/usr/lib/python2.7/dist-packages/spf.py is in python-spf 2.0.12t-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | #!/usr/bin/python3
from __future__ import print_function
"""SPF (Sender Policy Framework) implementation.
Copyright (c) 2003 Terence Way <terry@wayforward.net>
Portions Copyright(c) 2004,2005,2006,2007,2008,2011,2012 Stuart Gathman <stuart@bmsi.com>
Portions Copyright(c) 2005,2006,2007,2008,2011,2012,2013,2014 Scott Kitterman <scott@kitterman.com>
Portions Copyright(c) 2013,2014 Stuart Gathman <stuart@gathman.org>
This module is free software, and you may redistribute it and/or modify
it under the same terms as Python itself, so long as this copyright message
and disclaimer are retained in their original form.
IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS,
AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
For more information about SPF, a tool against email forgery, see
http://www.openspf.net/
For news, bugfixes, etc. visit the home page for this implementation at
http://cheeseshop.python.org/pypi/pyspf/
http://sourceforge.net/projects/pymilter/
http://www.wayforward.net/spf/
"""
# CVS Commits since last release (2.0.11):
# $Log: spf.py,v $
# Revision 1.108.2.150 2015/08/05 13:49:45 customdesigned
# Forgot tabnanny
#
# Revision 1.108.2.149 2015/08/05 13:07:09 customdesigned
# Release 2.0.12
#
# Revision 1.108.2.148 2015/08/05 04:49:48 customdesigned
# Reset void_lookups at top of check()
#
# Revision 1.108.2.147 2015/08/05 03:36:59 customdesigned
# Ignore permerror for best_guess
#
# Revision 1.108.2.146 2015/06/05 15:58:18 customdesigned
# Don't crash on null TXT record.
#
# Revision 1.108.2.145 2015/01/14 20:27:42 customdesigned
# Fix list feature
#
# Revision 1.108.2.144 2015/01/13 04:40:07 customdesigned
# Trailing spaces *are* allowed by 4.5/2
#
# Revision 1.108.2.143 2015/01/12 22:51:56 customdesigned
# Trailing space is PermError, but strip for extended result in lax mode.
#
# Revision 1.108.2.142 2015/01/06 14:13:50 customdesigned
# Make CNAME loop result in unknown host.
#
# Revision 1.108.2.141 2015/01/02 01:08:18 customdesigned
# Test case and fix for mixed case CNAME loop.
#
# Revision 1.108.2.140 2015/01/02 00:26:08 customdesigned
# Make CNAME loop check case insensitive.
#
# Revision 1.108.2.139 2014/12/19 00:16:12 kitterma
# Missed a spot bumping to 2.0.12.
#
# Revision 1.108.2.138 2014/12/19 00:15:12 kitterma
# Bump versions, etc. to start 2.0.12 development.
#
# Revision 1.108.2.137 2014/12/13 15:39:27 customdesigned
# Require ipaddress/ipaddr backport with Bytes for python2.
#
# See pyspf_changelog.txt for earlier CVS commits.
__author__ = "Terence Way, Stuart Gathman, Scott Kitterman"
__email__ = "pyspf@openspf.org"
__version__ = "2.0.12: Aug 5, 2015"
MODULE = 'spf'
USAGE = """To check an incoming mail request:
% python spf.py [-v] {ip} {sender} {helo}
% python spf.py 69.55.226.139 tway@optsw.com mx1.wayforward.net
To test an SPF record:
% python spf.py [-v] "v=spf1..." {ip} {sender} {helo}
% python spf.py "v=spf1 +mx +ip4:10.0.0.1 -all" 10.0.0.1 tway@foo.com a
To fetch an SPF record:
% python spf.py {domain}
% python spf.py wayforward.net
To test this script (and to output this usage message):
% python spf.py
"""
import re
import sys
import socket # for inet_ntoa() and inet_aton()
import struct # for pack() and unpack()
import time # for time()
try:
import urllib.parse as urllibparse # for quote()
except:
import urllib as urllibparse
import sys # for version_info()
from functools import reduce
try:
from email.message import Message
except ImportError:
from email.Message import Message
try:
# Python standard libarary as of python3.3
import ipaddress
if bytes is str:
from ipaddress import Bytes
except ImportError:
try:
import ipaddr as ipaddress
from ipaddr import Bytes
except ImportError:
print('ipaddr module required: http://code.google.com/p/ipaddr-py/')
import DNS # http://pydns.sourceforge.net
if not hasattr(DNS.Type, 'SPF'):
# patch in type99 support
DNS.Type.SPF = 99
DNS.Type.typemap[99] = 'SPF'
DNS.Lib.RRunpacker.getSPFdata = DNS.Lib.RRunpacker.getTXTdata
def DNSLookup(name, qtype, strict=True, timeout=20):
try:
req = DNS.DnsRequest(name, qtype=qtype, timeout=timeout)
resp = req.req()
#resp.show()
# key k: ('wayforward.net', 'A'), value v
# FIXME: pydns returns AAAA RR as 16 byte binary string, but
# A RR as dotted quad. For consistency, this driver should
# return both as binary string.
#
if resp.header['tc'] == True:
if strict > 1:
raise AmbiguityWarning('DNS: Truncated UDP Reply, SPF records should fit in a UDP packet, retrying TCP')
try:
req = DNS.DnsRequest(name, qtype=qtype, protocol='tcp', timeout=(timeout))
resp = req.req()
except DNS.DNSError as x:
raise TempError('DNS: TCP Fallback error: ' + str(x))
if resp.header['rcode'] != 0 and resp.header['rcode'] != 3:
raise IOError('Error: ' + resp.header['status'] + ' RCODE: ' + str(resp.header['rcode']))
return [((a['name'], a['typename']), a['data'])
for a in resp.answers] \
+ [((a['name'], a['typename']), a['data'])
for a in resp.additional]
except AttributeError as x:
raise TempError('DNS ' + str(x))
except IOError as x:
raise TempError('DNS ' + str(x))
except DNS.DNSError as x:
raise TempError('DNS ' + str(x))
RE_SPF = re.compile(br'^v=spf1$|^v=spf1 ',re.IGNORECASE)
# Regular expression to look for modifiers
RE_MODIFIER = re.compile(r'^([a-z][a-z0-9_\-\.]*)=', re.IGNORECASE)
# Regular expression to find macro expansions
PAT_CHAR = r'%(%|_|-|(\{[^\}]*\}))'
RE_CHAR = re.compile(PAT_CHAR)
RE_INVALID_MACRO = re.compile(r'(?<!%)%[^{%_-]|%$')
# Regular expression to break up a macro expansion
RE_ARGS = re.compile(r'([0-9]*)(r?)([^0-9a-zA-Z]*)')
RE_DUAL_CIDR = re.compile(r'//(0|[1-9]\d*)$')
RE_CIDR = re.compile(r'/(0|[1-9]\d*)$')
PAT_IP4 = r'\.'.join([r'(?:\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])']*4)
RE_IP4 = re.compile(PAT_IP4+'$')
RE_TOPLAB = re.compile(
r'\.(?:[0-9a-z]*[a-z][0-9a-z]*|[0-9a-z]+-[0-9a-z-]*[0-9a-z])\.?$|%s'
% PAT_CHAR, re.IGNORECASE)
RE_DOT_ATOM = re.compile(r'%(atext)s+([.]%(atext)s+)*$' % {
'atext': r"[0-9a-z!#$%&'*+/=?^_`{}|~-]" }, re.IGNORECASE)
# Derived from RFC 3986 appendix A
RE_IP6 = re.compile( '(?:%(hex4)s:){6}%(ls32)s$'
'|::(?:%(hex4)s:){5}%(ls32)s$'
'|(?:%(hex4)s)?::(?:%(hex4)s:){4}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,1}%(hex4)s)?::(?:%(hex4)s:){3}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,2}%(hex4)s)?::(?:%(hex4)s:){2}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,3}%(hex4)s)?::%(hex4)s:%(ls32)s$'
'|(?:(?:%(hex4)s:){0,4}%(hex4)s)?::%(ls32)s$'
'|(?:(?:%(hex4)s:){0,5}%(hex4)s)?::%(hex4)s$'
'|(?:(?:%(hex4)s:){0,6}%(hex4)s)?::$'
% {
'ls32': r'(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|%s)'%PAT_IP4,
'hex4': r'[0-9a-f]{1,4}'
}, re.IGNORECASE)
# Local parts and senders have their delimiters replaced with '.' during
# macro expansion
#
JOINERS = {'l': '.', 's': '.'}
RESULTS = {'+': 'pass', '-': 'fail', '?': 'neutral', '~': 'softfail',
'pass': 'pass', 'fail': 'fail', 'permerror': 'permerror',
'error': 'temperror', 'neutral': 'neutral', 'softfail': 'softfail',
'none': 'none', 'local': 'local', 'trusted': 'trusted',
'ambiguous': 'ambiguous', 'unknown': 'permerror' }
EXPLANATIONS = {'pass': 'sender SPF authorized',
'fail': 'SPF fail - not authorized',
'permerror': 'permanent error in processing',
'temperror': 'temporary DNS error in processing',
'softfail': 'domain owner discourages use of this host',
'neutral': 'access neither permitted nor denied',
'none': '',
#Note: The following are not formally SPF results
'local': 'No SPF result due to local policy',
'trusted': 'No SPF check - trusted-forwarder.org',
#Ambiguous only used in harsh mode for SPF validation
'ambiguous': 'No error, but results may vary'
}
DELEGATE = None
# standard default SPF record for best_guess
DEFAULT_SPF = 'v=spf1 a/24 mx/24 ptr'
#Whitelisted forwarders here. Additional locally trusted forwarders can be
#added to this record.
