328: Add reference implementation

bip-0328/_common.py

@@ -0,0 +1,47 @@
+"""
+Common Classes and Utilities
+****************************
+"""
+
+import hashlib
+
+def sha256(s: bytes) -> bytes:
+    """
+    Perform a single SHA256 hash.
+
+    :param s: Bytes to hash
+    :return: The hash
+    """
+    return hashlib.new('sha256', s).digest()
+
+
+def ripemd160(s: bytes) -> bytes:
+    """
+    Perform a single RIPEMD160 hash.
+
+    :param s: Bytes to hash
+    :return: The hash
+    """
+    return hashlib.new('ripemd160', s).digest()
+
+
+def hash256(s: bytes) -> bytes:
+    """
+    Perform a double SHA256 hash.
+    A SHA256 is performed on the input, and then a second
+    SHA256 is performed on the result of the first SHA256
+
+    :param s: Bytes to hash
+    :return: The hash
+    """
+    return sha256(sha256(s))
+
+
+def hash160(s: bytes) -> bytes:
+    """
+    perform a single SHA256 hash followed by a single RIPEMD160 hash on the result of the SHA256 hash.
+
+    :param s: Bytes to hash
+    :return: The hash
+    """
+    return ripemd160(sha256(s))