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##Copyright (C) 2003,2005 Jens B. Jorgensen <jbj1@ultraemail.net>
##
##This program is free software; you can redistribute it and/or
##modify it under the terms of the GNU General Public License
##as published by the Free Software Foundation; either version 2
##of the License, or (at your option) any later version.
##
##This program is distributed in the hope that it will be useful,
##but WITHOUT ANY WARRANTY; without even the implied warranty of
##MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
##GNU General Public License for more details.
##
##You should have received a copy of the GNU General Public License
##along with this program; if not, write to the Free Software
##Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
import struct, time, cStringIO, base64, types
# We use this so that we can work on python-2.4 and python-2.6, and thus.
# use import md5/import sha on the older one and import hashlib on the newer.
# Stupid deprecation warnings.
try:
import hashlib
except ImportError:
# Python-2.4.z ... gah!
import sha
import md5
class hashlib:
@staticmethod
def new(algo):
if algo == 'md5':
return md5.new()
if algo == 'sha1':
return sha.new()
raise ValueError, "Bad checksum type"
debug = None
# Cypher Type Byte
# bits 7,6 of the CTB say what kind it is
# we only have reserved defined
CTB_76_NORMAL = 0x80
CTB_76_NEW = 0xc0
CTB_76_MASK = 0xc0
# CTB packet type, bits 5,4,3,2
CTB_PKTV2_MASK = 0x3c # 1111 - mask for this field
CTB_PKT_MASK = 0x3f # 111111 - all the lower bits
CTB_PKT_PK_ENC = 1 # 0001 - public-key encrypted session packet
CTB_PKT_SIG = 2 # 0010 - signature packet
CTB_PKT_SK_ENC = 3 # 0011 - symmetric-key encrypted session packet
CTB_PKT_OP_SIG = 4 # 0100 - one-pass signature packet
CTB_PKT_SK_CERT = 5 # 0101 - secret-key certificate packet
CTB_PKT_PK_CERT = 6 # 0110 - public-key certificate packet
CTB_PKT_SK_SUB = 7 # 0111 - secret-key subkey packet
CTB_PKT_COMPRESSED = 8 # 1000 - compressed data packet
CTB_PKT_ENC = 9 # 1001 - symmetric-key encrypted data packet
CTB_PKT_MARKER = 10 # 1010 - marker packet
CTB_PKT_LIT = 11 # 1011 - literal data packet
CTB_PKT_TRUST = 12 # 1100 - trust packet
CTB_PKT_USER_ID = 13 # 1101 - user id packet
CTB_PKT_PK_SUB = 14 # 1110 - public subkey packet
ctb_pkt_to_str = {
CTB_PKT_PK_ENC : 'public-key encrypted session packet',
CTB_PKT_SIG : 'signature packet',
CTB_PKT_SK_ENC : 'symmetric-key encrypted session packet',
CTB_PKT_OP_SIG : 'one-pass signature packet',
CTB_PKT_SK_CERT : 'secret-key certificate packet',
CTB_PKT_PK_CERT : 'public-key certificate packet',
CTB_PKT_SK_SUB : 'secret-key subkey packet',
CTB_PKT_COMPRESSED : 'compressed data packet',
CTB_PKT_ENC : 'symmetric-key encrypted data packet',
CTB_PKT_MARKER : 'marker packet',
CTB_PKT_LIT : 'literal data packet',
CTB_PKT_TRUST : 'trust packet',
CTB_PKT_USER_ID : 'user id packet',
CTB_PKT_PK_SUB : 'public subkey packet'
}
# CTB packet-length
CTB_PKT_LEN_MASK = 0x3 # 11 - mask
CTB_PKT_LEN_1 = 0 # 00 - 1 byte
CTB_PKT_LEN_2 = 1 # 01 - 2 bytes
CTB_PKT_LEN_4 = 2 # 10 - 4 bytes
CTB_PKT_LEN_UNDEF = 3 # 11 - no packet length supplied
# Algorithms
# Public Key Algorithms
ALGO_PK_RSA_ENC_OR_SIGN = 1 # RSA (Encrypt or Sign)
ALGO_PK_RSA_ENC_ONLY = 2 # RSA Encrypt-Only
ALGO_PK_RSA_SIGN_ONLY = 3 # RSA Sign-Only
ALGO_PK_ELGAMAL_ENC_ONLY = 16 # Elgamal (Encrypt-Only)
ALGO_PK_DSA = 17 # DSA (Digital Signature Standard)
ALGO_PK_ELLIPTIC_CURVE = 18 # Elliptic Curve
ALGO_PK_ECDSA = 19 # ECDSA
ALGO_PK_ELGAMAL_ENC_OR_SIGN = 20 # Elgamal (Encrypt or Sign)
ALGO_PK_DH = 21 # Diffie-Hellman
algo_pk_to_str = {
ALGO_PK_RSA_ENC_OR_SIGN : 'RSA (Encrypt or Sign)',
ALGO_PK_RSA_ENC_ONLY : 'RSA Encrypt-Only',
ALGO_PK_RSA_SIGN_ONLY : 'RSA Sign-Only',
ALGO_PK_ELGAMAL_ENC_ONLY : 'Elgamal Encrypt-Only',
ALGO_PK_DSA : 'DSA (Digital Signature Standard)',
ALGO_PK_ELLIPTIC_CURVE : 'Elliptic Curve',
ALGO_PK_ECDSA : 'ECDSA',
ALGO_PK_ELGAMAL_ENC_OR_SIGN : 'Elgamal (Encrypt or Sign)',
ALGO_PK_DH : 'Diffie-Hellman'
}
# Symmetric Key Algorithms
ALGO_SK_PLAIN = 0 # Plaintext or unencrypted data
ALGO_SK_IDEA = 1 # IDEA
ALGO_SK_3DES = 2 # Triple-DES
ALGO_SK_CAST5 = 3 # CAST5
ALGO_SK_BLOWFISH = 4 # Blowfish
ALGO_SK_SAFER_SK128 = 5 # SAFER-SK128
ALGO_SK_DES_SK = 6 # DES/SK
ALGO_SK_AES_128 = 7 # AES 128-bit
ALGO_SK_AES_192 = 8 # AES 192-bit
ALGO_SK_AES_256 = 9 # AES 256-bit
algo_sk_to_str = {
ALGO_SK_PLAIN : 'Plaintext or unencrypted data',
ALGO_SK_IDEA : 'IDEA',
ALGO_SK_3DES : 'Triple-DES',
ALGO_SK_CAST5 : 'CAST5',
ALGO_SK_BLOWFISH : 'Blowfish',
ALGO_SK_SAFER_SK128 : 'SAFER-SK128',
ALGO_SK_DES_SK : 'DES/SK',
ALGO_SK_AES_128 : 'AES 128-bit',
ALGO_SK_AES_192 : 'AES 192-bit',
ALGO_SK_AES_256 : 'AES 256-bit'
}
# Compression Algorithms
ALGO_COMP_UNCOMP = 0 # Uncompressed
ALGO_COMP_ZIP = 1 # ZIP
ALGO_COMP_ZLIB = 2 # ZLIB
algo_comp_to_str = {
ALGO_COMP_UNCOMP : 'Uncompressed',
ALGO_COMP_ZIP : 'ZIP',
ALGO_COMP_ZLIB : 'ZLIB'
}
# Hash Algorithms
ALGO_HASH_MD5 = 1 # MD5
ALGO_HASH_SHA1 = 2 # SHA1
ALGO_HASH_RIPEMD160 = 3 # RIPEMD160
ALGO_HASH_SHA_DBL = 4 # double-width SHA
ALGO_HASH_MD2 = 5 # MD2
ALGO_HASH_TIGER192 = 6 # TIGER192
ALGO_HASH_HAVAL_5_160 = 7 # HAVAL-5-160
