# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-# GPG issues -
+# GPG issues -
# - gpgm with a status FD being fed keymaterial and other interesting
# things does nothing.. If it could ID the keys and stuff over the
# status-fd I could decide what to do with them. I would also like it
-# to report which key it selected for encryption (also if there
+# to report which key it selected for encryption (also if there
# were multi-matches..) Being able to detect a key-revoke cert would be
# good too.
-# - I would like to be able to fetch the comment and version fields from the
+# - I would like to be able to fetch the comment and version fields from the
# packets so I can tell if a signature is made by pgp2 to enable the
# pgp2 encrypting mode.
-import mimetools, multifile, sys, StringIO, os, tempfile, re;
-import rfc822, time, fcntl, anydbm
+import sys
+import StringIO
+import os
+import tempfile
+import re
+import time
+import fcntl
+import anydbm
+import email
+import email.message
+
+from userdir_exceptions import *
# General GPG options
GPGPath = "gpg"
-# "--load-extension","rsa",
-GPGBasicOptions = [
- "--no-options",
- "--batch",
- "--no-default-keyring",
- "--secret-keyring", "/dev/null",
- "--always-trust"];
-GPGKeyRings = [];
-GPGSigOptions = ["--output","-"];
-GPGSearchOptions = ["--dry-run","--with-colons","--fingerprint"];
-GPGEncryptOptions = ["--output","-","--quiet","--always-trust",\
- "--armor","--encrypt"];
-GPGEncryptPGP2Options = ["--set-filename","","--rfc1991",\
- "--load-extension","idea",\
- "--cipher-algo","idea"] + GPGEncryptOptions;
+# "--load-extension", "rsa",
+GPGBasicOptions = ["--no-options",
+ "--batch",
+ "--no-default-keyring",
+ "--secret-keyring", "/dev/null",
+ "--always-trust"]
+GPGKeyRings = []
+GPGSigOptions = ["--output", "-"]
+GPGSearchOptions = ["--dry-run", "--with-colons", "--fingerprint",
+ "--fingerprint", "--fixed-list-mode"]
+GPGEncryptOptions = ["--output", "-", "--quiet", "--always-trust",
+ "--armor", "--encrypt"]
+GPGEncryptPGP2Options = ["--set-filename", "", "--rfc1991",
+ "--load-extension", "idea",
+ "--cipher-algo", "idea"] + GPGEncryptOptions
# Replay cutoff times in seconds
-CleanCutOff = 7*24*60*60;
-AgeCutOff = 4*24*60*60;
-FutureCutOff = 3*24*60*60;
+CleanCutOff = 7 * 24 * 60 * 60
+AgeCutOff = 4 * 24 * 60 * 60
+FutureCutOff = 3 * 24 * 60 * 60
+
+
+def ClearKeyrings():
+ del GPGKeyRings[:]
+
# Set the keyrings, the input is a list of keyrings
def SetKeyrings(Rings):
for x in Rings:
- GPGKeyRings.append("--keyring");
- GPGKeyRings.append(x);
+ GPGKeyRings.append("--keyring")
+ GPGKeyRings.append(x)
+
-# GetClearSig takes an un-seekable email message stream (mimetools.Message)
-# and returns a standard PGP '---BEGIN PGP SIGNED MESSAGE---' bounded
+# GetClearSig takes an un-seekable email message stream (mimetools.Message)
+# and returns a standard PGP '---BEGIN PGP SIGNED MESSAGE---' bounded
# clear signed text.
# If this is fed to gpg/pgp it will verify the signature and spit out the
# signed text component. Email headers and PGP mime (RFC 2015) is understood
# element is the text itself the second is a mime flag indicating if the
# result should be mime processed after sig checking.
#
-# Paranoid will check the message text to make sure that all the plaintext is
+# Paranoid will check the message text to make sure that all the plaintext is
# in fact signed (bounded by a PGP packet)
-def GetClearSig(Msg,Paranoid = 0):
- Error = 'MIME Error';
+#
+# lax_multipart: treat multipart bodies other than multipart/signed
+# as one big plain text body
+def GetClearSig(Msg, Paranoid=0, lax_multipart=False):
+ if not Msg.__class__ == email.message.Message:
+ raise RuntimeError, "GetClearSign() not called with a email.message.Message"
+
+ if Paranoid and lax_multipart:
+ raise RuntimeError, "Paranoid and lax_multipart don't mix well"
+
# See if this is a MIME encoded multipart signed message
- if Msg.gettype() == "multipart/signed":
- Boundary = Msg.getparam("boundary");
- if not Boundary:
- raise Error, "multipart/* without a boundary parameter";
-
- # Create the multipart handler. Regrettably their implementation
- # Needs seeking..