TRUSTED_FORWARDERS = 'v=spf1 ?include:spf.trusted-forwarder.org -all'
# maximum DNS lookups allowed
MAX_LOOKUP = 10 #RFC 4408 Para 10.1/RFC 7208 4.6.4
MAX_MX = 10 #RFC 4408 Para 10.1/RFC 7208 4.6.4
MAX_PTR = 10 #RFC 4408 Para 10.1/RFC 7208 4.6.4
MAX_CNAME = 10 # analogous interpretation to MAX_PTR
MAX_RECURSION = 20
MAX_PER_LOOKUP_TIME = 20 # Per RFC 7208 4.6.4
MAX_VOID_LOOKUPS = 2 # RFC 7208 4.6.4
ALL_MECHANISMS = ('a', 'mx', 'ptr', 'exists', 'include', 'ip4', 'ip6', 'all')
COMMON_MISTAKES = {
'prt': 'ptr', 'ip': 'ip4', 'ipv4': 'ip4', 'ipv6': 'ip6', 'all.': 'all'
}
#If harsh processing, for the validator, is invoked, warn if results
#likely deviate from the publishers intention.
class AmbiguityWarning(Exception):
"SPF Warning - ambiguous results"
def __init__(self, msg, mech=None, ext=None):
Exception.__init__(self, msg, mech)
self.msg = msg
self.mech = mech
self.ext = ext
def __str__(self):
if self.mech:
return '%s: %s' %(self.msg, self.mech)
return self.msg
class TempError(Exception):
"Temporary SPF error"
def __init__(self, msg, mech=None, ext=None):
Exception.__init__(self, msg, mech)
self.msg = str(msg)
self.mech = mech
self.ext = ext
def __str__(self):
if self.mech:
return '%s: %s'%(self.msg, self.mech)
return self.msg
class PermError(Exception):
"Permanent SPF error"
def __init__(self, msg, mech=None, ext=None):
Exception.__init__(self, msg, mech)
self.msg = msg
self.mech = mech
self.ext = ext
def __str__(self):
if self.mech:
return '%s: %s'%(self.msg, self.mech)
return self.msg
def check2(i, s, h, local=None, receiver=None, timeout=MAX_PER_LOOKUP_TIME, verbose=False, querytime=20):
"""Test an incoming MAIL FROM:<s>, from a client with ip address i.
h is the HELO/EHLO domain name. This is the RFC4408/7208 compliant
pySPF2.0 interface. The interface returns an SPF result and explanation
only. SMTP response codes are not returned since neither RFC 4408 nor RFC
7208 does specify receiver policy. Applications updated for RFC 4408 and
RFC 7208 should use this interface. The maximum time, in seconds, this
function is allowed to run before a TempError is returned is controlled by
querytime. When set to 0 the timeout parameter (default 20 seconds)
controls the time allowed for each DNS lookup. When set to a non-zero
value, it total time for all processing related to the SPF check is
limited to querytime (default 20 seconds as recommended in RFC 7208,
paragraph 4.6.4).
Returns (result, explanation) where result in
['pass', 'permerror', 'fail', 'temperror', 'softfail', 'none', 'neutral' ].
Example:
#>>> check2(i='61.51.192.42', s='liukebing@bcc.com', h='bmsi.com')
"""
res,_,exp = query(i=i, s=s, h=h, local=local,
receiver=receiver,timeout=timeout,verbose=verbose,querytime=querytime).check()
return res,exp
def check(i, s, h, local=None, receiver=None, verbose=False):
"""Test an incoming MAIL FROM:<s>, from a client with ip address i.
h is the HELO/EHLO domain name. This is the pre-RFC SPF Classic interface.
Applications written for pySPF 1.6/1.7 can use this interface to allow
pySPF2 to be a drop in replacement for older versions. With the exception
of result codes, performance in RFC 4408 compliant.
Returns (result, code, explanation) where result in
['pass', 'unknown', 'fail', 'error', 'softfail', 'none', 'neutral' ].
Example:
#>>> check(i='61.51.192.42', s='liukebing@bcc.com', h='bmsi.com')
"""
res,code,exp = query(i=i, s=s, h=h, local=local, receiver=receiver,
verbose=verbose).check()
if res == 'permerror':
res = 'unknown'
elif res == 'tempfail':
res =='error'
return res, code, exp
class query(object):
"""A query object keeps the relevant information about a single SPF
query:
i: ip address of SMTP client in dotted notation
s: sender declared in MAIL FROM:<>
l: local part of sender s
d: current domain, initially domain part of sender s
h: EHLO/HELO domain
v: 'in-addr' for IPv4 clients and 'ip6' for IPv6 clients
t: current timestamp
p: SMTP client domain name
o: domain part of sender s
r: receiver
c: pretty ip address (different from i for IPv6)
This is also, by design, the same variables used in SPF macro
expansion.
Also keeps cache: DNS cache.
"""
def __init__(self, i, s, h, local=None, receiver=None, strict=True,
timeout=MAX_PER_LOOKUP_TIME,verbose=False,querytime=0):
self.s, self.h = s, h
if not s and h:
self.s = 'postmaster@' + h
self.ident = 'helo'
else:
self.ident = 'mailfrom'
self.l, self.o = split_email(s, h)
self.t = str(int(time.time()))
self.d = self.o
self.p = None # lazy evaluation
if receiver:
self.r = receiver
else:
self.r = 'unknown'
# Since the cache does not track Time To Live, it is created
# fresh for each query. It is important for efficiently using
# multiple results provided in DNS answers.
self.cache = {}
self.defexps = dict(EXPLANATIONS)
self.exps = dict(EXPLANATIONS)
self.libspf_local = local # local policy
self.lookups = 0
# New processing limit in RFC 7208, section 4.6.4
self.void_lookups = 0
# strict can be False, True, or 2 (numeric) for harsh
self.strict = strict
self.timeout = timeout
self.querytime = querytime # Default to not using a global check
# timelimit since this is an RFC 4408 MAY
if querytime > 0:
self.timeout = querytime
self.timer = 0
self.ipaddr = None
if i:
self.set_ip(i)
# Document bits of the object model not set up here:
# self.i = string, expanded dot notation, suitable for PTR lookups
# self.c = string, human readable form of the connect IP address
# single letter lowercase variable names (e.g. self.i) are used for SPF macros
# For IPv4, self.i = self.c, but not in IPv6
# self.iplist = list of IPv4/6 addresses that would pass, collected
# when list or list6 is passed as 'i'
# self.addr = ipaddr/ipaddress object representing the connect IP
self.default_modifier = True
self.verbose = verbose
self.authserv = None # Only used in A-R header generation tests
def log(self,mech,d,spf):
print('%s: %s "%s"'%(mech,d,spf))
def set_ip(self, i):
"Set connect ip, and ip6 or ip4 mode."
self.iplist = False
if i.lower() == 'list':
self.iplist = []
ip6 = False
elif i.lower() == 'list6':
self.iplist = []
ip6 = True
else:
try:
self.ipaddr = ipaddress.ip_address(i)
except AttributeError:
self.ipaddr = ipaddress.IPAddress(i)
if self.ipaddr.version == 6:
if self.ipaddr.ipv4_mapped:
self.ipaddr = ipaddress.IPv4Address(self.ipaddr.ipv4_mapped)
ip6 = False
else:
ip6 = True
else:
ip6 = False
self.c = str(self.ipaddr)
# NOTE: self.A is not lowercase, so isn't a macro. See query.expand()
if ip6:
self.A = 'AAAA'
self.v = 'ip6'
if self.ipaddr:
self.i = '.'.join(list(self.ipaddr.exploded.replace(':','').upper()))
self.cidrmax = 128
else:
self.A = 'A'
self.v = 'in-addr'
if self.ipaddr:
self.i = self.ipaddr.exploded
self.cidrmax = 32
def set_default_explanation(self, exp):
exps = self.exps
defexps = self.defexps
for i in 'softfail', 'fail', 'permerror':
exps[i] = exp
defexps[i] = exp
def set_explanation(self, exp):
exps = self.exps
for i in 'softfail', 'fail', 'permerror':
exps[i] = exp
# Compute p macro only if needed
def getp(self):
if not self.p:
p = self.validated_ptrs()
if not p:
self.p = "unknown"
elif self.d in p:
self.p = self.d
else:
sfx = '.' + self.d
for d in p:
if d.endswith(sfx):
self.p = d
break
else:
self.p = p[0]
return self.p
def best_guess(self, spf=DEFAULT_SPF):
"""Return a best guess based on a default SPF record.