algo_hash_to_str = {
ALGO_HASH_MD5 : 'MD5',
ALGO_HASH_SHA1 : 'SHA1',
ALGO_HASH_RIPEMD160 : 'RIPEMD160',
ALGO_HASH_SHA_DBL : 'double-width SHA',
ALGO_HASH_MD2 : 'MD2',
ALGO_HASH_TIGER192 : 'TIGER192',
ALGO_HASH_HAVAL_5_160 : 'HAVAL-5-160'
}
# Signature types
SIG_TYPE_DOCUMENT = 0x00 # document signature, binary image
SIG_TYPE_DOCUMENT_CANON = 0x01 # document signature, canonical text
SIG_TYPE_STANDALONE = 0x02 # signature over just subpackets
SIG_TYPE_PK_USER_GEN = 0x10 # public key packet and user ID packet, generic certification
SIG_TYPE_PK_USER_PER = 0x11 # public key packet and user ID packet, persona
SIG_TYPE_PK_USER_CAS = 0x12 # public key packet and user ID packet, casual certification
SIG_TYPE_PK_USER_POS = 0x13 # public key packet and user ID packet, positive certification
SIG_TYPE_SUBKEY_BIND = 0x18 # subkey binding
SIG_TYPE_KEY = 0x1F # key signature
SIG_TYPE_KEY_REVOKE = 0x20 # key revocation
SIG_TYPE_SUBKEY_REVOKE = 0x28 # subkey revocation
SIG_TYPE_CERT_REVOKE = 0x30 # certificate revocation
SIG_TYPE_TIMESTAMP = 0x40 # timestamp
sig_type_to_str = {
SIG_TYPE_DOCUMENT : 'document signature, binary image',
SIG_TYPE_DOCUMENT_CANON : 'document signature, canonical text',
SIG_TYPE_STANDALONE : 'signature over just subpackets',
SIG_TYPE_PK_USER_GEN : 'public key packet and user ID packet, generic certification',
SIG_TYPE_PK_USER_PER : 'public key packet and user ID packet, persona',
SIG_TYPE_PK_USER_CAS : 'public key packet and user ID packet, casual certification',
SIG_TYPE_PK_USER_POS : 'public key packet and user ID packet, positive certification',
SIG_TYPE_SUBKEY_BIND : 'subkey binding',
SIG_TYPE_KEY : 'key signature',
SIG_TYPE_KEY_REVOKE : 'key revocation',
SIG_TYPE_SUBKEY_REVOKE : 'subkey revocation',
SIG_TYPE_CERT_REVOKE : 'certificate revocation',
SIG_TYPE_TIMESTAMP : 'timestamp'
}
# Signature sub-packet types
SIG_SUB_TYPE_CREATE_TIME = 2 # signature creation time
SIG_SUB_TYPE_EXPIRE_TIME = 3 # signature expiration time
SIG_SUB_TYPE_EXPORT_CERT = 4 # exportable certification
SIG_SUB_TYPE_TRUST_SIG = 5 # trust signature
SIG_SUB_TYPE_REGEXP = 6 # regular expression
SIG_SUB_TYPE_REVOCABLE = 7 # revocable
SIG_SUB_TYPE_KEY_EXPIRE = 9 # key expiration time
SIG_SUB_TYPE_PLACEHOLDER = 10 # placeholder for backward compatibility
SIG_SUB_TYPE_PREF_SYMM_ALGO = 11 # preferred symmetric algorithms
SIG_SUB_TYPE_REVOKE_KEY = 12 # revocation key
SIG_SUB_TYPE_ISSUER_KEY_ID = 16 # issuer key ID
SIG_SUB_TYPE_NOTATION = 20 # notation data
SIG_SUB_TYPE_PREF_HASH_ALGO = 21 # preferred hash algorithms
SIG_SUB_TYPE_PREF_COMP_ALGO = 22 # preferred compression algorithms
SIG_SUB_TYPE_KEY_SRV_PREF = 23 # key server preferences
SIG_SUB_TYPE_PREF_KEY_SRVR = 24 # preferred key server
SIG_SUB_TYPE_PRIM_USER_ID = 25 # primary user id
SIG_SUB_TYPE_POLICY_URL = 26 # policy URL
SIG_SUB_TYPE_KEY_FLAGS = 27 # key flags
SIG_SUB_TYPE_SGNR_USER_ID = 28 # signer's user id
SIG_SUB_TYPE_REVOKE_REASON = 29 # reason for revocation
sig_sub_type_to_str = {
SIG_SUB_TYPE_CREATE_TIME : 'signature creation time',
SIG_SUB_TYPE_EXPIRE_TIME : 'signature expiration time',
SIG_SUB_TYPE_EXPORT_CERT : 'exportable certification',
SIG_SUB_TYPE_TRUST_SIG : 'trust signature',
SIG_SUB_TYPE_REGEXP : 'regular expression',
SIG_SUB_TYPE_REVOCABLE : 'revocable',
SIG_SUB_TYPE_KEY_EXPIRE : 'key expiration time',
SIG_SUB_TYPE_PLACEHOLDER : 'placeholder for backward compatibility',
SIG_SUB_TYPE_PREF_SYMM_ALGO : 'preferred symmetric algorithms',
SIG_SUB_TYPE_REVOKE_KEY : 'revocation key',
SIG_SUB_TYPE_ISSUER_KEY_ID : 'issuer key ID',
SIG_SUB_TYPE_NOTATION : 'notation data',
SIG_SUB_TYPE_PREF_HASH_ALGO : 'preferred hash algorithms',
SIG_SUB_TYPE_PREF_COMP_ALGO : 'preferred compression algorithms',
SIG_SUB_TYPE_KEY_SRV_PREF : 'key server preferences',
SIG_SUB_TYPE_PREF_KEY_SRVR : 'preferred key server',
SIG_SUB_TYPE_PRIM_USER_ID : 'primary user id',
SIG_SUB_TYPE_POLICY_URL : 'policy URL',
SIG_SUB_TYPE_KEY_FLAGS : 'key flags',
SIG_SUB_TYPE_SGNR_USER_ID : "signer's user id",
SIG_SUB_TYPE_REVOKE_REASON : 'reason for revocation'
}
# in a signature subpacket there may be a revocation reason, these codes indicate
# the reason
REVOKE_REASON_NONE = 0 # No reason specified
REVOKE_REASON_SUPER = 0x01 # Key is superceded
REVOKE_REASON_COMPR = 0x02 # Key has been compromised
REVOKE_REASON_NOT_USED = 0x03 # Key is no longer used
REVOKE_REASON_ID_INVALID = 0x20 # user id information is no longer valid
revoke_reason_to_str = {
REVOKE_REASON_NONE : 'No reason specified',
REVOKE_REASON_SUPER : 'Key is superceded',
REVOKE_REASON_COMPR : 'Key has been compromised',
REVOKE_REASON_NOT_USED : 'Key is no longer used',
REVOKE_REASON_ID_INVALID : 'user id information is no longer valid'
}
# These flags are used in a 'key flags' signature subpacket
KEY_FLAGS1_MAY_CERTIFY = 0x01 # This key may be used to certify other keys
KEY_FLAGS1_MAY_SIGN = 0x02 # This key may be used to sign data
KEY_FLAGS1_MAY_ENC_COMM = 0x04 # This key may be used to encrypt communications
KEY_FLAGS1_MAY_ENC_STRG = 0x08 # This key may be used to encrypt storage
KEY_FLAGS1_PRIV_MAYBE_SPLIT = 0x10 # Private component have be split through secret-sharing mech.
