diff options
| -rw-r--r-- | README.md | 12 | ||||
| -rw-r--r-- | aes.c | 18 | ||||
| -rw-r--r-- | aes.h | 4 |
3 files changed, 17 insertions, 17 deletions
@@ -15,8 +15,8 @@ void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv) void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv); /* Then start encrypting and decrypting with the functions below: */ -void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf); -void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf); void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); @@ -47,21 +47,21 @@ GCC size output when only CTR mode is compiled for ARM: $ arm-none-eabi-gcc -Os -DCBC=0 -DECB=0 -DCTR=1 -c aes.c $ size aes.o text data bss dec hex filename - 1203 0 0 1203 4b3 aes.o + 1343 0 0 1343 53f aes.o .. and when compiling for the THUMB instruction set, we end up just below 1K in code size. $ arm-none-eabi-gcc -Os -mthumb -DCBC=0 -DECB=0 -DCTR=1 -c aes.c $ size aes.o text data bss dec hex filename - 955 0 0 955 3bb aes.o + 979 0 0 979 3d3 aes.o I am using the Free Software Foundation, ARM GCC compiler: $ arm-none-eabi-gcc --version - arm-none-eabi-gcc (4.8.4-1+11-1) 4.8.4 20141219 (release) - Copyright (C) 2013 Free Software Foundation, Inc. + arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 8-2018-q4-major) 8.2.1 20181213 (release) + Copyright (C) 2018 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. @@ -240,7 +240,7 @@ void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv) // This function adds the round key to state. // The round key is added to the state by an XOR function. -static void AddRoundKey(uint8_t round,state_t* state,uint8_t* RoundKey) +static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey) { uint8_t i,j; for (i = 0; i < 4; ++i) @@ -408,7 +408,7 @@ static void InvShiftRows(state_t* state) #endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) // Cipher is the main function that encrypts the PlainText. -static void Cipher(state_t* state, uint8_t* RoundKey) +static void Cipher(state_t* state, const uint8_t* RoundKey) { uint8_t round = 0; @@ -434,7 +434,7 @@ static void Cipher(state_t* state, uint8_t* RoundKey) } #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) -static void InvCipher(state_t* state,uint8_t* RoundKey) +static void InvCipher(state_t* state, const uint8_t* RoundKey) { uint8_t round = 0; @@ -466,13 +466,13 @@ static void InvCipher(state_t* state,uint8_t* RoundKey) #if defined(ECB) && (ECB == 1) -void AES_ECB_encrypt(struct AES_ctx *ctx, uint8_t* buf) +void AES_ECB_encrypt(const struct AES_ctx *ctx, uint8_t* buf) { // The next function call encrypts the PlainText with the Key using AES algorithm. Cipher((state_t*)buf, ctx->RoundKey); } -void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf) +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf) { // The next function call decrypts the PlainText with the Key using AES algorithm. InvCipher((state_t*)buf, ctx->RoundKey); @@ -488,7 +488,7 @@ void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf) #if defined(CBC) && (CBC == 1) -static void XorWithIv(uint8_t* buf, uint8_t* Iv) +static void XorWithIv(uint8_t* buf, const uint8_t* Iv) { uint8_t i; for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size @@ -497,7 +497,7 @@ static void XorWithIv(uint8_t* buf, uint8_t* Iv) } } -void AES_CBC_encrypt_buffer(struct AES_ctx *ctx,uint8_t* buf, uint32_t length) +void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length) { uintptr_t i; uint8_t *Iv = ctx->Iv; @@ -552,9 +552,9 @@ void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length) /* Increment Iv and handle overflow */ for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) { - /* inc will owerflow */ + /* inc will overflow */ if (ctx->Iv[bi] == 255) - { + { ctx->Iv[bi] = 0; continue; } @@ -58,8 +58,8 @@ void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv); // buffer size is exactly AES_BLOCKLEN bytes; // you need only AES_init_ctx as IV is not used in ECB // NB: ECB is considered insecure for most uses -void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf); -void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf); #endif // #if defined(ECB) && (ECB == !) |