| micro-ecc |
| ========== |
| |
| A small and fast ECDH and ECDSA implementation for 8-bit, 32-bit, and 64-bit processors. |
| |
| The static version of micro-ecc (ie, where the curve was selected at compile-time) can be found in the "static" branch. |
| |
| Features |
| -------- |
| |
| * Resistant to known side-channel attacks. |
| * Written in C, with optional GCC inline assembly for AVR, ARM and Thumb platforms. |
| * Supports 8, 32, and 64-bit architectures. |
| * Small code size. |
| * No dynamic memory allocation. |
| * Support for 5 standard curves: secp160r1, secp192r1, secp224r1, secp256r1, and secp256k1. |
| * BSD 2-clause license. |
| |
| Usage Notes |
| ----------- |
| ### Point Representation ### |
| Compressed points are represented in the standard format as defined in http://www.secg.org/sec1-v2.pdf; uncompressed points are represented in standard format, but without the `0x04` prefix. All functions except `uECC_decompress()` only accept uncompressed points; use `uECC_compress()` and `uECC_decompress()` to convert between compressed and uncompressed point representations. |
| |
| Private keys are represented in the standard format. |
| |
| ### Using the Code ### |
| |
| I recommend just copying (or symlink) the uECC files into your project. Then just `#include "uECC.h"` to use the micro-ecc functions. |
| |
| For use with Arduino, you can use the Library Manager to download micro-ecc (**Sketch**=>**Include Library**=>**Manage Libraries**). You can then use uECC just like any other Arduino library (uECC should show up in the **Sketch**=>**Import Library** submenu). |
| |
| See uECC.h for documentation for each function. |
| |
| ### Compilation Notes ### |
| |
| * Should compile with any C/C++ compiler that supports stdint.h (this includes Visual Studio 2013). |
| * If you want to change the defaults for any of the uECC compile-time options (such as `uECC_OPTIMIZATION_LEVEL`), you must change them in your Makefile or similar so that uECC.c is compiled with the desired values (ie, compile uECC.c with `-DuECC_OPTIMIZATION_LEVEL=3` or whatever). |
| * When compiling for a Thumb-1 platform, you must use the `-fomit-frame-pointer` GCC option (this is enabled by default when compiling with `-O1` or higher). |
| * When compiling for an ARM/Thumb-2 platform with `uECC_OPTIMIZATION_LEVEL` >= 3, you must use the `-fomit-frame-pointer` GCC option (this is enabled by default when compiling with `-O1` or higher). |
| * When compiling for AVR, you must have optimizations enabled (compile with `-O1` or higher). |
| * When building for Windows, you will need to link in the `advapi32.lib` system library. |
