[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 1.25 2001/01/21 19:05:44 markus Exp $");

#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>

#include "cipher.h"
#include "xmalloc.h"
#include "buffer.h"
#include "bufaux.h"
#include "key.h"
#include "ssh.h"
#include "log.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_rsa1(const char *filename, const char *passphrase,
    RSA *key, const char *comment)
{
	Buffer buffer, encrypted;
	char buf[100], *cp;
	int fd, i;
	CipherContext ciphercontext;
	Cipher *cipher;
	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 = cipher_by_number(SSH_CIPHER_NONE);
	else
		cipher = cipher_by_number(SSH_AUTHFILE_CIPHER);
	if (cipher == NULL)
		fatal("save_private_key_rsa: bad 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->number);
	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(&ciphercontext, cipher, passphrase);
	cipher_encrypt(&ciphercontext, (u_char *) cp,
	    (u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
	memset(&ciphercontext, 0, sizeof(ciphercontext));

	/* 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);
		unlink(filename);
		return 0;
	}
	close(fd);
	buffer_free(&encrypted);
	return 1;
}

/* save SSH2 key in OpenSSL PEM format */
int
save_private_key_ssh2(const char *filename, const char *_passphrase,
    Key *key, const char *comment)
{
	FILE *fp;
	int fd;
	int success = 0;
	int len = strlen(_passphrase);
	char *passphrase = (len > 0) ? (char *)_passphrase : NULL;
	EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;

	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;
	}
	switch (key->type) {
		case KEY_DSA:
			success = PEM_write_DSAPrivateKey(fp, key->dsa,
			    cipher, passphrase, len, NULL, NULL);
			break;
		case KEY_RSA:
			success = PEM_write_RSAPrivateKey(fp, key->rsa,
			    cipher, passphrase, len, NULL, NULL);
			break;
	}
	fclose(fp);
	return success;
}

int
save_private_key(const char *filename, const char *passphrase, Key *key,
    const char *comment)
{
	switch (key->type) {
	case KEY_RSA1:
		return save_private_key_rsa1(filename, passphrase, key->rsa, comment);
		break;
	case KEY_DSA:
	case KEY_RSA:
		return save_private_key_ssh2(filename, passphrase, key, 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) {
		debug3("Bad RSA1 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 < (u_int) strlen(AUTHFILE_ID_STRING) + 1; i++)
		if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
			debug3("Bad RSA1 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_RSA1:
		return load_public_key_rsa(filename, key->rsa, comment_return);
		break;
	case KEY_DSA:
	case KEY_RSA:
	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_rsa1(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 ciphercontext;
	Cipher *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) {
		debug3("Bad RSA1 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 < (u_int) strlen(AUTHFILE_ID_STRING) + 1; i++)
		if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
			debug3("Bad RSA1 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. */
	cipher = cipher_by_number(cipher_type);
	if (cipher == NULL) {
		debug("Unsupported cipher %d used in key file %.200s.",
		    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(&ciphercontext, cipher, passphrase);
	cipher_decrypt(&ciphercontext, (u_char *) cp,
	    (u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
	memset(&ciphercontext, 0, sizeof(ciphercontext));
	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_ssh2(int fd, const char *passphrase, Key *k, char **comment_return)
{
	FILE *fp;
	int success = 0;
	EVP_PKEY *pk = NULL;
	char *name = "<no key>";

	fp = fdopen(fd, "r");
	if (fp == NULL) {
		error("fdopen failed");
		return 0;
	}
	pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
