[openssh.git] / authfd.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Functions for connecting the local authentication agent.
 *
 * 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".
 *
 * SSH2 implementation,
 * 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: authfd.c,v 1.33 2001/01/21 19:05:44 markus Exp $");

#include <openssl/evp.h>

#include "ssh.h"
#include "rsa.h"
#include "buffer.h"
#include "bufaux.h"
#include "xmalloc.h"
#include "getput.h"
#include "key.h"
#include "authfd.h"
#include "cipher.h"
#include "kex.h"
#include "compat.h"
#include "log.h"
#include "atomicio.h"
#include "authfd.h"

/* helper */
int	decode_reply(int type);

/* macro to check for "agent failure" message */
#define agent_failed(x) \
    ((x == SSH_AGENT_FAILURE) || (x == SSH_COM_AGENT2_FAILURE))

/* Returns the number of the authentication fd, or -1 if there is none. */

int
ssh_get_authentication_socket(void)
{
	const char *authsocket;
	int sock, len;
	struct sockaddr_un sunaddr;

	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
	if (!authsocket)
		return -1;

	sunaddr.sun_family = AF_UNIX;
	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
	sunaddr.sun_len = len = SUN_LEN(&sunaddr)+1;
#else /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
	len = SUN_LEN(&sunaddr)+1;
#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */

	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock < 0)
		return -1;

	/* close on exec */
	if (fcntl(sock, F_SETFD, 1) == -1) {
		close(sock);
		return -1;
	}
	if (connect(sock, (struct sockaddr *) & sunaddr, len) < 0) {
		close(sock);
		return -1;
	}
	return sock;
}

int
ssh_request_reply(AuthenticationConnection *auth, Buffer *request, Buffer *reply)
{
	int l, len;
	char buf[1024];

	/* Get the length of the message, and format it in the buffer. */
	len = buffer_len(request);
	PUT_32BIT(buf, len);

	/* Send the length and then the packet to the agent. */
	if (atomicio(write, auth->fd, buf, 4) != 4 ||
	    atomicio(write, auth->fd, buffer_ptr(request),
	    buffer_len(request)) != buffer_len(request)) {
		error("Error writing to authentication socket.");
		return 0;
	}
	/*
	 * Wait for response from the agent.  First read the length of the
	 * response packet.
	 */
	len = 4;
	while (len > 0) {
		l = read(auth->fd, buf + 4 - len, len);
		if (l <= 0) {
			error("Error reading response length from authentication socket.");
			return 0;
		}
		len -= l;
	}

	/* Extract the length, and check it for sanity. */
	len = GET_32BIT(buf);
	if (len > 256 * 1024)
		fatal("Authentication response too long: %d", len);

	/* Read the rest of the response in to the buffer. */
	buffer_clear(reply);
	while (len > 0) {
		l = len;
		if (l > sizeof(buf))
			l = sizeof(buf);
		l = read(auth->fd, buf, l);
		if (l <= 0) {
			error("Error reading response from authentication socket.");
			return 0;
		}
		buffer_append(reply, (char *) buf, l);
		len -= l;
	}
	return 1;
}

/*
 * Closes the agent socket if it should be closed (depends on how it was
 * obtained).  The argument must have been returned by
 * ssh_get_authentication_socket().
 */

void
ssh_close_authentication_socket(int sock)
{
	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
		close(sock);
}

/*
 * Opens and connects a private socket for communication with the
 * authentication agent.  Returns the file descriptor (which must be
 * shut down and closed by the caller when no longer needed).
 * Returns NULL if an error occurred and the connection could not be
 * opened.
 */

AuthenticationConnection *
ssh_get_authentication_connection(void)
{
	AuthenticationConnection *auth;
	int sock;

	sock = ssh_get_authentication_socket();

	/*
	 * Fail if we couldn't obtain a connection.  This happens if we
	 * exited due to a timeout.
	 */
	if (sock < 0)
		return NULL;

	auth = xmalloc(sizeof(*auth));
	auth->fd = sock;
	buffer_init(&auth->identities);
	auth->howmany = 0;

	return auth;
}

/*
 * Closes the connection to the authentication agent and frees any associated
 * memory.
 */

void
ssh_close_authentication_connection(AuthenticationConnection *auth)
{
	buffer_free(&auth->identities);
	close(auth->fd);
	xfree(auth);
}

/*
 * Returns the first authentication identity held by the agent.
 */

int
ssh_get_num_identities(AuthenticationConnection *auth, int version)
{
	int type, code1 = 0, code2 = 0;
	Buffer request;

	switch(version){
	case 1:
		code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
		code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
		break;
	case 2:
		code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
		code2 = SSH2_AGENT_IDENTITIES_ANSWER;
		break;
	default:
		return 0;
	}

