[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 1.39 2001/04/05 10:42:48 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"

/* 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));
	len = SUN_LEN(&sunaddr)+1;
#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
	sunaddr.sun_len = len;
#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 == -1 && (errno == EAGAIN || errno == EINTR))
			continue;
		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 == -1 && (errno == EAGAIN || errno == EINTR))
			continue;
		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",
		    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"
cd332296	38	RCSID("$OpenBSD: authfd.c,v 1.39 2001/04/05 10:42:48 markus Exp $");
42f11eb2	39
42f11eb2	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"
42f11eb2	54	#include "atomicio.h"
8efc0c15	55
089fbbd2	56	/* helper */
c345cf9d	57	int decode_reply(int type);
089fbbd2	58
94ec8c6b	59	/* macro to check for "agent failure" message */
	60	#define agent_failed(x) \
	61	((x == SSH_AGENT_FAILURE) \|\| (x == SSH_COM_AGENT2_FAILURE))
	62
8efc0c15	63	/* Returns the number of the authentication fd, or -1 if there is none. */
	64
	65	int
1e3b8b07	66	ssh_get_authentication_socket(void)
8efc0c15	67	{
5260325f	68	const char *authsocket;
c345cf9d	69	int sock, len;
5260325f	70	struct sockaddr_un sunaddr;
	71
	72	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
	73	if (!authsocket)
	74	return -1;
	75
	76	sunaddr.sun_family = AF_UNIX;
	77	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
c345cf9d	78	len = SUN_LEN(&sunaddr)+1;
c3f7d267	79	#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
c3f7d267	80	sunaddr.sun_len = len;
c345cf9d	81	#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
5260325f	82
	83	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	84	if (sock < 0)
	85	return -1;
	86
	87	/* close on exec */
	88	if (fcntl(sock, F_SETFD, 1) == -1) {
	89	close(sock);
	90	return -1;
	91	}
c345cf9d	92	if (connect(sock, (struct sockaddr *) & sunaddr, len) < 0) {
5260325f	93	close(sock);
	94	return -1;
	95	}
	96	return sock;
8efc0c15	97	}
8efc0c15	98
c345cf9d	99	int
2e73a022	100	ssh_request_reply(AuthenticationConnection auth, Buffer request, Buffer *reply)
c345cf9d	101	{
	102	int l, len;
	103	char buf[1024];
	104
	105	/* Get the length of the message, and format it in the buffer. */
	106	len = buffer_len(request);
	107	PUT_32BIT(buf, len);
	108
	109	/* Send the length and then the packet to the agent. */
	110	if (atomicio(write, auth->fd, buf, 4) != 4 \|\|
	111	atomicio(write, auth->fd, buffer_ptr(request),
	112	buffer_len(request)) != buffer_len(request)) {
	113	error("Error writing to authentication socket.");
	114	return 0;
	115	}
	116	/*
	117	* Wait for response from the agent. First read the length of the
	118	* response packet.
	119	*/
	120	len = 4;
	121	while (len > 0) {
	122	l = read(auth->fd, buf + 4 - len, len);
bbc62e59	123	if (l == -1 && (errno == EAGAIN \|\| errno == EINTR))
cd332296	124	continue;
c345cf9d	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);
bbc62e59	144	if (l == -1 && (errno == EAGAIN \|\| errno == EINTR))
cd332296	145	continue;
c345cf9d	146	if (l <= 0) {
	147	error("Error reading response from authentication socket.");
	148	return 0;
	149	}
	150	buffer_append(reply, (char *) buf, l);
	151	len -= l;
	152	}
	153	return 1;
	154	}
	155
aa3378df	156	/*
	157	* Closes the agent socket if it should be closed (depends on how it was
	158	* obtained). The argument must have been returned by
	159	* ssh_get_authentication_socket().
	160	*/
8efc0c15	161
6ae2364d	162	void
5260325f	163	ssh_close_authentication_socket(int sock)
8efc0c15	164	{
5260325f	165	if (getenv(SSH_AUTHSOCKET_ENV_NAME))
5260325f	166	close(sock);
8efc0c15	167	}
8efc0c15	168
aa3378df	169	/*
	170	* Opens and connects a private socket for communication with the
	171	* authentication agent. Returns the file descriptor (which must be
	172	* shut down and closed by the caller when no longer needed).