	if (pk == NULL) {
		debug("PEM_read_PrivateKey failed");
		(void)ERR_get_error();
	} else if (pk->type == EVP_PKEY_RSA) {
		/* replace k->rsa with loaded key */
		if (k->type == KEY_RSA || k->type == KEY_UNSPEC) {
			if (k->rsa != NULL)
				RSA_free(k->rsa);
			k->rsa = EVP_PKEY_get1_RSA(pk);
			k->type = KEY_RSA;
			name = "rsa w/o comment";
			success = 1;
#ifdef DEBUG_PK
			RSA_print_fp(stderr, k->rsa, 8);
#endif
		}
	} else if (pk->type == EVP_PKEY_DSA) {
		/* replace k->dsa with loaded key */
		if (k->type == KEY_DSA || k->type == KEY_UNSPEC) {
			if (k->dsa != NULL)
				DSA_free(k->dsa);
			k->dsa = EVP_PKEY_get1_DSA(pk);
			k->type = KEY_DSA;
			name = "dsa w/o comment";
#ifdef DEBUG_PK
			DSA_print_fp(stderr, k->dsa, 8);
#endif
			success = 1;
		}
	} else {
		error("PEM_read_PrivateKey: mismatch or "
		    "unknown EVP_PKEY save_type %d", pk->save_type);
	}
	fclose(fp);
	if (pk != NULL)
		EVP_PKEY_free(pk);
	if (success && comment_return)
		*comment_return = xstrdup(name);
	debug("read SSH2 private key done: name %s success %d", name, success);
	return success;
}

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 && getuid() != 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_RSA1:
		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_rsa1(fd, filename, passphrase,
		     key->rsa, comment_return);
		break;
	case KEY_DSA:
	case KEY_RSA:
	case KEY_UNSPEC:
		ret = load_private_key_ssh2(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;
	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) {
				if (key_read(k, &cp) == 1) {
					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"
42f11eb2	39	RCSID("$OpenBSD: authfile.c,v 1.25 2001/01/21 19:05:44 markus Exp $");
8efc0c15	40
fa08c86b	41	#include <openssl/err.h>
a306f2dd	42	#include <openssl/evp.h>
42f11eb2	43	#include <openssl/pem.h>
a306f2dd	44
42f11eb2	45	#include "cipher.h"
8efc0c15	46	#include "xmalloc.h"
	47	#include "buffer.h"
	48	#include "bufaux.h"
a306f2dd	49	#include "key.h"
42f11eb2	50	#include "ssh.h"
42f11eb2	51	#include "log.h"
8efc0c15	52
	53	/* Version identification string for identity files. */
	54	#define AUTHFILE_ID_STRING "SSH PRIVATE KEY FILE FORMAT 1.1\n"
	55
aa3378df	56	/*
	57	* Saves the authentication (private) key in a file, encrypting it with
	58	* passphrase. The identification of the file (lowest 64 bits of n) will
	59	* precede the key to provide identification of the key without needing a
	60	* passphrase.
	61	*/
8efc0c15	62
8efc0c15	63	int
fa08c86b	64	save_private_key_rsa1(const char filename, const char passphrase,
a306f2dd	65	RSA key, const char comment)
8efc0c15	66	{
5260325f	67	Buffer buffer, encrypted;
5260325f	68	char buf[100], *cp;
a408af76	69	int fd, i;
94ec8c6b	70	CipherContext ciphercontext;
94ec8c6b	71	Cipher *cipher;
5260325f	72	u_int32_t rand;
5260325f	73
aa3378df	74	/*
	75	* If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
	76	* to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
	77	*/
5260325f	78	if (strcmp(passphrase, "") == 0)
94ec8c6b	79	cipher = cipher_by_number(SSH_CIPHER_NONE);
5260325f	80	else
94ec8c6b	81	cipher = cipher_by_number(SSH_AUTHFILE_CIPHER);
	82	if (cipher == NULL)
	83	fatal("save_private_key_rsa: bad cipher");
5260325f	84
	85	/* This buffer is used to built the secret part of the private key. */
	86	buffer_init(&buffer);
	87
	88	/* Put checkbytes for checking passphrase validity. */
	89	rand = arc4random();
	90	buf[0] = rand & 0xff;
	91	buf[1] = (rand >> 8) & 0xff;
	92	buf[2] = buf[0];
	93	buf[3] = buf[1];
	94	buffer_append(&buffer, buf, 4);
	95
aa3378df	96	/*
	97	* Store the private key (n and e will not be stored because they
	98	* will be stored in plain text, and storing them also in encrypted
	99	* format would just give known plaintext).
