[openssh.git] / authfile.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * This file contains functions for reading and writing identity files, and
 * for reading the passphrase from the user.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 *
 *
 * 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.
 *
 * 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.
 */

#include "includes.h"
RCSID("$OpenBSD: authfile.c,v 1.19 2000/09/07 20:27:49 deraadt Exp $");

#include <openssl/bn.h>
#include <openssl/dsa.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>
#include <openssl/evp.h>

#include "xmalloc.h"
#include "buffer.h"
#include "bufaux.h"
#include "cipher.h"
#include "ssh.h"
#include "key.h"

/* Version identification string for identity files. */
#define AUTHFILE_ID_STRING "SSH PRIVATE KEY FILE FORMAT 1.1\n"

/*
 * Saves the authentication (private) key in a file, encrypting it with
 * passphrase.  The identification of the file (lowest 64 bits of n) will
 * precede the key to provide identification of the key without needing a
 * passphrase.
 */

int
save_private_key_rsa(const char *filename, const char *passphrase,
    RSA *key, const char *comment)
{
	Buffer buffer, encrypted;
	char buf[100], *cp;
	int fd, i;
	CipherContext cipher;
	int cipher_type;
	u_int32_t rand;

	/*
	 * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
	 * to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
	 */
	if (strcmp(passphrase, "") == 0)
		cipher_type = SSH_CIPHER_NONE;
	else
		cipher_type = SSH_AUTHFILE_CIPHER;

	/* This buffer is used to built the secret part of the private key. */
	buffer_init(&buffer);

	/* Put checkbytes for checking passphrase validity. */
	rand = arc4random();
	buf[0] = rand & 0xff;
	buf[1] = (rand >> 8) & 0xff;
	buf[2] = buf[0];
	buf[3] = buf[1];
	buffer_append(&buffer, buf, 4);

	/*
	 * Store the private key (n and e will not be stored because they
	 * will be stored in plain text, and storing them also in encrypted
	 * format would just give known plaintext).
	 */
	buffer_put_bignum(&buffer, key->d);
	buffer_put_bignum(&buffer, key->iqmp);
	buffer_put_bignum(&buffer, key->q);	/* reverse from SSL p */
	buffer_put_bignum(&buffer, key->p);	/* reverse from SSL q */

	/* Pad the part to be encrypted until its size is a multiple of 8. */
	while (buffer_len(&buffer) % 8 != 0)
		buffer_put_char(&buffer, 0);

	/* This buffer will be used to contain the data in the file. */
	buffer_init(&encrypted);

	/* First store keyfile id string. */
	cp = AUTHFILE_ID_STRING;
	for (i = 0; cp[i]; i++)
		buffer_put_char(&encrypted, cp[i]);
	buffer_put_char(&encrypted, 0);

	/* Store cipher type. */
	buffer_put_char(&encrypted, cipher_type);
	buffer_put_int(&encrypted, 0);	/* For future extension */

	/* Store public key.  This will be in plain text. */
	buffer_put_int(&encrypted, BN_num_bits(key->n));
	buffer_put_bignum(&encrypted, key->n);
	buffer_put_bignum(&encrypted, key->e);
	buffer_put_string(&encrypted, comment, strlen(comment));

	/* Allocate space for the private part of the key in the buffer. */
	buffer_append_space(&encrypted, &cp, buffer_len(&buffer));

	cipher_set_key_string(&cipher, cipher_type, passphrase);
	cipher_encrypt(&cipher, (unsigned char *) cp,
		       (unsigned char *) buffer_ptr(&buffer),
		       buffer_len(&buffer));
	memset(&cipher, 0, sizeof(cipher));

	/* Destroy temporary data. */
	memset(buf, 0, sizeof(buf));
	buffer_free(&buffer);

	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
	if (fd < 0)
		return 0;
	if (write(fd, buffer_ptr(&encrypted), buffer_len(&encrypted)) !=
	    buffer_len(&encrypted)) {
		debug("Write to key file %.200s failed: %.100s", filename,
		      strerror(errno));
		buffer_free(&encrypted);
		close(fd);
		remove(filename);
		return 0;
	}
	close(fd);
	buffer_free(&encrypted);
	return 1;
}