	/*
	 * Send a message to the agent requesting for a list of the
	 * identities it can represent.
	 */
	buffer_init(&request);
	buffer_put_char(&request, code1);

	buffer_clear(&auth->identities);
	if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
		buffer_free(&request);
		return 0;
	}
	buffer_free(&request);

	/* Get message type, and verify that we got a proper answer. */
	type = buffer_get_char(&auth->identities);
	if (agent_failed(type)) {
		return 0;
	} else if (type != code2) {
		fatal("Bad authentication reply message type: %d", type);
	}

	/* Get the number of entries in the response and check it for sanity. */
	auth->howmany = buffer_get_int(&auth->identities);
	if (auth->howmany > 1024)
		fatal("Too many identities in authentication reply: %d\n",
		    auth->howmany);

	return auth->howmany;
}

Key *
ssh_get_first_identity(AuthenticationConnection *auth, char **comment, int version)
{
	/* get number of identities and return the first entry (if any). */
	if (ssh_get_num_identities(auth, version) > 0)
		return ssh_get_next_identity(auth, comment, version);
	return NULL;
}

Key *
ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
{
	u_int bits;
	u_char *blob;
	u_int blen;
	Key *key = NULL;

	/* Return failure if no more entries. */
	if (auth->howmany <= 0)
		return NULL;

	/*
	 * Get the next entry from the packet.  These will abort with a fatal
	 * error if the packet is too short or contains corrupt data.
	 */
	switch(version){
	case 1:
		key = key_new(KEY_RSA1);
		bits = buffer_get_int(&auth->identities);
		buffer_get_bignum(&auth->identities, key->rsa->e);
		buffer_get_bignum(&auth->identities, key->rsa->n);
		*comment = buffer_get_string(&auth->identities, NULL);
		if (bits != BN_num_bits(key->rsa->n))
			log("Warning: identity keysize mismatch: actual %d, announced %u",
			    BN_num_bits(key->rsa->n), bits);
		break;
	case 2:
		blob = buffer_get_string(&auth->identities, &blen);
		*comment = buffer_get_string(&auth->identities, NULL);
		key = key_from_blob(blob, blen);
		xfree(blob);
		break;
	default:
		return NULL;
		break;
	}
	/* Decrement the number of remaining entries. */
	auth->howmany--;
	return key;
}

/*
 * Generates a random challenge, sends it to the agent, and waits for
 * response from the agent.  Returns true (non-zero) if the agent gave the
 * correct answer, zero otherwise.  Response type selects the style of
 * response desired, with 0 corresponding to protocol version 1.0 (no longer
 * supported) and 1 corresponding to protocol version 1.1.
 */

int
ssh_decrypt_challenge(AuthenticationConnection *auth,
    Key* key, BIGNUM *challenge,
    u_char session_id[16],
    u_int response_type,
    u_char response[16])
{
	Buffer buffer;
	int success = 0;
	int i;
	int type;

	if (key->type != KEY_RSA1)
		return 0;
	if (response_type == 0) {
		log("Compatibility with ssh protocol version 1.0 no longer supported.");
		return 0;
	}
	buffer_init(&buffer);
	buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
	buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
	buffer_put_bignum(&buffer, key->rsa->e);
	buffer_put_bignum(&buffer, key->rsa->n);
	buffer_put_bignum(&buffer, challenge);
	buffer_append(&buffer, (char *) session_id, 16);
	buffer_put_int(&buffer, response_type);

	if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
		buffer_free(&buffer);
		return 0;
	}
	type = buffer_get_char(&buffer);

	if (agent_failed(type)) {
		log("Agent admitted failure to authenticate using the key.");
	} else if (type != SSH_AGENT_RSA_RESPONSE) {
		fatal("Bad authentication response: %d", type);
	} else {
		success = 1;
		/*
		 * Get the response from the packet.  This will abort with a
		 * fatal error if the packet is corrupt.
		 */
		for (i = 0; i < 16; i++)
			response[i] = buffer_get_char(&buffer);
	}
	buffer_free(&buffer);
	return success;
}

