1 files changed, 83 insertions, 0 deletions
diff --git a/synapse/_scripts/hash_password.py b/synapse/_scripts/hash_password.py
new file mode 100755
index 0000000000..708640c7de
--- /dev/null
+++ b/synapse/_scripts/hash_password.py
@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+
+import argparse
+import getpass
+import sys
+import unicodedata
+
+import bcrypt
+import yaml
+
+
+def prompt_for_pass():
+    password = getpass.getpass("Password: ")
+
+    if not password:
+        raise Exception("Password cannot be blank.")
+
+    confirm_password = getpass.getpass("Confirm password: ")
+
+    if password != confirm_password:
+        raise Exception("Passwords do not match.")
+
+    return password
+
+
+def main():
+    bcrypt_rounds = 12
+    password_pepper = ""
+
+    parser = argparse.ArgumentParser(
+        description=(
+            "Calculate the hash of a new password, so that passwords can be reset"
+        )
+    )
+    parser.add_argument(
+        "-p",
+        "--password",
+        default=None,
+        help="New password for user. Will prompt if omitted.",
+    )
+    parser.add_argument(
+        "-c",
+        "--config",
+        type=argparse.FileType("r"),
+        help=(
+            "Path to server config file. "
+            "Used to read in bcrypt_rounds and password_pepper."
+        ),
+    )
+
+    args = parser.parse_args()
+    if "config" in args and args.config:
+        config = yaml.safe_load(args.config)
+        bcrypt_rounds = config.get("bcrypt_rounds", bcrypt_rounds)
+        password_config = config.get("password_config", None) or {}
+        password_pepper = password_config.get("pepper", password_pepper)
+    password = args.password
+
+    if not password:
+        password = prompt_for_pass()
+
+    # On Python 2, make sure we decode it to Unicode before we normalise it
+    if isinstance(password, bytes):
+        try:
+            password = password.decode(sys.stdin.encoding)
+        except UnicodeDecodeError:
+            print(
+                "ERROR! Your password is not decodable using your terminal encoding (%s)."
+                % (sys.stdin.encoding,)
+            )
+
+    pw = unicodedata.normalize("NFKC", password)
+
+    hashed = bcrypt.hashpw(
+        pw.encode("utf8") + password_pepper.encode("utf8"),
+        bcrypt.gensalt(bcrypt_rounds),
+    ).decode("ascii")
+
+    print(hashed)
+
+
+if __name__ == "__main__":
+    main()