/* save DSA key in OpenSSL PEM format */

int
save_private_key_dsa(const char *filename, const char *passphrase,
    DSA *dsa, const char *comment)
{
	FILE *fp;
	int fd;
	int success = 1;
	int len = strlen(passphrase);

	if (len > 0 && len <= 4) {
		error("passphrase too short: %d bytes", len);
		errno = 0;
		return 0;
	}
	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
	if (fd < 0) {
		debug("open %s failed", filename);
		return 0;
	}
	fp = fdopen(fd, "w");
	if (fp == NULL ) {
		debug("fdopen %s failed", filename);
		close(fd);
		return 0;
	}
	if (len > 0) {
		if (!PEM_write_DSAPrivateKey(fp, dsa, EVP_des_ede3_cbc(),
		    (char *)passphrase, strlen(passphrase), NULL, NULL))
			success = 0;
	} else {
		if (!PEM_write_DSAPrivateKey(fp, dsa, NULL,
		    NULL, 0, NULL, NULL))
			success = 0;
	}
	fclose(fp);
	return success;
}

int
save_private_key(const char *filename, const char *passphrase, Key *key,
    const char *comment)
{
	switch (key->type) {
	case KEY_RSA:
		return save_private_key_rsa(filename, passphrase, key->rsa, comment);
		break;
	case KEY_DSA:
		return save_private_key_dsa(filename, passphrase, key->dsa, comment);
		break;
	default:
		break;
	}
	return 0;
}

/*
 * Loads the public part of the key file.  Returns 0 if an error was
 * encountered (the file does not exist or is not readable), and non-zero
 * otherwise.
 */

int
load_public_key_rsa(const char *filename, RSA * pub, char **comment_return)
{
	int fd, i;
	off_t len;
	Buffer buffer;
	char *cp;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		return 0;
	len = lseek(fd, (off_t) 0, SEEK_END);
	lseek(fd, (off_t) 0, SEEK_SET);

	buffer_init(&buffer);
	buffer_append_space(&buffer, &cp, len);

	if (read(fd, cp, (size_t) len) != (size_t) len) {
		debug("Read from key file %.200s failed: %.100s", filename,
		    strerror(errno));
		buffer_free(&buffer);
		close(fd);
		return 0;
	}
	close(fd);

	/* Check that it is at least big enought to contain the ID string. */
	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
		debug("Bad key file %.200s.", filename);
		buffer_free(&buffer);
		return 0;
	}
	/*
	 * Make sure it begins with the id string.  Consume the id string
	 * from the buffer.
	 */
	for (i = 0; i < (unsigned int) strlen(AUTHFILE_ID_STRING) + 1; i++)
		if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
			debug("Bad key file %.200s.", filename);
			buffer_free(&buffer);
			return 0;
		}
	/* Skip cipher type and reserved data. */
	(void) buffer_get_char(&buffer);	/* cipher type */
	(void) buffer_get_int(&buffer);		/* reserved */

	/* Read the public key from the buffer. */
	buffer_get_int(&buffer);
	/* XXX alloc */
	if (pub->n == NULL)
		pub->n = BN_new();
	buffer_get_bignum(&buffer, pub->n);
	/* XXX alloc */
	if (pub->e == NULL)
		pub->e = BN_new();
	buffer_get_bignum(&buffer, pub->e);
	if (comment_return)
		*comment_return = buffer_get_string(&buffer, NULL);
	/* The encrypted private part is not parsed by this function. */

	buffer_free(&buffer);

	return 1;
}

/* load public key from private-key file */
int
load_public_key(const char *filename, Key * key, char **comment_return)
{
	switch (key->type) {
	case KEY_RSA:
		return load_public_key_rsa(filename, key->rsa, comment_return);
		break;
	case KEY_DSA:
	default:
		break;
	}
	return 0;
}

/*
 * Loads the private key from the file.  Returns 0 if an error is encountered
 * (file does not exist or is not readable, or passphrase is bad). This
 * initializes the private key.
 * Assumes we are called under uid of the owner of the file.
 */

int
load_private_key_rsa(int fd, const char *filename,
    const char *passphrase, RSA * prv, char **comment_return)
{
	int i, check1, check2, cipher_type;
	off_t len;
	Buffer buffer, decrypted;
	char *cp;
	CipherContext cipher;
	BN_CTX *ctx;
	BIGNUM *aux;

	len = lseek(fd, (off_t) 0, SEEK_END);
	lseek(fd, (off_t) 0, SEEK_SET);

	buffer_init(&buffer);
	buffer_append_space(&buffer, &cp, len);

	if (read(fd, cp, (size_t) len) != (size_t) len) {
		debug("Read from key file %.200s failed: %.100s", filename,
		      strerror(errno));
		buffer_free(&buffer);
		close(fd);
		return 0;
	}
	close(fd);

	/* Check that it is at least big enought to contain the ID string. */
	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
		debug("Bad key file %.200s.", filename);
		buffer_free(&buffer);
		return 0;
	}
	/*
	 * Make sure it begins with the id string.  Consume the id string
	 * from the buffer.
	 */
	for (i = 0; i < (unsigned int) strlen(AUTHFILE_ID_STRING) + 1; i++)
		if (buffer_get_char(&buffer) != (unsigned char) AUTHFILE_ID_STRING[i]) {
			debug("Bad key file %.200s.", filename);
			buffer_free(&buffer);
			return 0;
		}
	/* Read cipher type. */
	cipher_type = buffer_get_char(&buffer);
	(void) buffer_get_int(&buffer);	/* Reserved data. */

