Provide support script for adding new test subject

Tests/.gitignore

@@ -1,2 +1,3 @@
 htmlcov/
 .coverage
+.secret

Tests/add_subject.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+# vim: set ts=4 sw=4 et:
+#
+# add_subject.py
+#
+# (c) Matthias Büchse <[email protected]>
+# SPDX-License-Identifier: Apache-2.0
+import base64
+import getpass
+import os
+import os.path
+import re
+import shutil
+import subprocess
+import sys
+
+try:
+    from passlib.context import CryptContext
+    import argon2  # noqa:F401
+except ImportError:
+    print('Missing passlib and/or argon2. Please do:\npip install passlib argon2_cffi', file=sys.stderr)
+    sys.exit(1)
+
+# see ../compliance-monitor/monitor.py
+CRYPTCTX = CryptContext(schemes=('argon2', 'bcrypt'), deprecated='auto')
+SSH_KEYGEN = shutil.which('ssh-keygen')
+SUBJECT_RE = re.compile(r"[a-zA-Z0-9_\-]+")
+
+
+def main(argv, cwd):
+    if len(argv) != 1:
+        raise RuntimeError("Need to supply precisely one argument: name of subject")
+    subject = argv[0]
+    print(f"Attempt to add subject {subject!r}")
+    keyfile_path = os.path.join(cwd, '.secret', 'keyfile')
+    tokenfile_path = os.path.join(cwd, '.secret', 'tokenfile')
+    if os.path.exists(keyfile_path):
+        raise RuntimeError(f"Keyfile {keyfile_path} already present. Please proceed manually")
+    if os.path.exists(tokenfile_path):
+        raise RuntimeError(f"Tokenfile {tokenfile_path} already present. Please proceed manually")
+    if not SUBJECT_RE.fullmatch(subject):
+        raise RuntimeError(f"Subject name {subject!r} using disallowed characters")
+    sanitized_subject = subject.replace('-', '_')
+    print("Creating API key...")
+    while True:
+        password = getpass.getpass("Enter passphrase: ")
+        if password == getpass.getpass("Repeat passphrase: "):
+            break
+        print("No match. Try again...")
+    token = base64.b64encode(f"{subject}:{password}".encode('utf-8'))
+    hash_ = CRYPTCTX.hash(password)
+    with open(tokenfile_path, "wb") as fileobj:
+        fileobj.write(token)
+    print("Creating key file using `ssh-keygen`...")
+    subprocess.check_call([SSH_KEYGEN, '-t', 'ed25519', '-C', sanitized_subject, '-f', keyfile_path, '-N', '', '-q'])
+    with open(keyfile_path + '.pub', "r") as fileobj:
+        pubkey_components = fileobj.readline().split()
+    print(f'''
+The following SECRET files have been created:
+
+  - {keyfile_path}
+  - {tokenfile_path}
+
+They are required for submitting test reports. You MUST keep them secure and safe.
+
+Insert the following snippet into compliance-monitor/bootstrap.yaml:
+
+  - subject: {subject}
+    api_keys:
+      - "{hash_}"
+    keys:
+      - public_key: "{pubkey_components[1]}"
+        public_key_type: "{pubkey_components[0]}"
+        public_key_name: "primary"
+
+Make sure to submit a pull request with the changed file. Otherwise, the reports cannot be submitted.
+''', end='')
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main(sys.argv[1:], cwd=os.path.dirname(sys.argv[0]) or os.getcwd()) or 0)
+    except RuntimeError as e:
+        print(str(e), file=sys.stderr)
+        sys.exit(1)
+    except KeyboardInterrupt:
+        print("Interrupted", file=sys.stderr)