/* ask agent to sign data, returns -1 on error, 0 on success */
int
ssh_agent_sign(AuthenticationConnection *auth,
    Key *key,
    u_char **sigp, int *lenp,
    u_char *data, int datalen)
{
	extern int datafellows;
	Buffer msg;
	u_char *blob;
	u_int blen;
	int type, flags = 0;
	int ret = -1;

	if (key_to_blob(key, &blob, &blen) == 0)
		return -1;

	if (datafellows & SSH_BUG_SIGBLOB)
		flags = SSH_AGENT_OLD_SIGNATURE;

	buffer_init(&msg);
	buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
	buffer_put_string(&msg, blob, blen);
	buffer_put_string(&msg, data, datalen);
	buffer_put_int(&msg, flags);
	xfree(blob);

	if (ssh_request_reply(auth, &msg, &msg) == 0) {
		buffer_free(&msg);
		return -1;
	}
	type = buffer_get_char(&msg);
	if (agent_failed(type)) {
		log("Agent admitted failure to sign using the key.");
	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
		fatal("Bad authentication response: %d", type);
	} else {
		ret = 0;
		*sigp = buffer_get_string(&msg, lenp);
	}
	buffer_free(&msg);
	return ret;
}

/* Encode key for a message to the agent. */

void
ssh_encode_identity_rsa1(Buffer *b, RSA *key, const char *comment)
{
	buffer_clear(b);
	buffer_put_char(b, SSH_AGENTC_ADD_RSA_IDENTITY);
	buffer_put_int(b, BN_num_bits(key->n));
	buffer_put_bignum(b, key->n);
	buffer_put_bignum(b, key->e);
	buffer_put_bignum(b, key->d);
	/* To keep within the protocol: p < q for ssh. in SSL p > q */
	buffer_put_bignum(b, key->iqmp);	/* ssh key->u */
	buffer_put_bignum(b, key->q);	/* ssh key->p, SSL key->q */
	buffer_put_bignum(b, key->p);	/* ssh key->q, SSL key->p */
	buffer_put_string(b, comment, strlen(comment));
}

void
ssh_encode_identity_ssh2(Buffer *b, Key *key, const char *comment)
{
	buffer_clear(b);
	buffer_put_char(b, SSH2_AGENTC_ADD_IDENTITY);
	buffer_put_cstring(b, key_ssh_name(key));
	switch(key->type){
	case KEY_RSA:
		buffer_put_bignum2(b, key->rsa->n);
		buffer_put_bignum2(b, key->rsa->e);
		buffer_put_bignum2(b, key->rsa->d);
		buffer_put_bignum2(b, key->rsa->iqmp);
		buffer_put_bignum2(b, key->rsa->p);
		buffer_put_bignum2(b, key->rsa->q);
		break;
	case KEY_DSA:
		buffer_put_bignum2(b, key->dsa->p);
		buffer_put_bignum2(b, key->dsa->q);
		buffer_put_bignum2(b, key->dsa->g);
		buffer_put_bignum2(b, key->dsa->pub_key);
		buffer_put_bignum2(b, key->dsa->priv_key);
		break;
	}
	buffer_put_cstring(b, comment);
}

/*
 * Adds an identity to the authentication server.  This call is not meant to
 * be used by normal applications.
 */

int
ssh_add_identity(AuthenticationConnection *auth, Key *key, const char *comment)
{
	Buffer msg;
	int type;

	buffer_init(&msg);

	switch (key->type) {
	case KEY_RSA1:
		ssh_encode_identity_rsa1(&msg, key->rsa, comment);
		break;
	case KEY_RSA:
	case KEY_DSA:
		ssh_encode_identity_ssh2(&msg, key, comment);
		break;
	default:
		buffer_free(&msg);
		return 0;
		break;
	}
	if (ssh_request_reply(auth, &msg, &msg) == 0) {
		buffer_free(&msg);
		return 0;
	}
	type = buffer_get_char(&msg);
	buffer_free(&msg);
	return decode_reply(type);
}

/*
 * Removes an identity from the authentication server.  This call is not
 * meant to be used by normal applications.
 */

int
ssh_remove_identity(AuthenticationConnection *auth, Key *key)
{
	Buffer msg;
	int type;
	u_char *blob;
	u_int blen;

	buffer_init(&msg);

	if (key->type == KEY_RSA1) {
		buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
		buffer_put_int(&msg, BN_num_bits(key->rsa->n));
		buffer_put_bignum(&msg, key->rsa->e);
		buffer_put_bignum(&msg, key->rsa->n);
	} else if (key->type == KEY_DSA || key->type == KEY_RSA) {
		key_to_blob(key, &blob, &blen);
		buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
		buffer_put_string(&msg, blob, blen);
		xfree(blob);
	} else {
		buffer_free(&msg);
		return 0;
	}
	if (ssh_request_reply(auth, &msg, &msg) == 0) {
		buffer_free(&msg);
		return 0;
	}
	type = buffer_get_char(&msg);
	buffer_free(&msg);
	return decode_reply(type);
}

