md4.c File Reference

#include <inttypes.h>

Go to the source code of this file.

Macros
#define	ROTATELEFT32(x, s)   (((x)<<(s))|((x)>>(32-(s))))
#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	S(a, b, c, d, k, s)
#define	T(a, b, c, d, k, s)
#define	U(a, b, c, d, k, s)

Functions
static void	DoMD4 ()
static void	PerformMD4 (const unsigned char *buf, int length, unsigned char *digest)
unsigned	Com_BlockChecksum (void *buffer, int length)

Variables
static uint32_t	X [16]
static uint32_t	A
static uint32_t	AA
static uint32_t	B
static uint32_t	BB
static uint32_t	C
static uint32_t	CC
static uint32_t	D
static uint32_t	DD

Macro Definition Documentation

F

#define F	(		X,
			Y,
			Z
	)		(((X)&(Y)) | ((~X)&(Z)))

Definition at line 13 of file md4.c.

G

#define G	(		X,
			Y,
			Z
	)		(((X)&(Y)) | ((X)&(Z)) | ((Y)&(Z)))

Definition at line 14 of file md4.c.

H

#define H	(		X,
			Y,
			Z
	)		((X) ^ (Y) ^ (Z))

Definition at line 15 of file md4.c.

ROTATELEFT32

#define ROTATELEFT32	(		x,
			s
	)		(((x)<<(s))|((x)>>(32-(s))))

Definition at line 11 of file md4.c.

S

#define S	(		a,
			b,
			c,
			d,
			k,
			s
	)

Value:

                    {                           \
                    a += (F((b), (c), (d)) + X[(k)]);       \
                    a = ROTATELEFT32(a, s);             \
                }

Definition at line 17 of file md4.c.

T

#define T	(		a,
			b,
			c,
			d,
			k,
			s
	)

Value:

                    {                           \
                    a += (G((b), (c), (d)) + X[(k)] + 0x5A827999);  \
                    a = ROTATELEFT32(a, s);             \
                }

Definition at line 21 of file md4.c.

U

#define U	(		a,
			b,
			c,
			d,
			k,
			s
	)

Value:

                    {                           \
                    a += (H((b), (c), (d)) + X[(k)] + 0x6ED9EBA1);  \
                    a = ROTATELEFT32(a, s);             \
                }

Definition at line 25 of file md4.c.

Function Documentation

Com_BlockChecksum()

unsigned Com_BlockChecksum	(	void *	buffer,
		int	length
	)

Definition at line 165 of file md4.c.

{
    uint32_t digest[4];
    unsigned val;
    
    PerformMD4((unsigned char *)buffer, length, (unsigned char *)digest);
    
    val = digest[0] ^ digest[1] ^ digest[2] ^ digest[3];
    
    return val;
}

Referenced by CM_LoadMap(), COM_BlockSequenceCheckByte(), and FS_LoadPackFile().

DoMD4()

static void DoMD4 ( )

static

Definition at line 36 of file md4.c.

{
    AA = A;
    BB = B;
    CC = C;
    DD = D;
    
    S(A, B, C, D,  0,  3); S(D, A, B, C,  1,  7); S(C, D, A, B,  2, 11); S(B, C, D, A,  3, 19);
    S(A, B, C, D,  4,  3); S(D, A, B, C,  5,  7); S(C, D, A, B,  6, 11); S(B, C, D, A,  7, 19);
    S(A, B, C, D,  8,  3); S(D, A, B, C,  9,  7); S(C, D, A, B, 10, 11); S(B, C, D, A, 11, 19);
    S(A, B, C, D, 12,  3); S(D, A, B, C, 13,  7); S(C, D, A, B, 14, 11); S(B, C, D, A, 15, 19);
    
    T(A, B, C, D,  0,  3); T(D, A, B, C,  4,  5); T(C, D, A, B,  8,  9); T(B, C, D, A, 12, 13);
    T(A, B, C, D,  1,  3); T(D, A, B, C,  5,  5); T(C, D, A, B,  9,  9); T(B, C, D, A, 13, 13);
    T(A, B, C, D,  2,  3); T(D, A, B, C,  6,  5); T(C, D, A, B, 10,  9); T(B, C, D, A, 14, 13);
    T(A, B, C, D,  3,  3); T(D, A, B, C,  7,  5); T(C, D, A, B, 11,  9); T(B, C, D, A, 15, 13);
    
    U(A, B, C, D,  0,  3); U(D, A, B, C,  8,  9); U(C, D, A, B,  4, 11); U(B, C, D, A, 12, 15);
    U(A, B, C, D,  2,  3); U(D, A, B, C, 10,  9); U(C, D, A, B,  6, 11); U(B, C, D, A, 14, 15);
    U(A, B, C, D,  1,  3); U(D, A, B, C,  9,  9); U(C, D, A, B,  5, 11); U(B, C, D, A, 13, 15);
    U(A, B, C, D,  3,  3); U(D, A, B, C, 11,  9); U(C, D, A, B,  7, 11); U(B, C, D, A, 15, 15);
    
    A += AA;
    B += BB;
    C += CC;
    D += DD;
}

Referenced by PerformMD4().

