5 files changed, 188 insertions, 122 deletions

diff --git a/README.md b/README.md
index c261b78..374a02c 100644
--- a/README.md
+++ b/README.md
@@ -1,19 +1,20 @@
-### Tiny AES128 in C
+### Tiny AES in C
 
-This is a small and portable implementation of the AES128 ECB and CBC encryption algorithms written in C.
+This is a small and portable implementation of the AES ECB and CBC encryption algorithms written in C.
 
 The API is very simple and looks like this (I am using C99 `<stdint.h>`-style annotated types):
 
 ```C
-void AES128_ECB_encrypt(uint8_t* input, const uint8_t* key, uint8_t* output);
-void AES128_ECB_decrypt(uint8_t* input, const uint8_t* key, uint8_t* output);
-void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
-void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
+void AES_ECB_encrypt(uint8_t* input, const uint8_t* key, uint8_t* output);
+void AES_ECB_decrypt(uint8_t* input, const uint8_t* key, uint8_t* output);
+void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
+void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
 ```
+You can choose to use the standard 128b key or 192/256b by defining the symbols AES192 or AES256
 
 You can choose to use one or both of the modes-of-operation, by defining the symbols CBC and ECB. See the header file for clarification.
 
-There is no built-in error checking or protection from out-of-bounds memory access errors as a result of malicious input. The two functions AES128_ECB_xxcrypt() do most of the work, and they expect inputs of 128 bit length.
+There is no built-in error checking or protection from out-of-bounds memory access errors as a result of malicious input. The two functions AES_ECB_xxcrypt() do most of the work, and they expect inputs of 128 bit length.
 
 The module uses around 200 bytes of RAM and 2.5K ROM when compiled for ARM (~2K for Thumb but YMMV).
 
@@ -57,9 +58,7 @@ I am using Mentor Graphics free ARM toolchain:
 
 This implementation is verified against the data in:
 
-[National Institute of Standards and Technology Special Publication 800-38A 2001 ED](http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf) Appendix F: Example Vectors for Modes of Operation of the AES.
+[National Institute of Standards and Technology Special Publication 800-38A 2001 ED](http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38a.pdf) Appendix F: Example Vectors for Modes of Operation of the AES.
 
 
 All material in this repository is in the public domain.
-
-I am a bit slow to react to pull requests and issues, but I have an ambition to go through all issues sometime in the future and release an API-stable version.
diff --git a/aes.c b/aes.c
index d44d281..0bafcb0 100644
--- a/aes.c
+++ b/aes.c
@@ -37,18 +37,29 @@ NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)
 #include <string.h> // CBC mode, for memset
 #include "aes.h"
 
-
 /*****************************************************************************/
 /* Defines:                                                                  */
 /*****************************************************************************/
 // The number of columns comprising a state in AES. This is a constant in AES. Value=4
 #define Nb 4
-// The number of 32 bit words in a key.
-#define Nk 4
-// Key length in bytes [128 bit]
-#define KEYLEN 16
-// The number of rounds in AES Cipher.
-#define Nr 10
+#define BLOCKLEN 16 //Block length in bytes AES is 128b block only
+
+#ifdef AES256
+    #define Nk 8
+    #define KEYLEN 32
+    #define Nr 14
+    #define keyExpSize 240
+#elif defined(AES192)
+    #define Nk 6
+    #define KEYLEN 24
+    #define Nr 12
+    #define keyExpSize 208
+#else
+    #define Nk 4        // The number of 32 bit words in a key.
+    #define KEYLEN 16   // Key length in bytes
+    #define Nr 10       // The number of rounds in AES Cipher.
+    #define keyExpSize 176
+#endif
 
 // jcallan@github points out that declaring Multiply as a function 
 // reduces code size considerably with the Keil ARM compiler.
@@ -66,7 +77,7 @@ typedef uint8_t state_t[4][4];
 static state_t* state;
 