	100	*/
5260325f	101	buffer_put_bignum(&buffer, key->d);
	102	buffer_put_bignum(&buffer, key->iqmp);
	103	buffer_put_bignum(&buffer, key->q); /* reverse from SSL p */
	104	buffer_put_bignum(&buffer, key->p); /* reverse from SSL q */
	105
	106	/* Pad the part to be encrypted until its size is a multiple of 8. */
	107	while (buffer_len(&buffer) % 8 != 0)
	108	buffer_put_char(&buffer, 0);
	109
	110	/* This buffer will be used to contain the data in the file. */
	111	buffer_init(&encrypted);
	112
	113	/* First store keyfile id string. */
	114	cp = AUTHFILE_ID_STRING;
	115	for (i = 0; cp[i]; i++)
	116	buffer_put_char(&encrypted, cp[i]);
	117	buffer_put_char(&encrypted, 0);
	118
	119	/* Store cipher type. */
94ec8c6b	120	buffer_put_char(&encrypted, cipher->number);
5260325f	121	buffer_put_int(&encrypted, 0); /* For future extension */
	122
	123	/* Store public key. This will be in plain text. */
	124	buffer_put_int(&encrypted, BN_num_bits(key->n));
	125	buffer_put_bignum(&encrypted, key->n);
	126	buffer_put_bignum(&encrypted, key->e);
	127	buffer_put_string(&encrypted, comment, strlen(comment));
	128
	129	/* Allocate space for the private part of the key in the buffer. */
	130	buffer_append_space(&encrypted, &cp, buffer_len(&buffer));
	131
94ec8c6b	132	cipher_set_key_string(&ciphercontext, cipher, passphrase);
1e3b8b07	133	cipher_encrypt(&ciphercontext, (u_char *) cp,
1e3b8b07	134	(u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
94ec8c6b	135	memset(&ciphercontext, 0, sizeof(ciphercontext));
5260325f	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);
77bb0bca	150	unlink(filename);
5260325f	151	return 0;
5260325f	152	}
a408af76	153	close(fd);
5260325f	154	buffer_free(&encrypted);
5260325f	155	return 1;
8efc0c15	156	}
8efc0c15	157
fa08c86b	158	/* save SSH2 key in OpenSSL PEM format */
a306f2dd	159	int
fa08c86b	160	save_private_key_ssh2(const char filename, const char _passphrase,
fa08c86b	161	Key key, const char comment)
a306f2dd	162	{
	163	FILE *fp;
	164	int fd;
fa08c86b	165	int success = 0;
	166	int len = strlen(_passphrase);
	167	char passphrase = (len > 0) ? (char )_passphrase : NULL;
	168	EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;
a306f2dd	169
	170	if (len > 0 && len <= 4) {
	171	error("passphrase too short: %d bytes", len);
	172	errno = 0;
	173	return 0;
	174	}
	175	fd = open(filename, O_WRONLY \| O_CREAT \| O_TRUNC, 0600);
	176	if (fd < 0) {
	177	debug("open %s failed", filename);
	178	return 0;
	179	}
	180	fp = fdopen(fd, "w");
	181	if (fp == NULL ) {
	182	debug("fdopen %s failed", filename);
	183	close(fd);
	184	return 0;
	185	}
fa08c86b	186	switch (key->type) {
	187	case KEY_DSA:
	188	success = PEM_write_DSAPrivateKey(fp, key->dsa,
	189	cipher, passphrase, len, NULL, NULL);
	190	break;
	191	case KEY_RSA:
	192	success = PEM_write_RSAPrivateKey(fp, key->rsa,
	193	cipher, passphrase, len, NULL, NULL);
	194	break;
a306f2dd	195	}
	196	fclose(fp);
	197	return success;
	198	}
	199
	200	int
	201	save_private_key(const char filename, const char passphrase, Key *key,
	202	const char *comment)
	203	{
	204	switch (key->type) {
fa08c86b	205	case KEY_RSA1:
fa08c86b	206	return save_private_key_rsa1(filename, passphrase, key->rsa, comment);
a306f2dd	207	break;
a306f2dd	208	case KEY_DSA:
fa08c86b	209	case KEY_RSA:
fa08c86b	210	return save_private_key_ssh2(filename, passphrase, key, comment);
a306f2dd	211	break;
	212	default:
	213	break;
	214	}
	215	return 0;
	216	}
	217
aa3378df	218	/*
	219	* Loads the public part of the key file. Returns 0 if an error was
	220	* encountered (the file does not exist or is not readable), and non-zero
	221	* otherwise.
