1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
|
from __future__ import absolute_import
from __future__ import division
import logging
import os
import re
import shutil
import six
import string
import sys
import tarfile
import tempfile
import threading
import time
from pwnlib import term
from pwnlib.context import context, LocalContext
from pwnlib.exception import PwnlibException
from pwnlib.log import Logger
from pwnlib.log import getLogger
from pwnlib.term import text
from pwnlib.timeout import Timeout
from pwnlib.tubes.sock import sock
from pwnlib.util import hashes
from pwnlib.util import misc
from pwnlib.util import packing
from pwnlib.util import safeeval
from pwnlib.util.sh_string import sh_string
# Kill the warning line:
# No handlers could be found for logger "paramiko.transport"
paramiko_log = logging.getLogger("paramiko.transport")
h = logging.StreamHandler(open(os.devnull,'w+'))
h.setFormatter(logging.Formatter())
paramiko_log.addHandler(h)
class ssh_channel(sock):
#: Parent :class:`ssh` object
parent = None
#: Remote host
host = None
#: Return code, or :const:`None` if the process has not returned
#: Use :meth:`poll` to check.
returncode = None
#: :const:`True` if a tty was allocated for this channel
tty = False
#: Environment specified for the remote process, or :const:`None`
#: if the default environment was used
env = None
#: Command specified for the constructor
process = None
def __init__(self, parent, process = None, tty = False, cwd = None, env = None, raw = True, *args, **kwargs):
super(ssh_channel, self).__init__(*args, **kwargs)
# keep the parent from being garbage collected in some cases
self.parent = parent
self.returncode = None
self.host = parent.host
self.tty = tty
self.env = env
self.process = process
self.cwd = cwd or '.'
if isinstance(cwd, six.text_type):
cwd = packing._need_bytes(cwd, 2, 0x80)
env = env or {}
msg = 'Opening new channel: %r' % (process or 'shell')
if isinstance(process, (list, tuple)):
process = b' '.join(sh_string(packing._need_bytes(s, 2, 0x80)) for s in process)
if isinstance(process, six.text_type):
process = packing._need_bytes(process, 2, 0x80)
if process and cwd:
process = b'cd ' + sh_string(cwd) + b' >/dev/null 2>&1; ' + process
if process and env:
for name, value in env.items():
nameb = packing._need_bytes(name, 2, 0x80)
if not re.match(b'^[a-zA-Z_][a-zA-Z0-9_]*$', nameb):
self.error('run(): Invalid environment key %r' % name)
export = b'export %s=%s;' % (nameb, sh_string(packing._need_bytes(value, 2, 0x80)))
process = export + process
if process and tty:
if raw:
process = b'stty raw -ctlecho -echo; ' + process
else:
process = b'stty -ctlecho -echo; ' + process
# If this object is enabled for DEBUG-level logging, don't hide
# anything about the command that's actually executed.
if process and self.isEnabledFor(logging.DEBUG):
msg = 'Opening new channel: %r' % ((process,) or 'shell')
with self.waitfor(msg) as h:
import paramiko
try:
self.sock = parent.transport.open_session()
except paramiko.ChannelException as e:
if e.args == (1, 'Administratively prohibited'):
self.error("Too many sessions open! Use ssh_channel.close() or 'with'!")
raise e
if self.tty:
self.sock.get_pty('xterm', term.width, term.height)
def resizer():
if self.sock:
try:
self.sock.resize_pty(term.width, term.height)
except paramiko.ssh_exception.SSHException:
pass
self.resizer = resizer
term.term.on_winch.append(self.resizer) # XXX memory leak
else:
self.resizer = None
# Put stderr on stdout. This might not always be desirable,
# but our API does not support multiple streams
self.sock.set_combine_stderr(True)
self.settimeout(self.timeout)
if process:
self.sock.exec_command(process)
else:
self.sock.invoke_shell()
h.success()
def kill(self):
"""kill()
Kills the process.
"""
self.close()
def recvall(self, timeout = sock.forever):
# We subclass tubes.sock which sets self.sock to None.
#
# However, we need to wait for the return value to propagate,
# which may not happen by the time .close() is called by tube.recvall()
tmp_sock = self.sock
tmp_close = self.close
self.close = lambda: None
timeout = self.maximum if self.timeout is self.forever else self.timeout
data = super(ssh_channel, self).recvall(timeout)
# Restore self.sock to be able to call wait()
self.close = tmp_close
self.sock = tmp_sock
self.wait()
self.close()
# Again set self.sock to None
self.sock = None
return data
def wait(self, timeout=sock.default):
# TODO: deal with timeouts
return self.poll(block=True)
def poll(self, block=False):
"""poll() -> int
Poll the exit code of the process. Will return None, if the
process has not yet finished and the exit code otherwise.
"""
if self.returncode is None and self.sock \
and (block or self.sock.exit_status_ready()):
while not self.sock.status_event.is_set():
self.sock.status_event.wait(0.05)
self.returncode = self.sock.recv_exit_status()
return self.returncode
def can_recv_raw(self, timeout):
with self.countdown(timeout):
while self.countdown_active():
if self.sock.recv_ready():
return True
time.sleep(min(self.timeout, 0.05))
return False
def interactive(self, prompt = term.text.bold_red('$') + ' '):
"""interactive(prompt = pwnlib.term.text.bold_red('$') + ' ')
If not in TTY-mode, this does exactly the same as
meth:`pwnlib.tubes.tube.tube.interactive`, otherwise
it does mostly the same.
An SSH connection in TTY-mode will typically supply its own prompt,
thus the prompt argument is ignored in this case.
We also have a few SSH-specific hacks that will ideally be removed
once the :mod:`pwnlib.term` is more mature.
"""
# If we are only executing a regular old shell, we need to handle
# control codes (specifically Ctrl+C).
#
# Otherwise, we can just punt to the default implementation of interactive()
if self.process is not None:
return super(ssh_channel, self).interactive(prompt)
self.info('Switching to interactive mode')
# We would like a cursor, please!
term.term.show_cursor()
event = threading.Event()
def recv_thread(event):
while not event.is_set():
try:
cur = self.recv(timeout = 0.05)
cur = cur.replace(b'\r\n',b'\n')
cur = cur.replace(b'\r',b'')
if cur is None:
continue
elif cur == b'\a':
# Ugly hack until term unstands bell characters
continue
stdout = sys.stdout
if not term.term_mode:
stdout = getattr(stdout, 'buffer', stdout)
stdout.write(cur)
stdout.flush()
except EOFError:
self.info('Got EOF while reading in interactive')
event.set()
break
t = context.Thread(target = recv_thread, args = (event,))
t.daemon = True
t.start()
while not event.is_set():
if term.term_mode:
try:
data = term.key.getraw(0.1)
except KeyboardInterrupt:
data = [3] # This is ctrl-c
except IOError:
if not event.is_set():
raise
else:
stdin = getattr(sys.stdin, 'buffer', sys.stdin)
data = stdin.read(1)
if not data:
event.set()
else:
data = bytearray(data)
if data:
try:
self.send(bytes(bytearray(data)))
except EOFError:
event.set()
self.info('Got EOF while sending in interactive')
while t.is_alive():
t.join(timeout = 0.1)
# Restore
term.term.hide_cursor()
def close(self):
self.poll()
while self.resizer in term.term.on_winch:
term.term.on_winch.remove(self.resizer)
super(ssh_channel, self).close()
def spawn_process(self, *args, **kwargs):
self.error("Cannot use spawn_process on an SSH channel.""")
def _close_msg(self):
self.info('Closed SSH channel with %s' % self.host)
class ssh_process(ssh_channel):
#: Working directory
cwd = None
#: PID of the process
#: Only valid when instantiated through :meth:`ssh.process`
pid = None
#: Executable of the procesks
#: Only valid when instantiated through :meth:`ssh.process`
executable = None
#: Arguments passed to the process
#: Only valid when instantiated through :meth:`ssh.process`
argv = None
def libs(self):
"""libs() -> dict
Returns a dictionary mapping the address of each loaded library in the
process's address space.