KEY_FLAGS1_GROUP = 0x80 # Private component may be among group
# A revocation key subpacket has these class values
REVOKE_KEY_CLASS_MAND = 0x80 # this bit must always be set
REVOKE_KEY_CLASS_SENS = 0x40 # sensitive
def get_whole_number(msg, idx, numlen) :
"""get_whole_number(msg, idx, numlen)
extracts a "whole number" field of length numlen from msg at index idx
returns (<whole number>, new_idx) where the whole number is a long integer
and new_idx is the index of the next element in the message"""
n = 0L
while numlen > 0 :
b = (struct.unpack("B", msg[idx:idx+1]))[0]
n = n * 256L + long(b)
idx = idx + 1
numlen = numlen - 1
return (n, idx)
def get_whole_int(msg, idx, numlen) :
"""get_whole_int(msg, idx, numlen)
same as get_whole_number but returns the number as an int for convenience"""
n, idx = get_whole_number(msg, idx, numlen)
return int(n), idx
def pack_long(l) :
"""pack_long(l)
returns big-endian representation of unsigned long integer"""
arr = []
while l > 0 :
arr.insert(0, struct.pack("B", l & 0xff))
l >>= 8
return ''.join(arr)
def pack_mpi(l) :
"""pack_mpi(l)
returns the PGP Multi-Precision Integer representation of unsigned long integer"""
s = pack_long(l)
# the len is the number of bits, counting only from the MSB,
# so we need to account for that
bits = (len(s) - 1) * 8
if len(s) > 0 :
n = ord(s[0])
while n != 0 :
bits += 1
n >>= 1
else :
bits = 0 # otherwise bits == -8
return struct.pack(">H", bits) + s
def get_sig_subpak_len(msg, idx) :
"""get_sig_subpak_len(msg, idx)
extracts a signature subpacket length field
returns (subpak_len, new_idx)"""
plen, idx = get_whole_int(msg, idx, 1)
if plen < 192 :
return plen, idx
if plen < 255 :
plen2, idx = get_whole_int(msg, idx, 1)
return ((plen - 192) << 8) + plen2 + 192, idx
return get_whole_int(msg, idx, 4)
def get_n_mpi(msg, idx) :
"""get_mpi(msg, idx)
extracts a multi-precision integer field from the message msg at index idx
returns (n, <mpi>, new_idx) where the mpi is a long integer and new_idx is
the index of the next element in the message and n is the number of bits of
precision in <mpi>"""
ln, idx = get_whole_int(msg, idx, 2)
return (ln,) + get_whole_number(msg, idx, (ln+7)/8)
def get_mpi(msg, idx) :
"""get_mpi(msg, idx)
extracts a multi-precision integer field from the message msg at index idx
returns (<mpi>, new_idx) where the mpi is a long integer and new_idx is
the index of the next element in the message"""
l = get_n_mpi(msg, idx)
return (l[1], l[2])
def str_to_hex(s) :
return ''.join(map(lambda x : hex(ord(x))[2:].zfill(2), list(s)))
def duration_to_str(s) :
if s == 0 :
return 'never'
secs = s % 60
s = s / 60
mins = s % 60
s = s / 60
hrs = s % 60
s = s / 24
days = s
return '%d days %02d:%02d:%02d' % (days, hrs, mins, secs)
def map_to_str(m, vals) :
slist = []
# change to a list if it's a single value
if type(vals) != types.ListType and type(vals) != types.TupleType :
vals = list((vals,))
for i in vals :
if m.has_key(i) :
slist.append(m[i])
else :
slist.append('unknown(' + str(i) + ')')
return ', '.join(slist)
class pgp_packet :
def __init__(self) :
self.pkt_typ = None
def __str__(self) :
return map_to_str(ctb_pkt_to_str, self.pkt_typ)
class public_key(pgp_packet) :
def __init__(self) :
pgp_packet.__init__(self)
self.version = None
self.pk_algo = None
self.key_size = 0
self.fingerprint_ = None # we cache this upon calculation
def fingerprint(self) :
# return cached value if we have it
if self.fingerprint_ :
return self.fingerprint_
# otherwise calculate it now and cache it
# v3 and v4 are calculated differently
if self.version == 3 :
h = hashlib.new('md5')
h.update(pack_long(self.pk_rsa_mod))
h.update(pack_long(self.pk_rsa_exp))
self.fingerprint_ = h.digest()
elif self.version == 4 :
# we hash what would be the whole PGP message containing
# the pgp certificate
h = hashlib.new('sha1')
h.update('\x99')
# we need to has the length of the packet as well
buf = self.serialize()
h.update(struct.pack(">H", len(buf)))
h.update(buf)
self.fingerprint_ = h.digest()
else :
raise RuntimeError("unknown public key version %d" % self.version)
return self.fingerprint_
def key_id(self) :
if self.version == 3 :
return pack_long(self.pk_rsa_mod & 0xffffffffffffffffL)
elif self.version == 4 :
return self.fingerprint()[-8:]
def serialize(self) :
chunks = []
if self.version == 3 :
chunks.append(struct.pack('>BIHB', self.version, int(self.timestamp), self.validity, self.pk_algo))
chunks.append(pack_mpi(self.pk_rsa_mod))
chunks.append(pack_mpi(self.pk_rsa_exp))
elif self.version == 4 :
chunks.append(struct.pack('>BIB', self.version, int(self.timestamp), self.pk_algo))
if self.pk_algo == ALGO_PK_RSA_ENC_OR_SIGN or self.pk_algo == ALGO_PK_RSA_SIGN_ONLY :
chunks.append(pack_mpi(self.pk_rsa_mod))
chunks.append(pack_mpi(self.pk_rsa_exp))
elif self.pk_algo == ALGO_PK_DSA :
chunks.append(pack_mpi(self.pk_dsa_prime_p))
chunks.append(pack_mpi(self.pk_dsa_grp_ord_q))
chunks.append(pack_mpi(self.pk_dsa_grp_gen_g))
chunks.append(pack_mpi(self.pk_dsa_pub_key))