- SkMessage = StringIO.StringIO();
- SkMessage.write(Msg.fp.read());
- SkMessage.seek(0);
- mf = multifile.MultiFile(SkMessage)
- mf.push(Msg.getparam("boundary"));
-
- # Check the first bit of the message..
- if Paranoid != 0:
- Pos = mf.tell();
- while 1:
- x = mf.readline();
- if not x: break;
- if len(x.strip()) != 0:
- raise Error,"Unsigned text in message (at start)";
- mf.seek(Pos);
-
- # Get the first part of the multipart message
- if not mf.next():
- raise Error, "Invalid pgp/mime encoding [no section]";
-
- # Get the part as a safe seekable stream
- Signed = StringIO.StringIO();
- Signed.write(mf.read());
- InnerMsg = mimetools.Message(Signed);
-
- # Make sure it is the right type
- if InnerMsg.gettype() != "text/plain":
- raise Error, "Invalid pgp/mime encoding [wrong plaintext type]";
-
- # Get the next part of the multipart message
- if not mf.next():
- raise Error, "Invalid pgp/mime encoding [no section]";
- InnerMsg = mimetools.Message(mf);
- if InnerMsg.gettype() != "application/pgp-signature":
- raise Error, "Invalid pgp/mime encoding [wrong signature type]";
- Signature = ''.join(mf.readlines())
-
- # Check the last bit of the message..
- if Paranoid != 0:
- mf.pop();
- Pos = mf.tell();
- while 1:
- x = mf.readline();
- if not x: break;
- if len(x.strip()) != 0:
- raise Error,"Unsigned text in message (at end)";
- mf.seek(Pos);
-
+ if Msg.is_multipart():
+ if not Msg.get_content_type() == "multipart/signed":
+ if lax_multipart:
+ payloads = Msg.get_payload()
+ msg = "\n".join(map( lambda p: p.get_payload(decode=True), payloads))
+ return (msg, 0)
+ raise UDFormatError, "Cannot handle multipart messages not of type multipart/signed";
+
+ if Paranoid:
+ if Msg.preamble is not None and Msg.preamble.strip() != "":
+ raise UDFormatError,"Unsigned text in message (at start)";
+ if Msg.epilogue is not None and Msg.epilogue.strip() != "":
+ raise UDFormatError,"Unsigned text in message (at end)";
+
+ payloads = Msg.get_payload()
+ if len(payloads) != 2:
+ raise UDFormatError, "multipart/signed message with number of payloads != 2";
+
+ (Signed, Signature) = payloads
+
+ if Signed.get_content_type() != "text/plain" and not lax_multipart:
+ raise UDFormatError, "Invalid pgp/mime encoding for first part[wrong plaintext type]";
+ if Signature.get_content_type() != "application/pgp-signature":
+ raise UDFormatError, "Invalid pgp/mime encoding for second part [wrong signature type]";
+
# Append the PGP boundary header and the signature text to re-form the
# original signed block [needs to convert to \r\n]
Output = "-----BEGIN PGP SIGNED MESSAGE-----\r\n";
# Semi-evil hack to get the proper hash type inserted in the message
- if Msg.getparam('micalg') != None:
- Output = Output + "Hash: MD5,SHA1,%s\r\n"%(Msg.getparam('micalg')[4:].upper())
+ if Msg.get_param('micalg') != None:
+ Output = Output + "Hash: SHA1,%s\r\n"%(Msg.get_param('micalg')[4:].upper())
Output = Output + "\r\n";
- Output = Output + Signed.getvalue().replace("\n-","\n- -") + Signature
+ Output = Output + Signed.as_string().replace("\n-","\n- -") + "\n" + Signature.get_payload(decode=True)
return (Output,1);
else:
if Paranoid == 0:
# Just return the message body
- return (''.join(Msg.fp.readlines()),0);