>>> q = query('1.2.3.4','','SUPERVISION1',receiver='example.com')
>>> q.best_guess()[0]
'none'
"""
if RE_TOPLAB.split(self.d)[-1]:
return ('none', 250, '')
pe = self.perm_error
r,c,e = self.check(spf)
if r == 'permerror': # permerror not useful for bestguess
if self.perm_error and self.perm_error.ext:
r,c,e = self.perm_error.ext
else:
r,c = 'neutral',250
self.perm_error = pe
return r,c,e
def check(self, spf=None):
"""
Returns (result, mta-status-code, explanation) where result
in ['fail', 'softfail', 'neutral' 'permerror', 'pass', 'temperror', 'none']
Examples:
>>> q = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='192.0.2.3')
>>> q.check(spf='v=spf1 ?all')
('neutral', 250, 'access neither permitted nor denied')
>>> q.check(spf='v=spf1 redirect=controlledmail.com exp=_exp.controlledmail.com')
('fail', 550, 'SPF fail - not authorized')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ?all moo')
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.check(spf='v=spf1 =a ?all moo')
('permerror', 550, 'SPF Permanent Error: Unknown qualifier, RFC 4408 para 4.6.1, found in: =a')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ~all')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all moo=')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all match.sub-domains_9=yes')
('pass', 250, 'sender SPF authorized')
>>> q.strict = False
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all moo')
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.perm_error.ext
('pass', 250, 'sender SPF authorized')
>>> q.strict = True
>>> q.check(spf='v=spf1 ip4:192.1.0.0/16 moo -all')
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.check(spf='v=spf1 ip4:192.1.0.0/16 ~all')
('softfail', 250, 'domain owner discourages use of this host')
>>> q.check(spf='v=spf1 -ip4:192.1.0.0/6 ~all')
('fail', 550, 'SPF fail - not authorized')
# Assumes DNS available
>>> q.check()
('none', 250, '')
>>> q.check(spf='v=spf1 ip4:1.2.3.4 -a:example.net -all')
('fail', 550, 'SPF fail - not authorized')
>>> q.libspf_local='ip4:192.0.2.3 a:example.org'
>>> q.check(spf='v=spf1 ip4:1.2.3.4 -a:example.net -all')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:1.2.3.4 -all exp=_exp.controlledmail.com')
('fail', 550, 'Controlledmail.com does not send mail from itself.')
>>> q.check(spf='v=spf1 ip4:1.2.3.4 ?all exp=_exp.controlledmail.com')
('neutral', 250, 'access neither permitted nor denied')
"""
self.mech = [] # unknown mechanisms
# If not strict, certain PermErrors (mispelled
# mechanisms, strict processing limits exceeded)
# will continue processing. However, the exception
# that strict processing would raise is saved here
self.perm_error = None
self.mechanism = None
self.void_lookups = 0
self.options = {}
try:
self.lookups = 0
if not spf:
spf = self.dns_spf(self.d)
if self.verbose: self.log("top",self.d,spf)
if self.libspf_local and spf:
spf = insert_libspf_local_policy(
spf, self.libspf_local)
rc = self.check1(spf, self.d, 0)
if self.perm_error:
# lax processing encountered a permerror, but continued
self.perm_error.ext = rc
raise self.perm_error
return rc
except TempError as x:
self.prob = x.msg
if x.mech:
self.mech.append(x.mech)
return ('temperror', 451, 'SPF Temporary Error: ' + str(x))
except PermError as x:
if not self.perm_error:
self.perm_error = x
self.prob = x.msg
if x.mech:
self.mech.append(x.mech)
# Pre-Lentczner draft treats this as an unknown result
# and equivalent to no SPF record.
return ('permerror', 550, 'SPF Permanent Error: ' + str(x))
def check1(self, spf, domain, recursion):
# spf rfc: 3.7 Processing Limits
#
if recursion > MAX_RECURSION:
# This should never happen in strict mode
# because of the other limits we check,
# so if it does, there is something wrong with
# our code. It is not a PermError because there is not
# necessarily anything wrong with the SPF record.
if self.strict:
raise AssertionError('Too many levels of recursion')
# As an extended result, however, it should be
# a PermError.
raise PermError('Too many levels of recursion')
try:
try:
tmp, self.d = self.d, domain
return self.check0(spf, recursion)
finally:
self.d = tmp
except AmbiguityWarning as x:
self.prob = x.msg
if x.mech:
self.mech.append(x.mech)
return ('ambiguous', 000, 'SPF Ambiguity Warning: %s' % x)
def note_error(self, *msg):
if self.strict:
raise PermError(*msg)
# if lax mode, note error and continue
if not self.perm_error:
try:
raise PermError(*msg)
except PermError as x:
# FIXME: keep a list of errors for even friendlier diagnostics.
self.perm_error = x
return self.perm_error
def expand_domain(self,arg):
"validate and expand domain-spec"
# any trailing dot was removed by expand()
if RE_TOPLAB.split(arg)[-1]:
raise PermError('Invalid domain found (use FQDN)', arg)
return self.expand(arg)
def validate_mechanism(self, mech):
"""Parse and validate a mechanism.
Returns mech,m,arg,cidrlength,result
Examples:
>>> q = query(s='strong-bad@email.example.com.',
... h='mx.example.org', i='192.0.2.3')
>>> q.validate_mechanism('A')
('A', 'a', 'email.example.com', 32, 'pass')
>>> q = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='192.0.2.3')
>>> q.validate_mechanism('A//64')
('A//64', 'a', 'email.example.com', 32, 'pass')
>>> q.validate_mechanism('A/24//64')
('A/24//64', 'a', 'email.example.com', 24, 'pass')
>>> q.validate_mechanism('?mx:%{d}/27')
('?mx:%{d}/27', 'mx', 'email.example.com', 27, 'neutral')
>>> try: q.validate_mechanism('ip4:1.2.3.4/247')
... except PermError as x: print(x)
Invalid IP4 CIDR length: ip4:1.2.3.4/247
>>> try: q.validate_mechanism('ip4:1.2.3.4/33')
... except PermError as x: print(x)
Invalid IP4 CIDR length: ip4:1.2.3.4/33
>>> try: q.validate_mechanism('a:example.com:8080')
... except PermError as x: print(x)
Invalid domain found (use FQDN): example.com:8080
>>> try: q.validate_mechanism('ip4:1.2.3.444/24')
... except PermError as x: print(x)
Invalid IP4 address: ip4:1.2.3.444/24
>>> try: q.validate_mechanism('ip4:1.2.03.4/24')
... except PermError as x: print(x)
Invalid IP4 address: ip4:1.2.03.4/24
>>> try: q.validate_mechanism('-all:3030')
... except PermError as x: print(x)
Invalid all mechanism format - only qualifier allowed with all: -all:3030
>>> q.validate_mechanism('-mx:%%%_/.Clara.de/27')
('-mx:%%%_/.Clara.de/27', 'mx', '% /.Clara.de', 27, 'fail')
>>> q.validate_mechanism('~exists:%{i}.%{s1}.100/86400.rate.%{d}')
('~exists:%{i}.%{s1}.100/86400.rate.%{d}', 'exists', '192.0.2.3.com.100/86400.rate.email.example.com', 32, 'softfail')
>>> q.validate_mechanism('a:mail.example.com.')
