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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

hash/SHA2_32.cpp

Committer:: feb11
Date:: 2014-05-11
Revision:: 14:f04410cef037
Parent:: 13:ac8e23b98dae

File content as of revision 14:f04410cef037:

#include "SHA2_32.h"
#include <string.h>



static const uint8_t MASK = 0x0F;

#define W(t) (w[(t)] = SSIG1(w[((t)+14)&MASK]) + w[((t)+9)&MASK] + SSIG0(w[((t)+1)&MASK]) + w[t])

#define ROTL(W,N) (((W) << (N)) | ((W) >> (32-(N))))
#define ROTR(W,N) (rotRWord(W,N)) 
#define CH(X,Y,Z) (((X) & (Y)) ^ ((~(X)) & (Z)))
#define MAJ(X,Y,Z) (((X) & (Y)) ^ ((X) & (Z)) ^ ((Y) & (Z)))
#define BSIG0(X) (ROTR(X,2) ^ ROTR(X,13) ^ ROTR(X,22))
#define BSIG1(X) (ROTR(X,6) ^ ROTR(X,11) ^ ROTR(X,25))
#define SSIG0(X) (ROTR((X),7) ^ ROTR((X),18) ^ ((X) >> 3))
#define SSIG1(X) (ROTR((X),17) ^ ROTR((X),19) ^ ((X) >> 10))
#define R(A,B,C,D,E,F,G,H,T,K)  T1 = H + BSIG1(E) + CH(E,F,G) + K + (w[T] = revWord(buffer2[T])); \
                              T2 = BSIG0(A) + MAJ(A,B,C); \
                              D += T1; \
                              H = T1 + T2;
#define R2(A,B,C,D,E,F,G,H,T,K)  T1 = H + BSIG1(E) + CH(E,F,G) + K + W(T&MASK); \
                              T2 = BSIG0(A) + MAJ(A,B,C); \
                              D += T1; \
                              H = T1 + T2;
        
static const uint32_t H[] =
{
    // SHA-224
    0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
    0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4,
    
    // SHA-256      
    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
};

static uint32_t revWord(const uint32_t w)
{
#ifdef __CC_ARM
    return __rev(w);
#else
    return (w >> 24)
         | ((w & 0x00FF0000) >> 8)
         | ((w & 0x0000FF00) << 8)
         | ((w & 0x000000FF) << 24);
#endif
} 

static uint32_t rotRWord(const uint32_t w, const uint32_t n)
{
#ifdef __CC_ARM
    return __ror(w, n);
#else
    return (w >> n) | (w << (32-n));
#endif
}

SHA2_32::SHA2_32(SHA_32_TYPE t):
type(t),
totalBufferLength(0),
bufferLength(0)
{
    switch(type)
    {
        case SHA_224:
            h0 = H[0];
            h1 = H[1];
            h2 = H[2];
            h3 = H[3];
            h4 = H[4];
            h5 = H[5];
            h6 = H[6];
            h7 = H[7];
        break;
        
        case SHA_256:
            h0 = H[8];
            h1 = H[9];
            h2 = H[10];
            h3 = H[11];
            h4 = H[12];
            h5 = H[13];
            h6 = H[14];
            h7 = H[15];     
        break;
    }
}

void SHA2_32::update(uint8_t *data, uint32_t length)
{
    if((int)length < 64-bufferLength)
    {
        memcpy(&buffer[bufferLength], data, length);
        bufferLength += length;
        totalBufferLength += length;
        return;
    }
    int offset = 64-bufferLength;
    memcpy(&buffer[bufferLength], data, offset);
    computeBlock(&h0,&h1,&h2,&h3,&h4,&h5,&h6,&h7,buffer);
    while(length-offset > 64)
    {
        memcpy(buffer, &data[offset], 64);
        computeBlock(&h0,&h1,&h2,&h3,&h4,&h5,&h6,&h7,buffer);
        offset += 64;
    }
    if(offset > (int)length)
        offset -= 64;
    bufferLength = length - offset;
    memcpy(buffer, &data[offset], bufferLength);
    totalBufferLength += length;
}

void SHA2_32::finalize(uint8_t *hash)
{
    uint32_t *hash2 = (uint32_t*)hash;
    uint16_t padding;
    if(totalBufferLength % 64 < 56)
        padding = 56 - (totalBufferLength % 64);
    else
        padding = 56 + (64 - (totalBufferLength % 64));

    buffer[bufferLength++] = 0x80;
    padding--;
    if(padding+bufferLength == 56)
        memset(&buffer[bufferLength], 0, padding);
    else
    {
        memset(&buffer[bufferLength], 0, 64-bufferLength);
        computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);
        memset(buffer, 0, 56);
    }
    
    uint64_t lengthBit = totalBufferLength << 3;
    uint32_t lengthBitLow = lengthBit;
    uint32_t lengthBitHigh = lengthBit >> 32;
    lengthBitLow = revWord(lengthBitLow);
    lengthBitHigh = revWord(lengthBitHigh);
    memcpy(&buffer[60], &lengthBitLow, 4);    
    memcpy(&buffer[56], &lengthBitHigh, 4);    
    computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);

    hash2[0] = revWord(h0);
    hash2[1] = revWord(h1);
    hash2[2] = revWord(h2);
    hash2[3] = revWord(h3);
    hash2[4] = revWord(h4);
    hash2[5] = revWord(h5);
    hash2[6] = revWord(h6);

    
    if(type == SHA_256)
        hash2[7] = revWord(h7);
    
