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
Revision 9:e34e076fb223, committed 2013-09-16
- Comitter:
- feb11
- Date:
- Mon Sep 16 08:35:36 2013 +0000
- Parent:
- 8:a090264e9b2d
- Child:
- 10:bc9c23aa3870
- Commit message:
- implemented MD4
Changed in this revision
--- a/Crypto.h Sat Sep 14 20:54:59 2013 +0000 +++ b/Crypto.h Mon Sep 16 08:35:36 2013 +0000 @@ -7,6 +7,7 @@ #include "TDES.h" #include "MD2.h" +#include "MD4.h" #include "MD5.h" #include "SHA1.h" #include "SHA2.h"
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hash/MD4.cpp Mon Sep 16 08:35:36 2013 +0000
@@ -0,0 +1,183 @@
+#include "MD4.h"
+#include <string.h>
+
+static const uint32_t A = 0x67452301;
+static const uint32_t B = 0xefcdab89;
+static const uint32_t C = 0x98badcfe;
+static const uint32_t D = 0x10325476;
+
+#define F(X,Y,Z) ((X & Y) | ((~X) & Z))
+#define G(X,Y,Z) ((X & Y) | (X & Z) | (Y & Z))
+#define H(X,Y,Z) (X ^ Y ^ Z)
+
+
+#define ROTL(W,N) (((W) << N) | ((W) >> (32-N)))
+
+#define ROUND1(a,b,c,d,x,s) \
+ a = ROTL(a + F(b,c,d) + x,s);
+
+#define ROUND2(a,b,c,d,x,s) \
+ a = ROTL(a + G(b,c,d) + x + 0x5A827999,s);
+
+#define ROUND3(a,b,c,d,x,s) \
+ a = ROTL(a + H(b,c,d) + x + 0x6ED9EBA1,s);
+
+
+
+MD4::MD4():
+HashAlgorithm(),
+a(A),
+b(B),
+c(C),
+d(D),
+totalBufferLength(0),
+buffer(),
+bufferLength(0)
+{
+}
+
+uint8_t MD4::outputSize() const
+{
+ return 16;
+}
+
+void MD4::update(uint8_t *data, uint32_t length)
+{
+ if(length < 64-bufferLength)
+ {
+ memcpy(&buffer[bufferLength], data, length);
+ bufferLength += length;
+ totalBufferLength += length;
+ return;
+ }
+ int offset = 64-bufferLength;
+ memcpy(&buffer[bufferLength], data, offset);
+ computeRounds(&a, &b, &c, &d, buffer);
+ while(length-offset > 64)
+ {
+ memcpy(buffer, &data[offset], 64);
+ computeRounds(&a, &b, &c, &d, buffer);
+ offset += 64;
+ }
+ if(offset > length)
+ offset -= 64;
+ bufferLength = length - offset;
+ memcpy(buffer, &data[offset], bufferLength);
+ totalBufferLength += length;
+}
+
+void MD4::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);
+ computeRounds(&a, &b, &c, &d, buffer);
+ memset(buffer, 0, 56);
+ }
+ uint64_t lengthBit = totalBufferLength << 3;
+ uint32_t lengthBitLow = lengthBit;
+ uint32_t lengthBitHigh = lengthBit >> 32;
+ memcpy(&buffer[56], &lengthBitLow, 4);
+ memcpy(&buffer[60], &lengthBitHigh, 4);
+ computeRounds(&a, &b, &c, &d, buffer);
+
+ hash2[0] = a;
+ hash2[1] = b;
+ hash2[2] = c;
+ hash2[3] = d;
+ // reset state
+ a = A;
+ b = B;
+ c = C;
+ d = D;
+ totalBufferLength = 0;
+ bufferLength = 0;
+}
+
+
+void MD4::computeHash(uint8_t *hash, uint8_t *data, uint32_t length)
+{
+ uint32_t *hash2 = (uint32_t*)hash;
+ uint64_t lengthBit = length << 3;
+ uint16_t padding;
+ if(length % 64 < 56)
+ padding = 56 - (length % 64);
+ else
+ padding = 56 + (64 - (length % 64));