('a:mail.example.com.', 'a', 'mail.example.com', 32, 'pass')
>>> try: q.validate_mechanism('a:mail.example.com,')
... except PermError as x: print(x)
Do not separate mechnisms with commas: a:mail.example.com,
>>> q = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='2001:db8:1234::face:b007')
>>> q.validate_mechanism('A//64')
('A//64', 'a', 'email.example.com', 64, 'pass')
>>> q.validate_mechanism('A/16')
('A/16', 'a', 'email.example.com', 128, 'pass')
>>> q.validate_mechanism('A/16//48')
('A/16//48', 'a', 'email.example.com', 48, 'pass')
"""
if mech.endswith( "," ):
self.note_error('Do not separate mechnisms with commas', mech)
mech = mech[:-1]
# a mechanism
m, arg, cidrlength, cidr6length = parse_mechanism(mech, self.d)
# map '?' '+' or '-' to 'neutral' 'pass' or 'fail'
if m:
result = RESULTS.get(m[0])
if result:
# eat '?' '+' or '-'
m = m[1:]
else:
# default pass
result = 'pass'
if m in COMMON_MISTAKES:
self.note_error('Unknown mechanism found', mech)
m = COMMON_MISTAKES[m]
if m == 'a' and RE_IP4.match(arg):
x = self.note_error(
'Use the ip4 mechanism for ip4 addresses', mech)
m = 'ip4'
# validate cidr and dual-cidr
if m in ('a', 'mx'):
if cidrlength is None:
cidrlength = 32;
elif cidrlength > 32:
raise PermError('Invalid IP4 CIDR length', mech)
if cidr6length is None:
cidr6length = 128
elif cidr6length > 128:
raise PermError('Invalid IP6 CIDR length', mech)
if self.v == 'ip6':
cidrlength = cidr6length
elif m == 'ip4' or RE_IP4.match(m):
if m != 'ip4':
self.note_error( 'Missing IP4' , mech)
m,arg = 'ip4',m
if cidr6length is not None:
raise PermError('Dual CIDR not allowed', mech)
if cidrlength is None:
cidrlength = 32;
elif cidrlength > 32:
raise PermError('Invalid IP4 CIDR length', mech)
if not RE_IP4.match(arg):
raise PermError('Invalid IP4 address', mech)
elif m == 'ip6':
if cidr6length is not None:
raise PermError('Dual CIDR not allowed', mech)
if cidrlength is None:
cidrlength = 128
elif cidrlength > 128:
raise PermError('Invalid IP6 CIDR length', mech)
if not RE_IP6.match(arg):
raise PermError('Invalid IP6 address', mech)
else:
if cidrlength is not None or cidr6length is not None:
if m in ALL_MECHANISMS:
raise PermError('CIDR not allowed', mech)
cidrlength = self.cidrmax
if m in ('a', 'mx', 'ptr', 'exists', 'include'):
if m == 'exists' and not arg:
raise PermError('implicit exists not allowed', mech)
arg = self.expand_domain(arg)
if not arg:
raise PermError('empty domain:',mech)
if m == 'include':
if arg == self.d:
if mech != 'include':
raise PermError('include has trivial recursion', mech)
raise PermError('include mechanism missing domain', mech)
return mech, m, arg, cidrlength, result
# validate 'all' mechanism per RFC 4408 ABNF
if m == 'all' and mech.count(':'):
# print '|'+ arg + '|', mech, self.d,
self.note_error(
'Invalid all mechanism format - only qualifier allowed with all'
, mech)
if m in ALL_MECHANISMS:
return mech, m, arg, cidrlength, result
if m[1:] in ALL_MECHANISMS:
x = self.note_error(
'Unknown qualifier, RFC 4408 para 4.6.1, found in', mech)
else:
x = self.note_error('Unknown mechanism found', mech)
return mech, m, arg, cidrlength, x
def check0(self, spf, recursion):
"""Test this query information against SPF text.
Returns (result, mta-status-code, explanation) where
result in ['fail', 'unknown', 'pass', 'none']
"""
if not spf:
return ('none', 250, EXPLANATIONS['none'])
# Split string by space, drop the 'v=spf1'. Split by all whitespace
# casuses things like carriage returns being treated as valid space
# separators, so split() is not sufficient.
spf = spf.split(' ')
# Catch case where SPF record has no spaces.
# Can never happen with conforming dns_spf(), however
# in the future we might want to give warnings
# for common mistakes like IN TXT "v=spf1" "mx" "-all"
# in relaxed mode.
if spf[0].lower() != 'v=spf1':
if self.strict > 1:
raise AmbiguityWarning('Invalid SPF record in', self.d)
return ('none', 250, EXPLANATIONS['none'])
# Just to make it even more fun, the relevant piece of the ABNF for
# term separations is *( 1*SP ( directive / modifier ) ), so it's one
# or more spaces, not just one. So strip empty mechanisms.
spf = [mech for mech in spf[1:] if mech]
# copy of explanations to be modified by exp=
exps = self.exps
redirect = None
# no mechanisms at all cause unknown result, unless
# overridden with 'default=' modifier
#
default = 'neutral'
mechs = []
modifiers = []
# Look for modifiers
#
for mech in spf:
m = RE_MODIFIER.split(mech)[1:]
if len(m) != 2:
mechs.append(self.validate_mechanism(mech))
continue
mod,arg = m
if mod in modifiers:
if mod == 'redirect':
raise PermError('redirect= MUST appear at most once',mech)
self.note_error('%s= MUST appear at most once'%mod,mech)
# just use last one in lax mode
modifiers.append(mod)
if mod == 'exp':
# always fetch explanation to check permerrors
if not arg:
raise PermError('exp has empty domain-spec:',arg)
arg = self.expand_domain(arg)
if arg:
try:
exp = self.get_explanation(arg)
if exp and not recursion:
# only set explanation in base recursion level
self.set_explanation(exp)
except: pass
elif mod == 'redirect':
self.check_lookups()
redirect = self.expand_domain(arg)
if not redirect:
raise PermError('redirect has empty domain:',arg)
elif mod == 'default':
# default modifier is obsolete
if self.strict > 1:
raise AmbiguityWarning('The default= modifier is obsolete.')
if not self.strict and self.default_modifier:
# might be an old policy, so do it anyway
arg = self.expand(arg)
# default=- is the same as default=fail
default = RESULTS.get(arg, default)
elif mod == 'op':
if not recursion:
for v in arg.split('.'):
if v: self.options[v] = True
else:
# spf rfc: 3.6 Unrecognized Mechanisms and Modifiers
self.expand(m[1]) # syntax error on invalid macro
# Evaluate mechanisms
#
for mech, m, arg, cidrlength, result in mechs:
if m == 'include':
self.check_lookups()
d = self.dns_spf(arg)
if self.verbose: self.log("include",arg,d)
res, code, txt = self.check1(d,arg, recursion + 1)
if res == 'pass':
break
if res == 'none':
self.note_error(
'No valid SPF record for included domain: %s' %arg,
mech)
res = 'neutral'
continue
elif m == 'all':
break
elif m == 'exists':
self.check_lookups()
try:
if len(self.dns_a(arg,'A')) > 0:
break
except AmbiguityWarning:
# Exists wants no response sometimes so don't raise
# the warning.
pass
elif m == 'a':
self.check_lookups()
if self.cidrmatch(self.dns_a(arg,self.A), cidrlength):
break
elif m == 'mx':
self.check_lookups()
if self.cidrmatch(self.dns_mx(arg), cidrlength):
break
elif m == 'ip4':
if self.v == 'in-addr': # match own connection type only
try:
if self.cidrmatch([arg], cidrlength): break
except socket.error:
raise PermError('syntax error', mech)
elif m == 'ip6':
if self.v == 'ip6': # match own connection type only
try:
if self.cidrmatch([arg], cidrlength): break
except socket.error:
raise PermError('syntax error', mech)
elif m == 'ptr':
self.check_lookups()
if domainmatch(self.validated_ptrs(), arg):
break
else:
# no matches
if redirect:
#Catch redirect to a non-existant SPF record.
redirect_record = self.dns_spf(redirect)
if not redirect_record:
raise PermError('redirect domain has no SPF record',
redirect)
if self.verbose: self.log("redirect",redirect,redirect_record)
# forget modifiers on redirect
if not recursion:
self.exps = dict(self.defexps)
self.options = {}
return self.check1(redirect_record, redirect, recursion)
result = default
mech = None
if not recursion: # record matching mechanism at base level
self.mechanism = mech
if result == 'fail':
return (result, 550, exps[result])
else:
return (result, 250, exps[result])
def check_lookups(self):
self.lookups = self.lookups + 1
if self.lookups > MAX_LOOKUP*4:
raise PermError('More than %d DNS lookups'%(MAX_LOOKUP*4))
if self.lookups > MAX_LOOKUP:
self.note_error('Too many DNS lookups')
def get_explanation(self, spec):
"""Expand an explanation."""
if spec:
try:
a = self.dns_txt(spec,ignore_void=True)
if len(a) == 1:
return str(self.expand(to_ascii(a[0]), stripdot=False))
except PermError:
# RFC4408 6.2/4 syntax errors cause exp= to be ignored
if self.strict > 1:
raise # but report in harsh mode for record checking tools
pass
elif self.strict > 1:
raise PermError('Empty domain-spec on exp=')
# RFC4408 6.2/4 empty domain spec is ignored
# (unless you give precedence to the grammar).
return None
def expand(self, s, stripdot=True): # macros='slodipvh'
"""Do SPF RFC macro expansion.
