This library implements some hash and cryptographic algorithms.

Dependents:   mBuinoBlinky PB_Emma_Ethernet SLOTrashHTTP Garagem ... more

This library implements the following algorithms :

  • RC4
  • AES (AES-128, AES-192, AES-256)
  • DES
  • Triple DES (EDE)
  • MD2
  • MD4
  • MD5
  • SHA-1
  • SHA-2 (SHA-224, SHA-256, SHA-384, SHA-512)

The hash algorithms have been optimized for the mbed and you should get decent performance. However, I did not optimize the ciphers. Also, I did not test extensively these algorithms : it should work but you may find some bugs. Block ciphers support two modes : ECB and CBC.

Warning

If you are using SHA-384 or SHA-512, be aware that it produces large binary files and the compilation (using the online compiler) takes much longer to execute. It may happen that the compiler stops because it timed-out. In this case, just compile again and it should work.

Computing hash

You can compute the hash of some data in two different ways. The first one is the easiest, each hash algorithm has a static method that takes some data and compute the hash from it.

Computing hash using method 1

#include "Crypto.h"
#include "mbed.h"

static const char msg[] = "mbed is great !";

int main()
{
    uint8_t hash[16];
    MD2::computeHash(hash, (uint8_t*)msg, strlen(msg));
    printf("hash: ");
    for(int i = 0; i < 16; ++i)
        printf("%02x", hash[i]);
    printf("\n");
    
    return 0;
}

The second one is slightly slower (around 2-3% slower) but it allows you to compute the hash of some data in several steps (by calling update method). This is the method you should use if you need to compute the hash from a large source and you don't have enough memory to store it in a single buffer.

Computing hash using method 2

#include "Crypto.h"
#include "mbed.h"

static const char msg[] = "mbed is great !";

int main()
{
    uint8_t hash[16];
    MD2 h;
    h.update((uint8_t*)msg, strlen(msg));
    h.finalize(hash);
    printf("hash: ");
    for(int i = 0; i < 16; ++i)
        printf("%02x", hash[i]);
    printf("\n");
    
    return 0;
}

TODO

  • optimize ciphers
  • add doc
Committer:
feb11
Date:
Sat Sep 07 23:47:28 2013 +0000
Revision:
0:7a1237bd2d13
initial import

Who changed what in which revision?

UserRevisionLine numberNew contents of line
feb11 0:7a1237bd2d13 1 #ifndef AES_H
feb11 0:7a1237bd2d13 2 #define AES_H
feb11 0:7a1237bd2d13 3
feb11 0:7a1237bd2d13 4 #include "Cipher.h"
feb11 0:7a1237bd2d13 5
feb11 0:7a1237bd2d13 6 enum AES_TYPE
feb11 0:7a1237bd2d13 7 {
feb11 0:7a1237bd2d13 8 AES_128 = 4,
feb11 0:7a1237bd2d13 9 AES_192 = 6,
feb11 0:7a1237bd2d13 10 AES_256 = 8
feb11 0:7a1237bd2d13 11 };
feb11 0:7a1237bd2d13 12
feb11 0:7a1237bd2d13 13 class AES : public Cipher
feb11 0:7a1237bd2d13 14 {
feb11 0:7a1237bd2d13 15 public :
feb11 0:7a1237bd2d13 16
feb11 0:7a1237bd2d13 17 AES(const AES_TYPE type, uint8_t *key);
feb11 0:7a1237bd2d13 18
feb11 0:7a1237bd2d13 19 virtual void encrypt(uint8_t *out, uint8_t *in, uint32_t length);
feb11 0:7a1237bd2d13 20 virtual void decrypt(uint8_t *out, uint8_t *in, uint32_t length);
feb11 0:7a1237bd2d13 21 virtual uint32_t getBlockSize() const;
feb11 0:7a1237bd2d13 22
feb11 0:7a1237bd2d13 23 private :
feb11 0:7a1237bd2d13 24
feb11 0:7a1237bd2d13 25 void encryptBlock(uint8_t *out, uint8_t *in);
feb11 0:7a1237bd2d13 26 void decryptBlock(uint8_t *out, uint8_t *in);
feb11 0:7a1237bd2d13 27
feb11 0:7a1237bd2d13 28 void keyExpansion(uint8_t *key);
feb11 0:7a1237bd2d13 29 uint32_t rotWord(uint32_t w);
feb11 0:7a1237bd2d13 30 uint32_t invRotWord(uint32_t w);
feb11 0:7a1237bd2d13 31 uint32_t subWord(uint32_t w);
feb11 0:7a1237bd2d13 32 void subBytes();
feb11 0:7a1237bd2d13 33 void invSubBytes();
feb11 0:7a1237bd2d13 34 void shiftRows();
feb11 0:7a1237bd2d13 35 void invShiftRows();
feb11 0:7a1237bd2d13 36 void mul(uint8_t *r);
feb11 0:7a1237bd2d13 37 void invMul(uint8_t *r);
feb11 0:7a1237bd2d13 38 void mixColumns();
feb11 0:7a1237bd2d13 39 void invMixColumns();
feb11 0:7a1237bd2d13 40 void addRoundKey(int round);
feb11 0:7a1237bd2d13 41
feb11 0:7a1237bd2d13 42 uint8_t state[16];
feb11 0:7a1237bd2d13 43 uint32_t w[60];
feb11 0:7a1237bd2d13 44 uint8_t nr,nk;
feb11 0:7a1237bd2d13 45 };
feb11 0:7a1237bd2d13 46
feb11 0:7a1237bd2d13 47 #endif