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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/ssh/lib/../authfd.c	Lines:	0	221	0.0 %
Date:	2017-11-13	Branches:	0	210	0.0 %


/* $OpenBSD: authfd.c,v 1.105 2017/07/01 13:50:45 djm Exp $ */
/*
 * 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 <sys/types.h>
#include <sys/un.h>
#include <sys/socket.h>

#include <fcntl.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "xmalloc.h"
#include "ssh.h"
#include "sshbuf.h"
#include "sshkey.h"
#include "authfd.h"
#include "cipher.h"
#include "compat.h"
#include "log.h"
#include "atomicio.h"
#include "misc.h"
#include "ssherr.h"

#define MAX_AGENT_IDENTITIES	2048		/* Max keys in agent reply */
#define MAX_AGENT_REPLY_LEN	(256 * 1024) 	/* Max bytes in agent reply */

/* macro to check for "agent failure" message */
#define agent_failed(x) \
    ((x == SSH_AGENT_FAILURE) || \
    (x == SSH_COM_AGENT2_FAILURE) || \
    (x == SSH2_AGENT_FAILURE))

/* Convert success/failure response from agent to a err.h status */
static int
decode_reply(u_char type)
{
	if (agent_failed(type))
		return SSH_ERR_AGENT_FAILURE;
	else if (type == SSH_AGENT_SUCCESS)
		return 0;
	else
		return SSH_ERR_INVALID_FORMAT;
}

/* Returns the number of the authentication fd, or -1 if there is none. */
int
ssh_get_authentication_socket(int *fdp)
{
	const char *authsocket;
	int sock, oerrno;
	struct sockaddr_un sunaddr;

	if (fdp != NULL)
		*fdp = -1;

	authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
	if (!authsocket)
		return SSH_ERR_AGENT_NOT_PRESENT;

	memset(&sunaddr, 0, sizeof(sunaddr));
	sunaddr.sun_family = AF_UNIX;
	strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));

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

	/* close on exec */
	if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1 ||
	    connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
		oerrno = errno;
		close(sock);
		errno = oerrno;
		return SSH_ERR_SYSTEM_ERROR;
	}
	if (fdp != NULL)
		*fdp = sock;
	else
		close(sock);
	return 0;
}

/* Communicate with agent: send request and read reply */
static int
ssh_request_reply(int sock, struct sshbuf *request, struct sshbuf *reply)
{
	int r;
	size_t l, len;
	char buf[1024];

	/* Get the length of the message, and format it in the buffer. */
	len = sshbuf_len(request);
	put_u32(buf, len);

	/* Send the length and then the packet to the agent. */
	if (atomicio(vwrite, sock, buf, 4) != 4 ||
	    atomicio(vwrite, sock, (u_char *)sshbuf_ptr(request),
	    sshbuf_len(request)) != sshbuf_len(request))
		return SSH_ERR_AGENT_COMMUNICATION;
	/*
	 * Wait for response from the agent.  First read the length of the
	 * response packet.
	 */
	if (atomicio(read, sock, buf, 4) != 4)
	    return SSH_ERR_AGENT_COMMUNICATION;

	/* Extract the length, and check it for sanity. */
	len = get_u32(buf);
	if (len > MAX_AGENT_REPLY_LEN)
		return SSH_ERR_INVALID_FORMAT;

	/* Read the rest of the response in to the buffer. */
	sshbuf_reset(reply);
	while (len > 0) {
		l = len;
		if (l > sizeof(buf))
			l = sizeof(buf);
		if (atomicio(read, sock, buf, l) != l)
			return SSH_ERR_AGENT_COMMUNICATION;
		if ((r = sshbuf_put(reply, buf, l)) != 0)
			return r;
		len -= l;
	}
	return 0;
}

/*
 * 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);
}

/* Lock/unlock agent */
int
ssh_lock_agent(int sock, int lock, const char *password)
{
	int r;
	u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
	struct sshbuf *msg;