+
+ uint32_t a = A, b = B, c = C, d = D;
+ while(length >= 64)
+ {
+ computeRounds(&a, &b, &c, &d, data);
+ data += 64;
+ length -= 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);
+ computeRounds(&a, &b, &c, &d, data);
+ memset(buffer, 0, 56);
+ }
+
+ uint32_t lengthBitLow = lengthBit;
+ uint32_t lengthBitHigh = lengthBit >> 32;
+ memcpy(&buffer[56], &lengthBitLow, 4);
+ memcpy(&buffer[60], &lengthBitHigh, 4);
+
+ computeRounds(&a, &b, &c, &d, buffer);
+
+ hash2[0] = a;
+ hash2[1] = b;
+ hash2[2] = c;
+ hash2[3] = d;
+}
+
+void MD4::computeRounds(uint32_t *a2, uint32_t *b2, uint32_t *c2, uint32_t *d2, uint8_t *buffer)
+{
+ uint32_t a = *a2, b = *b2, c = *c2, d = *d2;
+ uint32_t tmpA = a, tmpB = b, tmpC = c, tmpD = d;
+
+ uint32_t *x = (uint32_t*)buffer;
+
+ // Round 1
+ ROUND1(a,b,c,d,x[0],3); ROUND1(d,a,b,c,x[1],7); ROUND1(c,d,a,b,x[2],11); ROUND1(b,c,d,a,x[3],19);
+ ROUND1(a,b,c,d,x[4],3); ROUND1(d,a,b,c,x[5],7); ROUND1(c,d,a,b,x[6],11); ROUND1(b,c,d,a,x[7],19);
+ ROUND1(a,b,c,d,x[8],3); ROUND1(d,a,b,c,x[9],7); ROUND1(c,d,a,b,x[10],11); ROUND1(b,c,d,a,x[11],19);
+ ROUND1(a,b,c,d,x[12],3); ROUND1(d,a,b,c,x[13],7); ROUND1(c,d,a,b,x[14],11); ROUND1(b,c,d,a,x[15],19);
+
+
+ // Round 2
+ ROUND2(a,b,c,d,x[0],3); ROUND2(d,a,b,c,x[4],5); ROUND2(c,d,a,b,x[8],9); ROUND2(b,c,d,a,x[12],13);
+ ROUND2(a,b,c,d,x[1],3); ROUND2(d,a,b,c,x[5],5); ROUND2(c,d,a,b,x[9],9); ROUND2(b,c,d,a,x[13],13);
+ ROUND2(a,b,c,d,x[2],3); ROUND2(d,a,b,c,x[6],5); ROUND2(c,d,a,b,x[10],9); ROUND2(b,c,d,a,x[14],13);
+ ROUND2(a,b,c,d,x[3],3); ROUND2(d,a,b,c,x[7],5); ROUND2(c,d,a,b,x[11],9); ROUND2(b,c,d,a,x[15],13);
+
+
+ // Round 3
+ ROUND3(a,b,c,d,x[0],3); ROUND3(d,a,b,c,x[8],9); ROUND3(c,d,a,b,x[4],11); ROUND3(b,c,d,a,x[12],15);
+ ROUND3(a,b,c,d,x[2],3); ROUND3(d,a,b,c,x[10],9); ROUND3(c,d,a,b,x[6],11); ROUND3(b,c,d,a,x[14],15);
+ ROUND3(a,b,c,d,x[1],3); ROUND3(d,a,b,c,x[9],9); ROUND3(c,d,a,b,x[5],11); ROUND3(b,c,d,a,x[13],15);
+ ROUND3(a,b,c,d,x[3],3); ROUND3(d,a,b,c,x[11],9); ROUND3(c,d,a,b,x[7],11); ROUND3(b,c,d,a,x[15],15);
+
+
+ *a2 = a + tmpA;
+ *b2 = b + tmpB;
+ *c2 = c + tmpC;
+ *d2 = d + tmpD;
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hash/MD4.h Mon Sep 16 08:35:36 2013 +0000
@@ -0,0 +1,28 @@
+#ifndef MD4_H
+#define MD4_H
+
+#include "HashAlgorithm.h"
+
+class MD4: public HashAlgorithm
+{
+ public :
+
+ MD4();
+
+ virtual uint8_t outputSize() const;
+ virtual void update(uint8_t *data, uint32_t length);
+ virtual void finalize(uint8_t *hash);
+
+ static void computeHash(uint8_t *hash, uint8_t *data, uint32_t length);
+
+ private :
+
+ static void computeRounds(uint32_t *a2, uint32_t *b2, uint32_t *c2, uint32_t *d2, uint8_t *buffer);
+
+ uint32_t a,b,c,d;
+ uint32_t totalBufferLength;
+ uint8_t buffer[64];
+ uint8_t bufferLength;
+};
+
+#endif