Add script to reseed a file

scripts/decrypt_blob.py

@@ -0,0 +1,57 @@
+"""Decrypt a single blob"""
+import argparse
+import binascii
+import logging
+import os
+import sys
+
+from twisted.internet import defer
+from twisted.internet import reactor
+
+from lbrynet import conf
+from lbrynet.cryptstream import CryptBlob
+from lbrynet.core import HashBlob
+from lbrynet.core import log_support
+
+
+log = logging.getLogger('decrypt_blob')
+
+
+def main():
+    conf.initialize_settings()
+    parser = argparse.ArgumentParser()
+    parser.add_argument('blob_file')
+    parser.add_argument('hex_key')
+    parser.add_argument('hex_iv')
+    parser.add_argument('output')
+    args = parser.parse_args()
+    log_support.configure_console()
+
+    d = run(args)
+    reactor.run()
+
+
+@defer.inlineCallbacks
+def run(args):
+    try:
+        yield decrypt_blob(args.blob_file, args.hex_key, args.hex_iv, args.output)
+    except Exception:
+        log.exception('Failed to decrypt blob')
+    finally:
+        reactor.callLater(0, reactor.stop)
+
+
+@defer.inlineCallbacks
+def decrypt_blob(blob_file, key, iv, output):
+    filename = os.path.abspath(blob_file)
+    length = os.path.getsize(filename)
+    directory, blob_hash = os.path.split(filename)
+    blob = HashBlob.BlobFile(directory, blob_hash, True, length)
+    decryptor = CryptBlob.StreamBlobDecryptor(
+        blob, binascii.unhexlify(key), binascii.unhexlify(iv), length)
+    with open(output, 'w') as f:
+        yield decryptor.decrypt(f.write)
+
+
+if __name__ == '__main__':
+    sys.exit(main())