[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 1.28 2001/02/21 09:05:54 deraadt 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"
#include "authfile.h"

/* Version identification string for identity files. */
static const char 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. */
	for (i = 0; authfile_id_string[i]; i++)
		buffer_put_char(&encrypted, authfile_id_string[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 enough to contain the ID string. */
	if (len < sizeof(authfile_id_string)) {
		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 < sizeof(authfile_id_string); i++)
		if (buffer_get_char(&buffer) != 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;
	}

	/* Check that it is at least big enough to contain the ID string. */
	if (len < sizeof(authfile_id_string)) {
		debug3("Bad RSA1 key file %.200s.", filename);
		buffer_free(&buffer);
		close(fd);
		return 0;
	}
	/*
	 * Make sure it begins with the id string.  Consume the id string
	 * from the buffer.
	 */
	for (i = 0; i < sizeof(authfile_id_string); i++)
		if (buffer_get_char(&buffer) != authfile_id_string[i]) {
			debug3("Bad RSA1 key file %.200s.", filename);
			buffer_free(&buffer);
			close(fd);
			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);
		close(fd);
		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);
	close(fd);
	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");
		close(fd);
		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);		/* closes fd */

		break;
	case KEY_DSA:
	case KEY_RSA:
	case KEY_UNSPEC:
		ret = load_private_key_ssh2(fd, passphrase, key,
		    comment_return);			/* closes fd */
		break;
	default:
		close(fd);
		break;
	}
	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"
81333640	39	RCSID("$OpenBSD: authfile.c,v 1.28 2001/02/21 09:05:54 deraadt 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"
5ca51e19	52	#include "authfile.h"
8efc0c15	53
8efc0c15	54	/* Version identification string for identity files. */
7e2183c0	55	static const char authfile_id_string[] =
7e2183c0	56	"SSH PRIVATE KEY FILE FORMAT 1.1\n";
8efc0c15	57
aa3378df	58	/*
	59	* Saves the authentication (private) key in a file, encrypting it with
	60	* passphrase. The identification of the file (lowest 64 bits of n) will
	61	* precede the key to provide identification of the key without needing a
	62	* passphrase.
	63	*/
8efc0c15	64
8efc0c15	65	int
fa08c86b	66	save_private_key_rsa1(const char filename, const char passphrase,
a306f2dd	67	RSA key, const char comment)
8efc0c15	68	{
5260325f	69	Buffer buffer, encrypted;
5260325f	70	char buf[100], *cp;
a408af76	71	int fd, i;
94ec8c6b	72	CipherContext ciphercontext;
94ec8c6b	73	Cipher *cipher;
5260325f	74	u_int32_t rand;
5260325f	75
aa3378df	76	/*
	77	* If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
	78	* to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
	79	*/
5260325f	80	if (strcmp(passphrase, "") == 0)
94ec8c6b	81	cipher = cipher_by_number(SSH_CIPHER_NONE);
5260325f	82	else
94ec8c6b	83	cipher = cipher_by_number(SSH_AUTHFILE_CIPHER);
	84	if (cipher == NULL)
	85	fatal("save_private_key_rsa: bad cipher");
5260325f	86
	87	/* This buffer is used to built the secret part of the private key. */
	88	buffer_init(&buffer);
	89
	90	/* Put checkbytes for checking passphrase validity. */
	91	rand = arc4random();
	92	buf[0] = rand & 0xff;
	93	buf[1] = (rand >> 8) & 0xff;
	94	buf[2] = buf[0];
	95	buf[3] = buf[1];
	96	buffer_append(&buffer, buf, 4);
	97
aa3378df	98	/*
	99	* Store the private key (n and e will not be stored because they
	100	* will be stored in plain text, and storing them also in encrypted
	101	* format would just give known plaintext).