elif self.pk_algo == ALGO_PK_ELGAMAL_ENC_OR_SIGN or self.pk_algo == ALGO_PK_ELGAMAL_ENC_ONLY :
chunks.append(pack_mpi(self.pk_elgamal_prime_p))
chunks.append(pack_mpi(self.pk_elgamal_grp_gen_g))
chunks.append(pack_mpi(self.pk_elgamal_pub_key))
else :
raise RuntimeError("unknown public key algorithm %d" % (self.pk_algo))
return ''.join(chunks)
def deserialize(self, msg, idx, pkt_len) :
idx_save = idx
self.version, idx = get_whole_int(msg, idx, 1)
if self.version != 2 and self.version != 3 and self.version != 4 :
raise RuntimeError('unknown public key packet version %d at %d' % (self.version, idx_save))
if self.version == 2 : # map v2 into v3 for coding simplicity since they're structurally the same
self.version = 3
self.timestamp, idx = get_whole_number(msg, idx, 4)
self.timestamp = float(self.timestamp)
if self.version == 3 :
self.validity, idx = get_whole_number(msg, idx, 2)
self.pk_algo, idx = get_whole_int(msg, idx, 1)
if self.pk_algo == ALGO_PK_RSA_ENC_OR_SIGN or self.pk_algo == ALGO_PK_RSA_SIGN_ONLY :
self.key_size, self.pk_rsa_mod, idx = get_n_mpi(msg, idx)
self.pk_rsa_exp, idx = get_mpi(msg, idx)
elif self.pk_algo == ALGO_PK_DSA :
l1, self.pk_dsa_prime_p, idx = get_n_mpi(msg, idx)
self.pk_dsa_grp_ord_q, idx = get_mpi(msg, idx)
self.pk_dsa_grp_gen_g, idx = get_mpi(msg, idx)
l2, self.pk_dsa_pub_key, idx = get_n_mpi(msg, idx)
self.key_size = l1 + l2
elif self.pk_algo == ALGO_PK_ELGAMAL_ENC_OR_SIGN or self.pk_algo == ALGO_PK_ELGAMAL_ENC_ONLY :
self.key_size, self.pk_elgamal_prime_p, idx = get_n_mpi(msg, idx)
self.pk_elgamal_grp_gen_g, idx = get_mpi(msg, idx)
self.pk_elgamal_pub_key, idx = get_mpi(msg, idx)
else :
raise RuntimeError("unknown public key algorithm %d at %d" % (self.pk_algo, idx_save))
def __str__(self) :
sio = cStringIO.StringIO()
sio.write(pgp_packet.__str__(self) + "\n")
sio.write("version: " + str(self.version) + "\n")
sio.write("timestamp: " + time.ctime(self.timestamp) + "\n")
if self.version == 3 :
sio.write("validity: " + time.ctime(self.timestamp + self.validity * 24 * 60 * 60) + "\n")
sio.write("pubkey algo: " + algo_pk_to_str[self.pk_algo] + "\n")
if self.pk_algo == ALGO_PK_RSA_ENC_OR_SIGN or self.pk_algo == ALGO_PK_RSA_SIGN_ONLY :
sio.write("pk_rsa_mod: " + hex(self.pk_rsa_mod) + "\n")
sio.write("pk_rsa_exp: " + hex(self.pk_rsa_exp) + "\n")
elif self.pk_algo == ALGO_PK_DSA :
sio.write("pk_dsa_prime_p: " + hex(self.pk_dsa_prime_p) + "\n")
sio.write("pk_dsa_grp_ord_q: " + hex(self.pk_dsa_grp_ord_q) + "\n")
sio.write("pk_dsa_grp_gen_g: " + hex(self.pk_dsa_grp_gen_g) + "\n")
sio.write("pk_dsa_pub_key: " + hex(self.pk_dsa_pub_key) + "\n")
elif self.pk_algo == ALGO_PK_ELGAMAL_ENC_OR_SIGN or self.pk_algo == ALGO_PK_ELGAMAL_ENC_ONLY :
sio.write("pk_elgamal_prime_p: " + hex(self.pk_elgamal_prime_p) + "\n")
sio.write("pk_elgamal_grp_gen_g: " + hex(self.pk_elgamal_grp_gen_g) + "\n")
sio.write("pk_elgamal_pub_key: " + hex(self.pk_elgamal_pub_key) + "\n")
return sio.getvalue()
class user_id(pgp_packet) :
def __init__(self) :
pgp_packet.__init__(self)
self.id = None
def deserialize(self, msg, idx, pkt_len) :
self.id = msg[idx:idx + pkt_len]
def __str__(self) :
return pgp_packet.__str__(self) + "\n" + "id: " + self.id + "\n"
class signature(pgp_packet) :
def __init__(self) :
pgp_packet.__init__(self)
self.version = None
self.sig_type = None
self.pk_algo = None
self.hash_algo = None
self.hash_frag = None
def key_id(self) :
if self.version == 3 :
return self.key_id_
else :
i = self.get_hashed_subpak(SIG_SUB_TYPE_ISSUER_KEY_ID)
if i :
return i[1]
i = self.get_unhashed_subpak(SIG_SUB_TYPE_ISSUER_KEY_ID)
if i :
return i[1]
return None
def expiration(self) :
if self.version != 4 :
raise ValueError('v3 signatures don\'t have expirations')
i = self.get_hashed_subpak(SIG_SUB_TYPE_KEY_EXPIRE)
if i :
return i[1]
return 0 # if not present then it never expires
def get_hashed_subpak(self, typ) :
for i in self.hashed_subpaks :
if i[0] == typ :
return i
return None
def get_unhashed_subpak(self, typ) :
for i in self.unhashed_subpaks :
if i[0] == typ :
return i
return None
def deserialize_subpacket(self, msg, idx) :
sublen, idx = get_sig_subpak_len(msg, idx)
subtype, idx = get_whole_int(msg, idx, 1)
if subtype == SIG_SUB_TYPE_CREATE_TIME : # key creation time
tm, idx = get_whole_number(msg, idx, 4)
return (subtype, float(tm)), idx
if subtype == SIG_SUB_TYPE_EXPIRE_TIME or subtype == SIG_SUB_TYPE_KEY_EXPIRE :
s, idx = get_whole_int(msg, idx, 4)
return (subtype, s), idx
if subtype == SIG_SUB_TYPE_EXPORT_CERT or subtype == SIG_SUB_TYPE_REVOCABLE :
bool, idx = get_whole_int(msg, idx, 1)
return (subtype, bool), idx
if subtype == SIG_SUB_TYPE_TRUST_SIG : # trust signature
trust_lvl, idx = get_whole_int(msg, idx, 1)
trust_amt, idx = get_whole_int(msg, idx, 1)
return (subtype, trust_lvl, trust_amt), idx
if subtype == SIG_SUB_TYPE_REGEXP : # regular expression
expr = msg[idx:idx+sublen-1]
idx = idx + sublen - 1
return (subtype, expr), idx
