md5 is not giving accurate result

[rohitnegi]

Hi All,
I am using MD5 algo. to encrypt username.I have took md5.h and md5.cpp from another project .In that project it is showing accurate result but it is not giving the correct output in my project .What could be the reason?Please give any solution?





thanks,
rohit

[Paul McKenzie]

Hi All,
I am using MD5 algo. to encrypt username.I have took md5.h and md5.cpp from another project .In that project it is showing accurate result but it is not giving the correct output in my project .What could be the reason?

I'll use my crystal ball and my telekinetic powers....

You have a bug on line 271 of your program.

Seriously, do you think anyone can help you with the information you gave us? What is "md5.cpp" and md5.h"? Where is your program so that others can compile and run it?

Regards,

Paul McKenzie

[rohitnegi]

When i call CString strUser = MD5String((char*)strUser.GetBuffer(0)); then it gives incorrect result . Following are the header and cpp file. If strUser = 1334066947 then it gives "C4CA4238A0B923820DCC509A6F75849B" but it should give "E56321F9A7FD3B62ACCBCBF51C3DAC2B" . Why it is happening ?please give any solution.

// MD5.h file

typedef unsigned int uint4;
typedef unsigned short int uint2;
typedef unsigned char uchar;

char* PrintMD5(uchar md5Digest[16]);
char* MD5String(char* szString);
char* MD5File(char* szFilename);

class md5
{
// Methods
public:
md5() { Init(); }
void Init();
void Update(uchar* chInput, uint4 nInputLen);
void Finalize();
uchar* Digest() { return m_Digest; }

private:

void Transform(uchar* block);
void Encode(uchar* dest, uint4* src, uint4 nLength);
void Decode(uint4* dest, uchar* src, uint4 nLength);


inline uint4 rotate_left(uint4 x, uint4 n)
{ return ((x << n) | (x >> (32-n))); }

inline uint4 F(uint4 x, uint4 y, uint4 z)
{ return ((x & y) | (~x & z)); }

inline uint4 G(uint4 x, uint4 y, uint4 z)
{ return ((x & z) | (y & ~z)); }

inline uint4 H(uint4 x, uint4 y, uint4 z)
{ return (x ^ y ^ z); }

inline uint4 I(uint4 x, uint4 y, uint4 z)
{ return (y ^ (x | ~z)); }

inline void FF(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += F(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }

inline void GG(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += G(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }

inline void HH(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += H(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }

inline void II(uint4& a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac)
{ a += I(b, c, d) + x + ac; a = rotate_left(a, s); a += b; }

// Data
private:
uint4 m_State[4];
uint4 m_Count[2];
uchar m_Buffer[64];
uchar m_Digest[16];
uchar m_Finalized;

};


and
MD5.cpp file

#include "stdafx.h"
#include <assert.h>
#include <memory.h>
#include <stdio.h>
#include <string.h>
#include "md5.h"


static unsigned char PADDING[64] =
{
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21


// PrintMD5: Converts a completed md5 digest into a char* string.
char* PrintMD5(uchar md5Digest[16])
{
char chBuffer[256];
char chEach[10];
int nCount;

memset(chBuffer,0,256);
memset(chEach, 0, 10);

for (nCount = 0; nCount < 16; nCount++)
{
sprintf(chEach, "%02X", md5Digest[nCount]);
strncat(chBuffer, chEach, sizeof(chEach));
}

return strdup(chBuffer);
}

// MD5String: Performs the MD5 algorithm on a char* string, returning
// the results as a char*.
char* MD5String(char* szString)
{
int nLen = strlen(szString);
md5 alg;

alg.Update((unsigned char*)szString, (unsigned int)nLen);
alg.Finalize();

return PrintMD5(alg.Digest());

}

// MD5File: Performs the MD5 algorithm on a file (binar or text),
// returning the results as a char*. Returns NULL if it fails.
char* MD5File(char* szFilename)
{
FILE* file;
md5 alg;
int nLen;
unsigned char chBuffer[1024];

try
{
memset(chBuffer, 0, 1024);

if ((file = fopen (szFilename, "rb")) != NULL)
{
while (nLen = fread (chBuffer, 1, 1024, file))
alg.Update(chBuffer, nLen);

alg.Finalize();

fclose (file);

return PrintMD5(alg.Digest());
}
}
catch(...)
{

}

return NULL; // failed
}


// md5::Init
// Initializes a new context.
void md5::Init()
{
memset(m_Count, 0, 2 * sizeof(uint4));

m_State[0] = 0x67452301;
m_State[1] = 0xefcdab89;
m_State[2] = 0x98badcfe;
m_State[3] = 0x10325476;
}