    // reset state
    switch(type)
    {
        case SHA_224:
            h0 = H[0];
            h1 = H[1];
            h2 = H[2];
            h3 = H[3];
            h4 = H[4];
            h5 = H[5];
            h6 = H[6];
            h7 = H[7];
        break;
        
        case SHA_256:
            h0 = H[8];
            h1 = H[9];
            h2 = H[10];
            h3 = H[11];
            h4 = H[12];
            h5 = H[13];
            h6 = H[14];
            h7 = H[15];     
        break;
    }
    totalBufferLength = 0;
    bufferLength = 0;
}

void SHA2_32::computeHash(SHA_32_TYPE type, uint8_t *hash, uint8_t *data, uint32_t length)
{
    uint32_t *hash2 = (uint32_t*)hash;
    
    uint32_t h[8];
    h[0] = H[type*8];
    h[1] = H[type*8+1];
    h[2] = H[type*8+2];
    h[3] = H[type*8+3];
    h[4] = H[type*8+4];
    h[5] = H[type*8+5];
    h[6] = H[type*8+6];
    h[7] = H[type*8+7];
    
    uint64_t lengthBit = length << 3;
    uint32_t padding;
    if(length % 64 < 56)
        padding = 56 - (length % 64);
    else
        padding = 56 + (64 - (length % 64));
        
    while(length >= 64)
    {
        computeBlock(h, &h[1], &h[2], &h[3], &h[4], &h[5], &h[6], &h[7], data);
        length -= 64;
        data += 64;
    }
    uint8_t buffer[64];
    memcpy(buffer, data,length); 
    buffer[length++] = 0x80;
    padding--;
    if(padding+length == 56)
        memset(&buffer[length], 0, padding);
    else
    {
        memset(&buffer[length], 0, 64-length);
        computeBlock(h, &h[1], &h[2], &h[3], &h[4], &h[5], &h[6], &h[7], buffer);
        memset(buffer, 0, 56);
    }
    
    uint32_t lengthBitLow = lengthBit;
    uint32_t lengthBitHigh = lengthBit >> 32;
    lengthBitLow = revWord(lengthBitLow);
    memcpy(&buffer[60], &lengthBitLow, 4);
    lengthBitHigh = revWord(lengthBitHigh);
    memcpy(&buffer[56], &lengthBitHigh, 4);    
    computeBlock(h, &h[1], &h[2], &h[3], &h[4], &h[5], &h[6], &h[7], buffer);

    hash2[0] = revWord(h[0]);
    hash2[1] = revWord(h[1]);
    hash2[2] = revWord(h[2]);
    hash2[3] = revWord(h[3]);
    hash2[4] = revWord(h[4]);
    hash2[5] = revWord(h[5]);
    hash2[6] = revWord(h[6]);

    
    if(type == SHA_256)
        hash2[7] = revWord(h[7]);
}


#ifdef __CC_ARM
__forceinline 
#endif 
void SHA2_32::computeBlock(uint32_t *h02, 
                        uint32_t *h12, 
                        uint32_t *h22, 
                        uint32_t *h32, 
                        uint32_t *h42, 
                        uint32_t *h52, 
                        uint32_t *h62,
                        uint32_t *h72,
                        uint8_t *buffer)
{
    uint32_t w[16];
    uint32_t *buffer2 = (uint32_t*)buffer;
    uint32_t a = *h02, b = *h12, c = *h22, d = *h32, e = *h42, f = *h52, g = *h62, h = *h72;
    uint32_t T1, T2;

    R(a,b,c,d,e,f,g,h,0,0x428a2f98)
    R(h,a,b,c,d,e,f,g,1,0x71374491)
    R(g,h,a,b,c,d,e,f,2,0xb5c0fbcf)
    R(f,g,h,a,b,c,d,e,3,0xe9b5dba5)
    R(e,f,g,h,a,b,c,d,4,0x3956c25b)
    R(d,e,f,g,h,a,b,c,5,0x59f111f1)
    R(c,d,e,f,g,h,a,b,6,0x923f82a4)
    R(b,c,d,e,f,g,h,a,7,0xab1c5ed5)