	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;
	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
	    (r = sshbuf_put_cstring(msg, password)) != 0)
		goto out;
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	r = decode_reply(type);
 out:
	sshbuf_free(msg);
	return r;
}


static int
deserialise_identity2(struct sshbuf *ids, struct sshkey **keyp, char **commentp)
{
	int r;
	char *comment = NULL;
	const u_char *blob;
	size_t blen;

	if ((r = sshbuf_get_string_direct(ids, &blob, &blen)) != 0 ||
	    (r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
		goto out;
	if ((r = sshkey_from_blob(blob, blen, keyp)) != 0)
		goto out;
	if (commentp != NULL) {
		*commentp = comment;
		comment = NULL;
	}
	r = 0;
 out:
	free(comment);
	return r;
}

/*
 * Fetch list of identities held by the agent.
 */
int
ssh_fetch_identitylist(int sock, struct ssh_identitylist **idlp)
{
	u_char type;
	u_int32_t num, i;
	struct sshbuf *msg;
	struct ssh_identitylist *idl = NULL;
	int r;

	/*
	 * Send a message to the agent requesting for a list of the
	 * identities it can represent.
	 */
	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;
	if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_REQUEST_IDENTITIES)) != 0)
		goto out;

	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;

	/* Get message type, and verify that we got a proper answer. */
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	if (agent_failed(type)) {
		r = SSH_ERR_AGENT_FAILURE;
		goto out;
	} else if (type != SSH2_AGENT_IDENTITIES_ANSWER) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}

	/* Get the number of entries in the response and check it for sanity. */
	if ((r = sshbuf_get_u32(msg, &num)) != 0)
		goto out;
	if (num > MAX_AGENT_IDENTITIES) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	if (num == 0) {
		r = SSH_ERR_AGENT_NO_IDENTITIES;
		goto out;
	}

	/* Deserialise the response into a list of keys/comments */
	if ((idl = calloc(1, sizeof(*idl))) == NULL ||
	    (idl->keys = calloc(num, sizeof(*idl->keys))) == NULL ||
	    (idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}
	for (i = 0; i < num;) {
		if ((r = deserialise_identity2(msg, &(idl->keys[i]),
		    &(idl->comments[i]))) != 0) {
			if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
				/* Gracefully skip unknown key types */
				num--;
				continue;
			} else
				goto out;
		}
		i++;
	}
	idl->nkeys = num;
	*idlp = idl;
	idl = NULL;
	r = 0;
 out:
	sshbuf_free(msg);
	if (idl != NULL)
		ssh_free_identitylist(idl);
	return r;
}

void
ssh_free_identitylist(struct ssh_identitylist *idl)
{
	size_t i;

	if (idl == NULL)
		return;
	for (i = 0; i < idl->nkeys; i++) {
		if (idl->keys != NULL)
			sshkey_free(idl->keys[i]);
		if (idl->comments != NULL)
			free(idl->comments[i]);
	}
	free(idl);
}

/*
 * Sends a challenge (typically from a server via ssh(1)) to the agent,
 * and waits for a response from the agent.
 * Returns true (non-zero) if the agent gave the correct answer, zero
 * otherwise.
 */


/* encode signature algoritm in flag bits, so we can keep the msg format */
static u_int
agent_encode_alg(const struct sshkey *key, const char *alg)
{
	if (alg != NULL && key->type == KEY_RSA) {
		if (strcmp(alg, "rsa-sha2-256") == 0)
			return SSH_AGENT_RSA_SHA2_256;
		else if (strcmp(alg, "rsa-sha2-512") == 0)
			return SSH_AGENT_RSA_SHA2_512;
	}
	return 0;
}

/* ask agent to sign data, returns err.h code on error, 0 on success */
int
ssh_agent_sign(int sock, const struct sshkey *key,
    u_char **sigp, size_t *lenp,
    const u_char *data, size_t datalen, const char *alg, u_int compat)
{
	struct sshbuf *msg;
	u_char *blob = NULL, type;
	size_t blen = 0, len = 0;
	u_int flags = 0;
	int r = SSH_ERR_INTERNAL_ERROR;