	222	*/
8efc0c15	223
8efc0c15	224	int
a306f2dd	225	load_public_key_rsa(const char filename, RSA pub, char **comment_return)
8efc0c15	226	{
a408af76	227	int fd, i;
5260325f	228	off_t len;
	229	Buffer buffer;
	230	char *cp;
	231
a408af76	232	fd = open(filename, O_RDONLY);
a408af76	233	if (fd < 0)
5260325f	234	return 0;
a408af76	235	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	236	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	237
	238	buffer_init(&buffer);
	239	buffer_append_space(&buffer, &cp, len);
	240
a408af76	241	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	242	debug("Read from key file %.200s failed: %.100s", filename,
a306f2dd	243	strerror(errno));
5260325f	244	buffer_free(&buffer);
a408af76	245	close(fd);
5260325f	246	return 0;
5260325f	247	}
a408af76	248	close(fd);
5260325f	249
	250	/* Check that it is at least big enought to contain the ID string. */
	251	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
fa08c86b	252	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	253	buffer_free(&buffer);
	254	return 0;
	255	}
aa3378df	256	/*
	257	* Make sure it begins with the id string. Consume the id string
	258	* from the buffer.
	259	*/
1e3b8b07	260	for (i = 0; i < (u_int) strlen(AUTHFILE_ID_STRING) + 1; i++)
a408af76	261	if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
fa08c86b	262	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	263	buffer_free(&buffer);
	264	return 0;
	265	}
	266	/* Skip cipher type and reserved data. */
	267	(void) buffer_get_char(&buffer); /* cipher type */
	268	(void) buffer_get_int(&buffer); /* reserved */
	269
	270	/* Read the public key from the buffer. */
	271	buffer_get_int(&buffer);
a306f2dd	272	/* XXX alloc */
	273	if (pub->n == NULL)
	274	pub->n = BN_new();
5260325f	275	buffer_get_bignum(&buffer, pub->n);
a306f2dd	276	/* XXX alloc */
	277	if (pub->e == NULL)
	278	pub->e = BN_new();
5260325f	279	buffer_get_bignum(&buffer, pub->e);
	280	if (comment_return)
	281	*comment_return = buffer_get_string(&buffer, NULL);
	282	/* The encrypted private part is not parsed by this function. */
	283
8efc0c15	284	buffer_free(&buffer);
5260325f	285
5260325f	286	return 1;
8efc0c15	287	}
8efc0c15	288
bcbf86ec	289	/* load public key from private-key file */
a306f2dd	290	int
	291	load_public_key(const char filename, Key key, char **comment_return)
	292	{
	293	switch (key->type) {
fa08c86b	294	case KEY_RSA1:
a306f2dd	295	return load_public_key_rsa(filename, key->rsa, comment_return);
	296	break;
	297	case KEY_DSA:
fa08c86b	298	case KEY_RSA:
a306f2dd	299	default:
	300	break;
	301	}
	302	return 0;
	303	}
	304
aa3378df	305	/*
	306	* Loads the private key from the file. Returns 0 if an error is encountered
	307	* (file does not exist or is not readable, or passphrase is bad). This
	308	* initializes the private key.