	102	*/
5260325f	103	buffer_put_bignum(&buffer, key->d);
	104	buffer_put_bignum(&buffer, key->iqmp);
	105	buffer_put_bignum(&buffer, key->q); /* reverse from SSL p */
	106	buffer_put_bignum(&buffer, key->p); /* reverse from SSL q */
	107
	108	/* Pad the part to be encrypted until its size is a multiple of 8. */
	109	while (buffer_len(&buffer) % 8 != 0)
	110	buffer_put_char(&buffer, 0);
	111
	112	/* This buffer will be used to contain the data in the file. */
	113	buffer_init(&encrypted);
	114
	115	/* First store keyfile id string. */
7e2183c0	116	for (i = 0; authfile_id_string[i]; i++)
7e2183c0	117	buffer_put_char(&encrypted, authfile_id_string[i]);
5260325f	118	buffer_put_char(&encrypted, 0);
	119
	120	/* Store cipher type. */
94ec8c6b	121	buffer_put_char(&encrypted, cipher->number);
5260325f	122	buffer_put_int(&encrypted, 0); /* For future extension */
	123
	124	/* Store public key. This will be in plain text. */
	125	buffer_put_int(&encrypted, BN_num_bits(key->n));
	126	buffer_put_bignum(&encrypted, key->n);
	127	buffer_put_bignum(&encrypted, key->e);
	128	buffer_put_string(&encrypted, comment, strlen(comment));
	129
	130	/* Allocate space for the private part of the key in the buffer. */
	131	buffer_append_space(&encrypted, &cp, buffer_len(&buffer));
	132
94ec8c6b	133	cipher_set_key_string(&ciphercontext, cipher, passphrase);
1e3b8b07	134	cipher_encrypt(&ciphercontext, (u_char *) cp,
1e3b8b07	135	(u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
94ec8c6b	136	memset(&ciphercontext, 0, sizeof(ciphercontext));
5260325f	137
	138	/* Destroy temporary data. */
	139	memset(buf, 0, sizeof(buf));
	140	buffer_free(&buffer);
	141
a408af76	142	fd = open(filename, O_WRONLY \| O_CREAT \| O_TRUNC, 0600);
a408af76	143	if (fd < 0)
5260325f	144	return 0;
a408af76	145	if (write(fd, buffer_ptr(&encrypted), buffer_len(&encrypted)) !=
5260325f	146	buffer_len(&encrypted)) {
	147	debug("Write to key file %.200s failed: %.100s", filename,
	148	strerror(errno));
	149	buffer_free(&encrypted);
a408af76	150	close(fd);
77bb0bca	151	unlink(filename);
5260325f	152	return 0;
5260325f	153	}
a408af76	154	close(fd);
5260325f	155	buffer_free(&encrypted);
5260325f	156	return 1;
8efc0c15	157	}
8efc0c15	158
fa08c86b	159	/* save SSH2 key in OpenSSL PEM format */
a306f2dd	160	int
fa08c86b	161	save_private_key_ssh2(const char filename, const char _passphrase,
fa08c86b	162	Key key, const char comment)
a306f2dd	163	{
	164	FILE *fp;
	165	int fd;
fa08c86b	166	int success = 0;
	167	int len = strlen(_passphrase);
	168	char passphrase = (len > 0) ? (char )_passphrase : NULL;
	169	EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;
a306f2dd	170
	171	if (len > 0 && len <= 4) {
	172	error("passphrase too short: %d bytes", len);
	173	errno = 0;
	174	return 0;
	175	}
	176	fd = open(filename, O_WRONLY \| O_CREAT \| O_TRUNC, 0600);
	177	if (fd < 0) {
	178	debug("open %s failed", filename);
	179	return 0;
	180	}
	181	fp = fdopen(fd, "w");
	182	if (fp == NULL ) {
	183	debug("fdopen %s failed", filename);
	184	close(fd);
	185	return 0;
	186	}
fa08c86b	187	switch (key->type) {
	188	case KEY_DSA:
	189	success = PEM_write_DSAPrivateKey(fp, key->dsa,
	190	cipher, passphrase, len, NULL, NULL);
	191	break;
	192	case KEY_RSA:
	193	success = PEM_write_RSAPrivateKey(fp, key->rsa,
	194	cipher, passphrase, len, NULL, NULL);
	195	break;
a306f2dd	196	}
	197	fclose(fp);
	198	return success;
	199	}
	200
	201	int
	202	save_private_key(const char filename, const char passphrase, Key *key,
	203	const char *comment)
	204	{
	205	switch (key->type) {
fa08c86b	206	case KEY_RSA1:
fa08c86b	207	return save_private_key_rsa1(filename, passphrase, key->rsa, comment);
a306f2dd	208	break;
a306f2dd	209	case KEY_DSA:
fa08c86b	210	case KEY_RSA:
fa08c86b	211	return save_private_key_ssh2(filename, passphrase, key, comment);
a306f2dd	212	break;
	213	default:
	214	break;
	215	}
	216	return 0;
	217	}
	218
aa3378df	219	/*
	220	* Loads the public part of the key file. Returns 0 if an error was
	221	* encountered (the file does not exist or is not readable), and non-zero
	222	* otherwise.