// md5::Update
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void md5::Update(uchar* chInput, uint4 nInputLen)
{
uint4 i, index, partLen;

// Compute number of bytes mod 64
index = (unsigned int)((m_Count[0] >> 3) & 0x3F);

// Update number of bits
if ((m_Count[0] += (nInputLen << 3)) < (nInputLen << 3))
m_Count[1]++;

m_Count[1] += (nInputLen >> 29);

partLen = 64 - index;

// Transform as many times as possible.
if (nInputLen >= partLen)
{
memcpy( &m_Buffer[index], chInput, partLen );
Transform(m_Buffer);

for (i = partLen; i + 63 < nInputLen; i += 64)
Transform(&chInput[i]);

index = 0;
}
else
i = 0;

// Buffer remaining input
memcpy( &m_Buffer[index], &chInput[i], nInputLen-i );
}

// md5::Finalize
// MD5 finalization. Ends an MD5 message-digest operation, writing
// the message digest and zeroizing the context.
void md5::Finalize()
{
uchar bits[8];
uint4 index, padLen;

// Save number of bits
Encode (bits, m_Count, 8);

// Pad out to 56 mod 64
index = (unsigned int)((m_Count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
Update(PADDING, padLen);

// Append length (before padding)
Update (bits, 8);

// Store state in digest
Encode (m_Digest, m_State, 16);

memset(m_Count, 0, 2 * sizeof(uint4));
memset(m_State, 0, 4 * sizeof(uint4));
memset(m_Buffer,0, 64 * sizeof(uchar));
}

// md5::Transform
// MD5 basic transformation. Transforms state based on block.
void md5::Transform (uchar* block)
{
uint4 a = m_State[0], b = m_State[1], c = m_State[2], d = m_State[3], x[16];

Decode (x, block, 64);

// Round 1
FF (a, b, c, d, x[ 0], S11, 0xd76aa478);
FF (d, a, b, c, x[ 1], S12, 0xe8c7b756);
FF (c, d, a, b, x[ 2], S13, 0x242070db);
FF (b, c, d, a, x[ 3], S14, 0xc1bdceee);
FF (a, b, c, d, x[ 4], S11, 0xf57c0faf);
FF (d, a, b, c, x[ 5], S12, 0x4787c62a);
FF (c, d, a, b, x[ 6], S13, 0xa8304613);
FF (b, c, d, a, x[ 7], S14, 0xfd469501);
FF (a, b, c, d, x[ 8], S11, 0x698098d8);
FF (d, a, b, c, x[ 9], S12, 0x8b44f7af);
FF (c, d, a, b, x[10], S13, 0xffff5bb1);
FF (b, c, d, a, x[11], S14, 0x895cd7be);
FF (a, b, c, d, x[12], S11, 0x6b901122);
FF (d, a, b, c, x[13], S12, 0xfd987193);
FF (c, d, a, b, x[14], S13, 0xa679438e);
FF (b, c, d, a, x[15], S14, 0x49b40821);

// Round 2
GG (a, b, c, d, x[ 1], S21, 0xf61e2562);
GG (d, a, b, c, x[ 6], S22, 0xc040b340);
GG (c, d, a, b, x[11], S23, 0x265e5a51);
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa);
GG (a, b, c, d, x[ 5], S21, 0xd62f105d);
GG (d, a, b, c, x[10], S22, 0x2441453);
GG (c, d, a, b, x[15], S23, 0xd8a1e681);
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8);
GG (a, b, c, d, x[ 9], S21, 0x21e1cde6);
GG (d, a, b, c, x[14], S22, 0xc33707d6);
GG (c, d, a, b, x[ 3], S23, 0xf4d50d87);
GG (b, c, d, a, x[ 8], S24, 0x455a14ed);
GG (a, b, c, d, x[13], S21, 0xa9e3e905);
GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8);
GG (c, d, a, b, x[ 7], S23, 0x676f02d9);
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);