	*sigp = NULL;
	*lenp = 0;

	if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
		return SSH_ERR_INVALID_ARGUMENT;
	if (compat & SSH_BUG_SIGBLOB)
		flags |= SSH_AGENT_OLD_SIGNATURE;
	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;
	if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
		goto out;
	flags |= agent_encode_alg(key, alg);
	if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
	    (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
	    (r = sshbuf_put_string(msg, data, datalen)) != 0 ||
	    (r = sshbuf_put_u32(msg, flags)) != 0)
		goto out;
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	if (agent_failed(type)) {
		r = SSH_ERR_AGENT_FAILURE;
		goto out;
	} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
		goto out;
	*lenp = len;
	r = 0;
 out:
	if (blob != NULL) {
		explicit_bzero(blob, blen);
		free(blob);
	}
	sshbuf_free(msg);
	return r;
}

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


static int
ssh_encode_identity_ssh2(struct sshbuf *b, struct sshkey *key,
    const char *comment)
{
	int r;

	if ((r = sshkey_private_serialize(key, b)) != 0 ||
	    (r = sshbuf_put_cstring(b, comment)) != 0)
		return r;
	return 0;
}

static int
encode_constraints(struct sshbuf *m, u_int life, u_int confirm)
{
	int r;

	if (life != 0) {
		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_LIFETIME)) != 0 ||
		    (r = sshbuf_put_u32(m, life)) != 0)
			goto out;
	}
	if (confirm != 0) {
		if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_CONFIRM)) != 0)
			goto out;
	}
	r = 0;
 out:
	return r;
}

/*
 * Adds an identity to the authentication server.
 * This call is intended only for use by ssh-add(1) and like applications.
 */
int
ssh_add_identity_constrained(int sock, struct sshkey *key, const char *comment,
    u_int life, u_int confirm)
{
	struct sshbuf *msg;
	int r, constrained = (life || confirm);
	u_char type;

	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;

	switch (key->type) {
#ifdef WITH_OPENSSL
	case KEY_RSA:
	case KEY_RSA_CERT:
	case KEY_DSA:
	case KEY_DSA_CERT:
	case KEY_ECDSA:
	case KEY_ECDSA_CERT:
#endif
	case KEY_ED25519:
	case KEY_ED25519_CERT:
		type = constrained ?
		    SSH2_AGENTC_ADD_ID_CONSTRAINED :
		    SSH2_AGENTC_ADD_IDENTITY;
		if ((r = sshbuf_put_u8(msg, type)) != 0 ||
		    (r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
			goto out;
		break;
	default:
		r = SSH_ERR_INVALID_ARGUMENT;
		goto out;
	}
	if (constrained &&
	    (r = encode_constraints(msg, life, confirm)) != 0)
		goto out;
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	r = decode_reply(type);
 out:
	sshbuf_free(msg);
	return r;
}

/*
 * Removes an identity from the authentication server.
 * This call is intended only for use by ssh-add(1) and like applications.
 */
int
ssh_remove_identity(int sock, struct sshkey *key)
{
	struct sshbuf *msg;
	int r;
	u_char type, *blob = NULL;
	size_t blen;

	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;

	if (key->type != KEY_UNSPEC) {
		if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
			goto out;
		if ((r = sshbuf_put_u8(msg,
		    SSH2_AGENTC_REMOVE_IDENTITY)) != 0 ||
		    (r = sshbuf_put_string(msg, blob, blen)) != 0)
			goto out;
	} else {
		r = SSH_ERR_INVALID_ARGUMENT;
		goto out;
	}
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	r = decode_reply(type);
 out:
	if (blob != NULL) {
		explicit_bzero(blob, blen);
		free(blob);
	}
	sshbuf_free(msg);
	return r;
}