	223	*/
8efc0c15	224
8efc0c15	225	int
a306f2dd	226	load_public_key_rsa(const char filename, RSA pub, char **comment_return)
8efc0c15	227	{
a408af76	228	int fd, i;
5260325f	229	off_t len;
	230	Buffer buffer;
	231	char *cp;
	232
a408af76	233	fd = open(filename, O_RDONLY);
a408af76	234	if (fd < 0)
5260325f	235	return 0;
a408af76	236	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	237	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	238
	239	buffer_init(&buffer);
	240	buffer_append_space(&buffer, &cp, len);
	241
a408af76	242	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	243	debug("Read from key file %.200s failed: %.100s", filename,
a306f2dd	244	strerror(errno));
5260325f	245	buffer_free(&buffer);
a408af76	246	close(fd);
5260325f	247	return 0;
5260325f	248	}
a408af76	249	close(fd);
5260325f	250
7e2183c0	251	/* Check that it is at least big enough to contain the ID string. */
7e2183c0	252	if (len < sizeof(authfile_id_string)) {
fa08c86b	253	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	254	buffer_free(&buffer);
	255	return 0;
	256	}
aa3378df	257	/*
	258	* Make sure it begins with the id string. Consume the id string
	259	* from the buffer.
	260	*/
7e2183c0	261	for (i = 0; i < sizeof(authfile_id_string); i++)
7e2183c0	262	if (buffer_get_char(&buffer) != authfile_id_string[i]) {
fa08c86b	263	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	264	buffer_free(&buffer);
	265	return 0;
	266	}
	267	/* Skip cipher type and reserved data. */
	268	(void) buffer_get_char(&buffer); /* cipher type */
	269	(void) buffer_get_int(&buffer); /* reserved */
	270
	271	/* Read the public key from the buffer. */
	272	buffer_get_int(&buffer);
a306f2dd	273	/* XXX alloc */
	274	if (pub->n == NULL)
	275	pub->n = BN_new();
5260325f	276	buffer_get_bignum(&buffer, pub->n);
a306f2dd	277	/* XXX alloc */
	278	if (pub->e == NULL)
	279	pub->e = BN_new();
5260325f	280	buffer_get_bignum(&buffer, pub->e);
	281	if (comment_return)
	282	*comment_return = buffer_get_string(&buffer, NULL);
	283	/* The encrypted private part is not parsed by this function. */
	284
8efc0c15	285	buffer_free(&buffer);
5260325f	286
5260325f	287	return 1;
8efc0c15	288	}
8efc0c15	289
bcbf86ec	290	/* load public key from private-key file */
a306f2dd	291	int
	292	load_public_key(const char filename, Key key, char **comment_return)
	293	{
	294	switch (key->type) {
fa08c86b	295	case KEY_RSA1:
a306f2dd	296	return load_public_key_rsa(filename, key->rsa, comment_return);
	297	break;
	298	case KEY_DSA:
fa08c86b	299	case KEY_RSA:
a306f2dd	300	default:
	301	break;
	302	}
	303	return 0;
	304	}
	305
aa3378df	306	/*
	307	* Loads the private key from the file. Returns 0 if an error is encountered
	308	* (file does not exist or is not readable, or passphrase is bad). This
	309	* initializes the private key.