	173	* Returns NULL if an error occurred and the connection could not be
	174	* opened.
	175	*/
8efc0c15	176
5260325f	177	AuthenticationConnection *
1e3b8b07	178	ssh_get_authentication_connection(void)
8efc0c15	179	{
5260325f	180	AuthenticationConnection *auth;
	181	int sock;
	182
	183	sock = ssh_get_authentication_socket();
	184
aa3378df	185	/*
	186	* Fail if we couldn't obtain a connection. This happens if we
	187	* exited due to a timeout.
	188	*/
5260325f	189	if (sock < 0)
	190	return NULL;
	191
5260325f	192	auth = xmalloc(sizeof(*auth));
5260325f	193	auth->fd = sock;
5260325f	194	buffer_init(&auth->identities);
	195	auth->howmany = 0;
	196
	197	return auth;
8efc0c15	198	}
8efc0c15	199
aa3378df	200	/*
	201	* Closes the connection to the authentication agent and frees any associated
	202	* memory.
	203	*/
8efc0c15	204
6ae2364d	205	void
2e73a022	206	ssh_close_authentication_connection(AuthenticationConnection *auth)
8efc0c15	207	{
2e73a022	208	buffer_free(&auth->identities);
	209	close(auth->fd);
	210	xfree(auth);
8efc0c15	211	}
8efc0c15	212
aa3378df	213	/*
aa3378df	214	* Returns the first authentication identity held by the agent.
aa3378df	215	*/
8efc0c15	216
fa08c86b	217	int
fa08c86b	218	ssh_get_num_identities(AuthenticationConnection *auth, int version)
8efc0c15	219	{
2e73a022	220	int type, code1 = 0, code2 = 0;
c345cf9d	221	Buffer request;
2e73a022	222
	223	switch(version){
	224	case 1:
	225	code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
	226	code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
	227	break;
	228	case 2:
	229	code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
	230	code2 = SSH2_AGENT_IDENTITIES_ANSWER;
	231	break;
	232	default:
fa08c86b	233	return 0;
2e73a022	234	}
5260325f	235
aa3378df	236	/*
	237	* Send a message to the agent requesting for a list of the
	238	* identities it can represent.
	239	*/
c345cf9d	240	buffer_init(&request);
2e73a022	241	buffer_put_char(&request, code1);
5260325f	242
5260325f	243	buffer_clear(&auth->identities);
c345cf9d	244	if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
c345cf9d	245	buffer_free(&request);
fa08c86b	246	return 0;
8efc0c15	247	}
c345cf9d	248	buffer_free(&request);
5260325f	249
5260325f	250	/* Get message type, and verify that we got a proper answer. */
c345cf9d	251	type = buffer_get_char(&auth->identities);
94ec8c6b	252	if (agent_failed(type)) {
fa08c86b	253	return 0;
2e73a022	254	} else if (type != code2) {
c345cf9d	255	fatal("Bad authentication reply message type: %d", type);
2e73a022	256	}
5260325f	257
	258	/* Get the number of entries in the response and check it for sanity. */
	259	auth->howmany = buffer_get_int(&auth->identities);
	260	if (auth->howmany > 1024)
54b974dc	261	fatal("Too many identities in authentication reply: %d",
c345cf9d	262	auth->howmany);
5260325f	263
fa08c86b	264	return auth->howmany;
	265	}
	266
	267	Key *
	268	ssh_get_first_identity(AuthenticationConnection auth, char *comment, int version)
	269	{
	270	/* get number of identities and return the first entry (if any). */
	271	if (ssh_get_num_identities(auth, version) > 0)
	272	return ssh_get_next_identity(auth, comment, version);
	273	return NULL;
8efc0c15	274	}
8efc0c15	275
2e73a022	276	Key *
2e73a022	277	ssh_get_next_identity(AuthenticationConnection auth, char *comment, int version)
8efc0c15	278	{
1e3b8b07	279	u_int bits;
	280	u_char *blob;
	281	u_int blen;
2e73a022	282	Key *key = NULL;
4d195447	283
5260325f	284	/* Return failure if no more entries. */
5260325f	285	if (auth->howmany <= 0)
2e73a022	286	return NULL;
8efc0c15	287
aa3378df	288	/*
	289	* Get the next entry from the packet. These will abort with a fatal
	290	* error if the packet is too short or contains corrupt data.