/*
 * Add/remove an token-based identity from the authentication server.
 * This call is intended only for use by ssh-add(1) and like applications.
 */
int
ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
    u_int life, u_int confirm)
{
	struct sshbuf *msg;
	int r, constrained = (life || confirm);
	u_char type;

	if (add) {
		type = constrained ?
		    SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
		    SSH_AGENTC_ADD_SMARTCARD_KEY;
	} else
		type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;

	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;
	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
	    (r = sshbuf_put_cstring(msg, reader_id)) != 0 ||
	    (r = sshbuf_put_cstring(msg, pin)) != 0)
		goto out;
	if (constrained &&
	    (r = encode_constraints(msg, life, confirm)) != 0)
		goto out;
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	r = decode_reply(type);
 out:
	sshbuf_free(msg);
	return r;
}

/*
 * Removes all identities from the agent.
 * This call is intended only for use by ssh-add(1) and like applications.
 *
 * This supports the SSH protocol 1 message to because, when clearing all
 * keys from an agent, we generally want to clear both protocol v1 and v2
 * keys.
 */
int
ssh_remove_all_identities(int sock, int version)
{
	struct sshbuf *msg;
	u_char type = (version == 1) ?
	    SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
	    SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
	int r;

	if ((msg = sshbuf_new()) == NULL)
		return SSH_ERR_ALLOC_FAIL;
	if ((r = sshbuf_put_u8(msg, type)) != 0)
		goto out;
	if ((r = ssh_request_reply(sock, msg, msg)) != 0)
		goto out;
	if ((r = sshbuf_get_u8(msg, &type)) != 0)
		goto out;
	r = decode_reply(type);
 out:
	sshbuf_free(msg);
	return r;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: authfd.c,v 1.105 2017/07/01 13:50:45 djm Exp $ */
2			/*
3			* Author: Tatu Ylonen <ylo@cs.hut.fi>
4			* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5			* All rights reserved
6			* Functions for connecting the local authentication agent.
7			*
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			* SSH2 implementation,
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.
36			*/
37
38
39			#include <sys/types.h>
40			#include <sys/un.h>
41			#include <sys/socket.h>
42
43			#include <fcntl.h>
44			#include <stdlib.h>
45			#include <signal.h>
46			#include <string.h>
47			#include <unistd.h>
48			#include <errno.h>
49
50			#include "xmalloc.h"
51			#include "ssh.h"
52			#include "sshbuf.h"
53			#include "sshkey.h"
54			#include "authfd.h"
55			#include "cipher.h"
56			#include "compat.h"
57			#include "log.h"
58			#include "atomicio.h"
59			#include "misc.h"
60			#include "ssherr.h"
61
62			#define MAX_AGENT_IDENTITIES 2048 /* Max keys in agent reply */
63			#define MAX_AGENT_REPLY_LEN (256 * 1024) /* Max bytes in agent reply */
64
65			/* macro to check for "agent failure" message */
66			#define agent_failed(x) \
67			((x == SSH_AGENT_FAILURE) \|\| \
68			(x == SSH_COM_AGENT2_FAILURE) \|\| \
69			(x == SSH2_AGENT_FAILURE))
70
71			/* Convert success/failure response from agent to a err.h status */
72			static int
73			decode_reply(u_char type)
74			{
75			if (agent_failed(type))
76			return SSH_ERR_AGENT_FAILURE;
77			else if (type == SSH_AGENT_SUCCESS)
78			return 0;
79			else
80			return SSH_ERR_INVALID_FORMAT;
81			}
82
83			/* Returns the number of the authentication fd, or -1 if there is none. */
84			int
85			ssh_get_authentication_socket(int *fdp)
