mdfour.c File Reference

#include "darkplaces.h"
#include "mdfour.h"

Include dependency graph for mdfour.c:

Go to the source code of this file.

Macros
#define	F(X, Y, Z)
#define	G(X, Y, Z)
#define	H(X, Y, Z)
#define	lshift(x, s)
#define	ROUND1(a, b, c, d, k, s)
#define	ROUND2(a, b, c, d, k, s)
#define	ROUND3(a, b, c, d, k, s)

Functions
unsigned	Com_BlockChecksum (void *buffer, int length)
void	Com_BlockFullChecksum (void *buffer, int len, unsigned char *outbuf)
static void	copy4 (unsigned char *out, uint32_t x)
static void	copy64 (uint32_t *M, const unsigned char *in)
void	mdfour (unsigned char *out, const unsigned char *in, int n)
static void	mdfour64 (struct mdfour_s *md, uint32_t *M)
void	mdfour_begin (struct mdfour_s *md)
void	mdfour_result (struct mdfour_s *md, unsigned char *out)
static void	mdfour_tail (struct mdfour_s *md, const unsigned char *in, int n)
void	mdfour_update (struct mdfour_s *md, const unsigned char *in, int n)

Macro Definition Documentation

F

#define F	(		X,
			Y,
			Z )

Value:

(((X)&(Y)) | ((~(X))&(Z)))

Definition at line 39 of file mdfour.c.

G

#define G	(		X,
			Y,
			Z )

Value:

(((X)&(Y)) | ((X)&(Z)) | ((Y)&(Z)))

Definition at line 40 of file mdfour.c.

H

#define H	(		X,
			Y,
			Z )

Value:

((X)^(Y)^(Z))

Definition at line 41 of file mdfour.c.

lshift

#define lshift	(		x,
			s )

Value:

(((x)<<(s)) | ((x)>>(32-(s))))

Definition at line 42 of file mdfour.c.

ROUND1

#define ROUND1	(		a,
			b,
			c,
			d,
			k,
			s )

Value:

a = lshift(a + F(b,c,d) + X[k], s)

Definition at line 44 of file mdfour.c.

Referenced by mdfour64().

ROUND2

#define ROUND2	(		a,
			b,
			c,
			d,
			k,
			s )

Value:

a = lshift(a + G(b,c,d) + X[k] + 0x5A827999,s)

Definition at line 45 of file mdfour.c.

Referenced by mdfour64().

ROUND3

#define ROUND3	(		a,
			b,
			c,
			d,
			k,
			s )

Value:

a = lshift(a + H(b,c,d) + X[k] + 0x6ED9EBA1,s)

Definition at line 46 of file mdfour.c.

Referenced by mdfour64().

Function Documentation

Com_BlockChecksum()

unsigned Com_BlockChecksum	(	void *	buffer,
		int	length )

Definition at line 198 of file mdfour.c.

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

References buffer, length, and mdfour().

Referenced by Mod_Q1BSP_Load(), Mod_Q2BSP_Load(), and Mod_Q3BSP_Load().

Com_BlockFullChecksum()

void Com_BlockFullChecksum	(	void *	buffer,
		int	len,
		unsigned char *	outbuf )

Definition at line 210 of file mdfour.c.

{
    mdfour ( outbuf, (unsigned char *) buffer, len );
}

References buffer, and mdfour().

copy4()

static void copy4 ( unsigned char * out, uint32_t x )

static

Definition at line 107 of file mdfour.c.

{
    out[0] = x&0xFF;
    out[1] = (x>>8)&0xFF;
    out[2] = (x>>16)&0xFF;
    out[3] = (x>>24)&0xFF;
}

References x.

Referenced by mdfour_result(), and mdfour_tail().

copy64()

static void copy64 ( uint32_t * M, const unsigned char * in )

static

Definition at line 97 of file mdfour.c.

{
    int i;
 
    // UBSan: (unsigned) is because promotion to int causes signed overflow when in[] >= 128
    for (i=0;i<16;i++)
        M[i] = ((unsigned)in[i*4+3]<<24) | (in[i*4+2]<<16) |
            (in[i*4+1]<<8) | (in[i*4+0]<<0);
}

References i, and M.

Referenced by mdfour_tail(), and mdfour_update().

mdfour()

void mdfour	(	unsigned char *	out,
		const unsigned char *	in,
		int	n )

Definition at line 182 of file mdfour.c.

{
    struct mdfour_s md;
    mdfour_begin(&md);
    mdfour_update(&md, in, n);
    mdfour_result(&md, out);
}

References mdfour_begin(), mdfour_result(), mdfour_update(), and n.

Referenced by Com_BlockChecksum(), Com_BlockFullChecksum(), and VM_digest_hex().

mdfour64()

static void mdfour64 ( struct mdfour_s * md, uint32_t * M )

static

Definition at line 49 of file mdfour.c.

