		*cpp = cp;
		break;
	default:
		fatal("key_read: bad key type: %d", ret->type);
		break;
	}
	return bits;
}
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) {
		int len, n;
		unsigned char *blob, *uu;
		dsa_make_key_blob(key, &blob, &len);
		uu = xmalloc(2*len);
		n = uuencode(blob, len, uu, 2*len);
		if (n > 0) {
			fprintf(f, "%s %s", SSH_DSS, uu);
			success = 1;
		}
		xfree(blob);
		xfree(uu);
	}
	return success;
}
char *
key_type(Key *k)
{
	switch (k->type) {
	case KEY_RSA:
		return "RSA";
		break;
	case KEY_DSA:
		return "DSA";
		break;
	}
	return "unknown";
}
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"
4fe2af09	40	#include "key.h"
a306f2dd	41	#include "dsa.h"
	42	#include "uuencode.h"
	43
e5a0294f	44	RCSID("$OpenBSD: key.c,v 1.9 2000/06/22 23:55:00 djm Exp $");
e5a0294f	45
a306f2dd	46	#define SSH_DSS "ssh-dss"
4fe2af09	47
	48	Key *
	49	key_new(int type)
	50	{
	51	Key *k;
	52	RSA *rsa;
	53	DSA *dsa;
	54	k = xmalloc(sizeof(*k));
	55	k->type = type;
a306f2dd	56	k->dsa = NULL;
a306f2dd	57	k->rsa = NULL;
4fe2af09	58	switch (k->type) {
	59	case KEY_RSA:
	60	rsa = RSA_new();
	61	rsa->n = BN_new();
	62	rsa->e = BN_new();
	63	k->rsa = rsa;
	64	break;
	65	case KEY_DSA:
	66	dsa = DSA_new();
	67	dsa->p = BN_new();
	68	dsa->q = BN_new();
	69	dsa->g = BN_new();
	70	dsa->pub_key = BN_new();
	71	k->dsa = dsa;
	72	break;
	73	case KEY_EMPTY:
4fe2af09	74	break;
	75	default:
	76	fatal("key_new: bad key type %d", k->type);
	77	break;
	78	}
	79	return k;
	80	}
	81	void
	82	key_free(Key *k)
	83	{
	84	switch (k->type) {
	85	case KEY_RSA:
	86	if (k->rsa != NULL)
	87	RSA_free(k->rsa);
	88	k->rsa = NULL;
	89	break;
	90	case KEY_DSA:
	91	if (k->dsa != NULL)
	92	DSA_free(k->dsa);
	93	k->dsa = NULL;
	94	break;
	95	default:
	96	fatal("key_free: bad key type %d", k->type);
	97	break;
	98	}
	99	xfree(k);
	100	}
	101	int
	102	key_equal(Key a, Key b)
	103	{
	104	if (a == NULL \|\| b == NULL \|\| a->type != b->type)
	105	return 0;
	106	switch (a->type) {
	107	case KEY_RSA:
	108	return a->rsa != NULL && b->rsa != NULL &&
	109	BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
	110	BN_cmp(a->rsa->n, b->rsa->n) == 0;
	111	break;
	112	case KEY_DSA:
	113	return a->dsa != NULL && b->dsa != NULL &&
	114	BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
	115	BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
	116	BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
	117	BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
	118	break;
	119	default:
a306f2dd	120	fatal("key_equal: bad key type %d", a->type);
4fe2af09	121	break;
	122	}
	123	return 0;
	124	}
	125
4fe2af09	126	/*
	127	* Generate key fingerprint in ascii format.
	128	* Based on ideas and code from Bjoern Groenvall <bg@sics.se>
	129	*/
	130	char *
	131	key_fingerprint(Key *k)
	132	{
74fc9186	133	static char retval[(EVP_MAX_MD_SIZE+1)*3];
a306f2dd	134	unsigned char *blob = NULL;
4fe2af09	135	int len = 0;
a306f2dd	136	int nlen, elen;
4fe2af09	137
	138	switch (k->type) {
	139	case KEY_RSA:
	140	nlen = BN_num_bytes(k->rsa->n);
	141	elen = BN_num_bytes(k->rsa->e);
	142	len = nlen + elen;
a306f2dd	143	blob = xmalloc(len);
	144	BN_bn2bin(k->rsa->n, blob);
	145	BN_bn2bin(k->rsa->e, blob + nlen);
4fe2af09	146	break;
4fe2af09	147	case KEY_DSA:
a306f2dd	148	dsa_make_key_blob(k, &blob, &len);
4fe2af09	149	break;
	150	default:
	151	fatal("key_fingerprint: bad key type %d", k->type);
	152	break;
	153	}
74fc9186	154	retval[0] = '\0';
74fc9186	155
a306f2dd	156	if (blob != NULL) {
74fc9186	157	int i;
	158	unsigned char digest[EVP_MAX_MD_SIZE];
	159	EVP_MD *md = EVP_md5();
	160	EVP_MD_CTX ctx;
	161	EVP_DigestInit(&ctx, md);
	162	EVP_DigestUpdate(&ctx, blob, len);
	163	EVP_DigestFinal(&ctx, digest, NULL);
	164	for(i = 0; i < md->md_size; i++) {
	165	char hex[4];
	166	snprintf(hex, sizeof(hex), "%02x:", digest[i]);
	167	strlcat(retval, hex, sizeof(retval));
	168	}
	169	retval[strlen(retval) - 1] = '\0';
a306f2dd	170	memset(blob, 0, len);
a306f2dd	171	xfree(blob);
4fe2af09	172	}
	173	return retval;
	174	}
	175
	176	/*
	177	* Reads a multiple-precision integer in decimal from the buffer, and advances
	178	* the pointer. The integer must already be initialized. This function is
	179	* permitted to modify the buffer. This leaves *cpp to point just beyond the
	180	* last processed (and maybe modified) character. Note that this may modify
	181	* the buffer containing the number.