/*
 * Removes all identities from the agent.  This call is not meant to be used
 * by normal applications.
 */

int
ssh_remove_all_identities(AuthenticationConnection *auth, int version)
{
	Buffer msg;
	int type;
	int code = (version==1) ?
		SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
		SSH2_AGENTC_REMOVE_ALL_IDENTITIES;

	buffer_init(&msg);
	buffer_put_char(&msg, code);

	if (ssh_request_reply(auth, &msg, &msg) == 0) {
		buffer_free(&msg);
		return 0;
	}
	type = buffer_get_char(&msg);
	buffer_free(&msg);
	return decode_reply(type);
}

int 
decode_reply(int type)
{
	switch (type) {
	case SSH_AGENT_FAILURE:
	case SSH_COM_AGENT2_FAILURE:
		log("SSH_AGENT_FAILURE");
		return 0;
	case SSH_AGENT_SUCCESS:
		return 1;
	default:
		fatal("Bad response from authentication agent: %d", type);
	}
	/* NOTREACHED */
	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	* Functions for connecting the local authentication agent.
6ae2364d	6	*
bcbf86ec	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
	12	*
2e73a022	13	* SSH2 implementation,
bcbf86ec	14	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions
	18	* are met:
	19	* 1. Redistributions of source code must retain the above copyright
	20	* notice, this list of conditions and the following disclaimer.
	21	* 2. Redistributions in binary form must reproduce the above copyright
	22	* notice, this list of conditions and the following disclaimer in the
	23	* documentation and/or other materials provided with the distribution.
2e73a022	24	*
bcbf86ec	25	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	26	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	28	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	29	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	30	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	31	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	32	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	33	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	34	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5260325f	35	*/
8efc0c15	36
8efc0c15	37	#include "includes.h"
42f11eb2	38	RCSID("$OpenBSD: authfd.c,v 1.33 2001/01/21 19:05:44 markus Exp $");
	39
	40	#include <openssl/evp.h>
8efc0c15	41
	42	#include "ssh.h"
	43	#include "rsa.h"
8efc0c15	44	#include "buffer.h"
	45	#include "bufaux.h"
	46	#include "xmalloc.h"
	47	#include "getput.h"
4c8722d9	48	#include "key.h"
4c8722d9	49	#include "authfd.h"
42f11eb2	50	#include "cipher.h"
4c8722d9	51	#include "kex.h"
188adeb2	52	#include "compat.h"
42f11eb2	53	#include "log.h"
	54	#include "atomicio.h"
	55	#include "authfd.h"
8efc0c15	56
089fbbd2	57	/* helper */
c345cf9d	58	int decode_reply(int type);
089fbbd2	59
94ec8c6b	60	/* macro to check for "agent failure" message */
	61	#define agent_failed(x) \
	62	((x == SSH_AGENT_FAILURE) \|\| (x == SSH_COM_AGENT2_FAILURE))
	63
8efc0c15	64	/* Returns the number of the authentication fd, or -1 if there is none. */
	65
	66	int
1e3b8b07	67	ssh_get_authentication_socket(void)
8efc0c15	68	{
5260325f	69	const char *authsocket;
c345cf9d	70	int sock, len;
5260325f	71	struct sockaddr_un sunaddr;
	72
	73	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
	74	if (!authsocket)
	75	return -1;
	76
	77	sunaddr.sun_family = AF_UNIX;
	78	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
c345cf9d	79	#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
	80	sunaddr.sun_len = len = SUN_LEN(&sunaddr)+1;
	81	#else /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
	82	len = SUN_LEN(&sunaddr)+1;
	83	#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
5260325f	84
	85	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	86	if (sock < 0)
	87	return -1;
	88
	89	/* close on exec */
	90	if (fcntl(sock, F_SETFD, 1) == -1) {
	91	close(sock);
	92	return -1;
	93	}
c345cf9d	94	if (connect(sock, (struct sockaddr *) & sunaddr, len) < 0) {
