Francois Berder
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/SHA1.cpp
- Committer:
- feb11
- Date:
- 2014-05-11
- Revision:
- 14:f04410cef037
- Parent:
- 13:ac8e23b98dae
File content as of revision 14:f04410cef037:
/**
Implementation of SHA-1 as described here:
http://tools.ietf.org/html/rfc1319
*/
#include "SHA1.h"
#include <string.h>
#define F0(B,C,D) ((B & C) | ((~B) & D))
#define F1(B,C,D) (B ^ C ^ D)
#define F2(B,C,D) ((B & C) | (B & D) | (C & D))
#define ROTL(W,N) (((W) << N) | ((W) >> (32-N)))
#define K0 0x5A827999
#define K1 0x6ED9EBA1
#define K2 0x8F1BBCDC
#define K3 0xCA62C1D6
#define H0 0x67452301
#define H1 0xEFCDAB89
#define H2 0x98BADCFE
#define H3 0x10325476
#define H4 0xC3D2E1F0
#define MASK 0xF
#define W(s) ( w[s] = ROTL(w[((s) + 13) & MASK] ^ w[((s) + 8) & MASK] ^ w[((s) + 2) & MASK] ^ w[s],1))
#define R0(A,B,C,D,E,T) E += ROTL(A, 5) + F0(B, C, D) + w[T] + K0; \
B = ROTL(B,30);
#define R1(A,B,C,D,E,T) E += ROTL(A, 5) + F0(B, C, D) + W(T & MASK) + K0; \
B = ROTL(B,30);
#define R2(A,B,C,D,E,T) E += ROTL(A, 5) + F1(B, C, D) + W(T & MASK) + K1; \
B = ROTL(B,30);
#define R3(A,B,C,D,E,T) E += ROTL(A, 5) + F2(B, C, D) + W(T & MASK) + K2; \
B = ROTL(B,30);
#define R4(A,B,C,D,E,T) E += ROTL(A, 5) + F1(B, C, D) + W(T & MASK) + K3; \
B = ROTL(B,30);
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
}
SHA1::SHA1():
HashAlgorithm(),
h0(H0),
h1(H1),
h2(H2),
h3(H3),
h4(H4),
totalBufferLength(0),
buffer(),
bufferLength(0)
{
}
uint8_t SHA1::outputSize() const
{
return 20;
}
void SHA1::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, buffer);
while(length-offset > 64)
{
memcpy(buffer, &data[offset], 64);
computeBlock(&h0,&h1,&h2,&h3,&h4, buffer);
offset += 64;
}
if(offset > (int)length)
offset -= 64;
bufferLength = length - offset;
memcpy(buffer, &data[offset], bufferLength);
totalBufferLength += length;
}
void SHA1::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, 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[56], &lengthBitHigh, 4);
memcpy(&buffer[60], &lengthBitLow, 4);
computeBlock(&h0,&h1,&h2,&h3,&h4, buffer);
hash2[0] = revWord(h0);
hash2[1] = revWord(h1);
hash2[2] = revWord(h2);
hash2[3] = revWord(h3);
hash2[4] = revWord(h4);
// reset state
h0 = H0;
h1 = H1;
h2 = H2;
h3 = H3;
h4 = H4;
totalBufferLength = 0;
bufferLength = 0;
}
void SHA1::computeHash(uint8_t *hash, uint8_t *data, uint32_t length)
{
uint32_t *hash2 = (uint32_t*)hash;
