blob: d0cd2d7d44348d20e5298c277fcc7f0bf72dc422 [file] [log] [blame]
# portage_checksum.py -- core Portage functionality
# Copyright 1998-2004 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$
if not hasattr(__builtins__, "set"):
from sets import Set as set
from portage_const import PRIVATE_PATH,PRELINK_BINARY,HASHING_BLOCKSIZE
import os
import errno
import stat
import portage_exception
import portage_exec
import portage_locks
import commands
import md5, sha
#dict of all available hash functions
hashfunc_map = {}
hashorigin_map = {}
def _generate_hash_function(hashtype, hashobject, origin="unknown"):
def pyhash(filename):
"""
Run a checksum against a file.
@param filename: File to run the checksum against
@type filename: String
@return: The hash and size of the data
"""
f = open(filename, 'rb')
blocksize = HASHING_BLOCKSIZE
data = f.read(blocksize)
size = 0L
sum = hashobject()
while data:
sum.update(data)
size = size + len(data)
data = f.read(blocksize)
f.close()
return (sum.hexdigest(), size)
hashfunc_map[hashtype] = pyhash
hashorigin_map[hashtype] = origin
return pyhash
# Define hash functions, try to use the best module available. Later definitions
# override earlier ones
# Use the internal modules as last fallback
md5hash = _generate_hash_function("MD5", md5.new, origin="internal")
sha1hash = _generate_hash_function("SHA1", sha.new, origin="internal")
# Use pycrypto when available, prefer it over the internal fallbacks
try:
from Crypto.Hash import MD5, SHA, SHA256, RIPEMD
md5hash = _generate_hash_function("MD5", MD5.new, origin="pycrypto")
sha1hash = _generate_hash_function("SHA1", SHA.new, origin="pycrypto")
sha256hash = _generate_hash_function("SHA256", SHA256.new, origin="pycrypto")
rmd160hash = _generate_hash_function("RMD160", RIPEMD.new, origin="pycrypto")
except ImportError, e:
pass
# Use hashlib from python-2.5 if available and prefer it over pycrypto and internal fallbacks.
# Need special handling for RMD160 as it may not always be provided by hashlib.
try:
import hashlib
md5hash = _generate_hash_function("MD5", hashlib.md5, origin="hashlib")
sha1hash = _generate_hash_function("SHA1", hashlib.sha1, origin="hashlib")
sha256hash = _generate_hash_function("SHA256", hashlib.sha256, origin="hashlib")
try:
hashlib.new('ripemd160')
except ValueError:
pass
else:
def rmd160():
return hashlib.new('ripemd160')
rmd160hash = _generate_hash_function("RMD160", rmd160, origin="hashlib")
except ImportError, e:
pass
# Use python-fchksum if available, prefer it over all other MD5 implementations
try:
import fchksum
def md5hash(filename):
return fchksum.fmd5t(filename)
hashfunc_map["MD5"] = md5hash
hashorigin_map["MD5"] = "python-fchksum"
except ImportError:
pass
# There is only one implementation for size
def getsize(filename):
size = os.stat(filename).st_size
return (size, size)
hashfunc_map["size"] = getsize
# end actual hash functions
prelink_capable = False
if os.path.exists(PRELINK_BINARY):
results = commands.getstatusoutput(PRELINK_BINARY+" --version > /dev/null 2>&1")
if (results[0] >> 8) == 0:
prelink_capable=1
del results
def perform_md5(x, calc_prelink=0):
return perform_checksum(x, "MD5", calc_prelink)[0]
def perform_all(x, calc_prelink=0):
mydict = {}
for k in hashfunc_map:
mydict[k] = perform_checksum(x, hashfunc_map[k], calc_prelink)[0]
return mydict
def get_valid_checksum_keys():
return hashfunc_map.keys()
def get_hash_origin(hashtype):
if hashtype not in hashfunc_map:
raise KeyError(hashtype)
return hashorigin_map.get(hashtype, "unknown")
def verify_all(filename, mydict, calc_prelink=0, strict=0):
"""
Verify all checksums against a file.