86			{
87			const char *authsocket;
88			int sock, oerrno;
89			struct sockaddr_un sunaddr;
90
91			if (fdp != NULL)
92			*fdp = -1;
93
94			authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
95			if (!authsocket)
96			return SSH_ERR_AGENT_NOT_PRESENT;
97
98			memset(&sunaddr, 0, sizeof(sunaddr));
99			sunaddr.sun_family = AF_UNIX;
100			strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
101
102			if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
103			return SSH_ERR_SYSTEM_ERROR;
104
105			/* close on exec */
106			if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1 \|\|
107			connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
108			oerrno = errno;
109			close(sock);
110			errno = oerrno;
111			return SSH_ERR_SYSTEM_ERROR;
112			}
113			if (fdp != NULL)
114			*fdp = sock;
115			else
116			close(sock);
117			return 0;
118			}
119
120			/* Communicate with agent: send request and read reply */
121			static int
122			ssh_request_reply(int sock, struct sshbuf request, struct sshbuf reply)
123			{
124			int r;
125			size_t l, len;
126			char buf[1024];
127
128			/* Get the length of the message, and format it in the buffer. */
129			len = sshbuf_len(request);
130			put_u32(buf, len);
131
132			/* Send the length and then the packet to the agent. */
133			if (atomicio(vwrite, sock, buf, 4) != 4 \|\|
134			atomicio(vwrite, sock, (u_char *)sshbuf_ptr(request),
135			sshbuf_len(request)) != sshbuf_len(request))
136			return SSH_ERR_AGENT_COMMUNICATION;
137			/*
138			* Wait for response from the agent. First read the length of the
139			* response packet.
140			*/
141			if (atomicio(read, sock, buf, 4) != 4)
142			return SSH_ERR_AGENT_COMMUNICATION;
143
144			/* Extract the length, and check it for sanity. */
145			len = get_u32(buf);
146			if (len > MAX_AGENT_REPLY_LEN)
147			return SSH_ERR_INVALID_FORMAT;
148
149			/* Read the rest of the response in to the buffer. */
150			sshbuf_reset(reply);
151			while (len > 0) {
152			l = len;
153			if (l > sizeof(buf))
154			l = sizeof(buf);
155			if (atomicio(read, sock, buf, l) != l)
156			return SSH_ERR_AGENT_COMMUNICATION;
157			if ((r = sshbuf_put(reply, buf, l)) != 0)
158			return r;
159			len -= l;
160			}
161			return 0;
162			}
163
164			/*
165			* Closes the agent socket if it should be closed (depends on how it was
166			* obtained). The argument must have been returned by
167			* ssh_get_authentication_socket().
168			*/
169			void
170			ssh_close_authentication_socket(int sock)
171			{
172			if (getenv(SSH_AUTHSOCKET_ENV_NAME))
173			close(sock);
174			}
175
176			/* Lock/unlock agent */
177			int
178			ssh_lock_agent(int sock, int lock, const char *password)
179			{
180			int r;
181			u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
182			struct sshbuf *msg;
183
184			if ((msg = sshbuf_new()) == NULL)
185			return SSH_ERR_ALLOC_FAIL;
186			if ((r = sshbuf_put_u8(msg, type)) != 0 \|\|
187			(r = sshbuf_put_cstring(msg, password)) != 0)
188			goto out;
189			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
190			goto out;
191			if ((r = sshbuf_get_u8(msg, &type)) != 0)
192			goto out;
193			r = decode_reply(type);
194			out:
195			sshbuf_free(msg);
196			return r;
197			}
198
199
200			static int
201			deserialise_identity2(struct sshbuf ids, struct sshkey keyp, char *commentp)
202			{
203			int r;
204			char *comment = NULL;
205			const u_char *blob;
206			size_t blen;
207
208			if ((r = sshbuf_get_string_direct(ids, &blob, &blen)) != 0 \|\|