 // The array that stores the round keys.
-static uint8_t RoundKey[176];
+static uint8_t RoundKey[keyExpSize];
 
 // The Key input to the AES Program
 static const uint8_t* Key;
@@ -116,27 +127,25 @@ static const uint8_t rsbox[256] =
   0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
   0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
 
-
 // The round constant word array, Rcon[i], contains the values given by 
 // x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
-// Note that i starts at 1, not 0).
-static const uint8_t Rcon[255] = {
-  0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 
-  0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 
-  0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 
-  0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 
-  0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 
-  0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 
-  0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 
-  0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 
-  0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 
-  0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 
-  0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 
-  0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 
-  0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 
-  0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 
-  0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 
-  0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb  };
+static const uint8_t Rcon[256] = {
+    0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
+    0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
+    0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
+    0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
+    0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
+    0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
+    0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
+    0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
+    0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
+    0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
+    0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
+    0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
+    0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
+    0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
+    0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
+    0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d };
 
 
 /*****************************************************************************/
@@ -155,7 +164,7 @@ static uint8_t getSBoxInvert(uint8_t num)
 // This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. 
 static void KeyExpansion(void)
 {
-  uint32_t i, j, k;
+  uint32_t i, k;
   uint8_t tempa[4]; // Used for the column/row operations
   
   // The first round key is the key itself.
@@ -168,15 +177,19 @@ static void KeyExpansion(void)
   }
 
   // All other round keys are found from the previous round keys.
-  for(; (i < (Nb * (Nr + 1))); ++i)
+  //i == Nk
+  for(; i < Nb * (Nr + 1); ++i)
   {
-    for(j = 0; j < 4; ++j)
     {
-      tempa[j]=RoundKey[(i-1) * 4 + j];
+      tempa[0]=RoundKey[(i-1) * 4 + 0];
+      tempa[1]=RoundKey[(i-1) * 4 + 1];
+      tempa[2]=RoundKey[(i-1) * 4 + 2];
+      tempa[3]=RoundKey[(i-1) * 4 + 3];
     }
+
     if (i % Nk == 0)
     {
-      // This function rotates the 4 bytes in a word to the left once.
+      // This function shifts the 4 bytes in a word to the left once.
       // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
 
       // Function RotWord()
@@ -201,7 +214,8 @@ static void KeyExpansion(void)
 
       tempa[0] =  tempa[0] ^ Rcon[i/Nk];
     }
-    else if (Nk > 6 && i % Nk == 4)
+#ifdef AES256
+    if (i % Nk == 4)
     {
       // Function Subword()
       {
@@ -211,6 +225,7 @@ static void KeyExpansion(void)
         tempa[3] = getSBoxValue(tempa[3]);
       }
     }
+#endif
     RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0];
     RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1];
     RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2];
@@ -434,16 +449,6 @@ static void InvCipher(void)
   AddRoundKey(0);
 }
 
-static void BlockCopy(uint8_t* output, const uint8_t* input)
-{
-  uint8_t i;
-  for (i=0;i<KEYLEN;++i)
-  {
-    output[i] = input[i];
-  }
-}
-
-
 
 /*****************************************************************************/
 /* Public functions:                                                         */
@@ -451,10 +456,10 @@ static void BlockCopy(uint8_t* output, const uint8_t* input)
 #if defined(ECB) && ECB
 
 
-void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output)
+void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output, const uint32_t length)
 {
   // Copy input to output, and work in-memory on output
-  BlockCopy(output, input);
+  memcpy(output, input, length);
   state = (state_t*)output;
 
   Key = key;
@@ -464,10 +469,10 @@ void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* outpu
   Cipher();
 }
 
-void AES128_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output)
+void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length)
 {
   // Copy input to output, and work in-memory on output
-  BlockCopy(output, input);
+  memcpy(output, input, length);
   state = (state_t*)output;
 