-
- Body = "";
+ return (Msg.get_payload(decode=True), 0);
+
+ Body = [];
State = 1;
- for x in Msg.fp.readlines():
- Body = Body + x;
- Tmp = x.strip()
- if len(Tmp) == 0:
- continue;
-
- # Leading up to the signature
- if State == 1:
- if Tmp == "-----BEGIN PGP SIGNED MESSAGE-----":
- State = 2;
- else:
- raise Error,"Unsigned text in message (at start)";
- continue;
-
- # In the signature plain text
- if State == 2:
- if Tmp == "-----BEGIN PGP SIGNATURE-----":
- State = 3;
- continue;
-
- # In the signature
- if State == 3:
- if Tmp == "-----END PGP SIGNATURE-----":
- State = 4;
- continue;
-
+ for x in Msg.get_payload(decode=True).split('\n'):
+ Body.append(x)
+
+ if x == "":
+ continue;
+
+ # Leading up to the signature
+ if State == 1:
+ if x == "-----BEGIN PGP SIGNED MESSAGE-----":
+ State = 2;
+ else:
+ raise UDFormatError,"Unsigned text in message (at start)";
+ continue;
+
+ # In the signature plain text
+ if State == 2:
+ if x == "-----BEGIN PGP SIGNATURE-----":
+ State = 3;
+ continue;
+
+ # In the signature
+ if State == 3:
+ if x == "-----END PGP SIGNATURE-----":
+ State = 4;
+ continue;
+
# Past the end
- if State == 4:
- raise Error,"Unsigned text in message (at end)";
- return (Body,0);
+ if State == 4:
+ raise UDFormatError,"Unsigned text in message (at end)";
+
+ return ("\n".join(Body), 0);
# This opens GPG in 'write filter' mode. It takes Message and sends it
# to GPGs standard input, pipes the standard output to a temp file along
def GPGWriteFilter(Program,Options,Message):
# Make sure the tmp files we open are unreadable, there is a short race
# between when the temp file is opened and unlinked that some one else
- # could open it or hard link it. This is not important however as no
+ # could open it or hard link it. This is not important however as no
# Secure data is fed through the temp files.
OldMask = os.umask(0777);
try:
InPipe = [InPipe[0],InPipe[1]];
finally:
os.umask(OldMask);
-
+
try:
# Fork off GPG in a horrible way, we redirect most of its FDs
# Input comes from a pipe and its two outputs are spooled to unlinked
Child = os.fork();
if Child == 0:
try:
- os.dup2(InPipe[0],0);
+ os.dup2(InPipe[0],0);
os.close(InPipe[1]);
- os.dup2(Output.fileno(),1);
- os.dup2(os.open("/dev/null",os.O_WRONLY),2);
- os.dup2(GPGText.fileno(),3);
-
- Args = [Program,"--status-fd","3"] + GPGBasicOptions + GPGKeyRings + Options
- os.execvp(Program,Args);
- finally:
- os._exit(100);
-
+ os.dup2(Output.fileno(),1);
+ os.dup2(os.open("/dev/null",os.O_WRONLY),2);
+ os.dup2(GPGText.fileno(),3);
+
+ Args = [Program,"--status-fd","3"] + GPGBasicOptions + GPGKeyRings + Options
+ os.execvp(Program,Args);
+ finally:
+ os._exit(100);
+
# Get rid of the other end of the pipe
os.close(InPipe[0])
InPipe[0] = -1;
Output.close();
GPGText.close();
-# This takes a text passage, a destination and a flag indicating the
+# This takes a text passage, a destination and a flag indicating the
# compatibility to use and returns an encrypted message to the recipient.
# It is best if the recipient is specified using the hex key fingerprint
# of the target, ie 0x64BE1319CCF6D393BF87FF9358A6D4EE
def GPGEncrypt(Message,To,PGP2):
+ Error = "KeyringError"