	310	* Assumes we are called under uid of the owner of the file.
	311	*/
8efc0c15	312
8efc0c15	313	int
fa08c86b	314	load_private_key_rsa1(int fd, const char *filename,
a306f2dd	315	const char passphrase, RSA prv, char **comment_return)
8efc0c15	316	{
a306f2dd	317	int i, check1, check2, cipher_type;
5260325f	318	off_t len;
	319	Buffer buffer, decrypted;
	320	char *cp;
94ec8c6b	321	CipherContext ciphercontext;
94ec8c6b	322	Cipher *cipher;
5260325f	323	BN_CTX *ctx;
5260325f	324	BIGNUM *aux;
5260325f	325
a408af76	326	len = lseek(fd, (off_t) 0, SEEK_END);
a408af76	327	lseek(fd, (off_t) 0, SEEK_SET);
5260325f	328
	329	buffer_init(&buffer);
	330	buffer_append_space(&buffer, &cp, len);
	331
a408af76	332	if (read(fd, cp, (size_t) len) != (size_t) len) {
5260325f	333	debug("Read from key file %.200s failed: %.100s", filename,
fa08c86b	334	strerror(errno));
5260325f	335	buffer_free(&buffer);
a408af76	336	close(fd);
5260325f	337	return 0;
5260325f	338	}
5260325f	339
7e2183c0	340	/* Check that it is at least big enough to contain the ID string. */
7e2183c0	341	if (len < sizeof(authfile_id_string)) {
fa08c86b	342	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	343	buffer_free(&buffer);
81333640	344	close(fd);
5260325f	345	return 0;
5260325f	346	}
aa3378df	347	/*
	348	* Make sure it begins with the id string. Consume the id string
	349	* from the buffer.
	350	*/
7e2183c0	351	for (i = 0; i < sizeof(authfile_id_string); i++)
7e2183c0	352	if (buffer_get_char(&buffer) != authfile_id_string[i]) {
fa08c86b	353	debug3("Bad RSA1 key file %.200s.", filename);
5260325f	354	buffer_free(&buffer);
81333640	355	close(fd);
5260325f	356	return 0;
5260325f	357	}
81333640	358
5260325f	359	/* Read cipher type. */
	360	cipher_type = buffer_get_char(&buffer);
	361	(void) buffer_get_int(&buffer); /* Reserved data. */
	362
	363	/* Read the public key from the buffer. */
	364	buffer_get_int(&buffer);
	365	prv->n = BN_new();
	366	buffer_get_bignum(&buffer, prv->n);
	367	prv->e = BN_new();
	368	buffer_get_bignum(&buffer, prv->e);
	369	if (comment_return)
	370	*comment_return = buffer_get_string(&buffer, NULL);
	371	else
	372	xfree(buffer_get_string(&buffer, NULL));
	373
	374	/* Check that it is a supported cipher. */
94ec8c6b	375	cipher = cipher_by_number(cipher_type);
	376	if (cipher == NULL) {
	377	debug("Unsupported cipher %d used in key file %.200s.",
	378	cipher_type, filename);
5260325f	379	buffer_free(&buffer);
	380	goto fail;
	381	}
	382	/* Initialize space for decrypted data. */
	383	buffer_init(&decrypted);
	384	buffer_append_space(&decrypted, &cp, buffer_len(&buffer));
	385
	386	/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
94ec8c6b	387	cipher_set_key_string(&ciphercontext, cipher, passphrase);
1e3b8b07	388	cipher_decrypt(&ciphercontext, (u_char *) cp,
1e3b8b07	389	(u_char *) buffer_ptr(&buffer), buffer_len(&buffer));
94ec8c6b	390	memset(&ciphercontext, 0, sizeof(ciphercontext));
8efc0c15	391	buffer_free(&buffer);
5260325f	392
	393	check1 = buffer_get_char(&decrypted);