	309	* Assumes we are called under uid of the owner of the file.
	310	*/
8efc0c15	311
8efc0c15	312	int
fa08c86b	313	load_private_key_rsa1(int fd, const char *filename,
a306f2dd	314	const char passphrase, RSA prv, char **comment_return)
8efc0c15	315	{
a306f2dd	316	int i, check1, check2, cipher_type;
5260325f	317	off_t len;
	318	Buffer buffer, decrypted;
	319	char *cp;
94ec8c6b	320	CipherContext ciphercontext;
94ec8c6b	321	Cipher *cipher;
5260325f	322	BN_CTX *ctx;
5260325f	323	BIGNUM *aux;
5260325f	324
a408af76	325	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	326	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	327
	328	buffer_init(&buffer);
	329	buffer_append_space(&buffer, &cp, len);
	330
a408af76	331	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	332	debug("Read from key file %.200s failed: %.100s", filename,
fa08c86b	333	strerror(errno));
5260325f	334	buffer_free(&buffer);
a408af76	335	close(fd);
5260325f	336	return 0;
5260325f	337	}
a408af76	338	close(fd);
5260325f	339
	340	/* Check that it is at least big enought to contain the ID string. */
	341	if (len < strlen(AUTHFILE_ID_STRING) + 1) {
fa08c86b	342	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	343	buffer_free(&buffer);
	344	return 0;
	345	}
aa3378df	346	/*
	347	* Make sure it begins with the id string. Consume the id string
	348	* from the buffer.
	349	*/
1e3b8b07	350	for (i = 0; i < (u_int) strlen(AUTHFILE_ID_STRING) + 1; i++)
fa08c86b	351	if (buffer_get_char(&buffer) != (u_char) AUTHFILE_ID_STRING[i]) {
fa08c86b	352	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	353	buffer_free(&buffer);
	354	return 0;
	355	}
	356	/* Read cipher type. */
	357	cipher_type = buffer_get_char(&buffer);
	358	(void) buffer_get_int(&buffer); /* Reserved data. */
	359
	360	/* Read the public key from the buffer. */
	361	buffer_get_int(&buffer);
	362	prv->n = BN_new();
	363	buffer_get_bignum(&buffer, prv->n);
	364	prv->e = BN_new();
	365	buffer_get_bignum(&buffer, prv->e);
	366	if (comment_return)
	367	*comment_return = buffer_get_string(&buffer, NULL);
	368	else
	369	xfree(buffer_get_string(&buffer, NULL));
	370
	371	/* Check that it is a supported cipher. */
94ec8c6b	372	cipher = cipher_by_number(cipher_type);
	373	if (cipher == NULL) {
	374	debug("Unsupported cipher %d used in key file %.200s.",
	375	cipher_type, filename);
5260325f	376	buffer_free(&buffer);
	377	goto fail;
	378	}
	379	/* Initialize space for decrypted data. */
	380	buffer_init(&decrypted);
	381	buffer_append_space(&decrypted, &cp, buffer_len(&buffer));
	382
	383	/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
94ec8c6b	384	cipher_set_key_string(&ciphercontext, cipher, passphrase);
1e3b8b07	385	cipher_decrypt(&ciphercontext, (u_char *) cp,
1e3b8b07	386	(u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
94ec8c6b	387	memset(&ciphercontext, 0, sizeof(ciphercontext));
8efc0c15	388	buffer_free(&buffer);