	/* Read the public key from the buffer. */
	buffer_get_int(&buffer);
	prv->n = BN_new();
	buffer_get_bignum(&buffer, prv->n);
	prv->e = BN_new();
	buffer_get_bignum(&buffer, prv->e);
	if (comment_return)
		*comment_return = buffer_get_string(&buffer, NULL);
	else
		xfree(buffer_get_string(&buffer, NULL));

	/* Check that it is a supported cipher. */
	if (((cipher_mask1() | SSH_CIPHER_NONE | SSH_AUTHFILE_CIPHER) &
	     (1 << cipher_type)) == 0) {
		debug("Unsupported cipher %.100s used in key file %.200s.",
		      cipher_name(cipher_type), filename);
		buffer_free(&buffer);
		goto fail;
	}
	/* Initialize space for decrypted data. */
	buffer_init(&decrypted);
	buffer_append_space(&decrypted, &cp, buffer_len(&buffer));

	/* Rest of the buffer is encrypted.  Decrypt it using the passphrase. */
	cipher_set_key_string(&cipher, cipher_type, passphrase);
	cipher_decrypt(&cipher, (unsigned char *) cp,
		       (unsigned char *) buffer_ptr(&buffer),
		       buffer_len(&buffer));

	buffer_free(&buffer);

	check1 = buffer_get_char(&decrypted);
	check2 = buffer_get_char(&decrypted);
	if (check1 != buffer_get_char(&decrypted) ||
	    check2 != buffer_get_char(&decrypted)) {
		if (strcmp(passphrase, "") != 0)
			debug("Bad passphrase supplied for key file %.200s.", filename);
		/* Bad passphrase. */
		buffer_free(&decrypted);
fail:
		BN_clear_free(prv->n);
		prv->n = NULL;
		BN_clear_free(prv->e);
		prv->e = NULL;
		if (comment_return)
			xfree(*comment_return);
		return 0;
	}
	/* Read the rest of the private key. */
	prv->d = BN_new();
	buffer_get_bignum(&decrypted, prv->d);
	prv->iqmp = BN_new();
	buffer_get_bignum(&decrypted, prv->iqmp);	/* u */
	/* in SSL and SSH p and q are exchanged */
	prv->q = BN_new();
	buffer_get_bignum(&decrypted, prv->q);		/* p */
	prv->p = BN_new();
	buffer_get_bignum(&decrypted, prv->p);		/* q */

	ctx = BN_CTX_new();
	aux = BN_new();

	BN_sub(aux, prv->q, BN_value_one());
	prv->dmq1 = BN_new();
	BN_mod(prv->dmq1, prv->d, aux, ctx);

	BN_sub(aux, prv->p, BN_value_one());
	prv->dmp1 = BN_new();
	BN_mod(prv->dmp1, prv->d, aux, ctx);

	BN_clear_free(aux);
	BN_CTX_free(ctx);

	buffer_free(&decrypted);

	return 1;
}

int
load_private_key_dsa(int fd, const char *passphrase, Key *k, char **comment_return)
{
	DSA *dsa;
	BIO *in;
	FILE *fp;

	in = BIO_new(BIO_s_file());
	if (in == NULL) {
		error("BIO_new failed");
		return 0;
	}
	fp = fdopen(fd, "r");
	if (fp == NULL) {
		error("fdopen failed");
		return 0;
	}
	BIO_set_fp(in, fp, BIO_NOCLOSE);
	dsa = PEM_read_bio_DSAPrivateKey(in, NULL, NULL, (char *)passphrase);
	if (dsa == NULL) {
		debug("PEM_read_bio_DSAPrivateKey failed");
	} else {
		/* replace k->dsa with loaded key */
		DSA_free(k->dsa);
		k->dsa = dsa;
	}
	BIO_free(in);
	fclose(fp);
	if (comment_return)
		*comment_return = xstrdup("dsa w/o comment");
	debug("read DSA private key done");
#ifdef DEBUG_DSS
	DSA_print_fp(stderr, dsa, 8);
#endif
	return dsa != NULL ? 1 : 0;
}

int
load_private_key(const char *filename, const char *passphrase, Key *key,
    char **comment_return)
{
	int fd;
	int ret = 0;
	struct stat st;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		return 0;