5260325f	95	close(sock);
	96	return -1;
	97	}
	98	return sock;
8efc0c15	99	}
8efc0c15	100
c345cf9d	101	int
2e73a022	102	ssh_request_reply(AuthenticationConnection auth, Buffer request, Buffer *reply)
c345cf9d	103	{
	104	int l, len;
	105	char buf[1024];
	106
	107	/* Get the length of the message, and format it in the buffer. */
	108	len = buffer_len(request);
	109	PUT_32BIT(buf, len);
	110
	111	/* Send the length and then the packet to the agent. */
	112	if (atomicio(write, auth->fd, buf, 4) != 4 \|\|
	113	atomicio(write, auth->fd, buffer_ptr(request),
	114	buffer_len(request)) != buffer_len(request)) {
	115	error("Error writing to authentication socket.");
	116	return 0;
	117	}
	118	/*
	119	* Wait for response from the agent. First read the length of the
	120	* response packet.
	121	*/
	122	len = 4;
	123	while (len > 0) {
	124	l = read(auth->fd, buf + 4 - len, len);
	125	if (l <= 0) {
	126	error("Error reading response length from authentication socket.");
	127	return 0;
	128	}
	129	len -= l;
	130	}
	131
	132	/* Extract the length, and check it for sanity. */
	133	len = GET_32BIT(buf);
	134	if (len > 256 * 1024)
	135	fatal("Authentication response too long: %d", len);
	136
	137	/* Read the rest of the response in to the buffer. */
	138	buffer_clear(reply);
	139	while (len > 0) {
	140	l = len;
	141	if (l > sizeof(buf))
	142	l = sizeof(buf);
	143	l = read(auth->fd, buf, l);
	144	if (l <= 0) {
	145	error("Error reading response from authentication socket.");
	146	return 0;
	147	}
	148	buffer_append(reply, (char *) buf, l);
	149	len -= l;
	150	}
	151	return 1;
	152	}
	153
aa3378df	154	/*
	155	* Closes the agent socket if it should be closed (depends on how it was
	156	* obtained). The argument must have been returned by
	157	* ssh_get_authentication_socket().
	158	*/
8efc0c15	159
6ae2364d	160	void
5260325f	161	ssh_close_authentication_socket(int sock)
8efc0c15	162	{
5260325f	163	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
5260325f	164	close(sock);
8efc0c15	165	}
8efc0c15	166
aa3378df	167	/*
	168	* Opens and connects a private socket for communication with the
	169	* authentication agent. Returns the file descriptor (which must be
	170	* shut down and closed by the caller when no longer needed).
	171	* Returns NULL if an error occurred and the connection could not be
	172	* opened.
	173	*/
8efc0c15	174
5260325f	175	AuthenticationConnection *
1e3b8b07	176	ssh_get_authentication_connection(void)
8efc0c15	177	{
5260325f	178	AuthenticationConnection *auth;
	179	int sock;
	180
	181	sock = ssh_get_authentication_socket();
	182
aa3378df	183	/*
	184	* Fail if we couldn't obtain a connection. This happens if we
	185	* exited due to a timeout.
	186	*/
5260325f	187	if (sock < 0)
	188	return NULL;
	189
5260325f	190	auth = xmalloc(sizeof(*auth));
5260325f	191	auth->fd = sock;
5260325f	192	buffer_init(&auth->identities);
	193	auth->howmany = 0;
	194
	195	return auth;
8efc0c15	196	}
8efc0c15	197
aa3378df	198	/*
	199	* Closes the connection to the authentication agent and frees any associated
	200	* memory.
	201	*/
8efc0c15	202
6ae2364d	203	void
2e73a022	204	ssh_close_authentication_connection(AuthenticationConnection *auth)
8efc0c15	205	{
2e73a022	206	buffer_free(&auth->identities);
	207	close(auth->fd);
	208	xfree(auth);
8efc0c15	209	}
8efc0c15	210
aa3378df	211	/*
aa3378df	212	* Returns the first authentication identity held by the agent.
aa3378df	213	*/
8efc0c15	214
fa08c86b	215	int
fa08c86b	216	ssh_get_num_identities(AuthenticationConnection *auth, int version)
8efc0c15	217	{
2e73a022	218	int type, code1 = 0, code2 = 0;
c345cf9d	219	Buffer request;
2e73a022	220
	221	switch(version){
	222	case 1:
	223	code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
	224	code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
	225	break;
	226	case 2:
	227	code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