Examples:
>>> q = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='192.0.2.3')
>>> q.p = 'mx.example.org'
>>> q.r = 'example.net'
>>> q.expand('%{d}')
'email.example.com'
>>> q.expand('%{d4}')
'email.example.com'
>>> q.expand('%{d3}')
'email.example.com'
>>> q.expand('%{d2}')
'example.com'
>>> q.expand('%{d1}')
'com'
>>> q.expand('%{p}')
'mx.example.org'
>>> q.expand('%{p2}')
'example.org'
>>> q.expand('%{dr}')
'com.example.email'
>>> q.expand('%{d2r}')
'example.email'
>>> q.expand('%{l}')
'strong-bad'
>>> q.expand('%{l-}')
'strong.bad'
>>> q.expand('%{lr}')
'strong-bad'
>>> q.expand('%{lr-}')
'bad.strong'
>>> q.expand('%{l1r-}')
'strong'
>>> q.expand('%{c}',stripdot=False)
'192.0.2.3'
>>> q.expand('%{r}',stripdot=False)
'example.net'
>>> q.expand('%{ir}.%{v}._spf.%{d2}')
'3.2.0.192.in-addr._spf.example.com'
>>> q.expand('%{lr-}.lp._spf.%{d2}')
'bad.strong.lp._spf.example.com'
>>> q.expand('%{lr-}.lp.%{ir}.%{v}._spf.%{d2}')
'bad.strong.lp.3.2.0.192.in-addr._spf.example.com'
>>> q.expand('%{ir}.%{v}.%{l1r-}.lp._spf.%{d2}')
'3.2.0.192.in-addr.strong.lp._spf.example.com'
>>> try: q.expand('%(ir).%{v}.%{l1r-}.lp._spf.%{d2}')
... except PermError as x: print(x)
invalid-macro-char : %(ir)
>>> q.expand('%{p2}.trusted-domains.example.net')
'example.org.trusted-domains.example.net'
>>> q.expand('%{p2}.trusted-domains.example.net.')
'example.org.trusted-domains.example.net'
>>> q = query(s='@email.example.com',
... h='mx.example.org', i='192.0.2.3')
>>> q.p = 'mx.example.org'
>>> q.expand('%{l}')
'postmaster'
"""
# Check for invalid macro syntax
if s.find('%') >= 0:
regex = RE_INVALID_MACRO
for label in s.split('.'):
if regex.search(s):
raise PermError ('invalid-macro-char ', label)
# expand macros
end = 0
result = ''
for i in RE_CHAR.finditer(s):
result += s[end:i.start()]
macro = s[i.start():i.end()]
if macro == '%%':
result += '%'
elif macro == '%_':
result += ' '
elif macro == '%-':
result += '%20'
else:
letter = macro[2].lower()
# print letter
if letter == 'p':
self.getp()
elif letter in 'crt' and stripdot:
raise PermError(
'c,r,t macros allowed in exp= text only', macro)
expansion = getattr(self, letter, self)
if expansion:
if expansion == self:
raise PermError('Unknown Macro Encountered', macro)
e = expand_one(expansion, macro[3:-1], JOINERS.get(letter))
if letter != macro[2]:
e = urllibparse.quote(e,'~')
result += e
end = i.end()
result += s[end:]
if stripdot and result.endswith('.'):
result = result[:-1]
if result.count('.') != 0:
if len(result) > 253:
result = result[(result.index('.')+1):]
return result
def dns_spf(self, domain):
"""Get the SPF record recorded in DNS for a specific domain
name. Returns None if not found, or if more than one record
is found.
"""
# Per RFC 4.3/1, check for malformed domain. This produces
# no results as a special case.
for label in domain.split('.'):
if not label or len(label) > 63:
return None
# for performance, check for most common case of TXT first
a = [t for t in self.dns_txt(domain) if RE_SPF.match(t)]
if len(a) > 1:
raise PermError('Two or more type TXT spf records found.')
if len(a) == 1 and self.strict < 2:
return to_ascii(a[0])
# check official SPF type first when it becomes more popular
if self.strict > 1:
#Only check for Type SPF in harsh mode until it is more popular.
try:
b = [t for t in self.dns_txt(domain,'SPF',ignore_void=True)
if RE_SPF.match(t)]
except TempError as x:
# some braindead DNS servers hang on type 99 query
if self.strict > 1: raise TempError(x)
b = []
if len(b) > 1:
raise PermError('Two or more type SPF spf records found.')
if len(b) == 1:
if self.strict > 1 and len(a) == 1 and a[0] != b[0]:
#Changed from permerror to warning based on RFC 4408 Auth 48 change
raise AmbiguityWarning(
'v=spf1 records of both type TXT and SPF (type 99) present, but not identical')
return to_ascii(b[0])
if len(a) == 1:
return to_ascii(a[0]) # return TXT if SPF wasn't found
if DELEGATE: # use local record if neither found
a = [t
for t in self.dns_txt(domain+'._spf.'+DELEGATE,ignore_void=True)
if RE_SPF.match(t)
]
if len(a) == 1: return to_ascii(a[0])
return None
## Get list of TXT records for a domain name.
# Any DNS library *must* return bytes (same as str in python2) for TXT
# or SPF since there is no general decoding to unicode. Py3dns-3.0.2
# incorrectly attempts to convert to str using idna encoding by default.
# We work around this by assuming any UnicodeErrors coming from py3dns
# are from a non-ascii SPF record (incorrect in general). Packages
# should require py3dns != 3.0.2.
#
# We cannot check for non-ascii here, because we must ignore non-SPF
# records - even when they are non-ascii. So we return bytes.
# The caller does the ascii check for SPF records and explanations.
#
def dns_txt(self, domainname, rr='TXT',ignore_void=False):
"Get a list of TXT records for a domain name."
if domainname:
try:
dns_list = self.dns(domainname, rr,ignore_void=ignore_void)
if dns_list:
# a[0][:0] is '' for py3dns-3.0.2, otherwise b''
a = [a[0][:0].join(a) for a in dns_list if a]
# FIXME: workaround for error in py3dns-3.0.2
if isinstance(a[0],bytes):
return a
return [s.encode('utf-8') for s in a]
# FIXME: workaround for error in py3dns-3.0.2
except UnicodeError:
raise PermError('Non-ascii characters found in %s record for %s'
%(rr,domainname))
return []
def dns_mx(self, domainname):
"""Get a list of IP addresses for all MX exchanges for a
domain name.
"""
# RFC 4408/7208 section 5.4 "mx"
# To prevent DoS attacks, more than 10 MX names MUST NOT be looked up
# Changed to permerror if more than 10 exist in 7208
mxnames = self.dns(domainname, 'MX')
if self.strict:
max = MAX_MX
if len(mxnames) > MAX_MX:
raise PermError(
'More than %d MX records returned'%MAX_MX)
if self.strict > 1:
if len(mxnames) == 0:
raise AmbiguityWarning(
'No MX records found for mx mechanism', domainname)
else:
max = MAX_MX * 4
mxnames.sort()
return [a for mx in mxnames[:max] for a in self.dns_a(mx[1],self.A)]
def dns_a(self, domainname, A='A'):
"""Get a list of IP addresses for a domainname.
"""
if not domainname: return []
r = self.dns(domainname, A)
if self.strict > 1 and len(r) == 0:
raise AmbiguityWarning(
'No %s records found for'%A, domainname)
if A == 'AAAA' and bytes is str:
# work around pydns inconsistency plus python2 bytes/str ambiguity
return [Bytes(ip) for ip in r]
return r
def validated_ptrs(self):
"""Figure out the validated PTR domain names for the connect IP."""
# To prevent DoS attacks, more than 10 PTR names MUST NOT be looked up
if self.strict:
max = MAX_PTR
if self.strict > 1:
#Break out the number of PTR records returned for testing
try:
ptrnames = self.dns_ptr(self.i)
if len(ptrnames) > max:
warning = 'More than %d PTR records returned' % max
raise AmbiguityWarning(warning, self.c)
else:
if len(ptrnames) == 0:
raise AmbiguityWarning(
'No PTR records found for ptr mechanism', self.c)
except:
raise AmbiguityWarning(
'No PTR records found for ptr mechanism', self.c)
else:
max = MAX_PTR * 4
cidrlength = self.cidrmax
return [p for p in self.dns_ptr(self.i)[:max]
if self.cidrmatch(self.dns_a(p,self.A),cidrlength)]
def dns_ptr(self, i):
"""Get a list of domain names for an IP address."""
return self.dns('%s.%s.arpa'%(reverse_dots(i),self.v), 'PTR')
# We have to be careful which additional DNS RRs we cache. For
# instance, PTR records are controlled by the connecting IP, and they
# could poison our local cache with bogus A and MX records.
SAFE2CACHE = {
('MX','A'): None,
('MX','MX'): None,
('CNAME','A'): None,
('A','A'): None,
('AAAA','AAAA'): None,
('PTR','PTR'): None,
('TXT','TXT'): None,
('SPF','SPF'): None
}
# FIXME: move to dnsplug
def dns(self, name, qtype, cnames=None, ignore_void=False):
"""DNS query.
If the result is in cache, return that. Otherwise pull the
result from DNS, and cache ALL answers, so additional info
is available for further queries later.
CNAMEs are followed.
