# file openpyxl/shared/password_hasher.py

# Copyright (c) 2010 openpyxl
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# @license: http://www.opensource.org/licenses/mit-license.php
# @author: Eric Gazoni

"""Basic password hashing."""


def hash_password(plaintext_password=''):
    """Create a password hash from a given string.

    This method is based on the algorithm provided by
    Daniel Rentz of OpenOffice and the PEAR package
    Spreadsheet_Excel_Writer by Xavier Noguer <xnoguer@rezebra.com>.

    """
    password = 0x0000
    i = 1
    for char in plaintext_password:
        value = ord(char) << i
        rotated_bits = value >> 15
        value &= 0x7fff
        password ^= (value | rotated_bits)
        i += 1
    password ^= len(plaintext_password)
    password ^= 0xCE4B
    return str(hex(password)).upper()[2:]
