文件都有唯一的md5值,所以网上就有那么多的md5验证工具来判断文件是否被修改过。自己动手delphi动怎么实现?难道就是提取文件的一些信息,比如说大小呀,建立时间等来组成一个字符串,然后md5加密,等到一个秘文??个人 肤浅的想法,望高手指点!看了一个代码,如下unit md5; // -----------------------------------------------------------------------------------------------
INTERFACE
// ----------------------------------------------------------------------------------------------- uses
Windows; type
MD5Count = array[0..1] of DWORD;
MD5State = array[0..3] of DWORD;
MD5Block = array[0..15] of DWORD;
MD5CBits = array[0..7] of byte;
MD5Digest = array[0..15] of byte;
MD5Buffer = array[0..63] of byte;
MD5Context = record
State: MD5State;
Count: MD5Count;
Buffer: MD5Buffer;
end; procedure MD5Init(var Context: MD5Context);
procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest); function MD5String(M: string): MD5Digest;
function MD5File(N: string): MD5Digest;
function MD5Print(D: MD5Digest): string; function MD5Match(D1, D2: MD5Digest): boolean; // -----------------------------------------------------------------------------------------------
IMPLEMENTATION
// ----------------------------------------------------------------------------------------------- var
PADDING: MD5Buffer = (
$80, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00
); function F(x, y, z: DWORD): DWORD;
begin
Result := (x and y) or ((not x) and z);
end; function G(x, y, z: DWORD): DWORD;
begin
Result := (x and z) or (y and (not z));
end; function H(x, y, z: DWORD): DWORD;
begin
Result := x xor y xor z;
end; function I(x, y, z: DWORD): DWORD;
begin
Result := y xor (x or (not z));
end; procedure rot(var x: DWORD; n: BYTE);
begin
x := (x shl n) or (x shr (32 - n));
end; procedure FF(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, F(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure GG(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, G(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure HH(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, H(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure II(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, I(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; // ----------------------------------------------------------------------------------------------- // Encode Count bytes at Source into (Count / 4) DWORDs at Target
procedure Encode(Source, Target: pointer; Count: longword);
var
S: PByte;
T: PDWORD;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count div 4 do begin
T^ := S^;
inc(S);
T^ := T^ or (S^ shl 8);
inc(S);
T^ := T^ or (S^ shl 16);
inc(S);
T^ := T^ or (S^ shl 24);
inc(S);
inc(T);
end;
end; // Decode Count DWORDs at Source into (Count * 4) Bytes at Target
procedure Decode(Source, Target: pointer; Count: longword);
var
S: PDWORD;
T: PByte;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count do begin
T^ := S^ and $ff;
inc(T);
T^ := (S^ shr 8) and $ff;
inc(T);
T^ := (S^ shr 16) and $ff;
inc(T);
T^ := (S^ shr 24) and $ff;
inc(T);
inc(S);
end;
end; // Transform State according to first 64 bytes at Buffer
procedure Transform(Buffer: pointer; var State: MD5State);
var
a, b, c, d: DWORD;
Block: MD5Block;
begin
Encode(Buffer, @Block, 64);
a := State[0];
b := State[1];
c := State[2];
d := State[3];
FF (a, b, c, d, Block[ 0], 7, $d76aa478);
FF (d, a, b, c, Block[ 1], 12, $e8c7b756);
FF (c, d, a, b, Block[ 2], 17, $242070db);
FF (b, c, d, a, Block[ 3], 22, $c1bdceee);
FF (a, b, c, d, Block[ 4], 7, $f57c0faf);
FF (d, a, b, c, Block[ 5], 12, $4787c62a);
FF (c, d, a, b, Block[ 6], 17, $a8304613);
FF (b, c, d, a, Block[ 7], 22, $fd469501);
FF (a, b, c, d, Block[ 8], 7, $698098d8);
FF (d, a, b, c, Block[ 9], 12, $8b44f7af);
FF (c, d, a, b, Block[10], 17, $ffff5bb1);
FF (b, c, d, a, Block[11], 22, $895cd7be);
FF (a, b, c, d, Block[12], 7, $6b901122);
FF (d, a, b, c, Block[13], 12, $fd987193);
FF (c, d, a, b, Block[14], 17, $a679438e);
FF (b, c, d, a, Block[15], 22, $49b40821);
GG (a, b, c, d, Block[ 1], 5, $f61e2562);
GG (d, a, b, c, Block[ 6], 9, $c040b340);
GG (c, d, a, b, Block[11], 14, $265e5a51);
GG (b, c, d, a, Block[ 0], 20, $e9b6c7aa);
GG (a, b, c, d, Block[ 5], 5, $d62f105d);
GG (d, a, b, c, Block[10], 9, $2441453);
GG (c, d, a, b, Block[15], 14, $d8a1e681);
GG (b, c, d, a, Block[ 4], 20, $e7d3fbc8);
GG (a, b, c, d, Block[ 9], 5, $21e1cde6);
GG (d, a, b, c, Block[14], 9, $c33707d6);
GG (c, d, a, b, Block[ 3], 14, $f4d50d87);
GG (b, c, d, a, Block[ 8], 20, $455a14ed);
GG (a, b, c, d, Block[13], 5, $a9e3e905);
GG (d, a, b, c, Block[ 2], 9, $fcefa3f8);
GG (c, d, a, b, Block[ 7], 14, $676f02d9);
