Index: decrypt-dump.sh =================================================================== --- decrypt-dump.sh (revision 0) +++ decrypt-dump.sh (working copy) @@ -0,0 +1,10 @@ +#!/bin/bash +# Decryptor script to handle encrypted SVN dumps +# arg1 AES256 key in hex text (32 bytes in 64 characters) +# arg2 Encryped dump file + +file_name=$2 +key=$1 +counter_prefix="$(echo -n ${file_name##*/} | openssl md5 | awk '{print substr($2,0,16)}')" +openssl enc -d -aes-256-ctr -K $1 -iv $counter_prefix -in $2 -out /tmp/mm/client_security.000000-001767.svndmp.bz2.clear +echo 'Decrypted SVN dump to '$2'.clear' Index: how_to_decrpyt_backups.txt =================================================================== --- how_to_decrpyt_backups.txt (revision 0) +++ how_to_decrpyt_backups.txt (working copy) @@ -0,0 +1 @@ +Look at decrypt-dump.sh which is based on "openssl enc -d -aes-256-ctr" Index: svn-backup-dumps.py =================================================================== --- svn-backup-dumps.py (revision 1684623) +++ svn-backup-dumps.py (working copy) @@ -39,6 +39,7 @@ # 6. Create bzipped dump files. # 7. Transfer the dumpfile to another host using ftp. # 8. Transfer the dumpfile to another host using smb. +# 9. Create encrypted dump files. # # See also 'svn-backup-dumps.py -h'. # @@ -143,13 +144,24 @@ # repository name (basename of the repository path). # # +# 9. Create encrypted dump files # +# svn-backup-dumps.py -k +# +# the encryption key which is used to encrypt the dump. +# it has to be 32 byte hex text (64 characters) like +# '000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f' +# +# The encryption feature works in conjuction with every other configuration / feature +# except -z option (stock zip). As for the encryption scheme the file name of the dump +# plays a crucial part in both encryption and decryption therefore it must not be changed! +# # TODO: # - find out how to report smbclient errors # - improve documentation # -__version = "0.6" +__version = "0.7" import sys import os @@ -169,12 +181,56 @@ except ImportError: have_bz2 = False +try: + from Crypto.Cipher import AES + from hashlib import md5 + import struct + have_aes = True +except ImportError: + have_aes = False +class SvnBackupAesCtrSchema: + ''' + Encryption schema uses AES256 in CTR mode (openssl compliant) + It uses the md5 hash of filename to create the counter/iv prefix + (not a secret but needs to be different per file) + + Example decryption with openssl (has to be 1.0.1 at least): + openssl enc -d -aes-256-ctr -K 3333333333333333333333333333333333333333333333333333333333333333 -iv 7392497a327cd49d -in /var/tmp/aes256_ctr_test.txt + ''' + def __init__(self,key,filename): + self.__key = key + self.__counter_prefix = md5(filename).digest()[:8] + self.__position = 0 + print 'In Init' + def encrypt(self, data): + # Create key stream + start_block = self.__position/AES.block_size + end_block = ((self.__position+len(data))/AES.block_size)+1 + counter_blocks = ''.join([ (self.__counter_prefix+struct.pack(">Q",c)) for c in range(start_block,end_block)]) + key_stream = AES.new(self.__key,AES.MODE_ECB).encrypt(counter_blocks)[self.__position%AES.block_size:] + # Encrypt the data + cipher_text = bytearray(data) + for i in range(len(cipher_text)): + cipher_text[i] = cipher_text[i]^ord(key_stream[i]) + self.__position+=len(data) + return str(cipher_text) + +class SvnBackupStubEncryptor: + def __init__(self): + pass + def encrypt(self, data): + return data + class SvnBackupOutput: - def __init__(self, abspath, filename): + def __init__(self, abspath, filename,encryption_key=None): self.__filename = filename self.__absfilename = os.path.join(abspath, filename) + if encryption_key: + self.encryptor = SvnBackupAesCtrSchema(encryption_key,filename) + else: + self.encryptor = SvnBackupStubEncryptor() def open(self): pass @@ -194,14 +250,14 @@ class SvnBackupOutputPlain(SvnBackupOutput): - def __init__(self, abspath, filename): - SvnBackupOutput.__init__(self, abspath, filename) + def __init__(self, abspath, filename, encryption_key=None): + SvnBackupOutput.