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/* Copyright StrongLoop, Inc. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "s5.h"
#include <errno.h>
#include <stdint.h>
#include <stdlib.h> /* abort() */
#include <string.h> /* memset() */
enum {
s5_version,
s5_nmethods,
s5_methods,
s5_auth_pw_version,
s5_auth_pw_userlen,
s5_auth_pw_username,
s5_auth_pw_passlen,
s5_auth_pw_password,
s5_req_version,
s5_req_cmd,
s5_req_reserved,
s5_req_atyp,
s5_req_atyp_host,
s5_req_daddr,
s5_req_dport0,
s5_req_dport1,
s5_dead
};
void s5_init(s5_ctx *cx) {
memset(cx, 0, sizeof(*cx));
cx->state = s5_version;
}
s5_err s5_parse(s5_ctx *cx, uint8_t **data, size_t *size) {
s5_err err;
uint8_t *p;
uint8_t c;
size_t i;
size_t n;
p = *data;
n = *size;
i = 0;
while (i < n) {
c = p[i];
i += 1;
switch (cx->state) {
case s5_version:
if (c != 5) {
err = s5_bad_version;
goto out;
}
cx->state = s5_nmethods;
break;
case s5_nmethods:
cx->arg0 = 0;
cx->arg1 = c; /* Number of bytes to read. */
cx->state = s5_methods;
break;
case s5_methods:
if (cx->arg0 < cx->arg1) {
switch (c) {
case 0:
cx->methods |= S5_AUTH_NONE;
break;
case 1:
cx->methods |= S5_AUTH_GSSAPI;
break;
case 2:
cx->methods |= S5_AUTH_PASSWD;
break;
/* Ignore everything we don't understand. */
}
cx->arg0 += 1;
}
if (cx->arg0 == cx->arg1) {
err = s5_auth_select;
goto out;
}
break;
case s5_auth_pw_version:
if (c != 1) {
err = s5_bad_version;
goto out;
}
cx->state = s5_auth_pw_userlen;
break;
case s5_auth_pw_userlen:
cx->arg0 = 0;
cx->userlen = c;
cx->state = s5_auth_pw_username;
break;
case s5_auth_pw_username:
if (cx->arg0 < cx->userlen) {
cx->username[cx->arg0] = c;
cx->arg0 += 1;
}
if (cx->arg0 == cx->userlen) {
cx->username[cx->userlen] = '\0';
cx->state = s5_auth_pw_passlen;
}
break;
case s5_auth_pw_passlen:
cx->arg0 = 0;
cx->passlen = c;
cx->state = s5_auth_pw_password;
break;
case s5_auth_pw_password:
if (cx->arg0 < cx->passlen) {
cx->password[cx->arg0] = c;
cx->arg0 += 1;
}
if (cx->arg0 == cx->passlen) {
cx->password[cx->passlen] = '\0';
cx->state = s5_req_version;
err = s5_auth_verify;
goto out;
}
break;
case s5_req_version:
if (c != 5) {
err = s5_bad_version;
goto out;
}
cx->state = s5_req_cmd;
break;
case s5_req_cmd:
switch (c) {
case 1: /* TCP connect */
cx->cmd = s5_cmd_tcp_connect;
break;
case 3: /* UDP associate */
cx->cmd = s5_cmd_udp_assoc;
break;
default:
err = s5_bad_cmd;
goto out;
}
cx->state = s5_req_reserved;
break;
case s5_req_reserved:
cx->state = s5_req_atyp;
break;
case s5_req_atyp:
cx->arg0 = 0;
switch (c) {
case 1: /* IPv4, four octets. */
cx->state = s5_req_daddr;
cx->atyp = s5_atyp_ipv4;
cx->arg1 = 4;
break;
case 3: /* Hostname. First byte is length. */
cx->state = s5_req_atyp_host;
cx->atyp = s5_atyp_host;
cx->arg1 = 0;
break;
case 4: /* IPv6, sixteen octets. */
cx->state = s5_req_daddr;
cx->atyp = s5_atyp_ipv6;
cx->arg1 = 16;
break;
default:
err = s5_bad_atyp;
goto out;
}
break;
case s5_req_atyp_host:
cx->arg1 = c;
cx->state = s5_req_daddr;
break;
case s5_req_daddr:
if (cx->arg0 < cx->arg1) {
cx->daddr[cx->arg0] = c;
cx->arg0 += 1;
}
if (cx->arg0 == cx->arg1) {
cx->daddr[cx->arg1] = '\0';
cx->state = s5_req_dport0;
}
break;
case s5_req_dport0:
cx->dport = c << 8;
cx->state = s5_req_dport1;
break;
case s5_req_dport1:
cx->dport |= c;
cx->state = s5_dead;
err = s5_exec_cmd;
goto out;
case s5_dead:
break;
default:
abort();
}
}
err = s5_ok;
out:
*data = p + i;
*size = n - i;
return err;
}
unsigned int s5_auth_methods(const s5_ctx *cx) {
return cx->methods;
}
int s5_select_auth(s5_ctx *cx, s5_auth_method method) {
int err;
err = 0;
switch (method) {
case S5_AUTH_NONE:
cx->state = s5_req_version;
break;
case S5_AUTH_PASSWD:
cx->state = s5_auth_pw_version;
break;
default:
err = -EINVAL;
}
return err;
}
const char *s5_strerror(s5_err err) {
#define S5_ERR_GEN(_, name, errmsg) case s5_ ## name: return errmsg;
switch (err) {
S5_ERR_MAP(S5_ERR_GEN)
default: ; /* Silence s5_max_errors -Wswitch warning. */
}
#undef S5_ERR_GEN
return "Unknown error.";
}