	/* check owner and modes */
#ifdef HAVE_CYGWIN
	if (check_ntsec(filename))
#endif
	if (fstat(fd, &st) < 0 ||
	    (st.st_uid != 0 && st.st_uid != getuid()) ||
	    (st.st_mode & 077) != 0) {
		close(fd);
		error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
		error("@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @");
		error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
		error("Bad ownership or mode(0%3.3o) for '%s'.",
		      st.st_mode & 0777, filename);
		error("It is recommended that your private key files are NOT accessible by others.");
		return 0;
	}
	switch (key->type) {
	case KEY_RSA:
		if (key->rsa->e != NULL) {
			BN_clear_free(key->rsa->e);
			key->rsa->e = NULL;
		}
		if (key->rsa->n != NULL) {
			BN_clear_free(key->rsa->n);
			key->rsa->n = NULL;
		}
		ret = load_private_key_rsa(fd, filename, passphrase,
		     key->rsa, comment_return);
		break;
	case KEY_DSA:
		ret = load_private_key_dsa(fd, passphrase, key, comment_return);
	default:
		break;
	}
	close(fd);
	return ret;
}

int
do_load_public_key(const char *filename, Key *k, char **commentp)
{
	FILE *f;
	unsigned int bits;
	char line[1024];
	char *cp;

	f = fopen(filename, "r");
	if (f != NULL) {
		while (fgets(line, sizeof(line), f)) {
			line[sizeof(line)-1] = '\0';
			cp = line;
			switch(*cp){
			case '#':
			case '\n':
			case '\0':
				continue;
			}
			/* Skip leading whitespace. */
			for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
				;
			if (*cp) {
				bits = key_read(k, &cp);
				if (bits != 0) {
					if (commentp)
						*commentp=xstrdup(filename);
					fclose(f);
					return 1;
				}
			}
		}
		fclose(f);
	}
	return 0;
}

/* load public key from pubkey file */
int
try_load_public_key(const char *filename, Key *k, char **commentp)
{
	char pub[MAXPATHLEN];