If ``/proc/$PID/maps`` cannot be opened, the output of ldd is used
verbatim, which may be different than the actual addresses if ASLR
is enabled.
"""
maps = self.parent.libs(self.executable)
maps_raw = self.parent.cat('/proc/%d/maps' % self.pid).decode()
for lib in maps:
remote_path = lib.split(self.parent.host)[-1]
remote_path = self.parent.readlink('-f', remote_path).decode()
for line in maps_raw.splitlines():
if line.endswith(remote_path):
address = line.split('-')[0]
maps[lib] = int(address, 16)
break
return maps
@property
def libc(self):
"""libc() -> ELF
Returns an ELF for the libc for the current process.
If possible, it is adjusted to the correct address
automatically.
Examples:
>>> s = ssh(host='example.pwnme')
>>> p = s.process('true')
>>> p.libc # doctest: +ELLIPSIS
ELF(.../libc.so.6')
"""
from pwnlib.elf import ELF
for lib, address in self.libs().items():
if 'libc.so' in lib:
e = ELF(lib)
e.address = address
return e
@property
def elf(self):
"""elf() -> pwnlib.elf.elf.ELF
Returns an ELF file for the executable that launched the process.
"""
import pwnlib.elf.elf
libs = self.parent.libs(self.executable)
for lib in libs:
# Cannot just check "executable in lib", see issue #1047
if lib.endswith(self.executable):
return pwnlib.elf.elf.ELF(lib)
@property
def corefile(self):
import pwnlib.elf.corefile
finder = pwnlib.elf.corefile.CorefileFinder(self)
if not finder.core_path:
self.error("Could not find core file for pid %i" % self.pid)
return pwnlib.elf.corefile.Corefile(finder.core_path)
def getenv(self, variable, **kwargs):
r"""Retrieve the address of an environment variable in the remote process.
Examples:
>>> s = ssh(host='example.pwnme')
>>> p = s.process(['python3', '-c', 'import time; time.sleep(10)'])
>>> hex(p.getenv('PATH')) # doctest: +ELLIPSIS
'0x...'
"""
argv0 = self.argv[0]
variable = bytearray(packing._need_bytes(variable, min_wrong=0x80))
script = ';'.join(('from ctypes import *',
'import os',
'libc = CDLL("libc.so.6")',
'getenv = libc.getenv',
'getenv.restype = c_void_p',
'print(os.path.realpath(%r))' % self.executable,
'print(getenv(bytes(%r)))' % variable,))
try:
with context.quiet:
python = self.parent.which('python2.7') or self.parent.which('python3') or self.parent.which('python')
if not python:
self.error("Python is not installed on the remote system.")
io = self.parent.process([argv0,'-c', script.strip()],
executable=python,
env=self.env,
**kwargs)
path = io.recvline()
address = int(io.recvall())
address -= len(python)
address += len(path)
return int(address) & context.mask
except Exception:
self.exception("Could not look up environment variable %r" % variable)
def _close_msg(self):
# If we never completely started up, just use the parent implementation
if self.executable is None:
return super(ssh_process, self)._close_msg()
self.info('Stopped remote process %r on %s (pid %i)' \
% (os.path.basename(self.executable),
self.host,
self.pid))
class ssh_connecter(sock):
def __init__(self, parent, host, port, *a, **kw):
super(ssh_connecter, self).__init__(*a, **kw)
# keep the parent from being garbage collected in some cases
self.parent = parent
self.host = parent.host
self.rhost = host
self.rport = port
msg = 'Connecting to %s:%d via SSH to %s' % (self.rhost, self.rport, self.host)
with self.waitfor(msg) as h:
try:
self.sock = parent.transport.open_channel('direct-tcpip', (host, port), ('127.0.0.1', 0))
except Exception as e:
self.exception(e.message)
raise
try:
# Iterate all layers of proxying to get to base-level Socket object
curr = self.sock.get_transport().sock
while getattr(curr, "get_transport", None):
curr = curr.get_transport().sock
sockname = curr.getsockname()
self.lhost = sockname[0]
self.lport = sockname[1]
except Exception as e:
self.exception("Could not find base-level Socket object.")
raise e
h.success()
def spawn_process(self, *args, **kwargs):
self.error("Cannot use spawn_process on an SSH channel.""")
def _close_msg(self):
self.info("Closed remote connection to %s:%d via SSH connection to %s" % (self.rhost, self.rport, self.host))
class ssh_listener(sock):
def __init__(self, parent, bind_address, port, *a, **kw):
super(ssh_listener, self).__init__(*a, **kw)
# keep the parent from being garbage collected in some cases
self.parent = parent
self.host = parent.host
try:
self.port = parent.transport.request_port_forward(bind_address, port)
except Exception:
h.failure('Failed create a port forwarding')
raise
def accepter():
msg = 'Waiting on port %d via SSH to %s' % (self.port, self.host)
h = self.waitfor(msg)
try:
self.sock = parent.transport.accept()
parent.transport.cancel_port_forward(bind_address, self.port)
except Exception:
self.sock = None
h.failure()
self.exception('Failed to get a connection')
return
self.rhost, self.rport = self.sock.origin_addr
h.success('Got connection from %s:%d' % (self.rhost, self.rport))
self._accepter = context.Thread(target = accepter)
self._accepter.daemon = True
self._accepter.start()
def _close_msg(self):
self.info("Closed remote connection to %s:%d via SSH listener on port %d via %s" % (self.rhost, self.rport, self.port, self.host))
def spawn_process(self, *args, **kwargs):
self.error("Cannot use spawn_process on an SSH channel.""")
def wait_for_connection(self):
"""Blocks until a connection has been established."""
_ = self.sock
return self
@property
def sock(self):
try:
return self.__dict__['sock']
except KeyError:
pass
while self._accepter.is_alive():
self._accepter.join(timeout=0.1)
return self.__dict__.get('sock')
@sock.setter
def sock(self, s):
self.__dict__['sock'] = s
class ssh(Timeout, Logger):
#: Remote host name (``str``)
host = None
#: Remote port (``int``)
port = None
#: Remote username (``str``)
user = None
#: Remote password (``str``)
password = None
#: Remote private key (``str``)
key = None
#: Remote private key file (``str``)
keyfile = None
#: Enable caching of SSH downloads (``bool``)
cache = True
#: Enable raw mode and don't probe the environment (``bool``)
raw = False
#: Paramiko SSHClient which backs this object
client = None
#: PID of the remote ``sshd`` process servicing this connection.
pid = None
_cwd = '.'
_tried_sftp = False
def __init__(self, user=None, host=None, port=22, password=None, key=None,
keyfile=None, proxy_command=None, proxy_sock=None, level=None,
cache=True, ssh_agent=False, ignore_config=False, raw=False,
auth_none=False, *a, **kw):
"""Creates a new ssh connection.