   // The KeyExpansion routine must be called before encryption.
@@ -490,19 +495,16 @@ void AES128_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *outpu
 static void XorWithIv(uint8_t* buf)
 {
   uint8_t i;
-  for(i = 0; i < KEYLEN; ++i)
+  for(i = 0; i < BLOCKLEN; ++i) //WAS for(i = 0; i < KEYLEN; ++i) but the block in AES is always 128bit so 16 bytes!
   {
     buf[i] ^= Iv[i];
   }
 }
 
-void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
+void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
 {
   uintptr_t i;
-  uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
-
-  BlockCopy(output, input);
-  state = (state_t*)output;
+  uint8_t extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */
 
   // Skip the key expansion if key is passed as 0
   if(0 != key)
@@ -516,33 +518,30 @@ void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
     Iv = (uint8_t*)iv;
   }
 
-  for(i = 0; i < length; i += KEYLEN)
+  for(i = 0; i < length; i += BLOCKLEN)
   {
     XorWithIv(input);
-    BlockCopy(output, input);
+    memcpy(output, input, BLOCKLEN);
     state = (state_t*)output;
     Cipher();
     Iv = output;
-    input += KEYLEN;
-    output += KEYLEN;
+    input += BLOCKLEN;
+    output += BLOCKLEN;
+    //printf("Step %d - %d", i/16, i);
   }
 
-  if(remainders)
+  if(extra)
   {
-    BlockCopy(output, input);
-    memset(output + remainders, 0, KEYLEN - remainders); /* add 0-padding */
+    memcpy(output, input, extra);
     state = (state_t*)output;
     Cipher();
   }
 }
 
-void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
+void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
 {
   uintptr_t i;
-  uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
-  
-  BlockCopy(output, input);
-  state = (state_t*)output;
+  uint8_t extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */
 
   // Skip the key expansion if key is passed as 0
   if(0 != key)
@@ -557,27 +556,23 @@ void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
     Iv = (uint8_t*)iv;
   }
 
-  for(i = 0; i < length; i += KEYLEN)
+  for(i = 0; i < length; i += BLOCKLEN)
   {
-    BlockCopy(output, input);
+    memcpy(output, input, BLOCKLEN);
     state = (state_t*)output;
     InvCipher();
     XorWithIv(output);
     Iv = input;
-    input += KEYLEN;
-    output += KEYLEN;
+    input += BLOCKLEN;
+    output += BLOCKLEN;
   }
 
-  if(remainders)
+  if(extra)
   {
-    BlockCopy(output, input);
-    memset(output+remainders, 0, KEYLEN - remainders); /* add 0-padding */
+    memcpy(output, input, extra);
     state = (state_t*)output;
     InvCipher();
   }
 }
 
-
 #endif // #if defined(CBC) && CBC
-
-
diff --git a/aes.h b/aes.h
index e86ab7f..624b4ab 100644
--- a/aes.h
+++ b/aes.h
@@ -6,7 +6,7 @@
 
 // #define the macros below to 1/0 to enable/disable the mode of operation.
 //
-// CBC enables AES128 encryption in CBC-mode of operation and handles 0-padding.
+// CBC enables AES encryption in CBC-mode of operation.
 // ECB enables the basic ECB 16-byte block algorithm. Both can be enabled simultaneously.
 
 // The #ifndef-guard allows it to be configured before #include'ing or at compile time.
@@ -18,23 +18,22 @@
   #define ECB 1
 #endif
 
-
+#define AES128
 
 #if defined(ECB) && ECB
 
-void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
-void AES128_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
+void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length);
+void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length);
 
 #endif // #if defined(ECB) && ECB
 
 
 #if defined(CBC) && CBC
 
-void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
-void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
+void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
+void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
 
 #endif // #if defined(CBC) && CBC
 
 
-
 #endif //_AES_H_
diff --git a/test.c b/test.c
index 96f5a2d..8908773 100644
--- a/test.c
+++ b/test.c
@@ -9,6 +9,7 @@
 
 #include "aes.h"
 