if subtype == SIG_SUB_TYPE_PREF_SYMM_ALGO or subtype == SIG_SUB_TYPE_PREF_HASH_ALGO or subtype == SIG_SUB_TYPE_PREF_COMP_ALGO or subtype == SIG_SUB_TYPE_KEY_FLAGS :
algo_list = map(lambda x : ord(x), list(msg[idx:idx+sublen-1]))
idx = idx + sublen - 1
return (subtype, algo_list), idx
if subtype == SIG_SUB_TYPE_REVOKE_KEY : # revocation key
cls, idx = get_whole_int(msg, idx, 1)
algo, idx = get_whole_int(msg, idx, 1)
fprint = msg[idx:idx+20]
idx = idx + 20
return (subtype, cls, algo, fprint), idx
if subtype == SIG_SUB_TYPE_ISSUER_KEY_ID : # issuer key ID
k_id = msg[idx:idx+8]
idx = idx + 8
return (subtype, k_id), idx
if subtype == SIG_SUB_TYPE_NOTATION : # notation data
flg1, idx = get_whole_int(msg, idx, 1)
flg2, idx = get_whole_int(msg, idx, 1)
flg3, idx = get_whole_int(msg, idx, 1)
flg4, idx = get_whole_int(msg, idx, 1)
name_len, idx = get_whole_int(msg, idx, 2)
val_len, idx = get_whole_int(msg, idx, 2)
nam = msg[idx:idx+name_len]
idx = idx + name_len
val = msg[idx:idx+val_len]
idx = idx + val_len
return (subtype, flg1, flg2, flg3, flg4, nam, val), idx
if subtype == SIG_SUB_TYPE_KEY_SRV_PREF : # key server preferences
prefs = [ ord(x) for x in msg[idx:idx+sublen-1] ]
idx = idx + sublen - 1
return (subtype, prefs), idx
if subtype == SIG_SUB_TYPE_PREF_KEY_SRVR : # preferred key server
url = msg[idx:idx+sublen-1]
idx = idx + sublen - 1
return (subtype, url), idx
if subtype == SIG_SUB_TYPE_PRIM_USER_ID : # primary user id
bool, idx = get_whole_int(msg, idx, 1)
return (subtype, bool), idx
if subtype == SIG_SUB_TYPE_POLICY_URL : # policy URL
url = msg[idx:idx+sublen-1]
idx = idx + sublen - 1
return (subtype, url), idx
if subtype == SIG_SUB_TYPE_SGNR_USER_ID : # signer's user id
signer_id = msg[idx:idx+sublen-1]
idx = idx + sublen - 1
return (subtype, signer_id), idx
if subtype == SIG_SUB_TYPE_REVOKE_REASON : # reason for revocation
rev_code, idx = get_whole_int(msg, idx, 1)
reas_len = sublen - 2
reas = msg[idx:idx+reas_len]
idx = idx + reas_len
return (subtype, rev_code, reas), idx
# otherwise the subpacket is an unknown type, so we just pack the data in it
dat = msg[idx:idx+sublen-1]
idx = idx + sublen - 1
return (subtype, dat), idx
def is_primary_user_id(self) :
"""is_primary_user_id()
returns true if this signature contains a primary user id subpacket with value true"""
for i in self.hashed_subpaks :
if i[0] == SIG_SUB_TYPE_PRIM_USER_ID :
return i[1]
return 0
def subpacket_to_str(self, sp) :
if sp[0] == SIG_SUB_TYPE_CREATE_TIME : # signature creation time
return 'creation time: ' + time.ctime(sp[1])
if sp[0] == SIG_SUB_TYPE_EXPIRE_TIME : # signature expiration time
return 'signature expires: ' + duration_to_str(sp[1])
if sp[0] == SIG_SUB_TYPE_EXPORT_CERT : # exportable certification
if sp[1] :
return 'signature exportable: TRUE'
else :
return 'signature exportable: FALSE'
if sp[0] == SIG_SUB_TYPE_TRUST_SIG : # trust signature
if sp[1] == 0 :
return 'trust: ordinary'
if sp[1] == 1 :
return 'trust: introducer (%d)' % sp[2]
if sp[1] == 2 :
return 'trust: meta-introducer (%d)' % sp[2]
return 'trust: %d %d' % (sp[1], sp[2])
if sp[0] == SIG_SUB_TYPE_REGEXP : # regular expression
return 'regexp: ' + sp[1]
if sp[0] == SIG_SUB_TYPE_REVOCABLE : # revocable
if sp[1] :
return 'signature revocable: TRUE'
else :
return 'signature revocable: FALSE'
if sp[0] == SIG_SUB_TYPE_KEY_EXPIRE : # key expiration time
return 'key expires: ' + duration_to_str(sp[1])
if sp[0] == SIG_SUB_TYPE_PREF_SYMM_ALGO : # preferred symmetric algorithms
return 'preferred symmetric algorithms: ' + map_to_str(algo_sk_to_str, sp[1])
if sp[0] == SIG_SUB_TYPE_REVOKE_KEY : # revocation key
s = 'revocation key: '
if sp[1] & REVOKE_KEY_CLASS_SENS :
s = s + '(sensitive) '
return s + map_to_str(algo_pk_to_str, sp[2]) + ' ' + str_to_hex(sp[3])
if sp[0] == SIG_SUB_TYPE_ISSUER_KEY_ID : # issuer key ID
return 'issuer key id: ' + str_to_hex(sp[1])
if sp[0] == SIG_SUB_TYPE_NOTATION : # notation data
return 'notation: flags(%d, %d, %d, %d) name(%s) value(%s)' % sp[1:]
if sp[0] == SIG_SUB_TYPE_PREF_HASH_ALGO : # preferred hash algorithms
return 'preferred hash algorithms: ' + map_to_str(algo_hash_to_str, sp[1])
if sp[0] == SIG_SUB_TYPE_PREF_COMP_ALGO : # preferred compression algorithms
return 'preferred compression algorithms: ' + map_to_str(algo_comp_to_str, sp[1])
if sp[0] == SIG_SUB_TYPE_KEY_SRV_PREF : # key server preferences
s = 'key server preferences: '
prefs = []
if sp[1][0] & 0x80 :
prefs.append('No-modify')
return s + ', '.join(prefs)
if sp[0] == SIG_SUB_TYPE_PREF_KEY_SRVR : # preferred key server
return 'preferred key server: %s' % sp[1]
if sp[0] == SIG_SUB_TYPE_PRIM_USER_ID : # primary user id
if sp[1] :
return 'is primary user id'
else :
return 'is not primary user id'
if sp[0] == SIG_SUB_TYPE_POLICY_URL : # policy URL
return 'policy url: %s' % sp[1]
if sp[0] == SIG_SUB_TYPE_KEY_FLAGS : # key flags
flags = []
flgs1 = 0
if len(sp[1]) >= 1 :
flgs1 = sp[1][0]
if flgs1 & KEY_FLAGS1_MAY_CERTIFY :
flags.append('may certify other keys')
if flgs1 & KEY_FLAGS1_MAY_SIGN :
flags.append('may sign data')
if flgs1 & KEY_FLAGS1_MAY_ENC_COMM :