Arguments:
user(str): The username to log in with
host(str): The hostname to connect to
port(int): The port to connect to
password(str): Try to authenticate using this password
key(str): Try to authenticate using this private key. The string should be the actual private key.
keyfile(str): Try to authenticate using this private key. The string should be a filename.
proxy_command(str): Use this as a proxy command. It has approximately the same semantics as ProxyCommand from ssh(1).
proxy_sock(str): Use this socket instead of connecting to the host.
timeout: Timeout, in seconds
level: Log level
cache(bool): Cache downloaded files (by hash/size/timestamp)
ssh_agent(bool): If :const:`True`, enable usage of keys via ssh-agent
ignore_config(bool): If :const:`True`, disable usage of ~/.ssh/config and ~/.ssh/authorized_keys
raw(bool): If :const:`True`, assume a non-standard shell and don't probe the environment
auth_none(bool): If :const:`True`, try to authenticate with no authentication methods
NOTE: The proxy_command and proxy_sock arguments is only available if a
fairly new version of paramiko is used.
Example proxying:
.. doctest::
:skipif: True
>>> s1 = ssh(host='example.pwnme')
>>> r1 = s1.remote('localhost', 22)
>>> s2 = ssh(host='example.pwnme', proxy_sock=r1.sock)
>>> r2 = s2.remote('localhost', 22) # and so on...
>>> for x in r2, s2, r1, s1: x.close()
"""
super(ssh, self).__init__(*a, **kw)
Logger.__init__(self)
if level is not None:
self.setLevel(level)
self.host = host
self.port = port
self.user = user
self.password = password
self.key = key
self.keyfile = keyfile
self._cachedir = os.path.join(tempfile.gettempdir(), 'pwntools-ssh-cache')
self.cache = cache
self.raw = raw
# Deferred attributes
self._platform_info = {}
self._aslr = None
self._aslr_ulimit = None
self._cpuinfo_cache = None
self._user_shstk = None
self._ibt = None
misc.mkdir_p(self._cachedir)
import paramiko
# Make a basic attempt to parse the ssh_config file
try:
config_file = os.path.expanduser('~/.ssh/config')
if not ignore_config and os.path.exists(config_file):
ssh_config = paramiko.SSHConfig()
ssh_config.parse(open(config_file))
host_config = ssh_config.lookup(host)
if 'hostname' in host_config:
self.host = host = host_config['hostname']
if not user and 'user' in host_config:
self.user = user = host_config['user']
if not keyfile and 'identityfile' in host_config:
keyfile = host_config['identityfile'][0]
if keyfile.lower() == 'none':
keyfile = None
except Exception as e:
self.debug("An error occurred while parsing ~/.ssh/config:\n%s" % e)
keyfiles = [os.path.expanduser(keyfile)] if keyfile else []
msg = 'Connecting to %s on port %d' % (host, port)
with self.waitfor(msg) as h:
self.client = paramiko.SSHClient()
self.client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
if not ignore_config:
known_hosts = os.path.expanduser('~/.ssh/known_hosts')
if os.path.exists(known_hosts):
self.client.load_host_keys(known_hosts)
has_proxy = bool(proxy_sock or proxy_command)
if has_proxy:
if 'ProxyCommand' not in dir(paramiko):
self.error('This version of paramiko does not support proxies.')
if proxy_sock and proxy_command:
self.error('Cannot have both a proxy command and a proxy sock')
if proxy_command:
proxy_sock = paramiko.ProxyCommand(proxy_command)
else:
proxy_sock = None
try:
self.client.connect(host, port, user, password, key, keyfiles, self.timeout, allow_agent=ssh_agent, compress=True, sock=proxy_sock, look_for_keys=not ignore_config)
except paramiko.BadHostKeyException as e:
self.error("Remote host %(host)s is using a different key than stated in known_hosts\n"
" To remove the existing entry from your known_hosts and trust the new key, run the following commands:\n"
" $ ssh-keygen -R %(host)s\n"
" $ ssh-keygen -R [%(host)s]:%(port)s" % locals())
except paramiko.SSHException as e:
if user and auth_none and str(e) == "No authentication methods available":
self.client.get_transport().auth_none(user)
else:
raise
self.transport = self.client.get_transport()
self.transport.use_compression(True)
h.success()
if self.raw:
return
self._tried_sftp = False
if self.sftp:
with context.quiet:
self.cwd = packing._decode(self.pwd())
else:
self.cwd = '.'
with context.local(log_level='error'):
def getppid():
print(os.getppid())
try:
self.pid = int(self.process('false', preexec_fn=getppid).recvall())
except Exception:
self.pid = None
try:
self.info_once(self.checksec())
except Exception:
self.warn_once("Couldn't check security settings on %r" % self.host)
def __repr__(self):
return "{}(user={!r}, host={!r})".format(self.__class__.__name__, self.user, self.host)
@property
def cwd(self):
return self._cwd
@cwd.setter
def cwd(self, cwd):
self._cwd = cwd
if self.sftp:
self.sftp.chdir(cwd)
@property
def sftp(self):
"""Paramiko SFTPClient object which is used for file transfers.
Set to :const:`None` to disable ``sftp``.
"""
if not self._tried_sftp:
try:
self._sftp = self.transport.open_sftp_client()
except Exception:
self._sftp = None
self._tried_sftp = True
return self._sftp
@sftp.setter
def sftp(self, value):
self._sftp = value
self._tried_sftp = True
def __enter__(self, *a):
return self
def __exit__(self, *a, **kw):
self.close()
def shell(self, shell = None, tty = True, timeout = Timeout.default):
"""shell(shell = None, tty = True, timeout = Timeout.default) -> ssh_channel
Open a new channel with a shell inside.
Arguments:
shell(str): Path to the shell program to run.
If :const:`None`, uses the default shell for the logged in user.
tty(bool): If :const:`True`, then a TTY is requested on the remote server.
Returns:
Return a :class:`pwnlib.tubes.ssh.ssh_channel` object.
Examples:
>>> s = ssh(host='example.pwnme')
>>> sh = s.shell('/bin/sh')
>>> sh.sendline(b'echo Hello; exit')
>>> print(b'Hello' in sh.recvall())
True
"""
return self.run(shell, tty, timeout = timeout)
def process(self, argv=None, executable=None, tty=True, cwd=None, env=None, ignore_environ=None, timeout=Timeout.default, run=True,
stdin=0, stdout=1, stderr=2, preexec_fn=None, preexec_args=(), raw=True, aslr=None, setuid=None,
shell=False):
r"""
Executes a process on the remote server, in the same fashion
as pwnlib.tubes.process.process.
To achieve this, a Python script is created to call ``os.execve``
with the appropriate arguments.
As an added bonus, the ``ssh_channel`` object returned has a
``pid`` property for the process pid.
Arguments:
argv(list):
List of arguments to pass into the process
executable(str):
Path to the executable to run.
If :const:`None`, ``argv[0]`` is used.
tty(bool):
Request a `tty` from the server. This usually fixes buffering problems
by causing `libc` to write data immediately rather than buffering it.
However, this disables interpretation of control codes (e.g. Ctrl+C)
and breaks `.shutdown`.
cwd(str):
Working directory. If :const:`None`, uses the working directory specified
on :attr:`cwd` or set via :meth:`set_working_directory`.
env(dict):
Environment variables to add to the environment.
ignore_environ(bool):
Ignore default environment. By default use default environment iff env not specified.
timeout(int):
Timeout to set on the `tube` created to interact with the process.
run(bool):
Set to :const:`True` to run the program (default).