# Encrypt using the PGP5 block encoding and with the PGP5 option set.
# This will handle either RSA or DSA/DH asymetric keys.
# In PGP2 compatible mode IDEA and rfc1991 encoding are used so that
# PGP2 can read the result. RSA keys do not need PGP2 to be set, as GPG
# can read a message encrypted with blowfish and RSA.
+ searchkey = GPGKeySearch(To);
+ if len(searchkey) == 0:
+ raise Error, "No key found matching %s"%(To);
+ elif len(searchkey) > 1:
+ raise Error, "Multiple keys found matching %s"%(To);
+ if searchkey[0][4].find("E") < 0:
+ raise Error, "Key %s has no encryption capability - are all encryption subkeys expired or revoked? Are there any encryption subkeys?"%(To);
+
if PGP2 == 0:
try:
Res = None;
# GetClearSig. It returns a large tuple of the form:
# (Why,(SigId,Date,KeyFinger),(KeyID,KeyFinger,Owner,Length,PGP2),Text);
# Where,
-# Why = None if checking was OK otherwise an error string.
+# Why = None if checking was OK otherwise an error string.
# SigID+Date represent something suitable for use in a replay cache. The
# date is returned as the number of seconds since the UTC epoch.
-# The keyID is also in this tuple for easy use of the replay
+# The keyID is also in this tuple for easy use of the replay
# cache
# KeyID, KeyFinger and Owner represent the Key used to sign this message
-# PGP2 indicates if the message was created using PGP 2.x
+# PGP2 indicates if the message was created using PGP 2.x
# Text is the full byte-for-byte signed text in a string
def GPGCheckSig(Message):
Res = None;
if Line == "":
break;
Split = re.split("[ \n]",Line);
- if Split[0] != "[GNUPG:]":
- continue;
+ if Split[0] != "[GNUPG:]":
+ continue;
# We only process the first occurance of any tag.
if TagMap.has_key(Split[1]):
continue;
TagMap[Split[1]] = None;
- # Good signature response
+ # Good signature response
if Split[1] == "GOODSIG":
# Just in case GPG returned a bad signal before this (bug?)
- if Why == None:
- GoodSig = 1;
- KeyID = Split[2];
- Owner = ' '.join(Split[3:])
- # If this message is signed with a subkey which has not yet
- # expired, GnuPG will say GOODSIG here, even if the primary
- # key already has expired. This came up in discussion of
- # bug #489225. GPGKeySearch only returns non-expired keys.
- Verify = GPGKeySearch(KeyID);
- if len(Verify) == 0:
- GoodSig = 0
- Why = "Key has expired (no unexpired key found in keyring matching %s)"%(KeyId);
-
- # Bad signature response
- if Split[1] == "BADSIG":
- GoodSig = 0;
- KeyID = Split[2];
+ if Why == None:
+ GoodSig = 1;
+ KeyID = Split[2];
+ Owner = ' '.join(Split[3:])
+ # If this message is signed with a subkey which has not yet
+ # expired, GnuPG will say GOODSIG here, even if the primary
+ # key already has expired. This came up in discussion of
+ # bug #489225. GPGKeySearch only returns non-expired keys.
+ Verify = GPGKeySearch(KeyID);
+ if len(Verify) == 0:
+ GoodSig = 0
+ Why = "Key has expired (no unexpired key found in keyring matching %s)"%(KeyId);
+
+ # Bad signature response
+ if Split[1] == "BADSIG":
+ GoodSig = 0;
+ KeyID = Split[2];
Why = "Verification of signature failed";
- # Bad signature response
- if Split[1] == "ERRSIG":
- GoodSig = 0;
- KeyID = Split[2];
+ # Bad signature response
+ if Split[1] == "ERRSIG":
+ GoodSig = 0;