If there is no data, [] is returned.
pre: qtype in ['A', 'AAAA', 'MX', 'PTR', 'TXT', 'SPF']
post: isinstance(__return__, types.ListType)
"""
if name.endswith('.'): name = name[:-1]
if not reduce(lambda x,y:x and 0 < len(y) < 64, name.split('.'),True):
return [] # invalid DNS name (too long or empty)
name = name.lower()
result = self.cache.get( (name, qtype), [])
if result: return result
cnamek = (name,'CNAME')
cname = self.cache.get( cnamek )
if cname:
cname = cname[0]
else:
safe2cache = query.SAFE2CACHE
if self.querytime < 0:
raise TempError('DNS Error: exceeded max query lookup time')
if self.querytime < self.timeout and self.querytime > 0:
timeout = self.querytime
else:
timeout = self.timeout
timethen = time.time()
for k, v in DNSLookup(name, qtype, self.strict, timeout):
# Force case insensitivity in cache, DNS servers often
# return random case in domain part of answers.
k = (k[0].lower(), k[1])
if k == cnamek:
cname = v
if k[1] == 'CNAME' or (qtype,k[1]) in safe2cache:
self.cache.setdefault(k, []).append(v)
#if ans and qtype == k[1]:
# self.cache.setdefault((name,qtype), []).append(v)
result = self.cache.get( (name, qtype), [])
if self.querytime > 0:
self.querytime = self.querytime - (time.time()-timethen)
if not result and cname:
if not cnames:
cnames = {}
elif len(cnames) >= MAX_CNAME:
#return result # if too many == NX_DOMAIN
raise PermError('Length of CNAME chain exceeds %d' % MAX_CNAME)
cnames[name] = cname
if cname.lower().rstrip('.') in cnames:
if self.strict > 1: raise AmbiguityWarning('CNAME loop', cname)
else:
result = self.dns(cname, qtype, cnames=cnames)
if result:
self.cache[(name,qtype)] = result
if not result and not ignore_void:
self.void_lookups += 1
if self.void_lookups > MAX_VOID_LOOKUPS:
raise PermError('Void lookup limit of %d exceeded' % MAX_VOID_LOOKUPS)
return result
def cidrmatch(self, ipaddrs, n):
"""Match connect IP against a CIDR network of other IP addresses.
Examples:
>>> c = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='192.0.2.3')
>>> c.p = 'mx.example.org'
>>> c.r = 'example.com'
>>> c.cidrmatch(['192.0.2.3'],32)
True
>>> c.cidrmatch(['192.0.2.2'],32)
False
>>> c.cidrmatch(['192.0.2.2'],31)
True
>>> six = query(s='strong-bad@email.example.com',
... h='mx.example.org', i='2001:0db8:0:0:0:0:0:0001')
>>> six.p = 'mx.example.org'
>>> six.r = 'example.com'
>>> six.cidrmatch(['2001:0DB8::'],127)
True
>>> six.cidrmatch(['2001:0DB8::'],128)
False
>>> six.cidrmatch(['2001:0DB8:0:0:0:0:0:0001'],128)
True
"""
try:
for netwrk in [ipaddress.ip_network(ip) for ip in ipaddrs]:
network = netwrk.supernet(new_prefix=n)
if isinstance(self.iplist, bool):
if network.__contains__(self.ipaddr):
return True
else:
if n < self.cidrmax:
self.iplist.append(network)
else:
self.iplist.append(network.ip)
except AttributeError:
for netwrk in [ipaddress.IPNetwork(ip,strict=False) for ip in ipaddrs]:
network = netwrk.supernet(new_prefix=n)
if isinstance(self.iplist, bool):
if network.__contains__(self.ipaddr):
return True
else:
if n < self.cidrmax:
self.iplist.append(network)
else:
self.iplist.append(network.ip)
return False
def parse_header_ar(self, val):
"""Set SPF values from RFC 5451 Authentication Results header.
Useful when SPF has already been run on a trusted gateway machine.
Expects the entire header as an input.
Examples:
>>> q = query('192.0.2.3','strong-bad@email.example.com','mx.example.org')
>>> q.mechanism = 'unknown'
>>> p = q.parse_header_ar('''Authentication-Results: bmsi.com; spf=neutral \\n (abuse@kitterman.com: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) \\n smtp.mailfrom=email.example.com \\n (sender=strong-bad@email.example.com; helo=mx.example.org; client-ip=192.0.2.3; receiver=abuse@kitterman.com; mechanism=?all)''')
>>> q.get_header(q.result, header_type='authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=neutral (unknown: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) smtp.mailfrom=email.example.com (sender=email.example.com; helo=mx.example.org; client-ip=192.0.2.3; receiver=unknown; mechanism=unknown)'
>>> p = q.parse_header_ar('''Authentication-Results: bmsi.com; spf=None (mail.bmsi.com: test; client-ip=163.247.46.150) smtp.mailfrom=admin@squiebras.cl (helo=mail.squiebras.cl; receiver=mail.bmsi.com;\\n mechanism=mx/24)''')
>>> q.get_header(q.result, header_type='authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=none (unknown: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) smtp.mailfrom=admin@squiebras.cl (sender=admin@squiebras.cl; helo=mx.example.org; client-ip=192.0.2.3; receiver=unknown; mechanism=unknown)'
"""
import authres
# Authres expects unwrapped headers according to docs
val = ' '.join(s.strip() for s in val.split('\n'))
arobj = authres.AuthenticationResultsHeader.parse(val)
# TODO extract and parse comments (not supported by authres)
for resobj in arobj.results:
if resobj.method == 'spf':
self.authserv = arobj.authserv_id
self.result = resobj.result
if resobj.properties[0].name == 'mailfrom':
self.d = resobj.properties[0].value
self.s = resobj.properties[0].value
if resobj.properties[0].name == 'helo':
self.h = resobj.properties[0].value
return
def parse_header_spf(self, val):
"""Set SPF values from Received-SPF header.
Useful when SPF has already been run on a trusted gateway machine.
Examples:
>>> q = query('0.0.0.0','','')
>>> p = q.parse_header_spf('''Pass (test) client-ip=70.98.79.77;
... envelope-from="evelyn@subjectsthum.com"; helo=mail.subjectsthum.com;
... receiver=mail.bmsi.com; mechanism=a; identity=mailfrom''')
>>> q.get_header(q.result)
'Pass (test) client-ip=70.98.79.77; envelope-from="evelyn@subjectsthum.com"; helo=mail.subjectsthum.com; receiver=mail.bmsi.com; mechanism=a; identity=mailfrom'
>>> o = q.parse_header_spf('''None (mail.bmsi.com: test)
... client-ip=163.247.46.150; envelope-from="admin@squiebras.cl";
... helo=mail.squiebras.cl; receiver=mail.bmsi.com; mechanism=mx/24;
... x-bestguess=pass; x-helo-spf=neutral; identity=mailfrom''')
>>> q.get_header(q.result,**o)
'None (mail.bmsi.com: test) client-ip=163.247.46.150; envelope-from="admin@squiebras.cl"; helo=mail.squiebras.cl; receiver=mail.bmsi.com; mechanism=mx/24; x-bestguess=pass; x-helo-spf=neutral; identity=mailfrom'
>>> o['bestguess']
'pass'
"""
a = val.split(None,1)
self.result = a[0].lower()
self.mechanism = None
if len(a) < 2: return 'none'
val = a[1]
if val.startswith('('):
pos = val.find(')')
if pos < 0: return self.result
self.comment = val[1:pos]
val = val[pos+1:]
msg = Message()
msg.add_header('Received-SPF','; '+val)
p = {}
for k,v in msg.get_params(header='Received-SPF'):
if k == 'client-ip':
self.set_ip(v)
elif k == 'envelope-from': self.s = v
elif k == 'helo': self.h = v
elif k == 'receiver': self.r = v
elif k == 'problem': self.mech = v
elif k == 'mechanism': self.mechanism = v
elif k == 'identity': self.ident = v
elif k.startswith('x-'): p[k[2:]] = v
self.l, self.o = split_email(self.s, self.h)
return p
def parse_header(self, val):
"""Set SPF values from Received-SPF or RFC 5451 Authentication Results header.
Useful when SPF has already been run on a trusted gateway machine. Auto
detects the header type and parses it. Use parse_header_spf or parse_header_ar
for each type if required.
