Application example using LoRaWAN-lib MAC layer implementation for STM32 + SX1276 on OpenChirp
Dependencies: mbed LoRaWAN-lib SX1276Lib
Diff: system/crypto/cmac.cpp
- Revision:
- 1:352f608c3337
- Child:
- 5:1e9f6a365854
diff -r 92bca02df485 -r 352f608c3337 system/crypto/cmac.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/system/crypto/cmac.cpp Thu Nov 26 12:59:52 2015 +0000 @@ -0,0 +1,153 @@ +/************************************************************************** +Copyright (C) 2009 Lander Casado, Philippas Tsigas + +All rights reserved. + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files +(the "Software"), to deal with the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimers. Redistributions in +binary form must reproduce the above copyright notice, this list of +conditions and the following disclaimers in the documentation and/or +other materials provided with the distribution. + +In no event shall the authors or copyright holders be liable for any special, +incidental, indirect or consequential damages of any kind, or any damages +whatsoever resulting from loss of use, data or profits, whether or not +advised of the possibility of damage, and on any theory of liability, +arising out of or in connection with the use or performance of this software. + +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 +CONTRIBUTORS OR COPYRIGHT HOLDERS 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 WITH THE SOFTWARE + +*****************************************************************************/ +//#include <sys/param.h> +//#include <sys/systm.h> +#include <stdint.h> +#include "aes.h" +#include "cmac.h" +#include "utilities.h" + +#define LSHIFT(v, r) do { \ + int32_t i; \ + for (i = 0; i < 15; i++) \ + (r)[i] = (v)[i] << 1 | (v)[i + 1] >> 7; \ + (r)[15] = (v)[15] << 1; \ + } while (0) + +#define XOR(v, r) do { \ + int32_t i; \ + for (i = 0; i < 16; i++) \ + { \ + (r)[i] = (r)[i] ^ (v)[i]; \ + } \ + } while (0) \ + + +void AES_CMAC_Init(AES_CMAC_CTX *ctx) +{ + memset1(ctx->X, 0, sizeof ctx->X); + ctx->M_n = 0; + memset1(ctx->rijndael.ksch, '\0', 240); +} + +void AES_CMAC_SetKey(AES_CMAC_CTX *ctx, const uint8_t key[AES_CMAC_KEY_LENGTH]) +{ + //rijndael_set_key_enc_only(&ctx->rijndael, key, 128); + aes_set_key( key, AES_CMAC_KEY_LENGTH, &ctx->rijndael); +} + +void AES_CMAC_Update(AES_CMAC_CTX *ctx, const uint8_t *data, uint32_t len) +{ + uint32_t mlen; + uint8_t in[16]; + + if (ctx->M_n > 0) { + mlen = MIN(16 - ctx->M_n, len); + memcpy1(ctx->M_last + ctx->M_n, data, mlen); + ctx->M_n += mlen; + if (ctx->M_n < 16 || len == mlen) + return; + XOR(ctx->M_last, ctx->X); + //rijndael_encrypt(&ctx->rijndael, ctx->X, ctx->X); + aes_encrypt( ctx->X, ctx->X, &ctx->rijndael); + data += mlen; + len -= mlen; + } + while (len > 16) { /* not last block */ + + XOR(data, ctx->X); + //rijndael_encrypt(&ctx->rijndael, ctx->X, ctx->X); + + memcpy1(in, &ctx->X[0], 16); //Bestela ez du ondo iten + aes_encrypt( in, in, &ctx->rijndael); + memcpy1(&ctx->X[0], in, 16); + + data += 16; + len -= 16; + } + /* potential last block, save it */ + memcpy1(ctx->M_last, data, len); + ctx->M_n = len; +} + +void AES_CMAC_Final(uint8_t digest[AES_CMAC_DIGEST_LENGTH], AES_CMAC_CTX *ctx) +{ + uint8_t K[16]; + uint8_t in[16]; + /* generate subkey K1 */ + memset1(K, '\0', 16); + + //rijndael_encrypt(&ctx->rijndael, K, K); + + aes_encrypt( K, K, &ctx->rijndael); + + if (K[0] & 0x80) { + LSHIFT(K, K); + K[15] ^= 0x87; + } else + LSHIFT(K, K); + + + if (ctx->M_n == 16) { + /* last block was a complete block */ + XOR(K, ctx->M_last); + + } else { + /* generate subkey K2 */ + if (K[0] & 0x80) { + LSHIFT(K, K); + K[15] ^= 0x87; + } else + LSHIFT(K, K); + + /* padding(M_last) */ + ctx->M_last[ctx->M_n] = 0x80; + while (++ctx->M_n < 16) + ctx->M_last[ctx->M_n] = 0; + + XOR(K, ctx->M_last); + + + } + XOR(ctx->M_last, ctx->X); + + //rijndael_encrypt(&ctx->rijndael, ctx->X, digest); + + memcpy1(in, &ctx->X[0], 16); //Bestela ez du ondo iten + aes_encrypt(in, digest, &ctx->rijndael); + memset1(K, 0, sizeof K); + +} +