	if (do_load_public_key(filename, k, commentp) == 1)
		return 1;
	if (strlcpy(pub, filename, sizeof pub) >= MAXPATHLEN)
		return 0;
	if (strlcat(pub, ".pub", sizeof pub) >= MAXPATHLEN)
		return 0;
	if (do_load_public_key(pub, k, commentp) == 1)
		return 1;
	return 0;
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
5260325f	5	* This file contains functions for reading and writing identity files, and
5260325f	6	* for reading the passphrase from the user.
6ae2364d	7	*
bcbf86ec	8	* As far as I am concerned, the code I have written for this software
	9	* can be used freely for any purpose. Any derived versions of this
	10	* software must be clearly marked as such, and if the derived work is
	11	* incompatible with the protocol description in the RFC file, it must be
	12	* called by a name other than "ssh" or "Secure Shell".
	13	*
	14	*
	15	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	16	*
	17	* Redistribution and use in source and binary forms, with or without
	18	* modification, are permitted provided that the following conditions
	19	* are met:
	20	* 1. Redistributions of source code must retain the above copyright
	21	* notice, this list of conditions and the following disclaimer.
	22	* 2. Redistributions in binary form must reproduce the above copyright
	23	* notice, this list of conditions and the following disclaimer in the
	24	* documentation and/or other materials provided with the distribution.
	25	*
	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	27	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	28	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	29	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	30	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	31	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	32	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	33	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	34	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	35	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5260325f	36	*/
8efc0c15	37
8efc0c15	38	#include "includes.h"
bcbf86ec	39	RCSID("$OpenBSD: authfile.c,v 1.19 2000/09/07 20:27:49 deraadt Exp $");
8efc0c15	40
8efc0c15	41	#include <openssl/bn.h>
a306f2dd	42	#include <openssl/dsa.h>
	43	#include <openssl/rsa.h>
	44	#include <openssl/pem.h>
	45	#include <openssl/evp.h>
	46
8efc0c15	47	#include "xmalloc.h"
	48	#include "buffer.h"
	49	#include "bufaux.h"
	50	#include "cipher.h"
	51	#include "ssh.h"
a306f2dd	52	#include "key.h"
8efc0c15	53
	54	/* Version identification string for identity files. */
	55	#define AUTHFILE_ID_STRING "SSH PRIVATE KEY FILE FORMAT 1.1\n"
	56
aa3378df	57	/*
	58	* Saves the authentication (private) key in a file, encrypting it with
	59	* passphrase. The identification of the file (lowest 64 bits of n) will
	60	* precede the key to provide identification of the key without needing a
	61	* passphrase.
	62	*/
8efc0c15	63
8efc0c15	64	int
a306f2dd	65	save_private_key_rsa(const char filename, const char passphrase,
a306f2dd	66	RSA key, const char comment)
8efc0c15	67	{
5260325f	68	Buffer buffer, encrypted;
5260325f	69	char buf[100], *cp;
a408af76	70	int fd, i;
5260325f	71	CipherContext cipher;
	72	int cipher_type;
	73	u_int32_t rand;
	74
aa3378df	75	/*
	76	* If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
	77	* to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
	78	*/
5260325f	79	if (strcmp(passphrase, "") == 0)
	80	cipher_type = SSH_CIPHER_NONE;
	81	else
	82	cipher_type = SSH_AUTHFILE_CIPHER;
	83
	84	/* This buffer is used to built the secret part of the private key. */
	85	buffer_init(&buffer);
	86
	87	/* Put checkbytes for checking passphrase validity. */
	88	rand = arc4random();
	89	buf[0] = rand & 0xff;
	90	buf[1] = (rand >> 8) & 0xff;
	91	buf[2] = buf[0];
	92	buf[3] = buf[1];
	93	buffer_append(&buffer, buf, 4);
	94
aa3378df	95	/*
	96	* Store the private key (n and e will not be stored because they
	97	* will be stored in plain text, and storing them also in encrypted
	98	* format would just give known plaintext).
	99	*/
5260325f	100	buffer_put_bignum(&buffer, key->d);
	101	buffer_put_bignum(&buffer, key->iqmp);
	102	buffer_put_bignum(&buffer, key->q); /* reverse from SSL p */
	103	buffer_put_bignum(&buffer, key->p); /* reverse from SSL q */
	104
	105	/* Pad the part to be encrypted until its size is a multiple of 8. */
	106	while (buffer_len(&buffer) % 8 != 0)
	107	buffer_put_char(&buffer, 0);
	108
	109	/* This buffer will be used to contain the data in the file. */
	110	buffer_init(&encrypted);
	111
