Add remove padding

This commit is contained in:
Eugen Wissner 2016-08-27 07:49:43 +02:00
parent 25c292662a
commit be9181698a

View File

@ -8,14 +8,12 @@
* Mozilla Public License, v. 2.0). * Mozilla Public License, v. 2.0).
* Authors: $(LINK2 mailto:belka@caraus.de, Eugene Wissner) * Authors: $(LINK2 mailto:belka@caraus.de, Eugene Wissner)
*/ */
module tanya.crypto.padding; module tanya.crypto.cipher;
import tanya.memory; import tanya.memory;
import std.algorithm.iteration; import std.algorithm.iteration;
import std.typecons; import std.typecons;
@nogc:
/** /**
* Supported padding mode. * Supported padding mode.
* *
@ -31,13 +29,13 @@ enum Mode
/** /**
* Params: * Params:
* allocator = Allocator that should be used if the block should be extended
* or a new block should be added.
* input = Sequence that should be padded. * input = Sequence that should be padded.
* mode = Padding mode. * mode = Padding mode.
* blockSize = Block size. * blockSize = Block size.
* allocator = Allocator that should be used if the block should be extended
* or a new block should be added.
* *
* Returns: The functions modifies the initial array and returns it. * Returns: The function modifies the initial array and returns it.
* *
* See_Also: * See_Also:
* $(D_PSYMBOL Mode) * $(D_PSYMBOL Mode)
@ -189,3 +187,93 @@ unittest
defaultAllocator.finalize(input); defaultAllocator.finalize(input);
} }
} }
/**
* Params:
* input = Sequence that should be padded.
* mode = Padding mode.
* blockSize = Block size.
* allocator = Allocator that should be used for freeing the space allocated
* for the padding.
*
* Returns: The function modifies the initial array and returns it.
*
* See_Also:
* $(D_PSYMBOL applyPadding)
*/
ref ubyte[] removePadding(ref ubyte[] input,
in Mode mode,
in ushort blockSize,
Allocator allocator = defaultAllocator)
in
{
assert(input.length != 0);
assert(input.length % 64 == 0);
}
body
{
final switch (mode) with (Mode)
{
case zero:
break;
case pkcs7:
case ansiX923:
immutable last = input[$ - 1];
allocator.shrinkArray(input, last ? last : blockSize);
break;
}
return input;
}
///
unittest
{
{ // Zeros
auto input = defaultAllocator.makeArray!ubyte(50);
auto inputDup = defaultAllocator.makeArray!ubyte(50);
applyPadding(input, Mode.zero, 64);
applyPadding(inputDup, Mode.zero, 64);
removePadding(input, Mode.zero, 64);
assert(input == inputDup);
defaultAllocator.finalize(input);
defaultAllocator.finalize(inputDup);
}
{ // PKCS#7
auto input = defaultAllocator.makeArray!ubyte(50);
auto inputDup = defaultAllocator.makeArray!ubyte(50);
for (ubyte i; i < 40; ++i)
{
input[i] = i;
inputDup[i] = i;
}
applyPadding(input, Mode.pkcs7, 64);
removePadding(input, Mode.pkcs7, 64);
assert(input == inputDup);
defaultAllocator.finalize(input);
defaultAllocator.finalize(inputDup);
}
{ // ANSI X.923
auto input = defaultAllocator.makeArray!ubyte(50);
auto inputDup = defaultAllocator.makeArray!ubyte(50);
for (ubyte i; i < 40; ++i)
{
input[i] = i;
inputDup[i] = i;
}
applyPadding(input, Mode.pkcs7, 64);
removePadding(input, Mode.pkcs7, 64);
assert(input == inputDup);
defaultAllocator.finalize(input);
defaultAllocator.finalize(inputDup);
}
}