5260325f	389
	390	check1 = buffer_get_char(&decrypted);
	391	check2 = buffer_get_char(&decrypted);
	392	if (check1 != buffer_get_char(&decrypted) \|\|
	393	check2 != buffer_get_char(&decrypted)) {
	394	if (strcmp(passphrase, "") != 0)
	395	debug("Bad passphrase supplied for key file %.200s.", filename);
	396	/* Bad passphrase. */
	397	buffer_free(&decrypted);
	398	fail:
	399	BN_clear_free(prv->n);
a306f2dd	400	prv->n = NULL;
5260325f	401	BN_clear_free(prv->e);
a306f2dd	402	prv->e = NULL;
5260325f	403	if (comment_return)
	404	xfree(*comment_return);
	405	return 0;
	406	}
	407	/* Read the rest of the private key. */
	408	prv->d = BN_new();
	409	buffer_get_bignum(&decrypted, prv->d);
	410	prv->iqmp = BN_new();
	411	buffer_get_bignum(&decrypted, prv->iqmp); /* u */
	412	/* in SSL and SSH p and q are exchanged */
	413	prv->q = BN_new();
	414	buffer_get_bignum(&decrypted, prv->q); /* p */
	415	prv->p = BN_new();
	416	buffer_get_bignum(&decrypted, prv->p); /* q */
	417
	418	ctx = BN_CTX_new();
	419	aux = BN_new();
	420
	421	BN_sub(aux, prv->q, BN_value_one());
	422	prv->dmq1 = BN_new();
	423	BN_mod(prv->dmq1, prv->d, aux, ctx);
	424
	425	BN_sub(aux, prv->p, BN_value_one());
	426	prv->dmp1 = BN_new();
	427	BN_mod(prv->dmp1, prv->d, aux, ctx);
	428
	429	BN_clear_free(aux);
	430	BN_CTX_free(ctx);
	431
	432	buffer_free(&decrypted);
	433
	434	return 1;
8efc0c15	435	}
a306f2dd	436
a306f2dd	437	int
fa08c86b	438	load_private_key_ssh2(int fd, const char passphrase, Key k, char **comment_return)
a306f2dd	439	{
a306f2dd	440	FILE *fp;
fa08c86b	441	int success = 0;
	442	EVP_PKEY *pk = NULL;
	443	char *name = "<no key>";
a306f2dd	444
a306f2dd	445	fp = fdopen(fd, "r");
	446	if (fp == NULL) {
	447	error("fdopen failed");
	448	return 0;
	449	}
fa08c86b	450	pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
	451	if (pk == NULL) {
	452	debug("PEM_read_PrivateKey failed");
	453	(void)ERR_get_error();
	454	} else if (pk->type == EVP_PKEY_RSA) {
	455	/* replace k->rsa with loaded key */
	456	if (k->type == KEY_RSA \|\| k->type == KEY_UNSPEC) {
	457	if (k->rsa != NULL)
	458	RSA_free(k->rsa);
	459	k->rsa = EVP_PKEY_get1_RSA(pk);
	460	k->type = KEY_RSA;
	461	name = "rsa w/o comment";
	462	success = 1;
	463	#ifdef DEBUG_PK
	464	RSA_print_fp(stderr, k->rsa, 8);
	465	#endif
	466	}
	467	} else if (pk->type == EVP_PKEY_DSA) {
a306f2dd	468	/* replace k->dsa with loaded key */
fa08c86b	469	if (k->type == KEY_DSA \|\| k->type == KEY_UNSPEC) {
	470	if (k->dsa != NULL)
	471	DSA_free(k->dsa);
	472	k->dsa = EVP_PKEY_get1_DSA(pk);
	473	k->type = KEY_DSA;
	474	name = "dsa w/o comment";
	475	#ifdef DEBUG_PK
	476	DSA_print_fp(stderr, k->dsa, 8);
	477	#endif
	478	success = 1;
	479	}
	480	} else {
	481	error("PEM_read_PrivateKey: mismatch or "
	482	"unknown EVP_PKEY save_type %d", pk->save_type);
a306f2dd	483	}
a306f2dd	484	fclose(fp);
fa08c86b	485	if (pk != NULL)
	486	EVP_PKEY_free(pk);