	112	/* First store keyfile id string. */
	113	cp = AUTHFILE_ID_STRING;
	114	for (i = 0; cp[i]; i++)
	115	buffer_put_char(&encrypted, cp[i]);
	116	buffer_put_char(&encrypted, 0);
	117
	118	/* Store cipher type. */
	119	buffer_put_char(&encrypted, cipher_type);
	120	buffer_put_int(&encrypted, 0); /* For future extension */
	121
	122	/* Store public key. This will be in plain text. */
	123	buffer_put_int(&encrypted, BN_num_bits(key->n));
	124	buffer_put_bignum(&encrypted, key->n);
	125	buffer_put_bignum(&encrypted, key->e);
	126	buffer_put_string(&encrypted, comment, strlen(comment));
	127
	128	/* Allocate space for the private part of the key in the buffer. */
	129	buffer_append_space(&encrypted, &cp, buffer_len(&buffer));
	130
8ce64345	131	cipher_set_key_string(&cipher, cipher_type, passphrase);
5260325f	132	cipher_encrypt(&cipher, (unsigned char *) cp,
	133	(unsigned char *) buffer_ptr(&buffer),
	134	buffer_len(&buffer));
	135	memset(&cipher, 0, sizeof(cipher));
	136
	137	/* Destroy temporary data. */
	138	memset(buf, 0, sizeof(buf));
	139	buffer_free(&buffer);
	140
a408af76	141	fd = open(filename, O_WRONLY \| O_CREAT \| O_TRUNC, 0600);
a408af76	142	if (fd < 0)
5260325f	143	return 0;
a408af76	144	if (write(fd, buffer_ptr(&encrypted), buffer_len(&encrypted)) !=
5260325f	145	buffer_len(&encrypted)) {
	146	debug("Write to key file %.200s failed: %.100s", filename,
	147	strerror(errno));
	148	buffer_free(&encrypted);
a408af76	149	close(fd);
5260325f	150	remove(filename);
	151	return 0;
	152	}
a408af76	153	close(fd);
5260325f	154	buffer_free(&encrypted);
5260325f	155	return 1;
8efc0c15	156	}
8efc0c15	157
a306f2dd	158	/* save DSA key in OpenSSL PEM format */
	159
	160	int
	161	save_private_key_dsa(const char filename, const char passphrase,
	162	DSA dsa, const char comment)
	163	{
	164	FILE *fp;
	165	int fd;
	166	int success = 1;
	167	int len = strlen(passphrase);
	168
	169	if (len > 0 && len <= 4) {
	170	error("passphrase too short: %d bytes", len);
	171	errno = 0;
	172	return 0;
	173	}
	174	fd = open(filename, O_WRONLY \| O_CREAT \| O_TRUNC, 0600);
	175	if (fd < 0) {
	176	debug("open %s failed", filename);
	177	return 0;
	178	}
	179	fp = fdopen(fd, "w");
	180	if (fp == NULL ) {
	181	debug("fdopen %s failed", filename);
	182	close(fd);
	183	return 0;
	184	}
	185	if (len > 0) {
	186	if (!PEM_write_DSAPrivateKey(fp, dsa, EVP_des_ede3_cbc(),
	187	(char *)passphrase, strlen(passphrase), NULL, NULL))
	188	success = 0;
	189	} else {
	190	if (!PEM_write_DSAPrivateKey(fp, dsa, NULL,
	191	NULL, 0, NULL, NULL))
	192	success = 0;
	193	}
	194	fclose(fp);
	195	return success;
	196	}
	197
	198	int
	199	save_private_key(const char filename, const char passphrase, Key *key,
	200	const char *comment)
	201	{
	202	switch (key->type) {
	203	case KEY_RSA:
	204	return save_private_key_rsa(filename, passphrase, key->rsa, comment);
	205	break;
	206	case KEY_DSA:
	207	return save_private_key_dsa(filename, passphrase, key->dsa, comment);
	208	break;
	209	default:
	210	break;
	211	}
	212	return 0;
	213	}
	214
aa3378df	215	/*
	216	* Loads the public part of the key file. Returns 0 if an error was
	217	* encountered (the file does not exist or is not readable), and non-zero
	218	* otherwise.
	219	*/
8efc0c15	220
8efc0c15	221	int
a306f2dd	222	load_public_key_rsa(const char filename, RSA pub, char **comment_return)
8efc0c15	223	{
a408af76	224	int fd, i;
5260325f	225	off_t len;
	226	Buffer buffer;
	227	char *cp;
	228
a408af76	229	fd = open(filename, O_RDONLY);
a408af76	230	if (fd < 0)
5260325f	231	return 0;
a408af76	232	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	233	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	234
	235	buffer_init(&buffer);
	236	buffer_append_space(&buffer, &cp, len);
	237
a408af76	238	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	239	debug("Read from key file %.200s failed: %.100s", filename,
a306f2dd	240	strerror(errno));
5260325f	241	buffer_free(&buffer);
a408af76	242	close(fd);
5260325f	243	return 0;
5260325f	244	}
a408af76	245	close(fd);
5260325f	246
	247	/* Check that it is at least big enought to contain the ID string. */
	248	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
	249	debug("Bad key file %.200s.", filename);
	250	buffer_free(&buffer);
	251	return 0;
	252	}
aa3378df	253	/*
	254	* Make sure it begins with the id string. Consume the id string
	255	* from the buffer.
	256	*/
5260325f	257	for (i = 0; i < (unsigned int) strlen(AUTHFILE_ID_STRING) + 1; i++)
a408af76	258	if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
5260325f	259	debug("Bad key file %.200s.", filename);