{
    int j;
    uint32_t AA, BB, CC, DD;
    uint32_t X[16];
    uint32_t A,B,C,D;
 
    for (j=0;j<16;j++)
        X[j] = M[j];
 
    A = md->A; B = md->B; C = md->C; D = md->D;
    AA = A; BB = B; CC = C; DD = D;
 
        ROUND1(A,B,C,D,  0,  3);  ROUND1(D,A,B,C,  1,  7);
    ROUND1(C,D,A,B,  2, 11);  ROUND1(B,C,D,A,  3, 19);
        ROUND1(A,B,C,D,  4,  3);  ROUND1(D,A,B,C,  5,  7);
    ROUND1(C,D,A,B,  6, 11);  ROUND1(B,C,D,A,  7, 19);
        ROUND1(A,B,C,D,  8,  3);  ROUND1(D,A,B,C,  9,  7);
    ROUND1(C,D,A,B, 10, 11);  ROUND1(B,C,D,A, 11, 19);
        ROUND1(A,B,C,D, 12,  3);  ROUND1(D,A,B,C, 13,  7);
    ROUND1(C,D,A,B, 14, 11);  ROUND1(B,C,D,A, 15, 19);
 
        ROUND2(A,B,C,D,  0,  3);  ROUND2(D,A,B,C,  4,  5);
    ROUND2(C,D,A,B,  8,  9);  ROUND2(B,C,D,A, 12, 13);
        ROUND2(A,B,C,D,  1,  3);  ROUND2(D,A,B,C,  5,  5);
    ROUND2(C,D,A,B,  9,  9);  ROUND2(B,C,D,A, 13, 13);
        ROUND2(A,B,C,D,  2,  3);  ROUND2(D,A,B,C,  6,  5);
    ROUND2(C,D,A,B, 10,  9);  ROUND2(B,C,D,A, 14, 13);
        ROUND2(A,B,C,D,  3,  3);  ROUND2(D,A,B,C,  7,  5);
    ROUND2(C,D,A,B, 11,  9);  ROUND2(B,C,D,A, 15, 13);
 
    ROUND3(A,B,C,D,  0,  3);  ROUND3(D,A,B,C,  8,  9);
    ROUND3(C,D,A,B,  4, 11);  ROUND3(B,C,D,A, 12, 15);
        ROUND3(A,B,C,D,  2,  3);  ROUND3(D,A,B,C, 10,  9);
    ROUND3(C,D,A,B,  6, 11);  ROUND3(B,C,D,A, 14, 15);
        ROUND3(A,B,C,D,  1,  3);  ROUND3(D,A,B,C,  9,  9);
    ROUND3(C,D,A,B,  5, 11);  ROUND3(B,C,D,A, 13, 15);
        ROUND3(A,B,C,D,  3,  3);  ROUND3(D,A,B,C, 11,  9);
    ROUND3(C,D,A,B,  7, 11);  ROUND3(B,C,D,A, 15, 15);
 
    A += AA; B += BB; C += CC; D += DD;
 
    for (j=0;j<16;j++)
        X[j] = 0;
 
    md->A = A; md->B = B; md->C = C; md->D = D;
}

References mdfour_s::A, mdfour_s::B, mdfour_s::C, mdfour_s::D, M, ROUND1, ROUND2, and ROUND3.

Referenced by mdfour_tail(), and mdfour_update().

mdfour_begin()

void mdfour_begin

(

struct mdfour_s *

md

)

Definition at line 115 of file mdfour.c.

{
    md->A = 0x67452301;
    md->B = 0xefcdab89;
    md->C = 0x98badcfe;
    md->D = 0x10325476;
    md->totalN = 0;
}

References mdfour_s::A, mdfour_s::B, mdfour_s::C, mdfour_s::D, and mdfour_s::totalN.

Referenced by mdfour().

mdfour_result()

void mdfour_result	(	struct mdfour_s *	md,
		unsigned char *	out )

Definition at line 173 of file mdfour.c.

{
    copy4(out, md->A);
    copy4(out+4, md->B);
    copy4(out+8, md->C);
    copy4(out+12, md->D);
}

References mdfour_s::A, mdfour_s::B, mdfour_s::C, copy4(), and mdfour_s::D.

Referenced by mdfour().

mdfour_tail()

static void mdfour_tail ( struct mdfour_s * md, const unsigned char * in, int n )

static

Definition at line 125 of file mdfour.c.

{
    unsigned char buf[128];
    uint32_t M[16];
    uint32_t b;
 
    md->totalN += n;
 
    b = md->totalN * 8;
 
    memset(buf, 0, 128);
    if (n) memcpy(buf, in, n);
    buf[n] = 0x80;
 
    if (n <= 55) {
        copy4(buf+56, b);
        copy64(M, buf);
        mdfour64(md, M);
    } else {
        copy4(buf+120, b);
        copy64(M, buf);
        mdfour64(md, M);
        copy64(M, buf+64);
        mdfour64(md, M);
    }
}

References b, buf, copy4(), copy64(), M, mdfour64(), n, and mdfour_s::totalN.

Referenced by mdfour_update().

mdfour_update()

void mdfour_update	(	struct mdfour_s *	md,
		const unsigned char *	in,
		int	n )

Definition at line 152 of file mdfour.c.

{
    uint32_t M[16];
 
// start of edit by Ashley Rose Hale (LadyHavoc)
// commented out to prevent crashing when length is 0
//  if (n == 0) mdfour_tail(in, n);
// end of edit by Ashley Rose Hale (LadyHavoc)
 
    while (n >= 64) {
        copy64(M, in);
        mdfour64(md, M);
        in += 64;
        n -= 64;
        md->totalN += 64;
    }
 
    mdfour_tail(md, in, n);
}

References copy64(), M, mdfour64(), mdfour_tail(), n, and mdfour_s::totalN.

Referenced by mdfour().