	228	code2 = SSH2_AGENT_IDENTITIES_ANSWER;
	229	break;
	230	default:
fa08c86b	231	return 0;
2e73a022	232	}
5260325f	233
aa3378df	234	/*
	235	* Send a message to the agent requesting for a list of the
	236	* identities it can represent.
	237	*/
c345cf9d	238	buffer_init(&request);
2e73a022	239	buffer_put_char(&request, code1);
5260325f	240
5260325f	241	buffer_clear(&auth->identities);
c345cf9d	242	if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
c345cf9d	243	buffer_free(&request);
fa08c86b	244	return 0;
8efc0c15	245	}
c345cf9d	246	buffer_free(&request);
5260325f	247
5260325f	248	/* Get message type, and verify that we got a proper answer. */
c345cf9d	249	type = buffer_get_char(&auth->identities);
94ec8c6b	250	if (agent_failed(type)) {
fa08c86b	251	return 0;
2e73a022	252	} else if (type != code2) {
c345cf9d	253	fatal("Bad authentication reply message type: %d", type);
2e73a022	254	}
5260325f	255
	256	/* Get the number of entries in the response and check it for sanity. */
	257	auth->howmany = buffer_get_int(&auth->identities);
	258	if (auth->howmany > 1024)
c345cf9d	259	fatal("Too many identities in authentication reply: %d\n",
c345cf9d	260	auth->howmany);
5260325f	261
fa08c86b	262	return auth->howmany;
	263	}
	264
	265	Key *
	266	ssh_get_first_identity(AuthenticationConnection auth, char *comment, int version)
	267	{
	268	/* get number of identities and return the first entry (if any). */
	269	if (ssh_get_num_identities(auth, version) > 0)
	270	return ssh_get_next_identity(auth, comment, version);
	271	return NULL;
8efc0c15	272	}
8efc0c15	273
2e73a022	274	Key *
2e73a022	275	ssh_get_next_identity(AuthenticationConnection auth, char *comment, int version)
8efc0c15	276	{
1e3b8b07	277	u_int bits;
	278	u_char *blob;
	279	u_int blen;
2e73a022	280	Key *key = NULL;
4d195447	281
5260325f	282	/* Return failure if no more entries. */
5260325f	283	if (auth->howmany <= 0)
2e73a022	284	return NULL;
8efc0c15	285
aa3378df	286	/*
	287	* Get the next entry from the packet. These will abort with a fatal
	288	* error if the packet is too short or contains corrupt data.
	289	*/
2e73a022	290	switch(version){
2e73a022	291	case 1:
fa08c86b	292	key = key_new(KEY_RSA1);
2e73a022	293	bits = buffer_get_int(&auth->identities);
	294	buffer_get_bignum(&auth->identities, key->rsa->e);
	295	buffer_get_bignum(&auth->identities, key->rsa->n);
	296	*comment = buffer_get_string(&auth->identities, NULL);
	297	if (bits != BN_num_bits(key->rsa->n))
	298	log("Warning: identity keysize mismatch: actual %d, announced %u",
	299	BN_num_bits(key->rsa->n), bits);
	300	break;
	301	case 2:
	302	blob = buffer_get_string(&auth->identities, &blen);
	303	*comment = buffer_get_string(&auth->identities, NULL);
fa08c86b	304	key = key_from_blob(blob, blen);
2e73a022	305	xfree(blob);
	306	break;
	307	default:
	308	return NULL;
	309	break;
	310	}
5260325f	311	/* Decrement the number of remaining entries. */
5260325f	312	auth->howmany--;
2e73a022	313	return key;
8efc0c15	314	}
8efc0c15	315
aa3378df	316	/*
	317	* Generates a random challenge, sends it to the agent, and waits for
	318	* response from the agent. Returns true (non-zero) if the agent gave the
	319	* correct answer, zero otherwise. Response type selects the style of
	320	* response desired, with 0 corresponding to protocol version 1.0 (no longer
	321	* supported) and 1 corresponding to protocol version 1.1.
	322	*/
8efc0c15	323
	324	int
	325	ssh_decrypt_challenge(AuthenticationConnection *auth,
2e73a022	326	Key* key, BIGNUM *challenge,
1e3b8b07	327	u_char session_id[16],
	328	u_int response_type,
	329	u_char response[16])
8efc0c15	330	{
5260325f	331	Buffer buffer;
c345cf9d	332	int success = 0;
	333	int i;
	334	int type;
5260325f	335
fa08c86b	336	if (key->type != KEY_RSA1)
2e73a022	337	return 0;
	338	if (response_type == 0) {