+
 static void phex(uint8_t* str);
 static void test_encrypt_ecb(void);
 static void test_decrypt_ecb(void);
@@ -17,25 +18,44 @@ static void test_encrypt_cbc(void);
 static void test_decrypt_cbc(void);
 
 
-
 int main(void)
 {
+
+#ifdef AES128
+    printf("\nTesting AES128\n\n");
+#elif defined(AES192)
+    printf("\nTesting AES192\n\n");
+#elif defined(AES256)
+    printf("\nTesting AES256\n\n");
+#else
+    printf("You need to specify a symbol between AES128, AES192 or AES256. Exiting");
+    return 0;
+#endif
+
     test_encrypt_cbc();
     test_decrypt_cbc();
     test_decrypt_ecb();
     test_encrypt_ecb();
     test_encrypt_ecb_verbose();
-    
+
     return 0;
 }
 
 
-
 // prints string as hex
 static void phex(uint8_t* str)
 {
+
+#ifdef AES128
+    uint8_t len = 16;
+#elif defined(AES192)
+    uint8_t len = 24;
+#elif defined(AES256)
+    uint8_t len = 32;
+#endif
+
     unsigned char i;
-    for(i = 0; i < 16; ++i)
+    for(i = 0; i < len; ++i)
         printf("%.2x", str[i]);
     printf("\n");
 }
@@ -74,7 +94,7 @@ static void test_encrypt_ecb_verbose(void)
     printf("ciphertext:\n");
     for(i = 0; i < 4; ++i)
     {
-        AES128_ECB_encrypt(plain_text + (i*16), key, buf+(i*16));
+        AES_ECB_encrypt(plain_text + (i*16), key, buf+(i*16), 16);
         phex(buf + (i*16));
     }
     printf("\n");
@@ -83,12 +103,23 @@ static void test_encrypt_ecb_verbose(void)
 
 static void test_encrypt_ecb(void)
 {
-  uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
+#ifdef AES128
+    uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
+    uint8_t out[] = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
+#elif defined(AES192)
+  uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
+                    0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b};
+  uint8_t out[] = { 0xbd, 0x33, 0x4f, 0x1d, 0x6e, 0x45, 0xf2, 0x5f, 0xf7, 0x12, 0xa2, 0x14, 0x57, 0x1f, 0xa5, 0xcc };
+#elif defined(AES256)
+    uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
+                      0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
+    uint8_t out[] = { 0xf3, 0xee, 0xd1, 0xbd, 0xb5, 0xd2, 0xa0, 0x3c, 0x06, 0x4b, 0x5a, 0x7e, 0x3d, 0xb1, 0x81, 0xf8 };
+#endif
+
   uint8_t in[]  = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
-  uint8_t out[] = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
   uint8_t buffer[16];
 
-  AES128_ECB_encrypt(in, key, buffer);
+  AES_ECB_encrypt(in, key, buffer, 16);
 
   printf("ECB encrypt: ");
 
@@ -104,24 +135,35 @@ static void test_encrypt_ecb(void)
 
 static void test_decrypt_cbc(void)
 {
-  // Example "simulating" a smaller buffer...
 
+#ifdef AES128
   uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
-  uint8_t iv[]  = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
-  uint8_t in[]  = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
+  uint8_t in[] = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
                     0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
-                    0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16, 
+                    0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
                     0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 };
-  uint8_t out[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-                    0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-                    0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-                    0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
+#elif defined(AES192)
+  uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5, 0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b};
+  uint8_t in[] = { 0x4f, 0x02, 0x1d, 0xb2, 0x43, 0xbc, 0x63, 0x3d, 0x71, 0x78, 0x18, 0x3a, 0x9f, 0xa0, 0x71, 0xe8,
+                    0xb4, 0xd9, 0xad, 0xa9, 0xad, 0x7d, 0xed, 0xf4, 0xe5, 0xe7, 0x38, 0x76, 0x3f, 0x69, 0x14, 0x5a,
+                    0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0,
+                    0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd };
+#elif defined(AES256)
+    uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
+                      0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
+    uint8_t in[] = { 0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba, 0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
+                      0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d, 0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
+                      0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
+                      0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b };
+#endif
+  uint8_t  iv[]  = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
+  uint8_t out[]  = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+                     0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+                     0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
+                     0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
   uint8_t buffer[64];
 