uint64_t lengthBit = length << 3;
uint32_t padding;
if(length % 64 < 56)
padding = 56 - (length % 64);
else
padding = 56 + (64 - (length % 64));
uint32_t h0 = H0, h1 = H1, h2 = H2, h3 = H3, h4 = H4;
while(length >= 64)
{
computeBlock(&h0,&h1,&h2,&h3,&h4, data);
length -= 64;
data += 64;
}
uint8_t buffer[64];
memcpy(buffer, data, length);
buffer[length++] = 0x80;
padding--;
if(padding+length+8 == 64)
memset(&buffer[length], 0, padding);
else
{
memset(&buffer[length], 0, 64-length);
computeBlock(&h0,&h1,&h2,&h3,&h4, buffer);
memset(buffer, 0, 56);
}
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, buffer);
hash2[0] = revWord(h0);
hash2[1] = revWord(h1);
hash2[2] = revWord(h2);
hash2[3] = revWord(h3);
hash2[4] = revWord(h4);
}
void SHA1::computeBlock(uint32_t *h02, uint32_t *h12, uint32_t *h22, uint32_t *h32, uint32_t *h42, uint8_t *buffer)
{
uint32_t *buffer2 = (uint32_t*)buffer;
uint32_t w[16];
for(int t = 0; t < 16; ++t)
w[t] = revWord(buffer2[t]);
uint32_t a = *h02, b = *h12, c = *h22, d = *h32, e = *h42;
R0(a,b,c,d,e, 0) R0(e,a,b,c,d, 1) R0(d,e,a,b,c, 2) R0(c,d,e,a,b, 3)
R0(b,c,d,e,a, 4) R0(a,b,c,d,e, 5) R0(e,a,b,c,d, 6) R0(d,e,a,b,c, 7)
R0(c,d,e,a,b, 8) R0(b,c,d,e,a, 9) R0(a,b,c,d,e,10) R0(e,a,b,c,d,11)
R0(d,e,a,b,c,12) R0(c,d,e,a,b,13) R0(b,c,d,e,a,14) R0(a,b,c,d,e,15)
R1(e,a,b,c,d,16) R1(d,e,a,b,c,17) R1(c,d,e,a,b,18) R1(b,c,d,e,a,19)
R2(a,b,c,d,e,20) R2(e,a,b,c,d,21) R2(d,e,a,b,c,22) R2(c,d,e,a,b,23)
R2(b,c,d,e,a,24) R2(a,b,c,d,e,25) R2(e,a,b,c,d,26) R2(d,e,a,b,c,27)
R2(c,d,e,a,b,28) R2(b,c,d,e,a,29) R2(a,b,c,d,e,30) R2(e,a,b,c,d,31)
R2(d,e,a,b,c,32) R2(c,d,e,a,b,33) R2(b,c,d,e,a,34) R2(a,b,c,d,e,35)
R2(e,a,b,c,d,36) R2(d,e,a,b,c,37) R2(c,d,e,a,b,38) R2(b,c,d,e,a,39)
R3(a,b,c,d,e,40) R3(e,a,b,c,d,41) R3(d,e,a,b,c,42) R3(c,d,e,a,b,43)
R3(b,c,d,e,a,44) R3(a,b,c,d,e,45) R3(e,a,b,c,d,46) R3(d,e,a,b,c,47)
R3(c,d,e,a,b,48) R3(b,c,d,e,a,49) R3(a,b,c,d,e,50) R3(e,a,b,c,d,51)
R3(d,e,a,b,c,52) R3(c,d,e,a,b,53) R3(b,c,d,e,a,54) R3(a,b,c,d,e,55)
R3(e,a,b,c,d,56) R3(d,e,a,b,c,57) R3(c,d,e,a,b,58) R3(b,c,d,e,a,59)
R4(a,b,c,d,e,60) R4(e,a,b,c,d,61) R4(d,e,a,b,c,62) R4(c,d,e,a,b,63)
R4(b,c,d,e,a,64) R4(a,b,c,d,e,65) R4(e,a,b,c,d,66) R4(d,e,a,b,c,67)
R4(c,d,e,a,b,68) R4(b,c,d,e,a,69) R4(a,b,c,d,e,70) R4(e,a,b,c,d,71)
R4(d,e,a,b,c,72) R4(c,d,e,a,b,73) R4(b,c,d,e,a,74) R4(a,b,c,d,e,75)
R4(e,a,b,c,d,76) R4(d,e,a,b,c,77) R4(c,d,e,a,b,78) R4(b,c,d,e,a,79)
*h02 += a;
*h12 += b;
*h22 += c;
*h32 += d;
*h42 += e;
}