__init__(self, abspath, filename, encryption_key) def open(self): self.__ofd = open(self.get_absfilename(), "wb") def write(self, data): - self.__ofd.write(data) + self.__ofd.write(self.encryptor.encrypt(data)) def close(self): self.__ofd.close() @@ -209,8 +265,10 @@ class SvnBackupOutputGzip(SvnBackupOutput): - def __init__(self, abspath, filename): - SvnBackupOutput.__init__(self, abspath, filename + ".gz") + def __init__(self, abspath, filename, encryption_key=None): + if encryption_key: + raise SvnBackupException("Backup encryption in stock Gzip mode is not supported! (use non-stock gzip or stock bz2 compression)") + SvnBackupOutput.__init__(self, abspath, filename + ".gz", encryption_key) def open(self): self.__compressor = gzip.GzipFile(filename=self.get_absfilename(), @@ -226,25 +284,25 @@ class SvnBackupOutputBzip2(SvnBackupOutput): - def __init__(self, abspath, filename): - SvnBackupOutput.__init__(self, abspath, filename + ".bz2") + def __init__(self, abspath, filename, encryption_key=None): + SvnBackupOutput.__init__(self, abspath, filename + ".bz2", encryption_key) def open(self): self.__compressor = bz2.BZ2Compressor() self.__ofd = open(self.get_absfilename(), "wb") def write(self, data): - self.__ofd.write(self.__compressor.compress(data)) + self.__ofd.write(self.encryptor.encrypt(self.__compressor.compress(data))) def close(self): - self.__ofd.write(self.__compressor.flush()) + self.__ofd.write(self.encryptor.encrypt(self.__compressor.flush())) self.__ofd.close() class SvnBackupOutputCommand(SvnBackupOutput): def __init__(self, abspath, filename, file_extension, cmd_path, - cmd_options): - SvnBackupOutput.__init__(self, abspath, filename + file_extension) + cmd_options,encryption_key=None): + SvnBackupOutput.__init__(self, abspath, filename + file_extension,encryption_key) self.__cmd_path = cmd_path self.__cmd_options = cmd_options @@ -262,7 +320,7 @@ self.__stdin = proc.stdin def write(self, data): - self.__stdin.write(data) + self.__stdin.write(self.encryptor.encrypt(data)) def close(self): self.__stdin.close() @@ -329,6 +387,11 @@ if options.svnlook_path: self.__svnlook_path = options.svnlook_path + # encryption + self.__encryption_key = None + if options.key: + self.__encryption_key = options.key.decode("hex") + # check compress option self.__gzip_path = options.gzip_path self.__bzip2_path = options.bzip2_path @@ -511,17 +574,17 @@ output = None if self.__bzip2_path: output = SvnBackupOutputCommand(self.__dumpdir, filename, ".bz2", - self.__bzip2_path, "-cz" ) + self.__bzip2_path, "-cz" , encryption_key=self.__encryption_key ) elif self.__gzip_path: output = SvnBackupOutputCommand(self.__dumpdir, filename, ".gz", - self.__gzip_path, "-cf" ) + self.__gzip_path, "-cf" , encryption_key=self.__encryption_key ) elif self.__zip: if self.__zip == "gzip": - output = SvnBackupOutputGzip(self.__dumpdir, filename) + output = SvnBackupOutputGzip(self.__dumpdir, filename, encryption_key=self.__encryption_key ) else: - output = SvnBackupOutputBzip2(self.__dumpdir, filename) + output = SvnBackupOutputBzip2(self.__dumpdir, filename, encryption_key=self.__encryption_key ) else: - output = SvnBackupOutputPlain(self.__dumpdir, filename) + output = SvnBackupOutputPlain(self.__dumpdir, filename, encryption_key=self.__encryption_key ) absfilename = output.get_absfilename() realfilename = output.get_filename() if checkonly: @@ -608,6 +671,13 @@ action="store_true", dest="bzip2", default=False, help="compress the dump using python bzip2 library.") + + if have_aes: + parser.add_option("-k", + action="store", type=str, + dest="key", default=None, + help="key for encrypted backups (AES256-CTR mode)") + parser.add_option("-i", action="store_true", dest="relative_incremental", default=False, @@ -676,6 +746,10 @@ print(" -t smb::::") print("") sys.exit(0) + if options.key and len(options.key)!=64: + print("Encryption key must be 32 bytes long represented in hex-text encoding in the argument!\n") + print("\tExample: -k 00112233445566778899aabbccddeeff000102030405060708090a0b0c0d0e0f\n") + sys.exit(0) rc = False try: backup = SvnBackup(options, args)