tinycrypt/block/aes/old

AES Block Cipher

AES-dust is a compact Implementation of the AES block cipher with support for 128 and 256-bit keys. The modes of encryption supported are Counter (CTR) and Electronic Code Book (ECB).

All code is intentionally optimized for size rather than speed making it suitable for resource constrained environments.

Side channel attacks

AES was never intended to be resistant against side channel attacks. However, if you decide to use this code for an embedded project that requires a high level of security, first evaluate whether the code is sufficient against such attacks before including in your project.

Files

All files with .s and .asm extensions are compatible with the GNU assembler (GAS) except for the files in the MSVC folder that will assemble with either NASM or YASM.

File	Description
ax.asm	AES-128 in x86 assembly
axx.asm	AES-128 in AMD64 assembly
ax.s	AES-128 in ARM32 assembly
axx.s	AES-128 in ARM64 assembly
aesb.c	AES-128 in C for 8-bit architectures.
aes.c	AES-128 and AES-256 in C for 32-bit / 64-bit architectures.
test.c	Test unit for AES-128
test2.c	Test unit for AES-256
tweet.c	Tweetable version of aes.c

Assembly

The below table shows code sizes for the hand written versions of AES-128

Architecture	ECB	CTR
x86	205	272
AMD64	253	339
ARM32	352
ARM64	352

C generated assembly

The following table lists the size of assembly code generated by the GNU C compiler.

Architecture	ECB	CTR
x86	524	701
AMD64	451	682
ARM32	480	668
ARM64	640	940

The following table lists the size of assembly code generated by the Microsoft C compiler.

Architecture	ECB	CTR
x86	321	477
AMD64	486	673
ARM32	372	502
ARM64	536	880

Licensing information

Initially this was published with a BSD license. I decided to unlicense hoping more people would use and provide useful feedback.

This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to http://unlicense.org/