@param filename: File to run the checksums against
@type filename: String
@param calc_prelink: Whether or not to reverse prelink before running the checksum
@type calc_prelink: Integer
@param strict: Enable/Disable strict checking (which stops exactly at a checksum failure and throws an exception)
@type strict: Integer
@rtype: Tuple
@return: Result of the checks and possible message:
1) If size fails, False, and a tuple containing a message, the given size, and the actual size
2) If there is an os error, False, and a tuple containing the system error followed by 2 nulls
3) If a checksum fails, False and a tuple containing a message, the given hash, and the actual hash
4) If all checks succeed, return True and a fake reason
"""
# Dict relates to single file only.
# returns: (passed,reason)
file_is_ok = True
reason = "Reason unknown"
try:
mysize = os.stat(filename)[stat.ST_SIZE]
if mydict["size"] != mysize:
return False,("Filesize does not match recorded size", mysize, mydict["size"])
except OSError, e:
if e.errno == errno.ENOENT:
raise portage_exception.FileNotFound(filename)
return False, (str(e), None, None)
verifiable_hash_types = set(mydict).intersection(hashfunc_map)
verifiable_hash_types.discard("size")
if not verifiable_hash_types:
expected = set(hashfunc_map)
expected.discard("size")
expected = list(expected)
expected.sort()
expected = " ".join(expected)
got = set(mydict)
got.discard("size")
got = list(got)
got.sort()
got = " ".join(got)
return False, ("Insufficient data for checksum verification", got, expected)
for x in mydict:
if x == "size":
continue
elif x in hashfunc_map:
myhash = perform_checksum(filename, x, calc_prelink=calc_prelink)[0]
if mydict[x] != myhash:
if strict:
raise portage_exception.DigestException, "Failed to verify '$(file)s' on checksum type '%(type)s'" % {"file":filename, "type":x}
else:
file_is_ok = False
reason = (("Failed on %s verification" % x), myhash,mydict[x])
break
return file_is_ok,reason
def perform_checksum(filename, hashname="MD5", calc_prelink=0):
"""
Run a specific checksum against a file.
@param filename: File to run the checksum against
@type filename: String
@param hashname: The type of hash function to run
@type hashname: String
@param calc_prelink: Whether or not to reverse prelink before running the checksum
@type calc_prelink: Integer
@rtype: Tuple
@return: The hash and size of the data
"""
global prelink_capable
myfilename = filename[:]
prelink_tmpfile = os.path.join("/", PRIVATE_PATH, "prelink-checksum.tmp." + str(os.getpid()))
mylock = None
try:
if calc_prelink and prelink_capable:
mylock = portage_locks.lockfile(prelink_tmpfile, wantnewlockfile=1)
# Create non-prelinked temporary file to checksum.
# Files rejected by prelink are summed in place.
try:
retval = portage_exec.spawn([PRELINK_BINARY, "--undo", "-o",
prelink_tmpfile, filename], fd_pipes={})
if retval == os.EX_OK:
myfilename = prelink_tmpfile
except portage_exception.CommandNotFound:
# This happens during uninstallation of prelink.
prelink_capable = False
try:
if hashname not in hashfunc_map:
raise portage_exception.DigestException(hashname + \
" hash function not available (needs dev-python/pycrypto)")
myhash, mysize = hashfunc_map[hashname](myfilename)
except (OSError, IOError), e:
if e.errno == errno.ENOENT:
raise portage_exception.FileNotFound(myfilename)
raise
if calc_prelink and prelink_capable:
try:
os.unlink(prelink_tmpfile)
except OSError, e:
if e.errno != errno.ENOENT:
raise
del e
return myhash, mysize
finally:
if mylock:
portage_locks.unlockfile(mylock)
def perform_multiple_checksums(filename, hashes=["MD5"], calc_prelink=0):
"""
Run a group of checksums against a file.
@param filename: File to run the checksums against
@type filename: String
@param hashes: A list of checksum functions to run against the file
@type hashname: List
@param calc_prelink: Whether or not to reverse prelink before running the checksum
@type calc_prelink: Integer
@rtype: Tuple
@return: A dictionary in the form:
return_value[hash_name] = (hash_result,size)
for each given checksum
"""
rVal = {}
for x in hashes:
if x not in hashfunc_map:
raise portage_exception.DigestException, x+" hash function not available (needs dev-python/pycrypto or >=dev-lang/python-2.5)"
rVal[x] = perform_checksum(filename, x, calc_prelink)[0]
return rVal