209			(r = sshbuf_get_cstring(ids, &comment, NULL)) != 0)
210			goto out;
211			if ((r = sshkey_from_blob(blob, blen, keyp)) != 0)
212			goto out;
213			if (commentp != NULL) {
214			*commentp = comment;
215			comment = NULL;
216			}
217			r = 0;
218			out:
219			free(comment);
220			return r;
221			}
222
223			/*
224			* Fetch list of identities held by the agent.
225			*/
226			int
227			ssh_fetch_identitylist(int sock, struct ssh_identitylist **idlp)
228			{
229			u_char type;
230			u_int32_t num, i;
231			struct sshbuf *msg;
232			struct ssh_identitylist *idl = NULL;
233			int r;
234
235			/*
236			* Send a message to the agent requesting for a list of the
237			* identities it can represent.
238			*/
239			if ((msg = sshbuf_new()) == NULL)
240			return SSH_ERR_ALLOC_FAIL;
241			if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_REQUEST_IDENTITIES)) != 0)
242			goto out;
243
244			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
245			goto out;
246
247			/* Get message type, and verify that we got a proper answer. */
248			if ((r = sshbuf_get_u8(msg, &type)) != 0)
249			goto out;
250			if (agent_failed(type)) {
251			r = SSH_ERR_AGENT_FAILURE;
252			goto out;
253			} else if (type != SSH2_AGENT_IDENTITIES_ANSWER) {
254			r = SSH_ERR_INVALID_FORMAT;
255			goto out;
256			}
257
258			/* Get the number of entries in the response and check it for sanity. */
259			if ((r = sshbuf_get_u32(msg, &num)) != 0)
260			goto out;
261			if (num > MAX_AGENT_IDENTITIES) {
262			r = SSH_ERR_INVALID_FORMAT;
263			goto out;
264			}
265			if (num == 0) {
266			r = SSH_ERR_AGENT_NO_IDENTITIES;
267			goto out;
268			}
269
270			/* Deserialise the response into a list of keys/comments */
271			if ((idl = calloc(1, sizeof(*idl))) == NULL \|\|
272			(idl->keys = calloc(num, sizeof(*idl->keys))) == NULL \|\|
273			(idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
274			r = SSH_ERR_ALLOC_FAIL;
275			goto out;
276			}
277			for (i = 0; i < num;) {
278			if ((r = deserialise_identity2(msg, &(idl->keys[i]),
279			&(idl->comments[i]))) != 0) {
280			if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
281			/* Gracefully skip unknown key types */
282			num--;
283			continue;
284			} else
285			goto out;
286			}
287			i++;
288			}
289			idl->nkeys = num;
290			*idlp = idl;
291			idl = NULL;
292			r = 0;
293			out:
294			sshbuf_free(msg);
295			if (idl != NULL)
296			ssh_free_identitylist(idl);
297			return r;
298			}
299
300			void
301			ssh_free_identitylist(struct ssh_identitylist *idl)
302			{
303			size_t i;
304
305			if (idl == NULL)
306			return;
307			for (i = 0; i < idl->nkeys; i++) {
308			if (idl->keys != NULL)
309			sshkey_free(idl->keys[i]);
310			if (idl->comments != NULL)
311			free(idl->comments[i]);
312			}
313			free(idl);
314			}
315
316			/*
317			* Sends a challenge (typically from a server via ssh(1)) to the agent,
318			* and waits for a response from the agent.
319			* Returns true (non-zero) if the agent gave the correct answer, zero
320			* otherwise.
321			*/
322
323
324			/* encode signature algoritm in flag bits, so we can keep the msg format */
325			static u_int
326			agent_encode_alg(const struct sshkey key, const char alg)
327			{
328			if (alg != NULL && key->type == KEY_RSA) {
329			if (strcmp(alg, "rsa-sha2-256") == 0)
330			return SSH_AGENT_RSA_SHA2_256;
331			else if (strcmp(alg, "rsa-sha2-512") == 0)
332			return SSH_AGENT_RSA_SHA2_512;
333			}
334			return 0;
335			}
336
337			/* ask agent to sign data, returns err.h code on error, 0 on success */