GG (b, c, d, a, Block[12], 20, $8d2a4c8a); 这样成么?怎么文件对比
INTERFACE
// ----------------------------------------------------------------------------------------------- uses
Windows; type
MD5Count = array[0..1] of DWORD;
MD5State = array[0..3] of DWORD;
MD5Block = array[0..15] of DWORD;
MD5CBits = array[0..7] of byte;
MD5Digest = array[0..15] of byte;
MD5Buffer = array[0..63] of byte;
MD5Context = record
State: MD5State;
Count: MD5Count;
Buffer: MD5Buffer;
end; procedure MD5Init(var Context: MD5Context);
procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest); function MD5String(M: string): MD5Digest;
function MD5File(N: string): MD5Digest;
function MD5Print(D: MD5Digest): string; function MD5Match(D1, D2: MD5Digest): boolean; // -----------------------------------------------------------------------------------------------
IMPLEMENTATION
// ----------------------------------------------------------------------------------------------- var
PADDING: MD5Buffer = (
$80, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00,
$00, $00, $00, $00, $00, $00, $00, $00
); function F(x, y, z: DWORD): DWORD;
begin
Result := (x and y) or ((not x) and z);
end; function G(x, y, z: DWORD): DWORD;
begin
Result := (x and z) or (y and (not z));
end; function H(x, y, z: DWORD): DWORD;
begin
Result := x xor y xor z;
end; function I(x, y, z: DWORD): DWORD;
begin
Result := y xor (x or (not z));
end; procedure rot(var x: DWORD; n: BYTE);
begin
x := (x shl n) or (x shr (32 - n));
end; procedure FF(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, F(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure GG(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, G(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure HH(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, H(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; procedure II(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, I(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end; // ----------------------------------------------------------------------------------------------- // Encode Count bytes at Source into (Count / 4) DWORDs at Target
procedure Encode(Source, Target: pointer; Count: longword);
var
S: PByte;
T: PDWORD;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count div 4 do begin
T^ := S^;
inc(S);
T^ := T^ or (S^ shl 8);
inc(S);
T^ := T^ or (S^ shl 16);
inc(S);
T^ := T^ or (S^ shl 24);
inc(S);
inc(T);
end;
end; // Decode Count DWORDs at Source into (Count * 4) Bytes at Target
procedure Decode(Source, Target: pointer; Count: longword);
var
S: PDWORD;
T: PByte;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count do begin
T^ := S^ and $ff;
inc(T);
T^ := (S^ shr 8) and $ff;
inc(T);
T^ := (S^ shr 16) and $ff;
inc(T);
T^ := (S^ shr 24) and $ff;
inc(T);
inc(S);
end;
end; // Transform State according to first 64 bytes at Buffer
procedure Transform(Buffer: pointer; var State: MD5State);
var
a, b, c, d: DWORD;
Block: MD5Block;
begin
Encode(Buffer, @Block, 64);
a := State[0];
b := State[1];
c := State[2];
d := State[3];
FF (a, b, c, d, Block[ 0], 7, $d76aa478);
FF (d, a, b, c, Block[ 1], 12, $e8c7b756);
FF (c, d, a, b, Block[ 2], 17, $242070db);
FF (b, c, d, a, Block[ 3], 22, $c1bdceee);
FF (a, b, c, d, Block[ 4], 7, $f57c0faf);
FF (d, a, b, c, Block[ 5], 12, $4787c62a);
FF (c, d, a, b, Block[ 6], 17, $a8304613);
FF (b, c, d, a, Block[ 7], 22, $fd469501);
FF (a, b, c, d, Block[ 8], 7, $698098d8);
FF (d, a, b, c, Block[ 9], 12, $8b44f7af);
FF (c, d, a, b, Block[10], 17, $ffff5bb1);
FF (b, c, d, a, Block[11], 22, $895cd7be);
FF (a, b, c, d, Block[12], 7, $6b901122);
FF (d, a, b, c, Block[13], 12, $fd987193);
FF (c, d, a, b, Block[14], 17, $a679438e);
FF (b, c, d, a, Block[15], 22, $49b40821);
GG (a, b, c, d, Block[ 1], 5, $f61e2562);
GG (d, a, b, c, Block[ 6], 9, $c040b340);
GG (c, d, a, b, Block[11], 14, $265e5a51);
GG (b, c, d, a, Block[ 0], 20, $e9b6c7aa);
GG (a, b, c, d, Block[ 5], 5, $d62f105d);
GG (d, a, b, c, Block[10], 9, $2441453);
GG (c, d, a, b, Block[15], 14, $d8a1e681);
GG (b, c, d, a, Block[ 4], 20, $e7d3fbc8);
GG (a, b, c, d, Block[ 9], 5, $21e1cde6);
GG (d, a, b, c, Block[14], 9, $c33707d6);
GG (c, d, a, b, Block[ 3], 14, $f4d50d87);
GG (b, c, d, a, Block[ 8], 20, $455a14ed);
GG (a, b, c, d, Block[13], 5, $a9e3e905);
GG (d, a, b, c, Block[ 2], 9, $fcefa3f8);
GG (c, d, a, b, Block[ 7], 14, $676f02d9);
GG (b, c, d, a, Block[12], 20, $8d2a4c8a); 这样成么?怎么文件对比
http://www.programfan.com/article/showarticle.asp?id=2811
源代码可在此下:
http://www.fourmilab.ch/md5/