PerformMD4()

static void PerformMD4 ( const unsigned char *  buf, int  length, unsigned char *  digest  )

static

Definition at line 65 of file md4.c.

{
    int len = length / 64;      /* number of full blocks */
    int rem = length % 64;      /* number of left over bytes */
 
    int i, j;
    const unsigned char *ptr = buf;
    
    /* initialize the MD buffer */
    A = 0x67452301;
    B = 0xEFCDAB89;
    C = 0x98BADCFE;
    D = 0x10325476;
    
    for (i = 0; i < len; i++) {
        for (j = 0; j < 16; j++) {
            X[j] = ((ptr[0]<< 0)|(ptr[1]<< 8)|
                (ptr[2]<<16)|(ptr[3]<<24));
            
            ptr += 4;
        }
        
        DoMD4();
    }
    
    i = rem / 4;
    for (j = 0; j < i; j++) {
        X[j] = ((ptr[0]<< 0)|(ptr[1]<< 8)|
            (ptr[2]<<16)|(ptr[3]<<24));
            
        ptr += 4;
    }
    
    switch(rem % 4) {
        case 0:
            X[j] = 0x80U;
            break;
        case 1:
            X[j] = ((ptr[0]<< 0)|((0x80U)<< 8));
            break;
        case 2:
            X[j] = ((ptr[0]<< 0)|(ptr[1]<< 8)|((0x80U)<<16));
            break;
        case 3:
            X[j] = ((ptr[0]<< 0)|(ptr[1]<< 8)|(ptr[2]<<16)|((0x80U)<<24));
            break;
    }
    j++;
    
    if (j > 14) {
        for (; j < 16; j++)
            X[j] = 0;
        DoMD4();
        
        j = 0;
    }
    
    for (; j < 14; j++)
        X[j] = 0;
    X[14] = (length &  0x1FFFFFFF) << 3;
    X[15] = (length & ~0x1FFFFFFF) >> 29;
    
    DoMD4();
 
#if 1
    digest[ 0] = (A & 0x000000FF) >> 0;
    digest[ 1] = (A & 0x0000FF00) >> 8;
    digest[ 2] = (A & 0x00FF0000) >> 16;
    digest[ 3] = (A & 0xFF000000) >> 24;
    digest[ 4] = (B & 0x000000FF) >> 0;
    digest[ 5] = (B & 0x0000FF00) >> 8;
    digest[ 6] = (B & 0x00FF0000) >> 16;
    digest[ 7] = (B & 0xFF000000) >> 24;
    digest[ 8] = (C & 0x000000FF) >> 0;
    digest[ 9] = (C & 0x0000FF00) >> 8;
    digest[10] = (C & 0x00FF0000) >> 16;
    digest[11] = (C & 0xFF000000) >> 24;
    digest[12] = (D & 0x000000FF) >> 0;
    digest[13] = (D & 0x0000FF00) >> 8;
    digest[14] = (D & 0x00FF0000) >> 16;
    digest[15] = (D & 0xFF000000) >> 24;
#else
    digest[0] = SWAPLSB(A);
    digest[1] = SWAPLSB(B);
    digest[2] = SWAPLSB(C);
    digest[3] = SWAPLSB(D);
#endif
    
    A = AA = 0;
    B = BB = 0;
    C = CC = 0;
    D = DD = 0;
    for (j = 0; j < 16; j++)
        X[j] = 0;
}

Referenced by Com_BlockChecksum().

Variable Documentation

A

uint32_t A

static

Definition at line 31 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

AA

uint32_t AA

static

Definition at line 31 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

B

uint32_t B

static

Definition at line 32 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

BB

uint32_t BB

static

Definition at line 32 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

C

uint32_t C

static

Definition at line 33 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

CC

uint32_t CC

static

Definition at line 33 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

D

uint32_t D

static

Definition at line 34 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

DD

uint32_t DD

static

Definition at line 34 of file md4.c.

Referenced by DoMD4(), and PerformMD4().

X

uint32_t X[16]

static

Definition at line 30 of file md4.c.

Referenced by PerformMD4().