338			int
339			ssh_agent_sign(int sock, const struct sshkey *key,
340			u_char *sigp, size_t lenp,
341			const u_char data, size_t datalen, const char alg, u_int compat)
342			{
343			struct sshbuf *msg;
344			u_char *blob = NULL, type;
345			size_t blen = 0, len = 0;
346			u_int flags = 0;
347			int r = SSH_ERR_INTERNAL_ERROR;
348
349			*sigp = NULL;
350			*lenp = 0;
351
352			if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
353			return SSH_ERR_INVALID_ARGUMENT;
354			if (compat & SSH_BUG_SIGBLOB)
355			flags \|= SSH_AGENT_OLD_SIGNATURE;
356			if ((msg = sshbuf_new()) == NULL)
357			return SSH_ERR_ALLOC_FAIL;
358			if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
359			goto out;
360			flags \|= agent_encode_alg(key, alg);
361			if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 \|\|
362			(r = sshbuf_put_string(msg, blob, blen)) != 0 \|\|
363			(r = sshbuf_put_string(msg, data, datalen)) != 0 \|\|
364			(r = sshbuf_put_u32(msg, flags)) != 0)
365			goto out;
366			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
367			goto out;
368			if ((r = sshbuf_get_u8(msg, &type)) != 0)
369			goto out;
370			if (agent_failed(type)) {
371			r = SSH_ERR_AGENT_FAILURE;
372			goto out;
373			} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
374			r = SSH_ERR_INVALID_FORMAT;
375			goto out;
376			}
377			if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
378			goto out;
379			*lenp = len;
380			r = 0;
381			out:
382			if (blob != NULL) {
383			explicit_bzero(blob, blen);
384			free(blob);
385			}
386			sshbuf_free(msg);
387			return r;
388			}
389
390			/* Encode key for a message to the agent. */
391
392
393			static int
394			ssh_encode_identity_ssh2(struct sshbuf b, struct sshkey key,
395			const char *comment)
396			{
397			int r;
398
399			if ((r = sshkey_private_serialize(key, b)) != 0 \|\|
400			(r = sshbuf_put_cstring(b, comment)) != 0)
401			return r;
402			return 0;
403			}
404
405			static int
406			encode_constraints(struct sshbuf *m, u_int life, u_int confirm)
407			{
408			int r;
409
410			if (life != 0) {
411			if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_LIFETIME)) != 0 \|\|
412			(r = sshbuf_put_u32(m, life)) != 0)
413			goto out;
414			}
415			if (confirm != 0) {
416			if ((r = sshbuf_put_u8(m, SSH_AGENT_CONSTRAIN_CONFIRM)) != 0)
417			goto out;
418			}
419			r = 0;
420			out:
421			return r;
422			}
423
424			/*
425			* Adds an identity to the authentication server.
426			* This call is intended only for use by ssh-add(1) and like applications.
427			*/
428			int
429			ssh_add_identity_constrained(int sock, struct sshkey key, const char comment,
430			u_int life, u_int confirm)
431			{
432			struct sshbuf *msg;
433			int r, constrained = (life \|\| confirm);
434			u_char type;
435
436			if ((msg = sshbuf_new()) == NULL)
437			return SSH_ERR_ALLOC_FAIL;
438
439			switch (key->type) {
440			#ifdef WITH_OPENSSL
441			case KEY_RSA:
442			case KEY_RSA_CERT:
443			case KEY_DSA:
444			case KEY_DSA_CERT:
445			case KEY_ECDSA:
446			case KEY_ECDSA_CERT:
447			#endif
448			case KEY_ED25519:
449			case KEY_ED25519_CERT:
450			type = constrained ?
451			SSH2_AGENTC_ADD_ID_CONSTRAINED :
452			SSH2_AGENTC_ADD_IDENTITY;
453			if ((r = sshbuf_put_u8(msg, type)) != 0 \|\|
454			(r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
455			goto out;
456			break;
457			default:
458			r = SSH_ERR_INVALID_ARGUMENT;
459			goto out;
460			}
461			if (constrained &&