If :const:`False`, returns the path to an executable Python script on the
remote server which, when executed, will do it.
stdin(int, str):
If an integer, replace stdin with the numbered file descriptor.
If a string, a open a file with the specified path and replace
stdin with its file descriptor. May also be one of ``sys.stdin``,
``sys.stdout``, ``sys.stderr``. If :const:`None`, the file descriptor is closed.
stdout(int, str):
See ``stdin``.
stderr(int, str):
See ``stdin``.
preexec_fn(callable):
Function which is executed on the remote side before execve().
This **MUST** be a self-contained function -- it must perform
all of its own imports, and cannot refer to variables outside
its scope.
preexec_args(object):
Argument passed to ``preexec_fn``.
This **MUST** only consist of native Python objects.
raw(bool):
If :const:`True`, disable TTY control code interpretation.
aslr(bool):
See :class:`pwnlib.tubes.process.process` for more information.
setuid(bool):
See :class:`pwnlib.tubes.process.process` for more information.
shell(bool):
Pass the command-line arguments to the shell.
Returns:
A new SSH channel, or a path to a script if ``run=False``.
Notes:
Requires Python on the remote server.
Examples:
>>> s = ssh(host='example.pwnme')
>>> sh = s.process('/bin/sh', env={'PS1':''})
>>> sh.sendline(b'echo Hello; exit')
>>> sh.recvall()
b'Hello\n'
>>> s.process(['/bin/echo', b'\xff']).recvall()
b'\xff\n'
>>> s.process(['readlink', '/proc/self/exe']).recvall() # doctest: +ELLIPSIS
b'.../bin/readlink\n'
>>> s.process(['LOLOLOL', '/proc/self/exe'], executable='readlink').recvall() # doctest: +ELLIPSIS
b'.../bin/readlink\n'
>>> s.process(['LOLOLOL\x00', '/proc/self/cmdline'], executable='cat').recvall()
b'LOLOLOL\x00/proc/self/cmdline\x00'
>>> sh = s.process(executable='/bin/sh')
>>> str(sh.pid).encode() in s.pidof('sh') # doctest: +SKIP
True
>>> io = s.process(['pwd'], cwd='/tmp')
>>> io.recvall()
b'/tmp\n'
>>> io.cwd
'/tmp'
>>> p = s.process(['python3','-c','import os; os.write(1, os.read(2, 1024))'], stderr=0)
>>> p.send(b'hello')
>>> p.recv()
b'hello'
>>> s.process(['/bin/echo', 'hello']).recvall()
b'hello\n'
>>> s.process(['/bin/echo', 'hello'], stdout='/dev/null').recvall()
b''
>>> s.process(['/usr/bin/env'], env={}).recvall()
b''
>>> s.process('/usr/bin/env', env={'A':'B'}).recvall()
b'A=B\n'
>>> s.process('false', preexec_fn=1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn must be a function
>>> s.process('false', preexec_fn=lambda: 1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn cannot be a lambda
>>> def uses_globals():
... foo = bar
>>> print(s.process('false', preexec_fn=uses_globals).recvall().strip().decode()) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
NameError: ...name 'bar' is not defined
>>> s.process('echo hello', shell=True).recvall()
b'hello\n'
>>> io = s.process(['cat'], timeout=5)
>>> io.recvline()
b''
>>> # Testing that empty argv works
>>> io = s.process([], executable='sh')
>>> io.sendline(b'echo $0')
>>> io.recvline()
b'$ \n'
>>> # Make sure that we have a shell
>>> io.sendline(b'echo hello')
>>> io.recvline()
b'$ hello\n'
>>> # Testing that empty argv[0] works
>>> io = s.process([''], executable='sh')
>>> io.sendline(b'echo $0')
>>> io.recvline()
b'$ \n'
"""
cwd = cwd or self.cwd
script = misc._create_execve_script(argv=argv, executable=executable,
cwd=cwd, env=env, stdin=stdin, stdout=stdout, stderr=stderr,
ignore_environ=ignore_environ, preexec_fn=preexec_fn, preexec_args=preexec_args,
aslr=aslr, setuid=setuid, shell=shell, log=self)
self.debug("Created execve script:\n" + script)
if not run:
with context.local(log_level='error'):
tmpfile = self.mktemp('-t', 'pwnlib-execve-XXXXXXXXXX')
self.chmod('+x', tmpfile)
self.info("Uploading execve script to %r" % tmpfile)
script = packing._encode(script)
self.upload_data(script, tmpfile)
return tmpfile
if self.isEnabledFor(logging.DEBUG):
execve_repr = "execve(%r, %s, %s)" % (executable,
argv,
'os.environ'
if (env in (None, getattr(os, "environb", os.environ)))
else env)
# Avoid spamming the screen
if self.isEnabledFor(logging.DEBUG) and len(execve_repr) > 512:
execve_repr = execve_repr[:512] + '...'
else:
execve_repr = repr(executable)
msg = 'Starting remote process %s on %s' % (execve_repr, self.host)
if timeout == Timeout.default:
timeout = self.timeout
with self.progress(msg) as h:
script = 'echo PWNTOOLS; for py in python3 python2.7 python2 python; do test -x "$(command -v $py 2>&1)" && echo $py && exec $py -c %s check; done; echo 2' % sh_string(script)
with context.quiet:
python = ssh_process(self, script, tty=True, cwd=cwd, raw=True, level=self.level, timeout=timeout)
try:
python.recvline_contains(b'PWNTOOLS') # Magic flag so that any sh/bash initialization errors are swallowed
try:
if b'python' not in python.recvline(): # Python interpreter that was selected
raise ValueError("Python not found on remote host")
except (EOFError, ValueError):
self.warn_once('Could not find a Python interpreter on %s\n' % self.host
+ "Use ssh.system() instead of ssh.process()\n")
h.failure("Process creation failed")
return None
result = safeeval.const(python.recvline()) # Status flag from the Python script
except (EOFError, ValueError):
h.failure("Process creation failed")
return None
# If an error occurred, try to grab as much output
# as we can.
if result != 1:
error_message = python.recvrepeat(timeout=1)
if result == 0:
self.error("%r does not exist or is not executable" % executable)
elif result == 3:
self.error("%r" % error_message)
elif result == 2:
self.error("python is not installed on the remote system %r" % self.host)
elif result != 1:
h.failure("something bad happened:\n%s" % error_message)
python.pid = safeeval.const(python.recvline())
python.uid = safeeval.const(python.recvline())
python.gid = safeeval.const(python.recvline())
python.suid = safeeval.const(python.recvline())
python.sgid = safeeval.const(python.recvline())
python.argv = argv
python.executable = packing._decode(python.recvuntil(b'\x00')[:-1])
h.success('pid %i' % python.pid)
if not aslr and setuid and (python.uid != python.suid or python.gid != python.sgid):
effect = "partial" if self.aslr_ulimit else "no"
message = "Specfied aslr=False on setuid binary %s\n" % python.executable
message += "This will have %s effect. Add setuid=False to disable ASLR for debugging.\n" % effect
if self.aslr_ulimit:
message += "Unlimited stack size should de-randomize shared libraries."
self.warn_once(message)
elif not aslr:
self.warn_once("ASLR is disabled for %r!" % python.executable)
return python
def which(self, program):
"""which(program) -> str
Minor modification to just directly invoking ``which`` on the remote
system which adds the current working directory to the end of ``$PATH``.
