md5implementation.pas

来自「支持CMPP/SGIP/SMGP/CNGP/SMPP协议的多功能网关模拟器:概述」· PAS 代码 · 共 354 行

(*==============================================================================
  来自http://www.fichtner.net/delphi/md5/
  精品代码，用流行的话说：I can't modify even in a single byte.
==============================================================================*)
unit MD5Implementation;

interface

uses
    Windows,
    SysUtils;

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;
    PMD5Digest = ^MD5Digest;

procedure MD5Init(var Context: MD5Context);
procedure MD5Update(var Context: MD5Context; input: PChar; Length: longword);
procedure MD5Final(var Context: MD5Context; var digest: MD5Digest);
function RivestStr(Str: string): string;
function RivestFile(FileName: string): string;
function MD5Print(D: MD5Digest): string;

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;

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;

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;

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;

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;

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;

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;

function MD5String(M: PChar): MD5Digest;
var
    Context: MD5Context;
begin
    MD5Init(Context);
    MD5Update(Context, M, Length(M));
    MD5Final(Context, Result);
end;

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;

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;

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;

function RivestStr(Str: string): string;
begin
    Result := MD5Print(MD5String(PChar(Str)));
end;

function RivestFile(FileName: string): string;
begin
    Result := MD5Print(MD5File(FileName));
end;

end.