flags.append('may encrypt communications')
if flgs1 & KEY_FLAGS1_MAY_ENC_STRG :
flags.append('may encrypt storage')
if flgs1 & KEY_FLAGS1_PRIV_MAYBE_SPLIT :
flags.append('private component may have been secret-sharing split')
if flgs1 & KEY_FLAGS1_GROUP :
flags.append('group key')
return 'key flags: ' + ', '.join(flags)
if sp[0] == SIG_SUB_TYPE_SGNR_USER_ID : # signer's user id
return 'signer id: ' + sp[1]
if sp[0] == SIG_SUB_TYPE_REVOKE_REASON : # reason for revocation
reas = ''
if revoke_reason_to_str.has_key(sp[1]) :
reas = revoke_reason_to_str[sp[1]]
return 'reason for revocation: %s, %s' % (reas, sp[2])
# this means we don't know what the thing is so we just have raw data
return 'unknown(%d): %s' % (sp[0], str_to_hex(sp[1]))
def deserialize(self, msg, idx, pkt_len) :
self.version, idx = get_whole_int(msg, idx, 1)
if self.version == 2 :
self.version = 3
if self.version == 3 :
hash_len, idx = get_whole_number(msg, idx, 1)
self.sig_type, idx = get_whole_int(msg, idx, 1)
self.timestamp, idx = get_whole_number(msg, idx, 4)
self.timestamp = float(self.timestamp)
self.key_id_ = msg[idx:idx+8]
idx = idx + 8
self.pk_algo, idx = get_whole_int(msg, idx, 1)
self.hash_algo, idx = get_whole_int(msg, idx, 1)
elif self.version == 4:
self.sig_type, idx = get_whole_int(msg, idx, 1)
self.pk_algo, idx = get_whole_int(msg, idx, 1)
self.hash_algo, idx = get_whole_int(msg, idx, 1)
sub_paks_len, idx = get_whole_int(msg, idx, 2)
sub_paks_end = idx + sub_paks_len
self.hashed_subpaks = []
while idx < sub_paks_end :
sp, idx = self.deserialize_subpacket(msg, idx)
self.hashed_subpaks.append(sp)
sub_paks_len, idx = get_whole_int(msg, idx, 2)
sub_paks_end = idx + sub_paks_len
self.unhashed_subpaks = []
while idx < sub_paks_end :
sp, idx = self.deserialize_subpacket(msg, idx)
self.unhashed_subpaks.append(sp)
else :
raise RuntimeError('unknown signature packet version %d at %d' % (self.version, idx))
self.hash_frag, idx = get_whole_number(msg, idx, 2)
if self.pk_algo == ALGO_PK_RSA_ENC_OR_SIGN or self.pk_algo == ALGO_PK_RSA_SIGN_ONLY :
self.rsa_sig, idx = get_mpi(msg, idx)
elif self.pk_algo == ALGO_PK_DSA :
self.dsa_sig_r, idx = get_mpi(msg, idx)
self.dsa_sig_s, idx = get_mpi(msg, idx)
else :
raise RuntimeError('unknown public-key algorithm (%d) in signature at %d' % (self.pk_algo, idx))
return idx
def __str__(self) :
sio = cStringIO.StringIO()
sio.write(pgp_packet.__str__(self) + "\n")
sio.write("version: " + str(self.version) + "\n")
sio.write("type: " + sig_type_to_str[self.sig_type] + "\n")
if self.version == 3 :
sio.write("timestamp: " + time.ctime(self.timestamp) + "\n")
sio.write("key_id: " + str_to_hex(self.key_id_) + "\n")
elif self.version == 4 :
sio.write("hashed subpackets:\n")
for i in self.hashed_subpaks :
sio.write(" " + self.subpacket_to_str(i) + "\n")
sio.write("unhashed subpackets:\n")
for i in self.unhashed_subpaks :
sio.write(" " + self.subpacket_to_str(i) + "\n")
sio.write("hash_algo: " + algo_hash_to_str[self.hash_algo] + "\n")
sio.write("hash_frag: " + hex(self.hash_frag) + "\n")
if self.pk_algo == ALGO_PK_RSA_ENC_OR_SIGN or self.pk_algo == ALGO_PK_RSA_SIGN_ONLY :
sio.write("pk_algo: RSA\n")
sio.write("rsa_sig: " + hex(self.rsa_sig) + "\n")
elif self.pk_algo == ALGO_PK_DSA :
sio.write("pk_algo: DSA\n")
sio.write("dsa_sig_r: " + hex(self.dsa_sig_r) + "\n")
sio.write("dsa_sig_s: " + hex(self.dsa_sig_s) + "\n")
return sio.getvalue()
#
# This class encapsulates an openpgp public "certificate", which is formed in a message as
# a series of PGP packets of certain types in certain orders
#
class pgp_certificate(object):
def __init__(self) :
self.version = None
self.public_key = None
self.revocation = None
#self.user_id = None
self.user_ids = []
self.rvkd_user_ids = []
def __str__(self) :
sio = cStringIO.StringIO()
sio.write("PGP Public Key Certificate v%d\n" % self.version)
sio.write("Primary ID: %s\n" % self.user_id)
sio.write(str(self.public_key))
for uid in self.user_ids :
sio.write(str(uid[0]))
for sig in uid[1:] :
sio.write(" " + str(sig))
return sio.getvalue()
def get_user_id(self):
# take the LAST one in the list, not first
# they appear to be ordered FIFO from the key and that means if you
# added a key later then it won't show the one you expect
return self.user_ids[-1][0].id
user_id = property(get_user_id)
def expiration(self) :
if self.version == 3 :
if self.public_key.validity == 0 :
return 0
return self.public_key.timestamp + self.public_key.validity * 24 * 60 * 60
else : # self.version == 4
# this is a bit more complex, we need to find the signature on the
# key and get its expiration
u_id = self.user_ids[0]
for i in u_id[1:] :
if i.sig_type == SIG_TYPE_PK_USER_GEN :
exp = i.expiration()
if exp == 0 :
return 0
return self.public_key.timestamp + exp
return 0
def key_size(self) :
return 0
def load(self, pkts) :
"""load(pkts)
Initialize the pgp_certificate with a list of OpenPGP packets. The list of packets will
be scanned to make sure they are valid for a pgp certificate."""