	394	check2 = buffer_get_char(&decrypted);
	395	if (check1 != buffer_get_char(&decrypted) \|\|
	396	check2 != buffer_get_char(&decrypted)) {
	397	if (strcmp(passphrase, "") != 0)
	398	debug("Bad passphrase supplied for key file %.200s.", filename);
	399	/* Bad passphrase. */
	400	buffer_free(&decrypted);
	401	fail:
	402	BN_clear_free(prv->n);
a306f2dd	403	prv->n = NULL;
5260325f	404	BN_clear_free(prv->e);
a306f2dd	405	prv->e = NULL;
5260325f	406	if (comment_return)
5260325f	407	xfree(*comment_return);
81333640	408	close(fd);
5260325f	409	return 0;
	410	}
	411	/* Read the rest of the private key. */
	412	prv->d = BN_new();
	413	buffer_get_bignum(&decrypted, prv->d);
	414	prv->iqmp = BN_new();
	415	buffer_get_bignum(&decrypted, prv->iqmp); /* u */
	416	/* in SSL and SSH p and q are exchanged */
	417	prv->q = BN_new();
	418	buffer_get_bignum(&decrypted, prv->q); /* p */
	419	prv->p = BN_new();
	420	buffer_get_bignum(&decrypted, prv->p); /* q */
	421
	422	ctx = BN_CTX_new();
	423	aux = BN_new();
	424
	425	BN_sub(aux, prv->q, BN_value_one());
	426	prv->dmq1 = BN_new();
	427	BN_mod(prv->dmq1, prv->d, aux, ctx);
	428
	429	BN_sub(aux, prv->p, BN_value_one());
	430	prv->dmp1 = BN_new();
	431	BN_mod(prv->dmp1, prv->d, aux, ctx);
	432
	433	BN_clear_free(aux);
	434	BN_CTX_free(ctx);
	435
	436	buffer_free(&decrypted);
81333640	437	close(fd);
5260325f	438	return 1;
8efc0c15	439	}
a306f2dd	440
a306f2dd	441	int
fa08c86b	442	load_private_key_ssh2(int fd, const char passphrase, Key k, char **comment_return)
a306f2dd	443	{
a306f2dd	444	FILE *fp;
fa08c86b	445	int success = 0;
	446	EVP_PKEY *pk = NULL;
	447	char *name = "<no key>";
a306f2dd	448
a306f2dd	449	fp = fdopen(fd, "r");
	450	if (fp == NULL) {
	451	error("fdopen failed");
81333640	452	close(fd);
a306f2dd	453	return 0;
a306f2dd	454	}
fa08c86b	455	pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
	456	if (pk == NULL) {
	457	debug("PEM_read_PrivateKey failed");
	458	(void)ERR_get_error();
	459	} else if (pk->type == EVP_PKEY_RSA) {
	460	/* replace k->rsa with loaded key */
	461	if (k->type == KEY_RSA \|\| k->type == KEY_UNSPEC) {
	462	if (k->rsa != NULL)
	463	RSA_free(k->rsa);
	464	k->rsa = EVP_PKEY_get1_RSA(pk);
	465	k->type = KEY_RSA;
	466	name = "rsa w/o comment";
	467	success = 1;
	468	#ifdef DEBUG_PK
	469	RSA_print_fp(stderr, k->rsa, 8);
	470	#endif
	471	}
	472	} else if (pk->type == EVP_PKEY_DSA) {
a306f2dd	473	/* replace k->dsa with loaded key */
fa08c86b	474	if (k->type == KEY_DSA \|\| k->type == KEY_UNSPEC) {
	475	if (k->dsa != NULL)
	476	DSA_free(k->dsa);
	477	k->dsa = EVP_PKEY_get1_DSA(pk);
	478	k->type = KEY_DSA;
	479	name = "dsa w/o comment";
	480	#ifdef DEBUG_PK
	481	DSA_print_fp(stderr, k->dsa, 8);
	482	#endif
	483	success = 1;
	484	}
	485	} else {
	486	error("PEM_read_PrivateKey: mismatch or "
	487	"unknown EVP_PKEY save_type %d", pk->save_type);
a306f2dd	488	}
a306f2dd	489	fclose(fp);
fa08c86b	490	if (pk != NULL)
	491	EVP_PKEY_free(pk);
	492	if (success && comment_return)
	493	*comment_return = xstrdup(name);