	487	if (success && comment_return)
	488	*comment_return = xstrdup(name);
	489	debug("read SSH2 private key done: name %s success %d", name, success);
	490	return success;
a306f2dd	491	}
	492
	493	int
	494	load_private_key(const char filename, const char passphrase, Key *key,
	495	char **comment_return)
	496	{
	497	int fd;
	498	int ret = 0;
	499	struct stat st;
	500
	501	fd = open(filename, O_RDONLY);
	502	if (fd < 0)
	503	return 0;
	504
22d89d24	505	/* check owner and modes */
9cd45ea4	506	#ifdef HAVE_CYGWIN
22d89d24	507	if (check_ntsec(filename))
9cd45ea4	508	#endif
a306f2dd	509	if (fstat(fd, &st) < 0 \|\|
1e3b8b07	510	(st.st_uid != 0 && getuid() != 0 && st.st_uid != getuid()) \|\|
a306f2dd	511	(st.st_mode & 077) != 0) {
	512	close(fd);
	513	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	514	error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
	515	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	516	error("Bad ownership or mode(0%3.3o) for '%s'.",
	517	st.st_mode & 0777, filename);
	518	error("It is recommended that your private key files are NOT accessible by others.");
	519	return 0;
	520	}
	521	switch (key->type) {
fa08c86b	522	case KEY_RSA1:
a306f2dd	523	if (key->rsa->e != NULL) {
	524	BN_clear_free(key->rsa->e);
	525	key->rsa->e = NULL;
	526	}
	527	if (key->rsa->n != NULL) {
	528	BN_clear_free(key->rsa->n);
	529	key->rsa->n = NULL;
	530	}
fa08c86b	531	ret = load_private_key_rsa1(fd, filename, passphrase,
a306f2dd	532	key->rsa, comment_return);
	533	break;
	534	case KEY_DSA:
fa08c86b	535	case KEY_RSA:
	536	case KEY_UNSPEC:
	537	ret = load_private_key_ssh2(fd, passphrase, key, comment_return);
a306f2dd	538	default:
	539	break;
	540	}
	541	close(fd);
	542	return ret;
	543	}
bcbf86ec	544
	545	int
	546	do_load_public_key(const char filename, Key k, char **commentp)
	547	{
	548	FILE *f;
bcbf86ec	549	char line[1024];
	550	char *cp;
	551
	552	f = fopen(filename, "r");
	553	if (f != NULL) {
	554	while (fgets(line, sizeof(line), f)) {
	555	line[sizeof(line)-1] = '\0';
	556	cp = line;
	557	switch(*cp){
	558	case '#':
	559	case '\n':
	560	case '\0':
	561	continue;
	562	}
	563	/* Skip leading whitespace. */
	564	for (; cp && (cp == ' ' \|\| *cp == '\t'); cp++)
	565	;
	566	if (*cp) {
fa08c86b	567	if (key_read(k, &cp) == 1) {
bcbf86ec	568	if (commentp)
	569	*commentp=xstrdup(filename);
	570	fclose(f);
	571	return 1;
	572	}
	573	}
	574	}
	575	fclose(f);
	576	}
	577	return 0;
	578	}
	579
	580	/* load public key from pubkey file */
	581	int
	582	try_load_public_key(const char filename, Key k, char **commentp)
	583	{
	584	char pub[MAXPATHLEN];
	585
	586	if (do_load_public_key(filename, k, commentp) == 1)
	587	return 1;
	588	if (strlcpy(pub, filename, sizeof pub) >= MAXPATHLEN)
	589	return 0;
	590	if (strlcat(pub, ".pub", sizeof pub) >= MAXPATHLEN)
	591	return 0;
	592	if (do_load_public_key(pub, k, commentp) == 1)
	593	return 1;
	594	return 0;
	595	}