# each certificate should begin with a public key packet
if pkts[0].pkt_typ != CTB_PKT_PK_CERT :
raise ValueError('first PGP packet should be a public-key packet, not %s' % map_to_str(ctb_pkt_to_str, pkts[0].pkt_typ))
# all versions have a public key although in a v4 cert the main key is only
# used for signing, never encryption
self.public_key = pkts[0]
# ok, then what's the version
self.version = self.public_key.version
# now the behavior splits a little depending on the version
if self.version == 3 :
pkt_idx = 1
# second packet could be a revocation
if pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].version != 3 :
raise ValueError('version 3 cert has version %d signature' % pkts[pkt_idx].version)
if pkts[pkt_idx].sig_type != SIG_TYPE_KEY_REVOKE :
raise ValueError('v3 cert revocation sig has type %s' % map_to_str(sig_type_to_str, pkts[pkt_idx].sig_type))
# ok, well at least the type is good, we'll assume the cert is
# revoked
self.revocation = pkts[pkt_idx]
# increment the pkt_idx to go to the next one
pkt_idx = pkt_idx + 1
# the following packets are User ID, Signature pairs
while pkt_idx < len(pkts) :
# this packet is supposed to be a user id
if pkts[pkt_idx].pkt_typ != CTB_PKT_USER_ID :
raise ValueError('pgp packet %d is not user id, is %s' % (pkt_idx, map_to_str(ctb_pkt_to_str, pkts[pkt_idx].pkt_typ)))
user_id = [pkts[pkt_idx]]
pkt_idx = pkt_idx + 1
is_revoked = 0
is_primary_user_id = 0
# there may be a sequence of signatures following the user id which
# bind it to the key
while pkt_idx < len(pkts) and pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].sig_type not in (SIG_TYPE_PK_USER_GEN, SIG_TYPE_PK_USER_PER, SIG_TYPE_PK_USER_CAS, SIG_TYPE_PK_USER_POS, SIG_TYPE_CERT_REVOKE) :
raise ValueError('signature %d doesn\'t bind user_id to key, is %s' % (pkt_idx, map_to_str(sig_type_to_str, pkts[pkt_idx].sig_typ)))
if pkts[pkt_idx].version != 3 :
raise ValueError('version 3 cert has version %d signature' % pkts[pkt_idx].version)
user_id.append(pkts[pkt_idx])
# was the a revocation?
if pkts[pkt_idx].sig_type == SIG_TYPE_CERT_REVOKE :
is_revoked = 1
# is this a primary user id?
if not self.cert_id and pkts[pkt_idx].sig_type == SIG_TYPE_PK_USER_GEN :
is_primary_user_id = pkt_idx
pkt_idx = pkt_idx + 1
# we get the cert id from the first sig that's a candidate for being
# the primary user id
if not self.cert_id and is_primary_user_id and not is_revoked :
# the cert type must be generic pubkey and user id
self.user_id = user_id[0].id
# append the user ID and signature(s) onto a list
if is_revoked :
self.rvkd_user_ids.append(user_id)
else :
self.user_ids.append(user_id)
else : # self.version == 4
pkt_idx = 1
self.direct_key_sigs = []
self.subkeys = []
self.rvkd_subkeys = []
# second packet could be a revocation (or a direct key self signature)
if pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].version != 4 :
raise ValueError('version 4 cert has version %d signature' % pkts[pkt_idx].version)
if pkts[pkt_idx].sig_type == SIG_TYPE_KEY_REVOKE :
# ok, well at least the type is good, we'll assume the cert is
# revoked
self.revocation = pkts[pkt_idx]
# increment the pkt_idx to go to the next one
pkt_idx = pkt_idx + 1
# there can then be a sequence of direct key signatures
while pkt_idx < len(pkts) and pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].sig_type != SIG_TYPE_KEY :
raise ValueError('v4 cert signature has type %s, supposed to be direct key' % map_to_str(sig_type_to_str, pkts[pkt_idx].sig_type))
self.direct_key_sigs.append(pkts[pkt_idx])
pkt_idx = pkt_idx + 1
# the following packets are User ID, Signature... sets or subkey, signature... sets
while pkt_idx < len(pkts) :
# this packet is supposed to be a user id
if pkts[pkt_idx].pkt_typ == CTB_PKT_USER_ID :
user_id = [pkts[pkt_idx]]
is_revoked = 0
is_primary_user_id = 0
pkt_idx = pkt_idx + 1
# there may be a sequence of signatures following the user id which
# bind it to the key
while pkt_idx < len(pkts) and pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].sig_type not in (SIG_TYPE_PK_USER_GEN, SIG_TYPE_PK_USER_PER, SIG_TYPE_PK_USER_CAS, SIG_TYPE_PK_USER_POS, SIG_TYPE_CERT_REVOKE) :
raise ValueError('signature %d doesn\'t bind user_id to key, is %s' % (pkt_idx, map_to_str(sig_type_to_str, pkts[pkt_idx].sig_typ)))
user_id.append(pkts[pkt_idx])
# was the a revocation?
if pkts[pkt_idx].sig_type == SIG_TYPE_CERT_REVOKE :