-  AES128_CBC_decrypt_buffer(buffer+0, in+0,  16, key, iv);
-  AES128_CBC_decrypt_buffer(buffer+16, in+16, 16, 0, 0);
-  AES128_CBC_decrypt_buffer(buffer+32, in+32, 16, 0, 0);
-  AES128_CBC_decrypt_buffer(buffer+48, in+48, 16, 0, 0);
+  AES_CBC_decrypt_buffer(buffer, in, 64, key, iv);
 
   printf("CBC decrypt: ");
 
@@ -137,19 +179,35 @@ static void test_decrypt_cbc(void)
 
 static void test_encrypt_cbc(void)
 {
+#ifdef AES128
   uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+  uint8_t out[] = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
+                    0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
+                    0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
+                    0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 };
+#elif defined(AES192)
+  uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5, 0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b};
+  uint8_t out[] = { 0x4f, 0x02, 0x1d, 0xb2, 0x43, 0xbc, 0x63, 0x3d, 0x71, 0x78, 0x18, 0x3a, 0x9f, 0xa0, 0x71, 0xe8,
+                    0xb4, 0xd9, 0xad, 0xa9, 0xad, 0x7d, 0xed, 0xf4, 0xe5, 0xe7, 0x38, 0x76, 0x3f, 0x69, 0x14, 0x5a,
+                    0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0,
+                    0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd };
+#elif defined(AES256)
+    uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
+                      0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
+    uint8_t out[] = { 0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba, 0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
+                      0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d, 0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
+                      0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
+                      0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b };
+#endif
   uint8_t iv[]  = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
   uint8_t in[]  = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
                     0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
                     0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
                     0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
-  uint8_t out[] = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
-                    0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
-                    0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16, 
-                    0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 };
+
   uint8_t buffer[64];
 
-  AES128_CBC_encrypt_buffer(buffer, in, 64, key, iv);
+  AES_CBC_encrypt_buffer(buffer, in, 64, key, iv);
 
   printf("CBC encrypt: ");
 
@@ -166,12 +224,23 @@ static void test_encrypt_cbc(void)
 
 static void test_decrypt_ecb(void)
 {
-  uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
-  uint8_t in[]  = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
-  uint8_t out[] = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
+#ifdef AES128
+    uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
+    uint8_t in[] = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
+#elif defined(AES192)
+  uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
+                    0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b};
+  uint8_t in[] = { 0xbd, 0x33, 0x4f, 0x1d, 0x6e, 0x45, 0xf2, 0x5f, 0xf7, 0x12, 0xa2, 0x14, 0x57, 0x1f, 0xa5, 0xcc };
+#elif defined(AES256)
+    uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
+                      0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
+    uint8_t in[] = { 0xf3, 0xee, 0xd1, 0xbd, 0xb5, 0xd2, 0xa0, 0x3c, 0x06, 0x4b, 0x5a, 0x7e, 0x3d, 0xb1, 0x81, 0xf8 };
+#endif
+
+  uint8_t out[]  = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
   uint8_t buffer[16];
 
-  AES128_ECB_decrypt(in, key, buffer);
+  AES_ECB_decrypt(in, key, buffer, 16);
 
   printf("ECB decrypt: ");
 
@@ -185,4 +254,3 @@ static void test_decrypt_ecb(void)
   }
 }
 
-
diff --git a/tiny-AES128-C.files b/tiny-AES128-C.files
new file mode 100644
index 0000000..ae78f94
--- /dev/null
+++ b/tiny-AES128-C.files
@@ -0,0 +1,5 @@
+README.md
+aes.c
+aes.h
+test.c
+unlicense.txt