"""
# If name is a path, do not attempt to resolve it.
if os.path.sep in program:
return program
program = packing._encode(program)
result = self.system(b'export PATH=$PATH:$PWD; command -v ' + program).recvall().strip()
if (b'/' + program) not in result:
return None
return packing._decode(result)
def system(self, process, tty = True, cwd = None, env = None, timeout = None, raw = True, wd = None):
r"""system(process, tty = True, cwd = None, env = None, timeout = Timeout.default, raw = True) -> ssh_channel
Open a new channel with a specific process inside. If `tty` is True,
then a TTY is requested on the remote server.
If `raw` is True, terminal control codes are ignored and input is not
echoed back.
Return a :class:`pwnlib.tubes.ssh.ssh_channel` object.
Examples:
>>> s = ssh(host='example.pwnme')
>>> py = s.system('python3 -i')
>>> _ = py.recvuntil(b'>>> ')
>>> py.sendline(b'print(2+2)')
>>> py.sendline(b'exit()')
>>> print(repr(py.recvline()))
b'4\n'
>>> s.system('env | grep -a AAAA', env={'AAAA': b'\x90'}).recvall()
b'AAAA=\x90\n'
>>> io = s.system('pwd', cwd='/tmp')
>>> io.recvall()
b'/tmp\n'
>>> io.cwd
'/tmp'
"""
if wd is not None:
self.warning_once("The 'wd' argument to ssh.system() is deprecated. Use 'cwd' instead.")
if cwd is None:
cwd = wd
if cwd is None:
cwd = self.cwd
if timeout is None:
timeout = self.timeout
return ssh_channel(self, process, tty, cwd, env, timeout = timeout, level = self.level, raw = raw)
#: Backward compatibility. Use :meth:`system`
run = system
def getenv(self, variable, **kwargs):
"""Retrieve the address of an environment variable on the remote
system.
Note:
The exact address will differ based on what other environment
variables are set, as well as argv[0]. In order to ensure that
the path is *exactly* the same, it is recommended to invoke the
process with ``argv=[]``.
"""
script = '''
from ctypes import *; libc = CDLL('libc.so.6'); print(libc.getenv(%r))
''' % variable
with context.local(log_level='error'):
python = self.which('python') or self.which('python2.7') or self.which('python3')
if not python:
self.error("Python is not installed on the remote system.")
io = self.process(['','-c', script.strip()], executable=python, **kwargs)
result = io.recvall()
try:
return int(result) & context.mask
except ValueError:
self.exception("Could not look up environment variable %r" % variable)
def run_to_end(self, process, tty = False, cwd = None, env = None, wd = None):
r"""run_to_end(process, tty = False, cwd = None, env = None, timeout = Timeout.default) -> str
Run a command on the remote server and return a tuple with
(data, exit_status). If `tty` is True, then the command is run inside
a TTY on the remote server.
Examples:
>>> s = ssh(host='example.pwnme')
>>> print(s.run_to_end('echo Hello; exit 17'))
(b'Hello\n', 17)
"""
if wd is not None:
self.warning_once("The 'wd' argument to ssh.run_to_end() is deprecated. Use 'cwd' instead.")
if cwd is None:
cwd = wd
with context.local(log_level = 'ERROR'):
c = self.run(process, tty, cwd = cwd, env = env, timeout = Timeout.default)
data = c.recvall()
retcode = c.wait()
c.close()
return data, retcode
def connect_remote(self, host, port, timeout = Timeout.default):
r"""connect_remote(host, port, timeout = Timeout.default) -> ssh_connecter
Connects to a host through an SSH connection. This is equivalent to
using the ``-L`` flag on ``ssh``.
Returns a :class:`pwnlib.tubes.ssh.ssh_connecter` object.
Examples:
>>> from pwn import *
>>> l = listen()
>>> s = ssh(host='example.pwnme')
>>> a = s.connect_remote(s.host, l.lport)
>>> a=a; b = l.wait_for_connection() # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'
"""
return ssh_connecter(self, host, port, timeout, level=self.level)
remote = connect_remote
def listen_remote(self, port = 0, bind_address = '', timeout = Timeout.default):
r"""listen_remote(port = 0, bind_address = '', timeout = Timeout.default) -> ssh_connecter
Listens remotely through an SSH connection. This is equivalent to
using the ``-R`` flag on ``ssh``.
Returns a :class:`pwnlib.tubes.ssh.ssh_listener` object.
Examples:
>>> from pwn import *
>>> s = ssh(host='example.pwnme')
>>> l = s.listen_remote()
>>> a = remote(s.host, l.port)
>>> a=a; b = l.wait_for_connection() # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'
"""
return ssh_listener(self, bind_address, port, timeout, level=self.level)
listen = listen_remote
def __getitem__(self, attr):
"""Permits indexed access to run commands over SSH
Examples:
>>> s = ssh(host='example.pwnme')
>>> print(repr(s['echo hello']))
b'hello'
"""
return self.run(attr).recvall().strip()
def __call__(self, attr):
"""Permits function-style access to run commands over SSH
Examples:
>>> s = ssh(host='example.pwnme')
>>> print(repr(s('echo hello')))
b'hello'
"""
return self.run(attr).recvall().strip()
def __getattr__(self, attr):
"""Permits member access to run commands over SSH
Examples:
>>> s = ssh(host='example.pwnme')
>>> s.echo('hello')
b'hello'
>>> s.whoami()
b'travis'
>>> s.echo(['huh','yay','args'])
b'huh yay args'
"""
bad_attrs = [
'trait_names', # ipython tab-complete
]
if attr in self.__dict__ \
or attr in bad_attrs \
or attr.startswith('_'):
raise AttributeError
@LocalContext
def runner(*args):
if len(args) == 1 and isinstance(args[0], (list, tuple)):
command = [attr]
command.extend(args[0])
else:
command = [attr]
command.extend(args)
command = b' '.join(packing._need_bytes(arg, min_wrong=0x80) for arg in command)
return self.run(command).recvall().strip()
return runner
def connected(self):
"""Returns True if we are connected.
Example:
>>> s = ssh(host='example.pwnme')
>>> s.connected()
True
>>> s.close()
>>> s.connected()
False
"""
return bool(self.client and self.client.get_transport().is_active())
def close(self):
"""Close the connection."""
if self.client:
self.client.close()
self.client = None
self.info("Closed connection to %r" % self.host)
def _libs_remote(self, remote):
"""Return a dictionary of the libraries used by a remote file."""