// Round 3
HH (a, b, c, d, x[ 5], S31, 0xfffa3942);
HH (d, a, b, c, x[ 8], S32, 0x8771f681);
HH (c, d, a, b, x[11], S33, 0x6d9d6122);
HH (b, c, d, a, x[14], S34, 0xfde5380c);
HH (a, b, c, d, x[ 1], S31, 0xa4beea44);
HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9);
HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60);
HH (b, c, d, a, x[10], S34, 0xbebfbc70);
HH (a, b, c, d, x[13], S31, 0x289b7ec6);
HH (d, a, b, c, x[ 0], S32, 0xeaa127fa);
HH (c, d, a, b, x[ 3], S33, 0xd4ef3085);
HH (b, c, d, a, x[ 6], S34, 0x4881d05);
HH (a, b, c, d, x[ 9], S31, 0xd9d4d039);
HH (d, a, b, c, x[12], S32, 0xe6db99e5);
HH (c, d, a, b, x[15], S33, 0x1fa27cf8);
HH (b, c, d, a, x[ 2], S34, 0xc4ac5665);

// Round 4
II (a, b, c, d, x[ 0], S41, 0xf4292244);
II (d, a, b, c, x[ 7], S42, 0x432aff97);
II (c, d, a, b, x[14], S43, 0xab9423a7);
II (b, c, d, a, x[ 5], S44, 0xfc93a039);
II (a, b, c, d, x[12], S41, 0x655b59c3);
II (d, a, b, c, x[ 3], S42, 0x8f0ccc92);
II (c, d, a, b, x[10], S43, 0xffeff47d);
II (b, c, d, a, x[ 1], S44, 0x85845dd1);
II (a, b, c, d, x[ 8], S41, 0x6fa87e4f);
II (d, a, b, c, x[15], S42, 0xfe2ce6e0);
II (c, d, a, b, x[ 6], S43, 0xa3014314);
II (b, c, d, a, x[13], S44, 0x4e0811a1);
II (a, b, c, d, x[ 4], S41, 0xf7537e82);
II (d, a, b, c, x[11], S42, 0xbd3af235);
II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb);
II (b, c, d, a, x[ 9], S44, 0xeb86d391);

m_State[0] += a;
m_State[1] += b;
m_State[2] += c;
m_State[3] += d;

memset(x, 0, sizeof(x));
}

// md5::Encode
// Encodes input (uint4) into output (uchar). Assumes nLength is
// a multiple of 4.
void md5::Encode(uchar* dest, uint4* src, uint4 nLength)
{
uint4 i, j;

assert(nLength % 4 == 0);

for (i = 0, j = 0; j < nLength; i++, j += 4)
{
dest[j] = (uchar)(src[i] & 0xff);
dest[j+1] = (uchar)((src[i] >> 8) & 0xff);
dest[j+2] = (uchar)((src[i] >> 16) & 0xff);
dest[j+3] = (uchar)((src[i] >> 24) & 0xff);
}
}

// md5:ecode
// Decodes input (uchar) into output (uint4). Assumes nLength is
// a multiple of 4.
void md5:ecode(uint4* dest, uchar* src, uint4 nLength)
{
uint4 i, j;

assert(nLength % 4 == 0);

for (i = 0, j = 0; j < nLength; i++, j += 4)
{
dest[i] = ((uint4)src[j]) | (((uint4)src[j+1])<<8) |
(((uint4)src[j+2])<<16) | (((uint4)src[j+3])<<24);
}
}

[Syslock]

I'm almost positive MD5 require keys that are multiples of 8, not 4.
But, might want to double-check that.

[rohitnegi]

Actually the problem is when i use strUser = MD5String((char*)L"1334066947"); then it gives incorrect value but when i use strUser = MD5String((char*)"1334066947"); then result is correct.
So how i will remove L in this case.

[Skizmo]

Did you know windows has standard MD5 routines ? Takes only a few lines of code to implement.

[S_M_A]

You do realize that casting a widechar pointer to a char pointer like that isn't a good idea?
This statement L"1334066947" create a string that looks like this in memory 0x31 0x00 0x31 0x00 and so on.

Try it yourself in the debugger. Just set a breakpoint at the first line in MD5String and then type szString,m in the watch window.