	182	*/
	183	int
	184	read_bignum(char *cpp, BIGNUM value)
	185	{
	186	char cp = cpp;
	187	int old;
	188
	189	/* Skip any leading whitespace. */
	190	for (; cp == ' ' \|\| cp == '\t'; cp++)
	191	;
	192
	193	/* Check that it begins with a decimal digit. */
	194	if (cp < '0' \|\| cp > '9')
	195	return 0;
	196
	197	/* Save starting position. */
	198	*cpp = cp;
	199
	200	/* Move forward until all decimal digits skipped. */
	201	for (; cp >= '0' && cp <= '9'; cp++)
	202	;
	203
	204	/* Save the old terminating character, and replace it by \0. */
	205	old = *cp;
	206	*cp = 0;
	207
	208	/* Parse the number. */
	209	if (BN_dec2bn(&value, *cpp) == 0)
	210	return 0;
	211
	212	/* Restore old terminating character. */
	213	*cp = old;
	214
	215	/* Move beyond the number and return success. */
	216	*cpp = cp;
	217	return 1;
	218	}
	219	int
	220	write_bignum(FILE f, BIGNUM num)
	221	{
	222	char *buf = BN_bn2dec(num);
	223	if (buf == NULL) {
	224	error("write_bignum: BN_bn2dec() failed");
	225	return 0;
	226	}
	227	fprintf(f, " %s", buf);
	228	free(buf);
	229	return 1;
	230	}
a306f2dd	231	unsigned int
a306f2dd	232	key_read(Key ret, char *cpp)
4fe2af09	233	{
a306f2dd	234	Key *k;
	235	unsigned int bits = 0;
	236	char *cp;
	237	int len, n;
	238	unsigned char *blob;
	239
	240	cp = *cpp;
	241
4fe2af09	242	switch(ret->type) {
4fe2af09	243	case KEY_RSA:
a306f2dd	244	/* Get number of bits. */
	245	if (cp < '0' \|\| cp > '9')
	246	return 0; /* Bad bit count... */
	247	for (bits = 0; cp >= '0' && cp <= '9'; cp++)
	248	bits = 10 * bits + *cp - '0';
4fe2af09	249	if (bits == 0)
4fe2af09	250	return 0;
a306f2dd	251	*cpp = cp;
4fe2af09	252	/* Get public exponent, public modulus. */
	253	if (!read_bignum(cpp, ret->rsa->e))
	254	return 0;
	255	if (!read_bignum(cpp, ret->rsa->n))
	256	return 0;
	257	break;
	258	case KEY_DSA:
a306f2dd	259	if (strncmp(cp, SSH_DSS " ", 7) != 0)
4fe2af09	260	return 0;
a306f2dd	261	cp += 7;
	262	len = 2*strlen(cp);
	263	blob = xmalloc(len);
	264	n = uudecode(cp, blob, len);
1d1ffb87	265	if (n < 0) {
71276795	266	error("key_read: uudecode %s failed", cp);
1d1ffb87	267	return 0;
1d1ffb87	268	}
a306f2dd	269	k = dsa_key_from_blob(blob, n);
71276795	270	if (k == NULL) {
	271	error("key_read: dsa_key_from_blob %s failed", cp);
	272	return 0;
	273	}
a306f2dd	274	xfree(blob);
	275	if (ret->dsa != NULL)
	276	DSA_free(ret->dsa);
	277	ret->dsa = k->dsa;
	278	k->dsa = NULL;
	279	key_free(k);
	280	bits = BN_num_bits(ret->dsa->p);
71276795	281	/* advance cp: skip whitespace and data */
	282	while (cp == ' ' \|\| cp == '\t')
	283	cp++;
	284	while (cp != '\0' && cp != ' ' && *cp != '\t')
	285	cp++;
	286	*cpp = cp;
4fe2af09	287	break;
4fe2af09	288	default:
a306f2dd	289	fatal("key_read: bad key type: %d", ret->type);
4fe2af09	290	break;
4fe2af09	291	}
a306f2dd	292	return bits;
4fe2af09	293	}
	294	int
	295	key_write(Key key, FILE f)
	296	{
	297	int success = 0;
	298	unsigned int bits = 0;
	299
	300	if (key->type == KEY_RSA && key->rsa != NULL) {
	301	/* size of modulus 'n' */
	302	bits = BN_num_bits(key->rsa->n);
	303	fprintf(f, "%u", bits);
	304	if (write_bignum(f, key->rsa->e) &&
	305	write_bignum(f, key->rsa->n)) {
	306	success = 1;
	307	} else {
	308	error("key_write: failed for RSA key");
	309	}
	310	} else if (key->type == KEY_DSA && key->dsa != NULL) {
a306f2dd	311	int len, n;
	312	unsigned char blob, uu;
	313	dsa_make_key_blob(key, &blob, &len);
	314	uu = xmalloc(2*len);
1d1ffb87	315	n = uuencode(blob, len, uu, 2*len);
	316	if (n > 0) {
	317	fprintf(f, "%s %s", SSH_DSS, uu);
	318	success = 1;
	319	}
a306f2dd	320	xfree(blob);
a306f2dd	321	xfree(uu);
4fe2af09	322	}
	323	return success;
	324	}
1d1ffb87	325	char *
	326	key_type(Key *k)
	327	{
	328	switch (k->type) {
	329	case KEY_RSA:
	330	return "RSA";
	331	break;
	332	case KEY_DSA:
	333	return "DSA";
	334	break;
	335	}
	336	return "unknown";
	337	}