escaped_remote = sh_string(remote)
cmd = ''.join([
'(',
'ulimit -s unlimited;',
'ldd %s > /dev/null &&' % escaped_remote,
'(',
'LD_TRACE_LOADED_OBJECTS=1 %s||' % escaped_remote,
'ldd %s' % escaped_remote,
'))',
' 2>/dev/null'
])
data, status = self.run_to_end(cmd)
if status != 0:
self.error('Unable to find libraries for %r' % remote)
return {}
return misc.parse_ldd_output(packing._decode(data))
def _get_fingerprint(self, remote):
cmd = '(sha256 || sha256sum || openssl sha256) 2>/dev/null < '
cmd = cmd + sh_string(remote)
data, status = self.run_to_end(cmd)
if status != 0:
return None
if not isinstance(data, str):
data = data.decode('ascii')
data = re.search("([a-fA-F0-9]{64})",data).group()
return data
def _get_cachefile(self, fingerprint):
return os.path.join(self._cachedir, fingerprint)
def _verify_local_fingerprint(self, fingerprint):
if not set(fingerprint).issubset(string.hexdigits) or \
len(fingerprint) != 64:
self.error('Invalid fingerprint %r' % fingerprint)
return False
local = self._get_cachefile(fingerprint)
if not os.path.isfile(local):
return False
if hashes.sha256filehex(local) == fingerprint:
return True
else:
os.unlink(local)
return False
def _download_raw(self, remote, local, h):
def update(has, total):
h.status("%s/%s" % (misc.size(has), misc.size(total)))
if self.sftp:
try:
self.sftp.get(remote, local, update)
return
except IOError:
pass
cmd = 'wc -c < ' + sh_string(remote)
total, exitcode = self.run_to_end(cmd)
if exitcode != 0:
h.failure("%r does not exist or is not accessible" % remote)
return
total = int(total)
with context.local(log_level = 'ERROR'):
cmd = 'cat < ' + sh_string(remote)
c = self.run(cmd)
data = b''
while True:
try:
data += c.recv()
except EOFError:
break
update(len(data), total)
result = c.wait()
if result != 0:
h.failure('Could not download file %r (%r)' % (remote, result))
return
with open(local, 'wb') as fd:
fd.write(data)
def _download_to_cache(self, remote, p, fingerprint=True):
with context.local(log_level='error'):
remote = self.readlink('-f',remote)
if not hasattr(remote, 'encode'):
remote = remote.decode('utf-8')
fingerprint = fingerprint and self._get_fingerprint(remote) or None
if fingerprint is None:
local = os.path.normpath(remote)
local = os.path.basename(local)
local += time.strftime('-%Y-%m-%d-%H:%M:%S')
local = os.path.join(self._cachedir, local)
self._download_raw(remote, local, p)
return local
local = self._get_cachefile(fingerprint)
if self.cache and self._verify_local_fingerprint(fingerprint):
p.success('Found %r in ssh cache' % remote)
else:
self._download_raw(remote, local, p)
if not self._verify_local_fingerprint(fingerprint):
self.error('Could not download file %r', remote)
return local
def download_data(self, remote, fingerprint=True):
"""Downloads a file from the remote server and returns it as a string.
Arguments:
remote(str): The remote filename to download.
Examples:
>>> with open('/tmp/bar','w+') as f:
... _ = f.write('Hello, world')
>>> s = ssh(host='example.pwnme',
... cache=False)
>>> s.download_data('/tmp/bar')
b'Hello, world'
>>> s._sftp = None
>>> s._tried_sftp = True
>>> s.download_data('/tmp/bar')
b'Hello, world'
"""
with self.progress('Downloading %r' % remote) as p:
with open(self._download_to_cache(remote, p, fingerprint), 'rb') as fd:
return fd.read()
def download_file(self, remote, local = None):
"""Downloads a file from the remote server.
The file is cached in /tmp/pwntools-ssh-cache using a hash of the file, so
calling the function twice has little overhead.
Arguments:
remote(str/bytes): The remote filename to download
local(str): The local filename to save it to. Default is to infer it from the remote filename.
Examples:
>>> with open('/tmp/foobar','w+') as f:
... _ = f.write('Hello, world')
>>> s = ssh(host='example.pwnme',
... cache=False)
>>> _ = s.set_working_directory(wd='/tmp')
>>> _ = s.download_file('foobar', 'barfoo')
>>> with open('barfoo','r') as f:
... print(f.read())
Hello, world
"""
if not local:
local = os.path.basename(os.path.normpath(remote))
with self.progress('Downloading %r to %r' % (remote, local)) as p:
local_tmp = self._download_to_cache(remote, p)
# Check to see if an identical copy of the file already exists
if not os.path.exists(local) or hashes.sha256filehex(local_tmp) != hashes.sha256filehex(local):
shutil.copy2(local_tmp, local)
def download_dir(self, remote=None, local=None, ignore_failed_read=False):
"""Recursively downloads a directory from the remote server
Arguments:
local: Local directory
remote: Remote directory
"""
remote = packing._encode(remote or self.cwd)
if self.sftp:
remote = packing._encode(self.sftp.normalize(remote))
else:
with context.local(log_level='error'):
remote = self.system(b'readlink -f ' + sh_string(remote)).recvall().strip()
local = local or '.'
local = os.path.expanduser(local)
self.info("Downloading %r to %r" % (remote, local))
if ignore_failed_read:
opts = b" --ignore-failed-read"
else:
opts = b""
with context.local(log_level='error'):
remote_tar = self.mktemp()
cmd = b'tar %s -C %s -czf %s .' % \
(opts,
sh_string(remote),
sh_string(remote_tar))
tar = self.system(cmd)
if 0 != tar.wait():
self.error("Could not create remote tar")
local_tar = tempfile.NamedTemporaryFile(suffix='.tar.gz')
self.download_file(remote_tar, local_tar.name)
# Delete temporary tarfile from remote host
if self.sftp:
self.unlink(remote_tar)
else:
self.system(b'rm ' + sh_string(remote_tar)).wait()
tar = tarfile.open(local_tar.name)
tar.extractall(local)
def upload_data(self, data, remote):
"""Uploads some data into a file on the remote server.
Arguments:
data(str): The data to upload.
remote(str): The filename to upload it to.
Example:
>>> s = ssh(host='example.pwnme')
>>> s.upload_data(b'Hello, world', '/tmp/upload_foo')
>>> print(open('/tmp/upload_foo').read())
Hello, world
>>> s._sftp = False
>>> s._tried_sftp = True
>>> s.upload_data(b'Hello, world', '/tmp/upload_bar')
>>> print(open('/tmp/upload_bar').read())
Hello, world
"""
data = packing._need_bytes(data)
# If a relative path was provided, prepend the cwd
if os.path.normpath(remote) == os.path.basename(remote):
remote = os.path.join(self.cwd, remote)
if self.sftp:
with tempfile.NamedTemporaryFile() as f:
f.write(data)
f.flush()
self.sftp.put(f.name, remote)
return
with context.local(log_level = 'ERROR'):
cmd = 'cat > ' + sh_string(remote)
s = self.run(cmd, tty=False)
s.send(data)
s.shutdown('send')
data = s.recvall()
result = s.wait()
if result != 0:
self.error("Could not upload file %r (%r)\n%s" % (remote, result, data))
def upload_file(self, filename, remote = None):
"""Uploads a file to the remote server. Returns the remote filename.
Arguments:
filename(str): The local filename to download
remote(str): The remote filename to save it to. Default is to infer it from the local filename."""
if remote is None:
remote = os.path.normpath(filename)
remote = os.path.basename(remote)
remote = os.path.join(self.cwd, remote)
with open(filename, 'rb') as fd:
data = fd.read()
self.info("Uploading %r to %r" % (filename,remote))
self.upload_data(data, remote)
return remote
def upload_dir(self, local, remote=None):
"""Recursively uploads a directory onto the remote server
Arguments:
local: Local directory
remote: Remote directory
"""
remote = packing._encode(remote or self.cwd)
local = os.path.expanduser(local)
dirname = os.path.dirname(local)
basename = os.path.basename(local)
if not os.path.isdir(local):
self.error("%r is not a directory" % local)
msg = "Uploading %r to %r" % (basename,remote)
with self.waitfor(msg):
# Generate a tarfile with everything inside of it
local_tar = tempfile.mktemp()
with tarfile.open(local_tar, 'w:gz') as tar:
tar.add(local, basename)
# Upload and extract it
with context.local(log_level='error'):
remote_tar = self.mktemp('--suffix=.tar.gz')
self.upload_file(local_tar, remote_tar)
untar = self.run(b'cd %s && tar -xzf %s' % (sh_string(remote), sh_string(remote_tar)))
message = untar.recvrepeat(2)
if untar.wait() != 0:
self.error("Could not untar %r on the remote end\n%s" % (remote_tar, message))
def upload(self, file_or_directory, remote=None):
"""upload(file_or_directory, remote=None)
Upload a file or directory to the remote host.