Examples:
>>> q = query('0.0.0.0','','')
>>> p = q.parse_header('''Pass (test) client-ip=70.98.79.77;
... envelope-from="evelyn@subjectsthum.com"; helo=mail.subjectsthum.com;
... receiver=mail.bmsi.com; mechanism=a; identity=mailfrom''')
>>> q.get_header(q.result)
'Pass (test) client-ip=70.98.79.77; envelope-from="evelyn@subjectsthum.com"; helo=mail.subjectsthum.com; receiver=mail.bmsi.com; mechanism=a; identity=mailfrom'
>>> r = q.parse_header('''None (mail.bmsi.com: test)
... client-ip=163.247.46.150; envelope-from="admin@squiebras.cl";
... helo=mail.squiebras.cl; receiver=mail.bmsi.com; mechanism=mx/24;
... x-bestguess=pass; x-helo-spf=neutral; identity=mailfrom''')
>>> q.get_header(q.result,**r)
'None (mail.bmsi.com: test) client-ip=163.247.46.150; envelope-from="admin@squiebras.cl"; helo=mail.squiebras.cl; receiver=mail.bmsi.com; mechanism=mx/24; x-bestguess=pass; x-helo-spf=neutral; identity=mailfrom'
>>> r['bestguess']
'pass'
>>> q = query('192.0.2.3','strong-bad@email.example.com','mx.example.org')
>>> q.mechanism = 'unknown'
>>> p = q.parse_header_ar('''Authentication-Results: bmsi.com; spf=neutral \\n (abuse@kitterman.com: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) \\n smtp.mailfrom=email.example.com \\n (sender=strong-bad@email.example.com; helo=mx.example.org; client-ip=192.0.2.3; receiver=abuse@kitterman.com; mechanism=?all)''')
>>> q.get_header(q.result, header_type='authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=neutral (unknown: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) smtp.mailfrom=email.example.com (sender=email.example.com; helo=mx.example.org; client-ip=192.0.2.3; receiver=unknown; mechanism=unknown)'
>>> p = q.parse_header_ar('''Authentication-Results: bmsi.com; spf=None (mail.bmsi.com: test; client-ip=163.247.46.150) smtp.mailfrom=admin@squiebras.cl (helo=mail.squiebras.cl; receiver=mail.bmsi.com; mechanism=mx/24)''')
>>> q.get_header(q.result, header_type='authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=none (unknown: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) smtp.mailfrom=admin@squiebras.cl (sender=admin@squiebras.cl; helo=mx.example.org; client-ip=192.0.2.3; receiver=unknown; mechanism=unknown)'
"""
if val.startswith('Authentication-Results:'):
return(self.parse_header_ar(val))
else:
return(self.parse_header_spf(val))
def get_header(self, res, receiver=None, header_type='spf', aid=None, **kv):
"""
Generate Received-SPF or Authentication Results header based on the
last lookup.
>>> q = query(s='strong-bad@email.example.com', h='mx.example.org',
... i='192.0.2.3')
>>> q.r='abuse@kitterman.com'
>>> q.check(spf='v=spf1 ?all')
('neutral', 250, 'access neither permitted nor denied')
>>> q.get_header('neutral')
'Neutral (abuse@kitterman.com: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) client-ip=192.0.2.3; envelope-from="strong-bad@email.example.com"; helo=mx.example.org; receiver=abuse@kitterman.com; mechanism=?all; identity=mailfrom'
>>> q.check(spf='v=spf1 redirect=controlledmail.com exp=_exp.controlledmail.com')
('fail', 550, 'SPF fail - not authorized')
>>> q.get_header('fail')
'Fail (abuse@kitterman.com: domain of email.example.com does not designate 192.0.2.3 as permitted sender) client-ip=192.0.2.3; envelope-from="strong-bad@email.example.com"; helo=mx.example.org; receiver=abuse@kitterman.com; mechanism=-all; identity=mailfrom'
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ?all moo')
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.get_header('permerror')
'PermError (abuse@kitterman.com: permanent error in processing domain of email.example.com: Unknown mechanism found) client-ip=192.0.2.3; envelope-from="strong-bad@email.example.com"; helo=mx.example.org; receiver=abuse@kitterman.com; problem=moo; identity=mailfrom'
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ~all')
('pass', 250, 'sender SPF authorized')
>>> q.get_header('pass')
'Pass (abuse@kitterman.com: domain of email.example.com designates 192.0.2.3 as permitted sender) client-ip=192.0.2.3; envelope-from="strong-bad@email.example.com"; helo=mx.example.org; receiver=abuse@kitterman.com; mechanism="ip4:192.0.0.0/8"; identity=mailfrom'
>>> q.check(spf='v=spf1 ?all')
('neutral', 250, 'access neither permitted nor denied')
>>> q.get_header('neutral', header_type = 'authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=neutral (abuse@kitterman.com: 192.0.2.3 is neither permitted nor denied by domain of email.example.com) smtp.mailfrom=email.example.com (sender=strong-bad@email.example.com; helo=mx.example.org; client-ip=192.0.2.3; receiver=abuse@kitterman.com; mechanism=?all)'
>>> p = query(s='strong-bad@email.example.com', h='mx.example.org',
... i='192.0.2.3')
>>> p.r='abuse@kitterman.com'
>>> p.check(spf='v=spf1 redirect=controlledmail.com exp=_exp.controlledmail.com')
('fail', 550, 'SPF fail - not authorized')
>>> p.ident = 'helo'
>>> p.get_header('fail', header_type = 'authres', aid='bmsi.com')
'Authentication-Results: bmsi.com; spf=fail (abuse@kitterman.com: domain of email.example.com does not designate 192.0.2.3 as permitted sender) smtp.helo=mx.example.org (sender=strong-bad@email.example.com; client-ip=192.0.2.3; receiver=abuse@kitterman.com; mechanism=-all)'
>>> q.check(spf='v=spf1 ?all')
('neutral', 250, 'access neither permitted nor denied')
>>> try: q.get_header('neutral', header_type = 'dkim')
... except SyntaxError as x: print(x)
Unknown results header type: dkim
"""
# If type is Authentication Results header (spf/authres)
if header_type == 'authres':
if not aid:
raise SyntaxError('authserv-id missing for Authentication Results header type, see RFC5451 2.3')
import authres
if not receiver:
receiver = self.r
client_ip = self.c
helo = quote_value(self.h)
resmap = { 'pass': 'Pass', 'neutral': 'Neutral', 'fail': 'Fail',
'softfail': 'SoftFail', 'none': 'None',
'temperror': 'TempError', 'permerror': 'PermError' }
identity = self.ident
if identity == 'helo':
envelope_from = None
else:
envelope_from = quote_value(self.s)
tag = resmap[res]
if res == 'permerror' and self.mech:
problem = quote_value(' '.join(self.mech))
else:
problem = None
mechanism = quote_value(self.mechanism)
if hasattr(self,'comment'):
comment = self.comment
else:
comment = '%s: %s' % (receiver,self.get_header_comment(res))
res = ['%s (%s)' % (tag,comment)]
if header_type == 'spf':
for k in ('client_ip','envelope_from','helo','receiver',
'problem','mechanism'):
v = locals()[k]
if v: res.append('%s=%s;'%(k.replace('_','-'),v))
for k,v in sorted(list(kv.items())):
if v: res.append('x-%s=%s;'%(k.replace('_','-'),quote_value(v)))
# do identity last so we can easily drop the trailing ';'
res.append('%s=%s'%('identity',identity))
return ' '.join(res)
elif header_type == 'authres':
if envelope_from:
return str(authres.AuthenticationResultsHeader(authserv_id = aid, \
results = [authres.SPFAuthenticationResult(result = tag, \
result_comment = comment, smtp_mailfrom = self.d, \
smtp_mailfrom_comment = \
'sender={0}; helo={1}; client-ip={2}; receiver={3}; mechanism={4}'.format(self.s, \
self.h, self.c, self.r, mechanism))]))
else:
return str(authres.AuthenticationResultsHeader(authserv_id = aid, \
results = [authres.SPFAuthenticationResult(result = tag, \
result_comment = comment, smtp_helo = self.h, \
smtp_helo_comment = \
'sender={0}; client-ip={1}; receiver={2}; mechanism={3}'.format(self.s, \
self.c, self.r, mechanism))]))
else:
raise SyntaxError('Unknown results header type: {0}'.format(header_type))
def get_header_comment(self, res):
"""Return comment for Received-SPF header. """
sender = self.o
if res == 'pass':
return \
"domain of %s designates %s as permitted sender" \
% (sender, self.c)
elif res == 'softfail': return \
"transitioning domain of %s does not designate %s as permitted sender" \
% (sender, self.c)
elif res == 'neutral': return \
"%s is neither permitted nor denied by domain of %s" \
% (self.c, sender)
elif res == 'none': return \
"%s is neither permitted nor denied by domain of %s" \
% (self.c, sender)
#"%s does not designate permitted sender hosts" % sender
elif res == 'permerror': return \
"permanent error in processing domain of %s: %s" \
% (sender, self.prob)
elif res == 'temperror': return \
"temporary error in processing during lookup of %s" % sender
elif res == 'fail': return \
"domain of %s does not designate %s as permitted sender" \
% (sender, self.c)
raise ValueError("invalid SPF result for header comment: "+res)
def split_email(s, h):
"""Given a sender email s and a HELO domain h, create a valid tuple
(l, d) local-part and domain-part.
Examples:
>>> split_email('', 'wayforward.net')
('postmaster', 'wayforward.net')
>>> split_email('foo.com', 'wayforward.net')
('postmaster', 'foo.com')
>>> split_email('terry@wayforward.net', 'optsw.com')
('terry', 'wayforward.net')
"""
if not s:
return 'postmaster', h
else:
parts = s.split('@', 1)
if parts[0] == '':
parts[0] = 'postmaster'
if len(parts) == 2:
return tuple(parts)
else:
return 'postmaster', s
def quote_value(s):
"""Quote the value for a key-value pair in Received-SPF header field
if needed. No quoting needed for a dot-atom value.
