[tests] Make rpcauth.py testable and add unit tests

refs #12995

share/rpcauth/rpcauth.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # Copyright (c) 2015-2017 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying 
+# Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 import sys
@@ -9,26 +9,36 @@ from random import SystemRandom
 import base64
 import hmac
 
-if len(sys.argv) < 2:
-    sys.stderr.write('Please include username as an argument.\n')
-    sys.exit(0)
+def generate_salt():
+    # This uses os.urandom() underneath
+    cryptogen = SystemRandom()
 
-username = sys.argv[1]
+    # Create 16 byte hex salt
+    salt_sequence = [cryptogen.randrange(256) for _ in range(16)]
+    return ''.join([format(r, 'x') for r in salt_sequence])
 
-#This uses os.urandom() underneath
-cryptogen = SystemRandom()
+def generate_password(salt):
+    """Create 32 byte b64 password"""
+    password = base64.urlsafe_b64encode(os.urandom(32)).decode('utf-8')
 
-#Create 16 byte hex salt
-salt_sequence = [cryptogen.randrange(256) for i in range(16)]
-hexseq = list(map(hex, salt_sequence))
-salt = "".join([x[2:] for x in hexseq])
+    m = hmac.new(bytearray(salt, 'utf-8'), bytearray(password, 'utf-8'), 'SHA256')
+    password_hmac = m.hexdigest()
 
-#Create 32 byte b64 password
-password = base64.urlsafe_b64encode(os.urandom(32)).decode("utf-8")
+    return password, password_hmac
 
-m = hmac.new(bytearray(salt, 'utf-8'), bytearray(password, 'utf-8'), "SHA256")
-result = m.hexdigest()
+def main():
+    if len(sys.argv) < 2:
+        sys.stderr.write('Please include username as an argument.\n')
+        sys.exit(0)
 
-print("String to be appended to bitcoin.conf:")
-print("rpcauth="+username+":"+salt+"$"+result)
-print("Your password:\n"+password)
+    username = sys.argv[1]
+
+    salt = generate_salt()
+    password, password_hmac = generate_password(salt)
+
+    print('String to be appended to bitcoin.conf:')
+    print('rpcauth={0}:{1}${2}'.format(username, salt, password_hmac))
+    print('Your password:\n{0}'.format(password))
+
+if __name__ == '__main__':
+    main()