	494	debug("read SSH2 private key done: name %s success %d", name, success);
	495	return success;
a306f2dd	496	}
	497
	498	int
	499	load_private_key(const char filename, const char passphrase, Key *key,
	500	char **comment_return)
	501	{
	502	int fd;
	503	int ret = 0;
	504	struct stat st;
	505
	506	fd = open(filename, O_RDONLY);
	507	if (fd < 0)
	508	return 0;
	509
22d89d24	510	/* check owner and modes */
9cd45ea4	511	#ifdef HAVE_CYGWIN
22d89d24	512	if (check_ntsec(filename))
9cd45ea4	513	#endif
a306f2dd	514	if (fstat(fd, &st) < 0 \|\|
1e3b8b07	515	(st.st_uid != 0 && getuid() != 0 && st.st_uid != getuid()) \|\|
a306f2dd	516	(st.st_mode & 077) != 0) {
	517	close(fd);
	518	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	519	error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
	520	error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
	521	error("Bad ownership or mode(0%3.3o) for '%s'.",
81333640	522	st.st_mode & 0777, filename);
a306f2dd	523	error("It is recommended that your private key files are NOT accessible by others.");
	524	return 0;
	525	}
	526	switch (key->type) {
fa08c86b	527	case KEY_RSA1:
a306f2dd	528	if (key->rsa->e != NULL) {
	529	BN_clear_free(key->rsa->e);
	530	key->rsa->e = NULL;
	531	}
	532	if (key->rsa->n != NULL) {
	533	BN_clear_free(key->rsa->n);
	534	key->rsa->n = NULL;
	535	}
fa08c86b	536	ret = load_private_key_rsa1(fd, filename, passphrase,
81333640	537	key->rsa, comment_return); /* closes fd */
81333640	538
a306f2dd	539	break;
a306f2dd	540	case KEY_DSA:
fa08c86b	541	case KEY_RSA:
fa08c86b	542	case KEY_UNSPEC:
81333640	543	ret = load_private_key_ssh2(fd, passphrase, key,
	544	comment_return); /* closes fd */
	545	break;
a306f2dd	546	default:
81333640	547	close(fd);
a306f2dd	548	break;
a306f2dd	549	}
a306f2dd	550	return ret;
a306f2dd	551	}
bcbf86ec	552
	553	int
	554	do_load_public_key(const char filename, Key k, char **commentp)
	555	{
	556	FILE *f;
bcbf86ec	557	char line[1024];
	558	char *cp;
	559
	560	f = fopen(filename, "r");
	561	if (f != NULL) {
	562	while (fgets(line, sizeof(line), f)) {
	563	line[sizeof(line)-1] = '\0';
	564	cp = line;
	565	switch(*cp){
	566	case '#':
	567	case '\n':
	568	case '\0':
	569	continue;
	570	}
	571	/* Skip leading whitespace. */
	572	for (; cp && (cp == ' ' \|\| *cp == '\t'); cp++)
	573	;
	574	if (*cp) {
fa08c86b	575	if (key_read(k, &cp) == 1) {
bcbf86ec	576	if (commentp)
	577	*commentp=xstrdup(filename);
	578	fclose(f);
	579	return 1;
	580	}
	581	}
	582	}
	583	fclose(f);
	584	}
	585	return 0;
	586	}
	587
	588	/* load public key from pubkey file */
	589	int
	590	try_load_public_key(const char filename, Key k, char **commentp)
	591	{
	592	char pub[MAXPATHLEN];
	593
	594	if (do_load_public_key(filename, k, commentp) == 1)
	595	return 1;
	596	if (strlcpy(pub, filename, sizeof pub) >= MAXPATHLEN)
	597	return 0;
	598	if (strlcat(pub, ".pub", sizeof pub) >= MAXPATHLEN)
	599	return 0;
	600	if (do_load_public_key(pub, k, commentp) == 1)
	601	return 1;
	602	return 0;
	603	}