462			(r = encode_constraints(msg, life, confirm)) != 0)
463			goto out;
464			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
465			goto out;
466			if ((r = sshbuf_get_u8(msg, &type)) != 0)
467			goto out;
468			r = decode_reply(type);
469			out:
470			sshbuf_free(msg);
471			return r;
472			}
473
474			/*
475			* Removes an identity from the authentication server.
476			* This call is intended only for use by ssh-add(1) and like applications.
477			*/
478			int
479			ssh_remove_identity(int sock, struct sshkey *key)
480			{
481			struct sshbuf *msg;
482			int r;
483			u_char type, *blob = NULL;
484			size_t blen;
485
486			if ((msg = sshbuf_new()) == NULL)
487			return SSH_ERR_ALLOC_FAIL;
488
489			if (key->type != KEY_UNSPEC) {
490			if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
491			goto out;
492			if ((r = sshbuf_put_u8(msg,
493			SSH2_AGENTC_REMOVE_IDENTITY)) != 0 \|\|
494			(r = sshbuf_put_string(msg, blob, blen)) != 0)
495			goto out;
496			} else {
497			r = SSH_ERR_INVALID_ARGUMENT;
498			goto out;
499			}
500			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
501			goto out;
502			if ((r = sshbuf_get_u8(msg, &type)) != 0)
503			goto out;
504			r = decode_reply(type);
505			out:
506			if (blob != NULL) {
507			explicit_bzero(blob, blen);
508			free(blob);
509			}
510			sshbuf_free(msg);
511			return r;
512			}
513
514			/*
515			* Add/remove an token-based identity from the authentication server.
516			* This call is intended only for use by ssh-add(1) and like applications.
517			*/
518			int
519			ssh_update_card(int sock, int add, const char reader_id, const char pin,
520			u_int life, u_int confirm)
521			{
522			struct sshbuf *msg;
523			int r, constrained = (life \|\| confirm);
524			u_char type;
525
526			if (add) {
527			type = constrained ?
528			SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
529			SSH_AGENTC_ADD_SMARTCARD_KEY;
530			} else
531			type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
532
533			if ((msg = sshbuf_new()) == NULL)
534			return SSH_ERR_ALLOC_FAIL;
535			if ((r = sshbuf_put_u8(msg, type)) != 0 \|\|
536			(r = sshbuf_put_cstring(msg, reader_id)) != 0 \|\|
537			(r = sshbuf_put_cstring(msg, pin)) != 0)
538			goto out;
539			if (constrained &&
540			(r = encode_constraints(msg, life, confirm)) != 0)
541			goto out;
542			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
543			goto out;
544			if ((r = sshbuf_get_u8(msg, &type)) != 0)
545			goto out;
546			r = decode_reply(type);
547			out:
548			sshbuf_free(msg);
549			return r;
550			}
551
552			/*
553			* Removes all identities from the agent.
554			* This call is intended only for use by ssh-add(1) and like applications.
555			*
556			* This supports the SSH protocol 1 message to because, when clearing all
557			* keys from an agent, we generally want to clear both protocol v1 and v2
558			* keys.
559			*/
560			int
561			ssh_remove_all_identities(int sock, int version)
562			{
563			struct sshbuf *msg;
564			u_char type = (version == 1) ?
565			SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
566			SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
567			int r;
568
569			if ((msg = sshbuf_new()) == NULL)
570			return SSH_ERR_ALLOC_FAIL;
571			if ((r = sshbuf_put_u8(msg, type)) != 0)
572			goto out;
573			if ((r = ssh_request_reply(sock, msg, msg)) != 0)
574			goto out;
575			if ((r = sshbuf_get_u8(msg, &type)) != 0)
576			goto out;
577			r = decode_reply(type);
578			out:
579			sshbuf_free(msg);
580			return r;
581			}