	291	*/
2e73a022	292	switch(version){
2e73a022	293	case 1:
fa08c86b	294	key = key_new(KEY_RSA1);
2e73a022	295	bits = buffer_get_int(&auth->identities);
	296	buffer_get_bignum(&auth->identities, key->rsa->e);
	297	buffer_get_bignum(&auth->identities, key->rsa->n);
	298	*comment = buffer_get_string(&auth->identities, NULL);
	299	if (bits != BN_num_bits(key->rsa->n))
	300	log("Warning: identity keysize mismatch: actual %d, announced %u",
	301	BN_num_bits(key->rsa->n), bits);
	302	break;
	303	case 2:
	304	blob = buffer_get_string(&auth->identities, &blen);
	305	*comment = buffer_get_string(&auth->identities, NULL);
fa08c86b	306	key = key_from_blob(blob, blen);
2e73a022	307	xfree(blob);
	308	break;
	309	default:
	310	return NULL;
	311	break;
	312	}
5260325f	313	/* Decrement the number of remaining entries. */
5260325f	314	auth->howmany--;
2e73a022	315	return key;
8efc0c15	316	}
8efc0c15	317
aa3378df	318	/*
	319	* Generates a random challenge, sends it to the agent, and waits for
	320	* response from the agent. Returns true (non-zero) if the agent gave the
	321	* correct answer, zero otherwise. Response type selects the style of
	322	* response desired, with 0 corresponding to protocol version 1.0 (no longer
	323	* supported) and 1 corresponding to protocol version 1.1.
	324	*/
8efc0c15	325
	326	int
	327	ssh_decrypt_challenge(AuthenticationConnection *auth,
2e73a022	328	Key* key, BIGNUM *challenge,
1e3b8b07	329	u_char session_id[16],
	330	u_int response_type,
	331	u_char response[16])
8efc0c15	332	{
5260325f	333	Buffer buffer;
c345cf9d	334	int success = 0;
	335	int i;
	336	int type;
5260325f	337
fa08c86b	338	if (key->type != KEY_RSA1)
2e73a022	339	return 0;
	340	if (response_type == 0) {
	341	log("Compatibility with ssh protocol version 1.0 no longer supported.");
	342	return 0;
	343	}
5260325f	344	buffer_init(&buffer);
c345cf9d	345	buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
2e73a022	346	buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
	347	buffer_put_bignum(&buffer, key->rsa->e);
	348	buffer_put_bignum(&buffer, key->rsa->n);
5260325f	349	buffer_put_bignum(&buffer, challenge);
	350	buffer_append(&buffer, (char *) session_id, 16);
	351	buffer_put_int(&buffer, response_type);
	352
c345cf9d	353	if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
5260325f	354	buffer_free(&buffer);
	355	return 0;
	356	}
c345cf9d	357	type = buffer_get_char(&buffer);
5260325f	358
94ec8c6b	359	if (agent_failed(type)) {
5260325f	360	log("Agent admitted failure to authenticate using the key.");
c345cf9d	361	} else if (type != SSH_AGENT_RSA_RESPONSE) {
	362	fatal("Bad authentication response: %d", type);
	363	} else {
	364	success = 1;
	365	/*
	366	* Get the response from the packet. This will abort with a
	367	* fatal error if the packet is corrupt.