Arguments:
file_or_directory(str): Path to the file or directory to download.
remote(str): Local path to store the data.
By default, uses the working directory.
"""
if isinstance(file_or_directory, str):
file_or_directory = os.path.expanduser(file_or_directory)
file_or_directory = os.path.expandvars(file_or_directory)
if os.path.isfile(file_or_directory):
return self.upload_file(file_or_directory, remote)
if os.path.isdir(file_or_directory):
return self.upload_dir(file_or_directory, remote)
self.error('%r does not exist' % file_or_directory)
def download(self, file_or_directory, local=None):
"""download(file_or_directory, local=None)
Download a file or directory from the remote host.
Arguments:
file_or_directory(str): Path to the file or directory to download.
local(str): Local path to store the data.
By default, uses the current directory.
Examples:
>>> with open('/tmp/foobar','w+') as f:
... _ = f.write('Hello, world')
>>> s = ssh(host='example.pwnme',
... cache=False)
>>> _ = s.set_working_directory('/tmp')
>>> _ = s.download('foobar', 'barfoo')
>>> with open('barfoo','r') as f:
... print(f.read())
Hello, world
"""
file_or_directory = packing._encode(file_or_directory)
with self.system(b'test -d ' + sh_string(file_or_directory)) as io:
is_dir = io.wait()
if 0 == is_dir:
self.download_dir(file_or_directory, local)
else:
self.download_file(file_or_directory, local)
put = upload
get = download
def unlink(self, file):
"""unlink(file)
Delete the file on the remote host
Arguments:
file(str): Path to the file
"""
if not self.sftp:
self.error("unlink() is only supported if SFTP is supported")
return self.sftp.unlink(file)
def libs(self, remote, directory = None, flatten = False):
"""Downloads the libraries referred to by a file.
This is done by running ldd on the remote server, parsing the output
and downloading the relevant files.
The directory argument specified where to download the files. This defaults
to './$HOSTNAME' where $HOSTNAME is the hostname of the remote server.
Arguments:
remote(str): Remote file path
directory(str): Output directory
flatten(bool): Flatten the file tree if True (defaults to False) and
ignore the remote directory structure. If there are duplicate
filenames, an error will be raised.
"""
libs = self._libs_remote(remote)
remote = packing._decode(self.readlink('-f',remote).strip())
libs[remote] = 0
if flatten:
basenames = dict()
# If there is a duplicate switch to unflattened download
for lib in libs:
name = os.path.basename(lib)
if name in basenames.values():
duplicate = [key for key, value in basenames.items() if
value == name][0]
self.error('Duplicate lib name: %r / %4r' % (lib, duplicate))
basenames[lib] = name
if directory is None:
directory = self.host
directory = os.path.realpath(directory)
res = {}
seen = set()
for lib, addr in libs.items():
local = os.path.realpath(os.path.join(directory, '.' + os.path.sep \
+ (basenames[lib] if flatten else lib)))
if not local.startswith(directory):
self.warning('This seems fishy: %r' % lib)
continue
misc.mkdir_p(os.path.dirname(local))
if lib not in seen:
self.download_file(lib, local)
seen.add(lib)
res[local] = addr
return res
def interactive(self, shell=None):
"""Create an interactive session.
This is a simple wrapper for creating a new
:class:`pwnlib.tubes.ssh.ssh_channel` object and calling
:meth:`pwnlib.tubes.ssh.ssh_channel.interactive` on it."""
s = self.shell(shell)
if self.cwd != '.':
cmd = 'cd ' + sh_string(self.cwd)
s.sendline(packing._need_bytes(cmd, 2, 0x80))
s.interactive()
s.close()
def set_working_directory(self, wd = None, symlink = False):
"""Sets the working directory in which future commands will
be run (via ssh.run) and to which files will be uploaded/downloaded
from if no path is provided
Note:
This uses ``mktemp -d`` under the covers, sets permissions
on the directory to ``0700``. This means that setuid binaries
will **not** be able to access files created in this directory.
In order to work around this, we also ``chmod +x`` the directory.
Arguments:
wd(string): Working directory. Default is to auto-generate a directory
based on the result of running 'mktemp -d' on the remote machine.
symlink(bool,str): Create symlinks in the new directory.
The default value, ``False``, implies that no symlinks should be
created.
A string value is treated as a path that should be symlinked.
It is passed directly to the shell on the remote end for expansion,
so wildcards work.
Any other value is treated as a boolean, where ``True`` indicates
that all files in the "old" working directory should be symlinked.
Examples:
>>> s = ssh(host='example.pwnme')
>>> cwd = s.set_working_directory()
>>> s.ls()
b''
>>> packing._decode(s.pwd()) == cwd
True
>>> s = ssh(host='example.pwnme')
>>> homedir = s.pwd()
>>> _=s.touch('foo')
>>> _=s.set_working_directory()
>>> assert s.ls() == b''
>>> _=s.set_working_directory(homedir)
>>> assert b'foo' in s.ls().split(), s.ls().split()
>>> _=s.set_working_directory(symlink=True)
>>> assert b'foo' in s.ls().split(), s.ls().split()
>>> assert homedir != s.pwd()
>>> symlink=os.path.join(homedir,b'*')
>>> _=s.set_working_directory(symlink=symlink)
>>> assert b'foo' in s.ls().split(), s.ls().split()
>>> assert homedir != s.pwd()
>>> _=s.set_working_directory()
>>> io = s.system('pwd')
>>> io.recvallS().strip() == io.cwd
True
>>> io.cwd == s.cwd
True
"""
status = 0
if symlink and not isinstance(symlink, (six.binary_type, six.text_type)):
symlink = os.path.join(self.pwd(), b'*')
if not hasattr(symlink, 'encode') and hasattr(symlink, 'decode'):
symlink = symlink.decode('utf-8')
if isinstance(wd, six.text_type):
wd = packing._need_bytes(wd, 2, 0x80)
if not wd:
wd, status = self.run_to_end('x=$(mktemp -d) && cd $x && chmod +x . && echo $PWD', cwd='.')
wd = wd.strip()
if status:
self.error("Could not generate a temporary directory (%i)\n%s" % (status, wd))
else:
cmd = b'ls ' + sh_string(wd)
_, status = self.run_to_end(cmd, wd = '.')
if status:
self.error("%r does not appear to exist" % wd)
if not isinstance(wd, str):
wd = wd.decode('utf-8')
self.cwd = wd
self.info("Working directory: %r" % self.cwd)
if symlink:
self.ln('-s', symlink, '.')