+ KeyID = Split[2];
if len(Split) <= 7:
Why = "GPG error, ERRSIG status tag is invalid";
elif Split[7] == '9':
Why = "Unable to verify signature, signing key missing.";
elif Split[7] == '4':
Why = "Unable to verify signature, unknown packet format/key type";
- else:
+ else:
Why = "Unable to verify signature, unknown reason";
if Split[1] == "NO_PUBKEY":
- GoodSig = 0;
+ GoodSig = 0;
Why = "Unable to verify signature, signing key missing.";
- # Expired signature
- if Split[1] == "EXPSIG":
- GoodSig = 0;
+ # Expired signature
+ if Split[1] == "EXPSIG":
+ GoodSig = 0;
Why = "Signature has expired";
- # Expired signature
- if Split[1] == "EXPKEYSIG":
- GoodSig = 0;
+ # Expired signature
+ if Split[1] == "EXPKEYSIG":
+ GoodSig = 0;
Why = "Signing key (%s, %s) has expired"%(Split[2], Split[3]);
- # Revoked key
- if Split[1] == "KEYREVOKED" or Split[1] == "REVKEYSIG":
- GoodSig = 0;
+ # Revoked key
+ if Split[1] == "KEYREVOKED" or Split[1] == "REVKEYSIG":
+ GoodSig = 0;
Why = "Signing key has been revoked";
- # Corrupted packet
- if Split[1] == "NODATA" or Split[1] == "BADARMOR":
- GoodSig = 0;
+ # Corrupted packet
+ if Split[1] == "NODATA" or Split[1] == "BADARMOR":
+ GoodSig = 0;
Why = "The packet was corrupted or contained no data";
-
+
# Signature ID
- if Split[1] == "SIG_ID":
- SigId = Split[2];
- Date = long(Split[4]);
+ if Split[1] == "SIG_ID":
+ SigId = Split[2];
+ Date = long(Split[4]);
# ValidSig has the key finger print
- if Split[1] == "VALIDSIG":
- # Use the fingerprint of the primary key when available
- if len(Split) >= 12:
+ if Split[1] == "VALIDSIG":
+ # Use the fingerprint of the primary key when available
+ if len(Split) >= 12:
KeyFinger = Split[11];
else:
- KeyFinger = Split[2];
+ KeyFinger = Split[2];
# Reopen the stream as a readable stream
Text = Res[2].read();
# A gpg failure is an automatic bad signature
if Exit[1] != 0 and Why == None:
GoodSig = 0;
- Why = "GPG execution failed " + str(Exit[0]);
+ Why = "GPG execution returned non-zero exit status: " + str(Exit[1]);
if GoodSig == 0 and (Why == None or len(Why) == 0):
Why = "Checking Failed";
Res[1].close();
Res[2].close();
+class GPGCheckSig2:
+ def __init__(self, msg):
+ res = GPGCheckSig(msg)
+ self.why = res[0]
+ self.sig_info = res[1]
+ self.key_info = res[2]
+ self.text = res[3]
+
+ self.ok = self.why is None
+
+ self.sig_id = self.sig_info[0]
+ self.sig_date = self.sig_info[1]
+ self.sig_fpr = self.sig_info[2]
+
+ self.key_id = self.key_info[0]
+ self.key_fpr = self.key_info[1]
+ self.key_owner = self.key_info[2]
+
+ self.is_pgp2 = self.key_info[4]
+
# Search for keys given a search pattern. The pattern is passed directly
# to GPG for processing. The result is a list of tuples of the form:
# (KeyID,KeyFinger,Owner,Length)
def GPGKeySearch(SearchCriteria):
Args = [GPGPath] + GPGBasicOptions + GPGKeyRings + GPGSearchOptions + \
[SearchCriteria," 2> /dev/null"]
- Strm = None;
- Result = [];
- Owner = "";
- KeyID = "";
- Expired = None;
- Hits = {};
+ Strm = None
+ Result = []
+ Validity = None
+ Length = 0
+ KeyID = ""
+ Capabilities = ""
+ Fingerprint = ""
+ Owner = ""
+ Hits = {}
dir = os.path.expanduser("~/.gnupg")
if not os.path.isdir(dir):
os.mkdir(dir, 0700)
-
+
try:
+ # The GPG output will contain zero or more stanza, one stanza per match found.
