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用delphi实现md5加密算法
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);
hh (a, b, c, d, block[ 5], 4, $fffa3942);
hh (d, a, b, c, block[ 8], 11, $8771f681);
hh (c, d, a, b, block[11], 16, $6d9d6122);
hh (b, c, d, a, block[14], 23, $fde5380c);
hh (a, b, c, d, block[ 1], 4, $a4beea44);
hh (d, a, b, c, block[ 4], 11, $4bdecfa9);
hh (c, d, a, b, block[ 7], 16, $f6bb4b60);
hh (b, c, d, a, block[10], 23, $bebfbc70);
hh (a, b, c, d, block[13], 4, $289b7ec6);
hh (d, a, b, c, block[ 0], 11, $eaa127fa);
hh (c, d, a, b, block[ 3], 16, $d4ef3085);
hh (b, c, d, a, block[ 6], 23, $4881d05);
hh (a, b, c, d, block[ 9], 4, $d9d4d039);
hh (d, a, b, c, block[12], 11, $e6db99e5);
hh (c, d, a, b, block[15], 16, $1fa27cf8);
hh (b, c, d, a, block[ 2], 23, $c4ac5665);
ii (a, b, c, d, block[ 0], 6, $f4292244);
ii (d, a, b, c, block[ 7], 10, $432aff97);
ii (c, d, a, b, block[14], 15, $ab9423a7);
ii (b, c, d, a, block[ 5], 21, $fc93a039);
ii (a, b, c, d, block[12], 6, $655b59c3);
ii (d, a, b, c, block[ 3], 10, $8f0ccc92);
ii (c, d, a, b, block[10], 15, $ffeff47d);
ii (b, c, d, a, block[ 1], 21, $85845dd1);
ii (a, b, c, d, block[ 8], 6, $6fa87e4f);
ii (d, a, b, c, block[15], 10, $fe2ce6e0);
ii (c, d, a, b, block[ 6], 15, $a3014314);
ii (b, c, d, a, block[13], 21, $4e0811a1);
ii (a, b, c, d, block[ 4], 6, $f7537e82);
ii (d, a, b, c, block[11], 10, $bd3af235);
ii (c, d, a, b, block[ 2], 15, $2ad7d2bb);
ii (b, c, d, a, block[ 9], 21, $eb86d391);
inc(state[0], a);
inc(state[1], b);
inc(state[2], c);
inc(state[3], d);
end;
// -----------------------------------------------------------------------------------------------
// initialize given context
procedure md5init(var context: md5context);
begin
with context do begin
state[0] := $67452301;
state[1] := $efcdab89;
state[2] := $98badcfe;
state[3] := $10325476;
count[0] := 0;
count[1] := 0;
zeromemory(@buffer, sizeof(md5buffer));
end;
end;
// update given context to include length bytes of input
procedure md5update(var context: md5context; input: pchar; length: longword);
var
index: longword;
partlen: longword;
i: longword;
begin
with context do begin
index := (count[0] shr 3) and $3f;
inc(count[0], length shl 3);
if count[0] < (length shl 3) then inc(count[1]);
inc(count[1], length shr 29);
end;
partlen := 64 - index;
if length >= partlen then begin
copymemory(@context.buffer[index], input, partlen);
transform(@context.buffer, context.state);
i := partlen;
while i + 63 < length do begin
transform(@input[i], context.state);
inc(i, 64);
end;
index := 0;
end else i := 0;
copymemory(@context.buffer[index], @input[i], length - i);
end;
// finalize given context, create digest and zeroize context
procedure md5final(var context: md5context; var digest: md5digest);
var
bits: md5cbits;
index: longword;
padlen: longword;
begin
decode(@context.count, @bits, 2);
index := (context.count[0] shr 3) and $3f;
if index < 56 then padlen := 56 - index else padlen := 120 - index;
md5update(context, @padding, padlen);
md5update(context, @bits, 8);
decode(@context.state, @digest, 4);
zeromemory(@context, sizeof(md5context));
end;
// -----------------------------------------------------------------------------------------------
// create digest of given message
function md5string(m: string): md5digest;
var
context: md5context;
begin
md5init(context);
md5update(context, pchar(m), length(m));
md5final(context, result);
end;
// create digest of file with given name
function md5file(n: string): md5digest;
var
filehandle: thandle;
maphandle: thandle;
viewpointer: pointer;
context: md5context;
begin
md5init(context);
filehandle := createfile(pchar(n), generic_read, file_share_read or file_share_write,
nil, open_existing, file_attribute_normal or file_flag_sequential_scan, 0);
if filehandle <>invalid_handle_value then try
maphandle := createfilemapping(filehandle, nil, page_readonly, 0, 0, nil);
if maphandle <>0 then try
viewpointer := mapviewoffile(maphandle, file_map_read, 0, 0, 0);
if viewpointer <>nil then try
md5update(context, viewpointer, getfilesize(filehandle, nil));
finally
unmapviewoffile(viewpointer);
end;
finally
closehandle(maphandle);
end;
finally
closehandle(filehandle);
end;
md5final(context, result);
end;
// create hex representation of given digest
function md5print(d: md5digest): string;
var
i: byte;
const
digits: array[0..15] of char =
('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f');
begin
result := '';
for i := 0 to 15 do result := result + digits[(d[i] shr 4) and $0f] + digits[d[i] and $0f];
end;
// -----------------------------------------------------------------------------------------------
// compare two digests
function md5match(d1, d2: md5digest): boolean;
var
i: byte;
begin
i := 0;
result := true;
while result and (i < 16) do begin
result := d1[i] = d2[i];
inc(i);
end;
end;
end.