    R(a,b,c,d,e,f,g,h,8,0xd807aa98)
    R(h,a,b,c,d,e,f,g,9,0x12835b01)
    R(g,h,a,b,c,d,e,f,10,0x243185be)
    R(f,g,h,a,b,c,d,e,11,0x550c7dc3)
    R(e,f,g,h,a,b,c,d,12,0x72be5d74)
    R(d,e,f,g,h,a,b,c,13,0x80deb1fe)
    R(c,d,e,f,g,h,a,b,14,0x9bdc06a7)
    R(b,c,d,e,f,g,h,a,15,0xc19bf174)

    R2(a,b,c,d,e,f,g,h,16,0xe49b69c1)
    R2(h,a,b,c,d,e,f,g,17,0xefbe4786)
    R2(g,h,a,b,c,d,e,f,18,0x0fc19dc6)
    R2(f,g,h,a,b,c,d,e,19,0x240ca1cc)
    R2(e,f,g,h,a,b,c,d,20,0x2de92c6f)
    R2(d,e,f,g,h,a,b,c,21,0x4a7484aa)
    R2(c,d,e,f,g,h,a,b,22,0x5cb0a9dc)
    R2(b,c,d,e,f,g,h,a,23,0x76f988da)
    
    R2(a,b,c,d,e,f,g,h,24,0x983e5152)
    R2(h,a,b,c,d,e,f,g,25,0xa831c66d)
    R2(g,h,a,b,c,d,e,f,26,0xb00327c8)
    R2(f,g,h,a,b,c,d,e,27,0xbf597fc7)
    R2(e,f,g,h,a,b,c,d,28,0xc6e00bf3)
    R2(d,e,f,g,h,a,b,c,29,0xd5a79147)
    R2(c,d,e,f,g,h,a,b,30,0x06ca6351)
    R2(b,c,d,e,f,g,h,a,31,0x14292967) 

    R2(a,b,c,d,e,f,g,h,32,0x27b70a85)
    R2(h,a,b,c,d,e,f,g,33,0x2e1b2138)
    R2(g,h,a,b,c,d,e,f,34,0x4d2c6dfc)
    R2(f,g,h,a,b,c,d,e,35,0x53380d13)
    R2(e,f,g,h,a,b,c,d,36,0x650a7354)
    R2(d,e,f,g,h,a,b,c,37,0x766a0abb)
    R2(c,d,e,f,g,h,a,b,38,0x81c2c92e)
    R2(b,c,d,e,f,g,h,a,39,0x92722c85)
    
    R2(a,b,c,d,e,f,g,h,40,0xa2bfe8a1)
    R2(h,a,b,c,d,e,f,g,41,0xa81a664b)
    R2(g,h,a,b,c,d,e,f,42,0xc24b8b70)
    R2(f,g,h,a,b,c,d,e,43,0xc76c51a3)
    R2(e,f,g,h,a,b,c,d,44,0xd192e819)
    R2(d,e,f,g,h,a,b,c,45,0xd6990624)
    R2(c,d,e,f,g,h,a,b,46,0xf40e3585)
    R2(b,c,d,e,f,g,h,a,47,0x106aa070)
    
    R2(a,b,c,d,e,f,g,h,48,0x19a4c116)
    R2(h,a,b,c,d,e,f,g,49,0x1e376c08)
    R2(g,h,a,b,c,d,e,f,50,0x2748774c)
    R2(f,g,h,a,b,c,d,e,51,0x34b0bcb5)
    R2(e,f,g,h,a,b,c,d,52,0x391c0cb3)
    R2(d,e,f,g,h,a,b,c,53,0x4ed8aa4a)
    R2(c,d,e,f,g,h,a,b,54,0x5b9cca4f)
    R2(b,c,d,e,f,g,h,a,55,0x682e6ff3)
    
    R2(a,b,c,d,e,f,g,h,56,0x748f82ee)
    R2(h,a,b,c,d,e,f,g,57,0x78a5636f)
    R2(g,h,a,b,c,d,e,f,58,0x84c87814)
    R2(f,g,h,a,b,c,d,e,59,0x8cc70208)
    R2(e,f,g,h,a,b,c,d,60,0x90befffa)
    R2(d,e,f,g,h,a,b,c,61,0xa4506ceb)
    R2(c,d,e,f,g,h,a,b,62,0xbef9a3f7)
    R2(b,c,d,e,f,g,h,a,63,0xc67178f2)
    
    
    *h02 += a;
    *h12 += b;
    *h22 += c;
    *h32 += d;
    *h42 += e;
    *h52 += f;
    *h62 += g;
    *h72 += h;
}

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Type:	Library
Created:	07 Sep 2013
Imports:	764
Forks:	2
Commits:	15
Dependents:	10
Dependencies:	0
Followers:	16

The code in this repository is Apache licensed.