	339	log("Compatibility with ssh protocol version 1.0 no longer supported.");
	340	return 0;
	341	}
5260325f	342	buffer_init(&buffer);
c345cf9d	343	buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
2e73a022	344	buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
	345	buffer_put_bignum(&buffer, key->rsa->e);
	346	buffer_put_bignum(&buffer, key->rsa->n);
5260325f	347	buffer_put_bignum(&buffer, challenge);
	348	buffer_append(&buffer, (char *) session_id, 16);
	349	buffer_put_int(&buffer, response_type);
	350
c345cf9d	351	if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
5260325f	352	buffer_free(&buffer);
	353	return 0;
	354	}
c345cf9d	355	type = buffer_get_char(&buffer);
5260325f	356
94ec8c6b	357	if (agent_failed(type)) {
5260325f	358	log("Agent admitted failure to authenticate using the key.");
c345cf9d	359	} else if (type != SSH_AGENT_RSA_RESPONSE) {
	360	fatal("Bad authentication response: %d", type);
	361	} else {
	362	success = 1;
	363	/*
	364	* Get the response from the packet. This will abort with a
	365	* fatal error if the packet is corrupt.
	366	*/
	367	for (i = 0; i < 16; i++)
	368	response[i] = buffer_get_char(&buffer);
8efc0c15	369	}
5260325f	370	buffer_free(&buffer);
c345cf9d	371	return success;
5260325f	372	}
8efc0c15	373
2e73a022	374	/* ask agent to sign data, returns -1 on error, 0 on success */
	375	int
	376	ssh_agent_sign(AuthenticationConnection *auth,
	377	Key *key,
1e3b8b07	378	u_char *sigp, int lenp,
1e3b8b07	379	u_char *data, int datalen)
2e73a022	380	{
188adeb2	381	extern int datafellows;
2e73a022	382	Buffer msg;
1e3b8b07	383	u_char *blob;
1e3b8b07	384	u_int blen;
188adeb2	385	int type, flags = 0;
2e73a022	386	int ret = -1;
2e73a022	387
fa08c86b	388	if (key_to_blob(key, &blob, &blen) == 0)
2e73a022	389	return -1;
2e73a022	390
188adeb2	391	if (datafellows & SSH_BUG_SIGBLOB)
	392	flags = SSH_AGENT_OLD_SIGNATURE;
	393
2e73a022	394	buffer_init(&msg);
	395	buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
	396	buffer_put_string(&msg, blob, blen);
	397	buffer_put_string(&msg, data, datalen);
188adeb2	398	buffer_put_int(&msg, flags);
2e73a022	399	xfree(blob);
	400
	401	if (ssh_request_reply(auth, &msg, &msg) == 0) {
	402	buffer_free(&msg);
	403	return -1;
	404	}
	405	type = buffer_get_char(&msg);
94ec8c6b	406	if (agent_failed(type)) {
2e73a022	407	log("Agent admitted failure to sign using the key.");
	408	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
	409	fatal("Bad authentication response: %d", type);
	410	} else {
	411	ret = 0;
	412	*sigp = buffer_get_string(&msg, lenp);
	413	}
	414	buffer_free(&msg);
	415	return ret;
	416	}
	417
4c8722d9	418	/* Encode key for a message to the agent. */
	419
	420	void
fa08c86b	421	ssh_encode_identity_rsa1(Buffer b, RSA key, const char *comment)
4c8722d9	422	{
	423	buffer_clear(b);
	424	buffer_put_char(b, SSH_AGENTC_ADD_RSA_IDENTITY);
	425	buffer_put_int(b, BN_num_bits(key->n));
	426	buffer_put_bignum(b, key->n);
	427	buffer_put_bignum(b, key->e);
	428	buffer_put_bignum(b, key->d);
	429	/* To keep within the protocol: p < q for ssh. in SSL p > q */
	430	buffer_put_bignum(b, key->iqmp); /* ssh key->u */
	431	buffer_put_bignum(b, key->q); /* ssh key->p, SSL key->q */
	432	buffer_put_bignum(b, key->p); /* ssh key->q, SSL key->p */
	433	buffer_put_string(b, comment, strlen(comment));
	434	}
	435
	436	void
fa08c86b	437	ssh_encode_identity_ssh2(Buffer b, Key key, const char *comment)
4c8722d9	438	{
	439	buffer_clear(b);
	440	buffer_put_char(b, SSH2_AGENTC_ADD_IDENTITY);
fa08c86b	441	buffer_put_cstring(b, key_ssh_name(key));
	442	switch(key->type){
	443	case KEY_RSA:
	444	buffer_put_bignum2(b, key->rsa->n);
	445	buffer_put_bignum2(b, key->rsa->e);
	446	buffer_put_bignum2(b, key->rsa->d);
	447	buffer_put_bignum2(b, key->rsa->iqmp);
	448	buffer_put_bignum2(b, key->rsa->p);
	449	buffer_put_bignum2(b, key->rsa->q);
	450	break;
	451	case KEY_DSA:
