created tool to encrypt/decrypt files using aes128 with compression

diff --git a/file_crypt.py b/file_crypt.py
new file mode 100755 (executable)
index 0000000..d91744d
--- /dev/null
+++ b/file_crypt.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+
+""" Encrypt a single file
+
+low-cost quick-devel badly-documented
+
+.. codeauthor:: Intra2net <info@intra2net.com>
+"""
+
+import sys
+from deltatar import tarfile
+from traceback import print_exc
+
+
+def main(do_encrypt, in_file, out_file, password, comptype='gz', enctype='aes',
+         key_length=128, bufsize=tarfile.RECORDSIZE, encoding='UTF-8'):
+    """ Main function, called when running file as script
+
+    see module doc for more info
+    """
+
+    write_handle = read_handle = None
+    return_code = 4
+
+    try:
+        # open file to read
+        if do_encrypt:
+            read_handle = open(in_file, 'rt')
+        else:
+            read_handle = tarfile._Stream(name=in_file, mode='r',
+                                          comptype=comptype, bufsize=bufsize,
+                                          fileobj=None, enctype=enctype,
+                                          key_length=key_length,
+                                          password=password)
+        return_code = 3
+
+        # open file to write
+        if do_encrypt:
+            write_handle = tarfile._Stream(name=out_file, mode='w',
+                                           comptype=comptype, bufsize=bufsize,
+                                           fileobj=None, enctype=enctype,
+                                           key_length=key_length,
+                                           password=password)
+        else:
+            write_handle = open(out_file, 'wt')
+        return_code = 1
+
+        # convert
+        while True:
+            buf = read_handle.read(bufsize)
+            print('.', end='')
+            if do_encrypt:
+                write_handle.write(buf.encode(encoding, errors='strict'))
+            else:
+                write_handle.write(buf.decode(encoding, errors='replace'))
+            if len(buf) < bufsize:
+                if do_encrypt:
+                    print('successfully encrypted {} into {}'
+                          .format(in_file, out_file))
+                else:
+                    print('successfully decrypted {} into {}'
+                          .format(in_file, out_file))
+                break   # reached EOF
+
+        return_code = 0
+
+    except Exception:
+        print('error encrypting file')
+        print_exc()
+
+    finally:
+        # close everything
+        if write_handle:
+            try:
+                write_handle.close()
+            except Exception:
+                return_code += 8
+                print('error closing out file')
+                print_exc()
+
+        if read_handle:
+            try:
+                read_handle.close()
+            except Exception:
+                return_code += 16
+                print('error closing in file')
+                print_exc()
+
+    # done
+    return return_code
+
+
+if __name__ == '__main__':
+    if len(sys.argv) < 4:
+        print('file_crypt.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
+        sys.exit(2)
+    elif sys.argv[1] == '-h':
+        print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
+        sys.exit(0)
+
+    comptype = 'tar'  # auto-detect, not sure whether this would work
+    idx = 1
+    if sys.argv[idx] == '-c':
+        print('assuming gzip compression')
+        comptype = 'gz'
+        idx += 1
+
+    do_encrypt = None
+    if sys.argv[idx] == 'enc':
+        do_encrypt = True
+    elif sys.argv[idx] == 'dec':
+        do_encrypt = False
+    else:
+        print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
+        sys.exit(2)
+
+    if len(sys.argv) != idx+4:
+        print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
+        sys.exit(2)
+
+    sys.exit(main(do_encrypt, sys.argv[idx+1], sys.argv[idx+2],
+                  sys.argv[idx+3], comptype))