	368	*/
	369	for (i = 0; i < 16; i++)
	370	response[i] = buffer_get_char(&buffer);
8efc0c15	371	}
5260325f	372	buffer_free(&buffer);
c345cf9d	373	return success;
5260325f	374	}
8efc0c15	375
2e73a022	376	/* ask agent to sign data, returns -1 on error, 0 on success */
	377	int
	378	ssh_agent_sign(AuthenticationConnection *auth,
	379	Key *key,
1e3b8b07	380	u_char *sigp, int lenp,
1e3b8b07	381	u_char *data, int datalen)
2e73a022	382	{
188adeb2	383	extern int datafellows;
2e73a022	384	Buffer msg;
1e3b8b07	385	u_char *blob;
1e3b8b07	386	u_int blen;
188adeb2	387	int type, flags = 0;
2e73a022	388	int ret = -1;
2e73a022	389
fa08c86b	390	if (key_to_blob(key, &blob, &blen) == 0)
2e73a022	391	return -1;
2e73a022	392
188adeb2	393	if (datafellows & SSH_BUG_SIGBLOB)
	394	flags = SSH_AGENT_OLD_SIGNATURE;
	395
2e73a022	396	buffer_init(&msg);
	397	buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
	398	buffer_put_string(&msg, blob, blen);
	399	buffer_put_string(&msg, data, datalen);
188adeb2	400	buffer_put_int(&msg, flags);
2e73a022	401	xfree(blob);
	402
	403	if (ssh_request_reply(auth, &msg, &msg) == 0) {
	404	buffer_free(&msg);
	405	return -1;
	406	}
	407	type = buffer_get_char(&msg);
94ec8c6b	408	if (agent_failed(type)) {
2e73a022	409	log("Agent admitted failure to sign using the key.");
	410	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
	411	fatal("Bad authentication response: %d", type);
	412	} else {
	413	ret = 0;
	414	*sigp = buffer_get_string(&msg, lenp);
	415	}
	416	buffer_free(&msg);
	417	return ret;
	418	}
	419
4c8722d9	420	/* Encode key for a message to the agent. */
	421
	422	void
fa08c86b	423	ssh_encode_identity_rsa1(Buffer b, RSA key, const char *comment)
4c8722d9	424	{
	425	buffer_clear(b);
	426	buffer_put_char(b, SSH_AGENTC_ADD_RSA_IDENTITY);
	427	buffer_put_int(b, BN_num_bits(key->n));
	428	buffer_put_bignum(b, key->n);
	429	buffer_put_bignum(b, key->e);
	430	buffer_put_bignum(b, key->d);
	431	/* To keep within the protocol: p < q for ssh. in SSL p > q */
	432	buffer_put_bignum(b, key->iqmp); /* ssh key->u */
	433	buffer_put_bignum(b, key->q); /* ssh key->p, SSL key->q */
	434	buffer_put_bignum(b, key->p); /* ssh key->q, SSL key->p */
	435	buffer_put_string(b, comment, strlen(comment));
	436	}
	437
	438	void
fa08c86b	439	ssh_encode_identity_ssh2(Buffer b, Key key, const char *comment)
4c8722d9	440	{
	441	buffer_clear(b);
	442	buffer_put_char(b, SSH2_AGENTC_ADD_IDENTITY);
fa08c86b	443	buffer_put_cstring(b, key_ssh_name(key));
	444	switch(key->type){
	445	case KEY_RSA:
	446	buffer_put_bignum2(b, key->rsa->n);
	447	buffer_put_bignum2(b, key->rsa->e);
	448	buffer_put_bignum2(b, key->rsa->d);
	449	buffer_put_bignum2(b, key->rsa->iqmp);
	450	buffer_put_bignum2(b, key->rsa->p);
	451	buffer_put_bignum2(b, key->rsa->q);
	452	break;
	453	case KEY_DSA:
	454	buffer_put_bignum2(b, key->dsa->p);
	455	buffer_put_bignum2(b, key->dsa->q);
	456	buffer_put_bignum2(b, key->dsa->g);
	457	buffer_put_bignum2(b, key->dsa->pub_key);
	458	buffer_put_bignum2(b, key->dsa->priv_key);
	459	break;
	460	}
	461	buffer_put_cstring(b, comment);
4c8722d9	462	}
4c8722d9	463
aa3378df	464	/*
	465	* Adds an identity to the authentication server. This call is not meant to
	466	* be used by normal applications.