	260	buffer_free(&buffer);
	261	return 0;
	262	}
	263	/* Skip cipher type and reserved data. */
	264	(void) buffer_get_char(&buffer); /* cipher type */
	265	(void) buffer_get_int(&buffer); /* reserved */
	266
	267	/* Read the public key from the buffer. */
	268	buffer_get_int(&buffer);
a306f2dd	269	/* XXX alloc */
	270	if (pub->n == NULL)
	271	pub->n = BN_new();
5260325f	272	buffer_get_bignum(&buffer, pub->n);
a306f2dd	273	/* XXX alloc */
	274	if (pub->e == NULL)
	275	pub->e = BN_new();
5260325f	276	buffer_get_bignum(&buffer, pub->e);
	277	if (comment_return)
	278	*comment_return = buffer_get_string(&buffer, NULL);
	279	/* The encrypted private part is not parsed by this function. */
	280
8efc0c15	281	buffer_free(&buffer);
5260325f	282
5260325f	283	return 1;
8efc0c15	284	}
8efc0c15	285
bcbf86ec	286	/* load public key from private-key file */
a306f2dd	287	int
	288	load_public_key(const char filename, Key key, char **comment_return)
	289	{
	290	switch (key->type) {
	291	case KEY_RSA:
	292	return load_public_key_rsa(filename, key->rsa, comment_return);
	293	break;
	294	case KEY_DSA:
	295	default:
	296	break;
	297	}
	298	return 0;
	299	}
	300
aa3378df	301	/*
	302	* Loads the private key from the file. Returns 0 if an error is encountered
	303	* (file does not exist or is not readable, or passphrase is bad). This
	304	* initializes the private key.
	305	* Assumes we are called under uid of the owner of the file.
	306	*/
8efc0c15	307
8efc0c15	308	int
a306f2dd	309	load_private_key_rsa(int fd, const char *filename,
a306f2dd	310	const char passphrase, RSA prv, char **comment_return)
8efc0c15	311	{
a306f2dd	312	int i, check1, check2, cipher_type;
5260325f	313	off_t len;
	314	Buffer buffer, decrypted;
	315	char *cp;
	316	CipherContext cipher;
	317	BN_CTX *ctx;
	318	BIGNUM *aux;
5260325f	319
a408af76	320	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	321	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	322
	323	buffer_init(&buffer);
	324	buffer_append_space(&buffer, &cp, len);
	325
a408af76	326	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	327	debug("Read from key file %.200s failed: %.100s", filename,
	328	strerror(errno));
	329	buffer_free(&buffer);
a408af76	330	close(fd);
5260325f	331	return 0;
5260325f	332	}
a408af76	333	close(fd);
5260325f	334
	335	/* Check that it is at least big enought to contain the ID string. */
	336	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
	337	debug("Bad key file %.200s.", filename);
	338	buffer_free(&buffer);
	339	return 0;
	340	}
aa3378df	341	/*
	342	* Make sure it begins with the id string. Consume the id string
	343	* from the buffer.
	344	*/
5260325f	345	for (i = 0; i < (unsigned int) strlen(AUTHFILE_ID_STRING) + 1; i++)
	346	if (buffer_get_char(&buffer) != (unsigned char) AUTHFILE_ID_STRING[i]) {
	347	debug("Bad key file %.200s.", filename);
	348	buffer_free(&buffer);
	349	return 0;
	350	}
	351	/* Read cipher type. */
	352	cipher_type = buffer_get_char(&buffer);
	353	(void) buffer_get_int(&buffer); /* Reserved data. */
	354
	355	/* Read the public key from the buffer. */
	356	buffer_get_int(&buffer);
	357	prv->n = BN_new();
	358	buffer_get_bignum(&buffer, prv->n);
	359	prv->e = BN_new();
	360	buffer_get_bignum(&buffer, prv->e);
	361	if (comment_return)
	362	*comment_return = buffer_get_string(&buffer, NULL);
	363	else
	364	xfree(buffer_get_string(&buffer, NULL));
	365
	366	/* Check that it is a supported cipher. */
8ce64345	367	if (((cipher_mask1() \| SSH_CIPHER_NONE \| SSH_AUTHFILE_CIPHER) &
5260325f	368	(1 << cipher_type)) == 0) {
	369	debug("Unsupported cipher %.100s used in key file %.200s.",
	370	cipher_name(cipher_type), filename);
	371	buffer_free(&buffer);
	372	goto fail;
	373	}
	374	/* Initialize space for decrypted data. */
	375	buffer_init(&decrypted);
	376	buffer_append_space(&decrypted, &cp, buffer_len(&buffer));
	377
	378	/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
8ce64345	379	cipher_set_key_string(&cipher, cipher_type, passphrase);
5260325f	380	cipher_decrypt(&cipher, (unsigned char *) cp,
	381	(unsigned char *) buffer_ptr(&buffer),
	382	buffer_len(&buffer));
	383
8efc0c15	384	buffer_free(&buffer);
5260325f	385
	386	check1 = buffer_get_char(&decrypted);
	387	check2 = buffer_get_char(&decrypted);
	388	if (check1 != buffer_get_char(&decrypted) \|\|
	389	check2 != buffer_get_char(&decrypted)) {
	390	if (strcmp(passphrase, "") != 0)
	391	debug("Bad passphrase supplied for key file %.200s.", filename);
	392	/* Bad passphrase. */
	393	buffer_free(&decrypted);
	394	fail:
