10gic · March 7, 2021 14:09 · Mar 7, 2021
diff --git a/addr_to_hash160.py b/addr_to_hash160.py
@@ -0,0 +1,170 @@
+import sys
+import binascii
+import argparse
+
+# base58 from https://github.com/keis/base58
+BITCOIN_ALPHABET = b'123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
+
+
+def b58decode_int(
+        v: bytes, alphabet: bytes = BITCOIN_ALPHABET
+) -> int:
+    """
+    Decode a Base58 encoded string as an integer
+    """
+    v = v.rstrip()
+
+    decimal = 0
+    for char in v:
+        decimal = decimal * 58 + alphabet.index(char)
+    return decimal
+
+
+def b58decode(
+        v: str, alphabet: bytes = BITCOIN_ALPHABET
+) -> bytes:
+    """
+    Decode a Base58 encoded string
+    """
+    v = v.rstrip()
+    v = v.encode('ascii')  # str -> bytes
+
+    origlen = len(v)
+    v = v.lstrip(alphabet[0:1])
+    newlen = len(v)
+
+    acc = b58decode_int(v, alphabet=alphabet)
+
+    result = []
+    while acc > 0:
+        acc, mod = divmod(acc, 256)
+        result.append(mod)
+
+    return b'\0' * (origlen - newlen) + bytes(reversed(result))
+
+
+"""Reference implementation for Bech32 and segwit addresses."""
+# https://raw.githubusercontent.com/sipa/bech32/master/ref/python/segwit_addr.py
+CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+
+
+def bech32_polymod(values):
+    """Internal function that computes the Bech32 checksum."""
+    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
+    chk = 1
+    for value in values:
+        top = chk >> 25
+        chk = (chk & 0x1ffffff) << 5 ^ value
+        for i in range(5):
+            chk ^= generator[i] if ((top >> i) & 1) else 0
+    return chk
+
+
+def bech32_hrp_expand(hrp):
+    """Expand the HRP into values for checksum computation."""
+    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]
+
+
+def bech32_verify_checksum(hrp, data):
+    """Verify a checksum given HRP and converted data characters."""
+    return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1
+
+
+def bech32_decode(bech):
+    """Validate a Bech32 string, and determine HRP and data."""
+    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
+            (bech.lower() != bech and bech.upper() != bech)):
+        return None, None
+    bech = bech.lower()
+    pos = bech.rfind('1')
+    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
+        return None, None
+    if not all(x in CHARSET for x in bech[pos + 1:]):
+        return None, None
+    hrp = bech[:pos]
+    data = [CHARSET.find(x) for x in bech[pos + 1:]]
+    if not bech32_verify_checksum(hrp, data):
+        return None, None
+    return hrp, data[:-6]
+
+
+def convertbits(data, frombits, tobits, pad=True):
+    """General power-of-2 base conversion."""
+    acc = 0
+    bits = 0
+    ret = []
+    maxv = (1 << tobits) - 1
+    max_acc = (1 << (frombits + tobits - 1)) - 1
+    for value in data:
+        if value < 0 or (value >> frombits):
+            return None
+        acc = ((acc << frombits) | value) & max_acc
+        bits += frombits
+        while bits >= tobits:
+            bits -= tobits
+            ret.append((acc >> bits) & maxv)
+    if pad:
+        if bits:
+            ret.append((acc << (tobits - bits)) & maxv)
+    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
+        return None
+    return ret
+
+
+def decode(hrp, addr):
+    """Decode a segwit address."""
+    hrpgot, data = bech32_decode(addr)
+    if hrpgot != hrp:
+        return None, None
+    decoded = convertbits(data[1:], 5, 8, False)
+    if decoded is None or len(decoded) < 2 or len(decoded) > 40:
+        return None, None
+    if data[0] > 16:
+        return None, None
+    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
+        return None, None
+    return data[0], decoded
+
+
+def input_args():
+    parser = argparse.ArgumentParser(description='Read csv file with btc address as first column'
+                                                 ' encodes it to hash160 and writes to stdout'
+                                     )
+    parser.add_argument(
+        'csvin',
+        metavar='csvfile',
+        type=str,
+        help='path to csv file with btc address in first column, - means stdin'
+    )
+
+    a = parser.parse_args()
+    return a
+
+
+def process(csvfile):
+    """ Converts p2pkh or p2wpkh address to hash160, i.e. ripemd(sha256(pubkey)) """
+    if csvfile == '-':
+        infile = sys.stdin
+    else:
+        infile = open(csvfile, 'r')
+    for row in infile:
+        first_column = row.split(',')[0].strip()
+        if len(first_column) == 0:
+            print('')
+        elif first_column.startswith('1') and 26 <= len(first_column) <= 35:  # P2PKH
+            ripemd_bin = b58decode(first_column)[1:-4]
+            ripemd_encoded = binascii.hexlify(ripemd_bin)
+            print(ripemd_encoded.decode())
+        elif first_column.startswith('bc1') and len(first_column) == 42:  # P2WPKH
+            _, script_int = decode('bc', first_column.lower())
+            ripemd_encoded = binascii.hexlify(bytearray(script_int))
+            print(ripemd_encoded.decode())
+        else:
+            print("btc address not supported")
+    if infile is not sys.stdin:
+        infile.close()
+
+
+if __name__ == '__main__':
+    args = input_args()
+    process(args.csvin)