diff options
Diffstat (limited to 'frozen_deps/Cryptodome/Util/strxor.py')
| -rw-r--r-- | frozen_deps/Cryptodome/Util/strxor.py | 51 |
1 files changed, 30 insertions, 21 deletions
diff --git a/frozen_deps/Cryptodome/Util/strxor.py b/frozen_deps/Cryptodome/Util/strxor.py index 91fb4c9..6b16155 100644 --- a/frozen_deps/Cryptodome/Util/strxor.py +++ b/frozen_deps/Cryptodome/Util/strxor.py @@ -32,7 +32,8 @@ from Cryptodome.Util._raw_api import (load_pycryptodome_raw_lib, c_size_t, create_string_buffer, get_raw_buffer, c_uint8_ptr, is_writeable_buffer) -_raw_strxor = load_pycryptodome_raw_lib("Cryptodome.Util._strxor", +_raw_strxor = load_pycryptodome_raw_lib( + "Cryptodome.Util._strxor", """ void strxor(const uint8_t *in1, const uint8_t *in2, @@ -45,33 +46,38 @@ _raw_strxor = load_pycryptodome_raw_lib("Cryptodome.Util._strxor", def strxor(term1, term2, output=None): - """XOR two byte strings. - + """From two byte strings of equal length, + create a third one which is the byte-by-byte XOR of the two. + Args: term1 (bytes/bytearray/memoryview): - The first term of the XOR operation. + The first byte string to XOR. term2 (bytes/bytearray/memoryview): - The second term of the XOR operation. + The second byte string to XOR. output (bytearray/memoryview): - The location where the result must be written to. + The location where the result will be written to. + It must have the same length as ``term1`` and ``term2``. If ``None``, the result is returned. :Return: - If ``output`` is ``None``, a new ``bytes`` string with the result. + If ``output`` is ``None``, a new byte string with the result. Otherwise ``None``. + + .. note:: + ``term1`` and ``term2`` must have the same length. """ if len(term1) != len(term2): raise ValueError("Only byte strings of equal length can be xored") - + if output is None: result = create_string_buffer(len(term1)) else: # Note: output may overlap with either input result = output - + if not is_writeable_buffer(output): raise TypeError("output must be a bytearray or a writeable memoryview") - + if len(term1) != len(output): raise ValueError("output must have the same length as the input" " (%d bytes)" % len(term1)) @@ -88,15 +94,19 @@ def strxor(term1, term2, output=None): def strxor_c(term, c, output=None): - """XOR a byte string with a repeated sequence of characters. + """From a byte string, create a second one of equal length + where each byte is XOR-red with the same value. Args: - term(bytes/bytearray/memoryview): - The first term of the XOR operation. - c (bytes): - The byte that makes up the second term of the XOR operation. - output (None or bytearray/memoryview): - If not ``None``, the location where the result is stored into. + term(bytes/bytearray/memoryview): + The byte string to XOR. + c (int): + Every byte in the string will be XOR-ed with this value. + It must be between 0 and 255 (included). + output (None or bytearray/memoryview): + The location where the result will be written to. + It must have the same length as ``term``. + If ``None``, the result is returned. Return: If ``output`` is ``None``, a new ``bytes`` string with the result. @@ -105,16 +115,16 @@ def strxor_c(term, c, output=None): if not 0 <= c < 256: raise ValueError("c must be in range(256)") - + if output is None: result = create_string_buffer(len(term)) else: # Note: output may overlap with either input result = output - + if not is_writeable_buffer(output): raise TypeError("output must be a bytearray or a writeable memoryview") - + if len(term) != len(output): raise ValueError("output must have the same length as the input" " (%d bytes)" % len(term)) @@ -134,4 +144,3 @@ def strxor_c(term, c, output=None): def _strxor_direct(term1, term2, result): """Very fast XOR - check conditions!""" _raw_strxor.strxor(term1, term2, result, c_size_t(len(term1))) - |