Examples:
>>> quote_value('foo@bar.com')
'"foo@bar.com"'
>>> quote_value('mail.example.com')
'mail.example.com'
>>> quote_value('A:1.2.3.4')
'"A:1.2.3.4"'
>>> quote_value('abc"def')
'"abc\\\\"def"'
>>> quote_value(r'abc\def')
'"abc\\\\\\\\def"'
>>> quote_value('abc..def')
'"abc..def"'
>>> quote_value('')
'""'
>>> quote_value(None)
"""
if s is None or RE_DOT_ATOM.match(s):
return s
return '"' + s.replace('\\',r'\\').replace('"',r'\"'
).replace('\x00',r'\x00') + '"'
def parse_mechanism(str, d):
"""Breaks A, MX, IP4, and PTR mechanisms into a (name, domain,
cidr,cidr6) tuple. The domain portion defaults to d if not present,
the cidr defaults to 32 if not present.
Examples:
>>> parse_mechanism('a', 'foo.com')
('a', 'foo.com', None, None)
>>> parse_mechanism('exists','foo.com')
('exists', None, None, None)
>>> parse_mechanism('a:bar.com', 'foo.com')
('a', 'bar.com', None, None)
>>> parse_mechanism('a/24', 'foo.com')
('a', 'foo.com', 24, None)
>>> parse_mechanism('A:foo:bar.com/16//48', 'foo.com')
('a', 'foo:bar.com', 16, 48)
>>> parse_mechanism('-exists:%{i}.%{s1}.100/86400.rate.%{d}','foo.com')
('-exists', '%{i}.%{s1}.100/86400.rate.%{d}', None, None)
>>> parse_mechanism('mx:%%%_/.Claranet.de/27','foo.com')
('mx', '%%%_/.Claranet.de', 27, None)
>>> parse_mechanism('mx:%{d}//97','foo.com')
('mx', '%{d}', None, 97)
>>> parse_mechanism('iP4:192.0.0.0/8','foo.com')
('ip4', '192.0.0.0', 8, None)
"""
a = RE_DUAL_CIDR.split(str)
if len(a) == 3:
str, cidr6 = a[0], int(a[1])
else:
cidr6 = None
a = RE_CIDR.split(str)
if len(a) == 3:
str, cidr = a[0], int(a[1])
else:
cidr = None
a = str.split(':', 1)
if len(a) < 2:
str = str.lower()
if str == 'exists': d = None
return str, d, cidr, cidr6
return a[0].lower(), a[1], cidr, cidr6
def reverse_dots(name):
"""Reverse dotted IP addresses or domain names.
Example:
>>> reverse_dots('192.168.0.145')
'145.0.168.192'
>>> reverse_dots('email.example.com')
'com.example.email'
"""
a = name.split('.')
a.reverse()
return '.'.join(a)
def domainmatch(ptrs, domainsuffix):
"""grep for a given domain suffix against a list of validated PTR
domain names.
Examples:
>>> domainmatch(['FOO.COM'], 'foo.com')
1
>>> domainmatch(['moo.foo.com'], 'FOO.COM')
1
>>> domainmatch(['moo.bar.com'], 'foo.com')
0
"""
domainsuffix = domainsuffix.lower()
for ptr in ptrs:
ptr = ptr.lower()
if ptr == domainsuffix or ptr.endswith('.' + domainsuffix):
return True
return False
def expand_one(expansion, str, joiner):
if not str:
return expansion
ln, reverse, delimiters = RE_ARGS.split(str)[1:4]
if not delimiters:
delimiters = '.'
expansion = split(expansion, delimiters, joiner)
if reverse: expansion.reverse()
if ln: expansion = expansion[-int(ln)*2+1:]
return ''.join(expansion)
def split(str, delimiters, joiner=None):
"""Split a string into pieces by a set of delimiter characters. The
resulting list is delimited by joiner, or the original delimiter if
joiner is not specified.
Examples:
>>> split('192.168.0.45', '.')
['192', '.', '168', '.', '0', '.', '45']
>>> split('terry@wayforward.net', '@.')
['terry', '@', 'wayforward', '.', 'net']
>>> split('terry@wayforward.net', '@.', '.')
['terry', '.', 'wayforward', '.', 'net']
"""
result, element = [], ''
for c in str:
if c in delimiters:
result.append(element)
element = ''
if joiner:
result.append(joiner)
else:
result.append(c)
else:
element += c
result.append(element)
return result
def insert_libspf_local_policy(spftxt, local=None):
"""Returns spftxt with local inserted just before last non-fail
mechanism. This is how the libspf{2} libraries handle "local-policy".
Examples:
>>> insert_libspf_local_policy('v=spf1 -all')
'v=spf1 -all'
>>> insert_libspf_local_policy('v=spf1 -all','mx')
'v=spf1 -all'
>>> insert_libspf_local_policy('v=spf1','a mx ptr')
'v=spf1 a mx ptr'
>>> insert_libspf_local_policy('v=spf1 mx -all','a ptr')
'v=spf1 mx a ptr -all'
>>> insert_libspf_local_policy('v=spf1 mx -include:foo.co +all','a ptr')
'v=spf1 mx a ptr -include:foo.co +all'
# FIXME: is this right? If so, "last non-fail" is a bogus description.
>>> insert_libspf_local_policy('v=spf1 mx ?include:foo.co +all','a ptr')
'v=spf1 mx a ptr ?include:foo.co +all'
>>> spf='v=spf1 ip4:1.2.3.4 -a:example.net -all'
>>> local='ip4:192.0.2.3 a:example.org'
>>> insert_libspf_local_policy(spf,local)
'v=spf1 ip4:1.2.3.4 ip4:192.0.2.3 a:example.org -a:example.net -all'
"""
# look to find the all (if any) and then put local
# just after last non-fail mechanism. This is how
# libspf2 handles "local policy", and some people
# apparently find it useful (don't ask me why).
if not local: return spftxt
spf = spftxt.split()[1:]
if spf:
# local policy is SPF mechanisms/modifiers with no
# 'v=spf1' at the start
spf.reverse() #find the last non-fail mechanism
for mech in spf:
# map '?' '+' or '-' to 'neutral' 'pass'
# or 'fail'
if not RESULTS.get(mech[0]):
# actually finds last mech with default result
where = spf.index(mech)
spf[where:where] = [local]
spf.reverse()
local = ' '.join(spf)
break
else:
return spftxt # No local policy adds for v=spf1 -all
# Processing limits not applied to local policy. Suggest
# inserting 'local' mechanism to handle this properly
#MAX_LOOKUP = 100
return 'v=spf1 '+local
if sys.version_info[0] == 2:
def to_ascii(s):
"Raise PermError if arg is not 7-bit ascii."
try:
return s.encode('ascii')
except UnicodeError:
raise PermError('Non-ascii characters found',repr(s))
else:
def to_ascii(s):
"Raise PermError if arg is not 7-bit ascii."
try:
return s.decode('ascii')
except UnicodeError:
raise PermError('Non-ascii characters found',repr(s))
def _test():
import doctest, spf
return doctest.testmod(spf)
DNS.DiscoverNameServers() # Fails on Mac OS X? Add domain to /etc/resolv.conf
if __name__ == '__main__':
import getopt
try:
opts,argv = getopt.getopt(sys.argv[1:],"hvs:",
["help","verbose","strict"])
except getopt.GetoptError as err:
print(str(err))
print(USAGE)
sys.exit(2)
verbose = False
strict = True
for o,a in opts:
if o in ('-v','--verbose'):
verbose = True
if o in ('-s','--strict'):
strict = int(a)
elif o in ('-h','--help'):
print(USAGE)
if len(argv) == 0:
print(USAGE)
_test()
elif len(argv) == 1:
try:
q = query(i='127.0.0.1', s='localhost', h='unknown',
receiver=socket.gethostname())
print(q.dns_spf(argv[0]))
except TempError as x:
print("Temporary DNS error: ", x)
except PermError as x:
print("PermError: ", x)
elif len(argv) == 3:
i, s, h = argv
q = query(i=i, s=s, h=h,receiver=socket.gethostname(),verbose=verbose,
strict=strict)
r = q.check()
print('result:',r,q.mechanism)
if r[0] == 'none':
print('guessed:',q.best_guess(),q.mechanism)
if q.perm_error and q.perm_error.ext:
print('lax:',q.perm_error.ext)
if q.iplist:
for ip in q.iplist:
print(ip)
elif len(argv) == 4:
i, s, h = argv[1:]
q = query(i=i, s=s, h=h, receiver=socket.gethostname(),
strict=False, verbose=verbose)
r = q.check(argv[0])
print('result:',r,q.mechanism)
if r[0] == 'none':
print('guessed:',q.best_guess(),q.mechanism)
if q.perm_error and q.perm_error.ext:
print('lax:',q.perm_error.ext)
else:
print(USAGE)
|