	467	*/
8efc0c15	468
6ae2364d	469	int
4c8722d9	470	ssh_add_identity(AuthenticationConnection auth, Key key, const char *comment)
8efc0c15	471	{
2e73a022	472	Buffer msg;
c345cf9d	473	int type;
5260325f	474
2e73a022	475	buffer_init(&msg);
4c8722d9	476
4c8722d9	477	switch (key->type) {
fa08c86b	478	case KEY_RSA1:
fa08c86b	479	ssh_encode_identity_rsa1(&msg, key->rsa, comment);
4c8722d9	480	break;
fa08c86b	481	case KEY_RSA:
4c8722d9	482	case KEY_DSA:
fa08c86b	483	ssh_encode_identity_ssh2(&msg, key, comment);
4c8722d9	484	break;
4c8722d9	485	default:
2e73a022	486	buffer_free(&msg);
4c8722d9	487	return 0;
	488	break;
	489	}
2e73a022	490	if (ssh_request_reply(auth, &msg, &msg) == 0) {
2e73a022	491	buffer_free(&msg);
5260325f	492	return 0;
5260325f	493	}
2e73a022	494	type = buffer_get_char(&msg);
2e73a022	495	buffer_free(&msg);
c345cf9d	496	return decode_reply(type);
5260325f	497	}
5260325f	498
aa3378df	499	/*
	500	* Removes an identity from the authentication server. This call is not
	501	* meant to be used by normal applications.
	502	*/
8efc0c15	503
6ae2364d	504	int
2e73a022	505	ssh_remove_identity(AuthenticationConnection auth, Key key)
8efc0c15	506	{
2e73a022	507	Buffer msg;
c345cf9d	508	int type;
1e3b8b07	509	u_char *blob;
1e3b8b07	510	u_int blen;
2e73a022	511
	512	buffer_init(&msg);
	513
fa08c86b	514	if (key->type == KEY_RSA1) {
2e73a022	515	buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
	516	buffer_put_int(&msg, BN_num_bits(key->rsa->n));
	517	buffer_put_bignum(&msg, key->rsa->e);
	518	buffer_put_bignum(&msg, key->rsa->n);
fa08c86b	519	} else if (key->type == KEY_DSA \|\| key->type == KEY_RSA) {
fa08c86b	520	key_to_blob(key, &blob, &blen);
2e73a022	521	buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
	522	buffer_put_string(&msg, blob, blen);
	523	xfree(blob);
	524	} else {
	525	buffer_free(&msg);
5260325f	526	return 0;
5260325f	527	}
2e73a022	528	if (ssh_request_reply(auth, &msg, &msg) == 0) {
	529	buffer_free(&msg);
	530	return 0;
	531	}
	532	type = buffer_get_char(&msg);
	533	buffer_free(&msg);
c345cf9d	534	return decode_reply(type);
5260325f	535	}
5260325f	536
aa3378df	537	/*
	538	* Removes all identities from the agent. This call is not meant to be used
	539	* by normal applications.
	540	*/
8efc0c15	541
6ae2364d	542	int
2e73a022	543	ssh_remove_all_identities(AuthenticationConnection *auth, int version)
8efc0c15	544	{
2e73a022	545	Buffer msg;
c345cf9d	546	int type;
2e73a022	547	int code = (version==1) ?
	548	SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
	549	SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
5260325f	550
2e73a022	551	buffer_init(&msg);
2e73a022	552	buffer_put_char(&msg, code);
5260325f	553
2e73a022	554	if (ssh_request_reply(auth, &msg, &msg) == 0) {
2e73a022	555	buffer_free(&msg);
5260325f	556	return 0;
5260325f	557	}
2e73a022	558	type = buffer_get_char(&msg);
2e73a022	559	buffer_free(&msg);
c345cf9d	560	return decode_reply(type);
089fbbd2	561	}
089fbbd2	562
2b87da3b	563	int
c345cf9d	564	decode_reply(int type)
089fbbd2	565	{
5260325f	566	switch (type) {
5260325f	567	case SSH_AGENT_FAILURE:
94ec8c6b	568	case SSH_COM_AGENT2_FAILURE:
c345cf9d	569	log("SSH_AGENT_FAILURE");
5260325f	570	return 0;
5260325f	571	case SSH_AGENT_SUCCESS:
5260325f	572	return 1;
5260325f	573	default:
089fbbd2	574	fatal("Bad response from authentication agent: %d", type);
8efc0c15	575	}
5260325f	576	/* NOTREACHED */
	577	return 0;
	578	}