is_revoked = 1
# is this the primary user id?
if pkts[pkt_idx].version == 4 and pkts[pkt_idx].is_primary_user_id() :
is_primary_user_id = 1
pkt_idx = pkt_idx + 1
# append the user ID and signature(s) onto the list
if is_revoked :
self.rvkd_user_ids.append(user_id)
else :
self.user_ids.append(user_id)
elif pkts[pkt_idx].pkt_typ == CTB_PKT_PK_SUB :
# collect this list of subkey + signatures
subkey = [pkts[pkt_idx]]
pkt_idx = pkt_idx + 1
is_revoked = 0
# there may be a sequence of signatures following the user id which
# bind it to the key
while pkt_idx < len(pkts) and pkts[pkt_idx].pkt_typ == CTB_PKT_SIG :
if pkts[pkt_idx].sig_type not in (SIG_TYPE_SUBKEY_BIND, SIG_TYPE_SUBKEY_REVOKE) :
raise ValueError('signature %d doesn\'t bind subkey to key, is %s' % (pkt_idx, map_to_str(sig_type_to_str, pkts[pkt_idx].sig_typ)))
subkey.append(pkts[pkt_idx])
# was this a revocation?
if pkts[pkt_idx].sig_type == SIG_TYPE_SUBKEY_REVOKE :
is_revoked = 1
pkt_idx = pkt_idx + 1
# append the user ID and signature(s) onto the list
if is_revoked :
self.rvkd_subkeys.append(subkey)
else :
self.subkeys.append(subkey)
else :
raise ValueError('pgp packet %d is not user id or subkey, is %s' % (pkt_idx, map_to_str(ctb_pkt_to_str, pkts[pkt_idx].pkt_typ)))
# did we get all the things we needed?
#if not self.user_id :
# just take the first valid user id we encountered then
if len(self.user_ids) == 0 :
raise ValueError('no user id packet was present in the cert')
def get_ctb(msg, idx) :
"""get_ctb(msg, idx)
extracts a the "cypher type bit" information from message msg at index idx
returns (type, len, new_idx) where type is the enumerated type of the packet,
len is the length of the packet, and new_idx is the index of the next element
in the message"""
b, idx = get_whole_int(msg, idx, 1)
if (b & CTB_76_MASK) == CTB_76_NORMAL :
n_len = 0 # undefined length
if (b & CTB_PKT_LEN_MASK) == CTB_PKT_LEN_1 :
n_len = 1
if (b & CTB_PKT_LEN_MASK) == CTB_PKT_LEN_2 :
n_len = 2
if (b & CTB_PKT_LEN_MASK) == CTB_PKT_LEN_4 :
n_len = 4
if (b & CTB_PKT_LEN_MASK) == CTB_PKT_LEN_UNDEF :
n_len = 0
pkt_len = 0
if n_len > 0 :
pkt_len, idx = get_whole_int(msg, idx, n_len)
return (b & CTB_PKTV2_MASK) >> 2, pkt_len, idx
elif (b & CTB_76_MASK) == CTB_76_NEW :
plen, idx = get_whole_int(msg, idx, 1)
if plen < 192 :
return b & CTB_PKT_MASK, plen, idx
if plen < 224 :
plen2, idx = get_whole_int(msg, idx, 1)
return b & CTB_PKT_MASK, ((plen - 192) << 8) + plen2 + 192, idx
if plen == 255 :
plen, idx = get_whole_int(msg, idx, 4)
return b & CTB_PKT_MASK, plen, idx
else :
raise Exception, 'partial message bodies are not supported by this version (%d)', b
else :
raise Exception, "unknown (not \"normal\") cypher type bit %d at byte %d" % (b, idx)
def crc24(msg) :
crc24_init = 0xb704ce
crc24_poly = 0x1864cfb
crc = crc24_init
for i in list(msg) :
crc = crc ^ (ord(i) << 16)
for j in range(0, 8) :
crc = crc << 1
if crc & 0x1000000 :
crc = crc ^ crc24_poly
return crc & 0xffffff
def decode(msg) :
# each message is a sequence of packets so we go through the message
# and generate a list of packets and return that
pkt_list = []
idx = 0
msg_len = len(msg)
while idx < msg_len :
pkt_typ, pkt_len, idx = get_ctb(msg, idx)
pkt = None
if pkt_typ == CTB_PKT_PK_CERT or pkt_typ == CTB_PKT_PK_SUB :
pkt = public_key()
elif pkt_typ == CTB_PKT_USER_ID :
pkt = user_id()
elif pkt_typ == CTB_PKT_SIG :
pkt = signature()
if pkt :
pkt.pkt_typ = pkt_typ
pkt.deserialize(msg, idx, pkt_len)
if debug :
debug.write(pkt.__str__() + "\n")
else :
raise RuntimeError('unknown pgp packet type %d at %d' % (pkt_typ, idx))
pkt_list.append(pkt)
idx = idx + pkt_len
return pkt_list
def decode_msg(msg) :
# first we'll break the block up into lines and trim each line of any
# carriage return chars
pgpkey_lines = map(lambda x : x.rstrip(), msg.split('\n'))
# check out block
in_block = 0
in_data = 0
block_buf = cStringIO.StringIO()
for l in pgpkey_lines :
if not in_block :
if l == '-----BEGIN PGP PUBLIC KEY BLOCK-----' :
in_block = 1
continue
# are we at the actual data yet?
if not in_data :
if len(l) == 0 :
in_data = 1
continue
# are we at the checksum line?
if l[0] == '=' :
# get the checksum number
csum = base64.decodestring(l[1:5])
i = 0
csum, i = get_whole_number(csum, i, 3)
# convert the base64 cert data to binary data
cert_msg = base64.decodestring(block_buf.getvalue())
block_buf.close()
# check the checksum
if csum != crc24(cert_msg) :
raise Exception, 'bad checksum on pgp message'
# ok, the sum looks ok so we'll actually decode the thing
pkt_list = decode(cert_msg)
# turn it into a real cert
cert = pgp_certificate()
cert.load(pkt_list)
cert.raw_key = msg
return cert
# add the data to our buffer then
block_buf.write(l)
return None
def decode_multiple_keys(msg):
#ditto of above - but handling multiple certs/keys per file
certs = []
pgpkey_lines = map(lambda x : x.rstrip(), msg.split('\n'))
in_block = 0
block = ''
for l in pgpkey_lines :
if not in_block :
if l == '-----BEGIN PGP PUBLIC KEY BLOCK-----' :
in_block = 1
block += '%s\n' % l
continue
block += '%s\n' % l
if l == '-----END PGP PUBLIC KEY BLOCK-----':
in_block = 0
cert = decode_msg(block)
if cert:
certs.append(cert)
block = ''
continue
return certs
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