	452	buffer_put_bignum2(b, key->dsa->p);
	453	buffer_put_bignum2(b, key->dsa->q);
	454	buffer_put_bignum2(b, key->dsa->g);
	455	buffer_put_bignum2(b, key->dsa->pub_key);
	456	buffer_put_bignum2(b, key->dsa->priv_key);
	457	break;
	458	}
	459	buffer_put_cstring(b, comment);
4c8722d9	460	}
4c8722d9	461
aa3378df	462	/*
	463	* Adds an identity to the authentication server. This call is not meant to
	464	* be used by normal applications.
	465	*/
8efc0c15	466
6ae2364d	467	int
4c8722d9	468	ssh_add_identity(AuthenticationConnection auth, Key key, const char *comment)
8efc0c15	469	{
2e73a022	470	Buffer msg;
c345cf9d	471	int type;
5260325f	472
2e73a022	473	buffer_init(&msg);
4c8722d9	474
4c8722d9	475	switch (key->type) {
fa08c86b	476	case KEY_RSA1:
fa08c86b	477	ssh_encode_identity_rsa1(&msg, key->rsa, comment);
4c8722d9	478	break;
fa08c86b	479	case KEY_RSA:
4c8722d9	480	case KEY_DSA:
fa08c86b	481	ssh_encode_identity_ssh2(&msg, key, comment);
4c8722d9	482	break;
4c8722d9	483	default:
2e73a022	484	buffer_free(&msg);
4c8722d9	485	return 0;
	486	break;
	487	}
2e73a022	488	if (ssh_request_reply(auth, &msg, &msg) == 0) {
2e73a022	489	buffer_free(&msg);
5260325f	490	return 0;
5260325f	491	}
2e73a022	492	type = buffer_get_char(&msg);
2e73a022	493	buffer_free(&msg);
c345cf9d	494	return decode_reply(type);
5260325f	495	}
5260325f	496
aa3378df	497	/*
	498	* Removes an identity from the authentication server. This call is not
	499	* meant to be used by normal applications.
	500	*/
8efc0c15	501
6ae2364d	502	int
2e73a022	503	ssh_remove_identity(AuthenticationConnection auth, Key key)
8efc0c15	504	{
2e73a022	505	Buffer msg;
c345cf9d	506	int type;
1e3b8b07	507	u_char *blob;
1e3b8b07	508	u_int blen;
2e73a022	509
	510	buffer_init(&msg);
	511
fa08c86b	512	if (key->type == KEY_RSA1) {
2e73a022	513	buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
	514	buffer_put_int(&msg, BN_num_bits(key->rsa->n));
	515	buffer_put_bignum(&msg, key->rsa->e);
	516	buffer_put_bignum(&msg, key->rsa->n);
fa08c86b	517	} else if (key->type == KEY_DSA \|\| key->type == KEY_RSA) {
fa08c86b	518	key_to_blob(key, &blob, &blen);
2e73a022	519	buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
	520	buffer_put_string(&msg, blob, blen);
	521	xfree(blob);
	522	} else {
	523	buffer_free(&msg);
5260325f	524	return 0;
5260325f	525	}
2e73a022	526	if (ssh_request_reply(auth, &msg, &msg) == 0) {
	527	buffer_free(&msg);
	528	return 0;
	529	}
	530	type = buffer_get_char(&msg);
	531	buffer_free(&msg);
c345cf9d	532	return decode_reply(type);
5260325f	533	}
5260325f	534
aa3378df	535	/*
	536	* Removes all identities from the agent. This call is not meant to be used
	537	* by normal applications.
	538	*/
8efc0c15	539
6ae2364d	540	int
2e73a022	541	ssh_remove_all_identities(AuthenticationConnection *auth, int version)
8efc0c15	542	{
2e73a022	543	Buffer msg;
c345cf9d	544	int type;
2e73a022	545	int code = (version==1) ?
	546	SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
	547	SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
5260325f	548
2e73a022	549	buffer_init(&msg);
2e73a022	550	buffer_put_char(&msg, code);
5260325f	551
2e73a022	552	if (ssh_request_reply(auth, &msg, &msg) == 0) {
2e73a022	553	buffer_free(&msg);
5260325f	554	return 0;
5260325f	555	}
2e73a022	556	type = buffer_get_char(&msg);
2e73a022	557	buffer_free(&msg);
c345cf9d	558	return decode_reply(type);
089fbbd2	559	}
089fbbd2	560
089fbbd2	561	int
c345cf9d	562	decode_reply(int type)
089fbbd2	563	{
5260325f	564	switch (type) {
5260325f	565	case SSH_AGENT_FAILURE:
94ec8c6b	566	case SSH_COM_AGENT2_FAILURE:
c345cf9d	567	log("SSH_AGENT_FAILURE");
5260325f	568	return 0;
5260325f	569	case SSH_AGENT_SUCCESS:
5260325f	570	return 1;
5260325f	571	default:
089fbbd2	572	fatal("Bad response from authentication agent: %d", type);
8efc0c15	573	}
5260325f	574	/* NOTREACHED */
	575	return 0;
	576	}