	395	BN_clear_free(prv->n);
a306f2dd	396	prv->n = NULL;
5260325f	397	BN_clear_free(prv->e);
a306f2dd	398	prv->e = NULL;
5260325f	399	if (comment_return)
	400	xfree(*comment_return);
	401	return 0;
	402	}
	403	/* Read the rest of the private key. */
	404	prv->d = BN_new();
	405	buffer_get_bignum(&decrypted, prv->d);
	406	prv->iqmp = BN_new();
	407	buffer_get_bignum(&decrypted, prv->iqmp); /* u */
	408	/* in SSL and SSH p and q are exchanged */
	409	prv->q = BN_new();
	410	buffer_get_bignum(&decrypted, prv->q); /* p */
	411	prv->p = BN_new();
	412	buffer_get_bignum(&decrypted, prv->p); /* q */
	413
	414	ctx = BN_CTX_new();
	415	aux = BN_new();
	416
	417	BN_sub(aux, prv->q, BN_value_one());
	418	prv->dmq1 = BN_new();
	419	BN_mod(prv->dmq1, prv->d, aux, ctx);
	420
	421	BN_sub(aux, prv->p, BN_value_one());
	422	prv->dmp1 = BN_new();
	423	BN_mod(prv->dmp1, prv->d, aux, ctx);
	424
	425	BN_clear_free(aux);
	426	BN_CTX_free(ctx);
	427
	428	buffer_free(&decrypted);
	429
	430	return 1;
8efc0c15	431	}
a306f2dd	432
	433	int
	434	load_private_key_dsa(int fd, const char passphrase, Key k, char **comment_return)
	435	{
	436	DSA *dsa;
	437	BIO *in;
	438	FILE *fp;
	439
	440	in = BIO_new(BIO_s_file());
	441	if (in == NULL) {
	442	error("BIO_new failed");
	443	return 0;
	444	}
	445	fp = fdopen(fd, "r");
	446	if (fp == NULL) {
	447	error("fdopen failed");
	448	return 0;
	449	}
	450	BIO_set_fp(in, fp, BIO_NOCLOSE);
	451	dsa = PEM_read_bio_DSAPrivateKey(in, NULL, NULL, (char *)passphrase);
	452	if (dsa == NULL) {
	453	debug("PEM_read_bio_DSAPrivateKey failed");
	454	} else {
	455	/* replace k->dsa with loaded key */
	456	DSA_free(k->dsa);
	457	k->dsa = dsa;
	458	}
	459	BIO_free(in);
	460	fclose(fp);
	461	if (comment_return)
	462	*comment_return = xstrdup("dsa w/o comment");
	463	debug("read DSA private key done");
	464	#ifdef DEBUG_DSS
	465	DSA_print_fp(stderr, dsa, 8);
	466	#endif
	467	return dsa != NULL ? 1 : 0;
	468	}
	469
	470	int
	471	load_private_key(const char filename, const char passphrase, Key *key,
	472	char **comment_return)
	473	{
	474	int fd;
	475	int ret = 0;
	476	struct stat st;
	477
	478	fd = open(filename, O_RDONLY);
	479	if (fd < 0)
	480	return 0;
	481
22d89d24	482	/* check owner and modes */
9cd45ea4	483	#ifdef HAVE_CYGWIN
22d89d24	484	if (check_ntsec(filename))
9cd45ea4	485	#endif
a306f2dd	486	if (fstat(fd, &st) < 0 \|\|
	487	(st.st_uid != 0 && st.st_uid != getuid()) \|\|
	488	(st.st_mode & 077) != 0) {
	489	close(fd);
	490	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	491	error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
	492	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	493	error("Bad ownership or mode(0%3.3o) for '%s'.",
	494	st.st_mode & 0777, filename);
	495	error("It is recommended that your private key files are NOT accessible by others.");
	496	return 0;
	497	}
	498	switch (key->type) {
	499	case KEY_RSA:
	500	if (key->rsa->e != NULL) {
	501	BN_clear_free(key->rsa->e);
	502	key->rsa->e = NULL;
	503	}
	504	if (key->rsa->n != NULL) {
	505	BN_clear_free(key->rsa->n);
	506	key->rsa->n = NULL;
	507	}
	508	ret = load_private_key_rsa(fd, filename, passphrase,
	509	key->rsa, comment_return);
	510	break;
	511	case KEY_DSA:
	512	ret = load_private_key_dsa(fd, passphrase, key, comment_return);
	513	default:
	514	break;
	515	}
	516	close(fd);
	517	return ret;
	518	}
bcbf86ec	519
	520	int
	521	do_load_public_key(const char filename, Key k, char **commentp)
	522	{
	523	FILE *f;
	524	unsigned int bits;
	525	char line[1024];
	526	char *cp;
	527
	528	f = fopen(filename, "r");
	529	if (f != NULL) {
	530	while (fgets(line, sizeof(line), f)) {
	531	line[sizeof(line)-1] = '\0';
	532	cp = line;
	533	switch(*cp){
	534	case '#':
	535	case '\n':
	536	case '\0':
	537	continue;
	538	}
	539	/* Skip leading whitespace. */
	540	for (; cp && (cp == ' ' \|\| *cp == '\t'); cp++)
	541	;
	542	if (*cp) {
	543	bits = key_read(k, &cp);
	544	if (bits != 0) {
	545	if (commentp)
	546	*commentp=xstrdup(filename);
	547	fclose(f);
	548	return 1;
	549	}
	550	}
	551	}
	552	fclose(f);
	553	}
	554	return 0;
	555	}
	556
	557	/* load public key from pubkey file */
	558	int
	559	try_load_public_key(const char filename, Key k, char **commentp)
	560	{
	561	char pub[MAXPATHLEN];
	562
	563	if (do_load_public_key(filename, k, commentp) == 1)
	564	return 1;
	565	if (strlcpy(pub, filename, sizeof pub) >= MAXPATHLEN)
	566	return 0;
	567	if (strlcat(pub, ".pub", sizeof pub) >= MAXPATHLEN)
	568	return 0;
	569	if (do_load_public_key(pub, k, commentp) == 1)
	570	return 1;
	571	return 0;
	572	}