return wd
def write(self, path, data):
"""Wrapper around upload_data to match :func:`pwnlib.util.misc.write`"""
data = packing._need_bytes(data)
return self.upload_data(data, path)
def read(self, path):
"""Wrapper around download_data to match :func:`pwnlib.util.misc.read`"""
return self.download_data(path)
def _init_remote_platform_info(self):
r"""Fills _platform_info, e.g.:
::
{'distro': 'Ubuntu\n',
'distro_ver': '14.04\n',
'machine': 'x86_64',
'node': 'pwnable.kr',
'processor': 'x86_64',
'release': '3.11.0-12-generic',
'system': 'linux',
'version': '#19-ubuntu smp wed oct 9 16:20:46 utc 2013'}
"""
if self._platform_info:
return
def preexec():
import platform
print('\n'.join(platform.uname()))
with context.quiet:
with self.process('true', preexec_fn=preexec) as io:
self._platform_info = {
'system': io.recvline().lower().strip().decode(),
'node': io.recvline().lower().strip().decode(),
'release': io.recvline().lower().strip().decode(),
'version': io.recvline().lower().strip().decode(),
'machine': io.recvline().lower().strip().decode(),
'processor': io.recvline().lower().strip().decode(),
'distro': 'Unknown',
'distro_ver': ''
}
try:
if not self.which('lsb_release'):
return
with self.process(['lsb_release', '-irs']) as io:
lsb_info = io.recvall().strip().decode()
self._platform_info['distro'], self._platform_info['distro_ver'] = lsb_info.split()
except Exception:
pass
@property
def os(self):
""":class:`str`: Operating System of the remote machine."""
try:
self._init_remote_platform_info()
with context.local(os=self._platform_info['system']):
return context.os
except Exception:
return "Unknown"
@property
def arch(self):
""":class:`str`: CPU Architecture of the remote machine."""
try:
self._init_remote_platform_info()
with context.local(arch=self._platform_info['machine']):
return context.arch
except Exception:
return "Unknown"
@property
def bits(self):
""":class:`str`: Pointer size of the remote machine."""
try:
with context.local():
context.clear()
context.arch = self.arch
return context.bits
except Exception:
return context.bits
@property
def version(self):
""":class:`tuple`: Kernel version of the remote machine."""
try:
self._init_remote_platform_info()
vers = self._platform_info['release']
# 3.11.0-12-generic
expr = r'([0-9]+\.?)+'
vers = re.search(expr, vers).group()
return tuple(map(int, vers.split('.')))
except Exception:
return (0,0,0)
@property
def distro(self):
""":class:`tuple`: Linux distribution name and release."""
try:
self._init_remote_platform_info()
return (self._platform_info['distro'], self._platform_info['distro_ver'])
except Exception:
return ("Unknown", "Unknown")
@property
def aslr(self):
""":class:`bool`: Whether ASLR is enabled on the system.
Example:
>>> s = ssh("travis", "example.pwnme")
>>> s.aslr
True
"""
if self._aslr is None:
if self.os != 'linux':
self.warn_once("Only Linux is supported for ASLR checks.")
self._aslr = False
else:
with context.quiet:
rvs = self.read('/proc/sys/kernel/randomize_va_space')
self._aslr = not rvs.startswith(b'0')
return self._aslr
@property
def aslr_ulimit(self):
""":class:`bool`: Whether the entropy of 32-bit processes can be reduced with ulimit."""
import pwnlib.elf.elf
import pwnlib.shellcraft
if self._aslr_ulimit is not None:
return self._aslr_ulimit
# This test must run a 32-bit binary, fix the architecture
arch = {
'amd64': 'i386',
'aarch64': 'arm'
}.get(self.arch, self.arch)
with context.local(arch=arch, bits=32, os=self.os, aslr=True):
with context.quiet:
try:
sc = pwnlib.shellcraft.cat('/proc/self/maps') \
+ pwnlib.shellcraft.exit(0)
elf = pwnlib.elf.elf.ELF.from_assembly(sc, shared=True)
except Exception:
self.warn_once("Can't determine ulimit ASLR status")
self._aslr_ulimit = False
return self._aslr_ulimit
def preexec():
import resource
try:
resource.setrlimit(resource.RLIMIT_STACK, (-1, -1))
except Exception:
pass
# Move to a new temporary directory
cwd = self.cwd
tmp = self.set_working_directory()
try:
self.upload(elf.path, './aslr-test')
except IOError:
self.warn_once("Couldn't check ASLR ulimit trick")
self._aslr_ulimit = False
return False
self.process(['chmod', '+x', './aslr-test']).wait()
maps = self.process(['./aslr-test'], preexec_fn=preexec).recvall()
# Move back to the old directory
self.cwd = cwd
# Clean up the files
self.process(['rm', '-rf', tmp]).wait()
# Check for 555555000 (1/3 of the address space for PAE)
# and for 40000000 (1/3 of the address space with 3BG barrier)
self._aslr_ulimit = bool(b'55555000' in maps or b'40000000' in maps)
return self._aslr_ulimit
def _cpuinfo(self):
if self._cpuinfo_cache is None:
with context.quiet:
try:
self._cpuinfo_cache = self.download_data('/proc/cpuinfo', fingerprint=False)
except PwnlibException:
self._cpuinfo_cache = b''
return self._cpuinfo_cache
@property
def user_shstk(self):
""":class:`bool`: Whether userspace shadow stack is supported on the system.
Example:
>>> s = ssh("travis", "example.pwnme")
>>> s.user_shstk # doctest: +SKIP
False
"""
if self._user_shstk is None:
if self.os != 'linux':
self.warn_once("Only Linux is supported for userspace shadow stack checks.")
self._user_shstk = False
else:
cpuinfo = self._cpuinfo()
self._user_shstk = b' user_shstk' in cpuinfo
return self._user_shstk
@property
def ibt(self):
""":class:`bool`: Whether kernel indirect branch tracking is supported on the system.
Example:
>>> s = ssh("travis", "example.pwnme")
>>> s.ibt
False
"""
if self._ibt is None:
if self.os != 'linux':
self.warn_once("Only Linux is supported for kernel indirect branch tracking checks.")
self._ibt = False
else:
cpuinfo = self._cpuinfo()
self._ibt = b' ibt ' in cpuinfo or b' ibt\n' in cpuinfo
return self._ibt
def _checksec_cache(self, value=None):
path = self._get_cachefile('%s-%s' % (self.host, self.port))
if value is not None:
with open(path, 'w+') as f:
f.write(value)
elif os.path.exists(path):
with open(path, 'r+') as f:
return f.read()
def checksec(self, banner=True):
"""checksec()
Prints a helpful message about the remote system.
Arguments:
banner(bool): Whether to print the path to the ELF binary.
"""
cached = self._checksec_cache()
if cached:
return cached
red = text.red
green = text.green
yellow = text.yellow
res = [
"%s@%s:" % (self.user, self.host),
"Distro".ljust(10) + ' '.join(self.distro),
"OS:".ljust(10) + self.os,
"Arch:".ljust(10) + self.arch,
"Version:".ljust(10) + '.'.join(map(str, self.version)),
"ASLR:".ljust(10) + {
True: green("Enabled"),
False: red("Disabled")
}[self.aslr],
"SHSTK:".ljust(10) + {
True: green("Enabled"),
False: red("Disabled")
}[self.user_shstk],
"IBT:".ljust(10) + {
True: green("Enabled"),
False: red("Disabled")
}[self.ibt],
]
if self.aslr_ulimit:
res += [ "Note:".ljust(10) + red("Susceptible to ASLR ulimit trick (CVE-2016-3672)")]
cached = '\n'.join(res)
self._checksec_cache(cached)
return cached
|