+ # Each stanza consists of the following records, in order:
+ # tru : trust database information
+ # pub : primary key from which we extract
+ # field 1 - Validity
+ # field 2 - Length
+ # field 4 - KeyID
+ # field 11 - Capabilities
+ # fpr : fingerprint of primary key from which we extract
+ # field 9 - Fingerprint
+ # uid : first User ID attached to primary key from which we extract
+ # Field 9 - Owner
+ # uid : (optional) additional multiple User IDs attached to primary key
+ # sub : (optional) secondary key
+ # fpr : (opitonal) fingerprint of secondary key if sub is present
Strm = os.popen(" ".join(Args),"r")
-
+ Want = "pub"
while(1):
- # Grab and split up line
- Line = Strm.readline();
+ Line = Strm.readline()
if Line == "":
- break;
+ break
Split = Line.split(":")
- # Store some of the key fields
- if Split[0] == 'pub':
- KeyID = Split[4];
- Owner = Split[9];
- Length = int(Split[2]);
- Expired = Split[1] == 'e'
-
- # Output the key
- if Split[0] == 'fpr':
- if Hits.has_key(Split[9]):
- continue;
- Hits[Split[9]] = None;
- if not Expired:
- Result.append( (KeyID,Split[9],Owner,Length) );
+ if Split[0] != Want:
+ continue
+
+ if Want == 'pub':
+ Validity = Split[1]
+ Length = int(Split[2])
+ KeyID = Split[4]
+ Capabilities = Split[11]
+ Want = 'fpr'
+ continue
+
+ if Want == 'fpr':
+ Fingerprint = Split[9]
+ if Hits.has_key(Fingerprint):
+ Want = 'pub' # already seen, skip to next stanza
+ else:
+ Hits[Fingerprint] = None
+ Want = 'uid'
+ continue
+
+ if Want == 'uid':
+ Owner = Split[9]
+ if Validity != 'e': # if not expired
+ Result.append( (KeyID,Fingerprint,Owner,Length,Capabilities) )
+ Want = 'pub' # finished, skip to next stanza
+ continue
+
finally:
if Strm != None:
- Strm.close();
- return Result;
+ Strm.close()
+ return Result
# Print the available key information in a format similar to GPG's output
# We do not know the values of all the feilds so they are just replaced
print "pub %u?/%s ??-??-?? %s" % (Ident[3],Ident[0][-8:],Ident[2]);
print " key fingerprint = 0x%s" % (Ident[1]);
-# Perform a substition of template
+# Perform a substition of template
def TemplateSubst(Map,Template):
for x in Map.keys():
Template = Template.replace(x, Map[x])
# The replay class uses a python DB (BSD db if avail) to implement
# protection against replay. Replay is an attacker capturing the
# plain text signed message and sending it back to the victim at some
-# later date. Each signature has a unique signature ID (and signing
+# later date. Each signature has a unique signature ID (and signing
# Key Fingerprint) as well as a timestamp. The first stage of replay
# protection is to ensure that the timestamp is reasonable, in particular
# not to far ahead or too far behind the current system time. The next
# step is to look up the signature + key fingerprint in the replay database
-# and determine if it has been recived. The database is cleaned out
+# and determine if it has been recived. The database is cleaned out
# periodically and old signatures are discarded. By using a timestamp the
# database size is bounded to being within the range of the allowed times
# plus a little fuzz. The cache is serialized with a flocked lock file
self.CleanCutOff = CleanCutOff;
self.AgeCutOff = AgeCutOff;
self.FutureCutOff = FutureCutOff;
-
+ self.Clean()
+
# Close the cache and lock
def __del__(self):
self.close();
def close(self):
self.DB.close();
self.Lock.close();
-
+
# Clean out any old signatures
def Clean(self):
CutOff = time.time() - self.CleanCutOff;
for x in self.DB.keys():
if int(self.DB[x]) <= CutOff:
- del self.DB[x];
-
+ del self.DB[x];
+
# Check a signature. 'sig' is a 3 tuple that has the sigId, date and
# key ID
def Check(self,Sig):
return "Signature has passed the age cut off ";
# + str(int(Sig[1])) + ',' + str(time.time()) + "," + str(Sig);
return None;
-
+
# Add a signature, the sig is the same as is given to Check
def Add(self,Sig):
if Sig[0] == None or Sig[1] == None:
return;
Key = Sig[0] + '-' + Sig[2]
if self.DB.has_key(Key):
- if int(self.DB[Key]) < Sig[1]:
- self.DB[Key] = str(int(Sig[1]));
+ if int(self.DB[Key]) < Sig[1]:
+ self.DB[Key] = str(int(Sig[1]));
else:
self.DB[Key] = str(int(Sig[1]));
-
+
+ def process(self, sig_info):
+ r = self.Check(sig_info);
+ if r is not None:
+ raise RuntimeError, "The replay cache rejected your message: %s." % (r,)
+ self.Add(sig_info)
+ self.close()
+
+# vim:set et:
+# vim:set ts=3:
+# vim:set shiftwidth=3:
projects / mirror / userdir-ldap.git / blobdiff