icsmd5.pas

BaiduMp3 search baidu mp3

        Inc(W, (X xor Y xor Z) + Data);
        W := (W shl S) or (W shr (32 - S));
        Inc(W, X)
    end;

    procedure Round4(var W: LongInt; X, Y, Z, Data: LongInt; S: Byte);
    begin
        Inc(W, (Y xor (X or not Z)) + Data);
        W := (W shl S) or (W shr (32 - S));
        Inc(W, X)
    end;
begin
    A := Buf[0];
    B := Buf[1];
    C := Buf[2];
    D := Buf[3];

    Round1(A, B, C, D, Data[ 0] + LongInt($d76aa478),  7);
    Round1(D, A, B, C, Data[ 1] + LongInt($e8c7b756), 12);
    Round1(C, D, A, B, Data[ 2] + LongInt($242070db), 17);
    Round1(B, C, D, A, Data[ 3] + LongInt($c1bdceee), 22);
    Round1(A, B, C, D, Data[ 4] + LongInt($f57c0faf),  7);
    Round1(D, A, B, C, Data[ 5] + LongInt($4787c62a), 12);
    Round1(C, D, A, B, Data[ 6] + LongInt($a8304613), 17);
    Round1(B, C, D, A, Data[ 7] + LongInt($fd469501), 22);
    Round1(A, B, C, D, Data[ 8] + LongInt($698098d8),  7);
    Round1(D, A, B, C, Data[ 9] + LongInt($8b44f7af), 12);
    Round1(C, D, A, B, Data[10] + LongInt($ffff5bb1), 17);
    Round1(B, C, D, A, Data[11] + LongInt($895cd7be), 22);
    Round1(A, B, C, D, Data[12] + LongInt($6b901122),  7);
    Round1(D, A, B, C, Data[13] + LongInt($fd987193), 12);
    Round1(C, D, A, B, Data[14] + LongInt($a679438e), 17);
    Round1(B, C, D, A, Data[15] + LongInt($49b40821), 22);

    Round2(A, B, C, D, Data[ 1] + LongInt($f61e2562),  5);
    Round2(D, A, B, C, Data[ 6] + LongInt($c040b340),  9);
    Round2(C, D, A, B, Data[11] + LongInt($265e5a51), 14);
    Round2(B, C, D, A, Data[ 0] + LongInt($e9b6c7aa), 20);
    Round2(A, B, C, D, Data[ 5] + LongInt($d62f105d),  5);
    Round2(D, A, B, C, Data[10] + LongInt($02441453),  9);
    Round2(C, D, A, B, Data[15] + LongInt($d8a1e681), 14);
    Round2(B, C, D, A, Data[ 4] + LongInt($e7d3fbc8), 20);
    Round2(A, B, C, D, Data[ 9] + LongInt($21e1cde6),  5);
    Round2(D, A, B, C, Data[14] + LongInt($c33707d6),  9);
    Round2(C, D, A, B, Data[ 3] + LongInt($f4d50d87), 14);
    Round2(B, C, D, A, Data[ 8] + LongInt($455a14ed), 20);
    Round2(A, B, C, D, Data[13] + LongInt($a9e3e905),  5);
    Round2(D, A, B, C, Data[ 2] + LongInt($fcefa3f8),  9);
    Round2(C, D, A, B, Data[ 7] + LongInt($676f02d9), 14);
    Round2(B, C, D, A, Data[12] + LongInt($8d2a4c8a), 20);

    Round3(A, B, C, D, Data[ 5] + LongInt($fffa3942),  4);
    Round3(D, A, B, C, Data[ 8] + LongInt($8771f681), 11);
    Round3(C, D, A, B, Data[11] + LongInt($6d9d6122), 16);
    Round3(B, C, D, A, Data[14] + LongInt($fde5380c), 23);
    Round3(A, B, C, D, Data[ 1] + LongInt($a4beea44),  4);
    Round3(D, A, B, C, Data[ 4] + LongInt($4bdecfa9), 11);
    Round3(C, D, A, B, Data[ 7] + LongInt($f6bb4b60), 16);
    Round3(B, C, D, A, Data[10] + LongInt($bebfbc70), 23);
    Round3(A, B, C, D, Data[13] + LongInt($289b7ec6),  4);
    Round3(D, A, B, C, Data[ 0] + LongInt($eaa127fa), 11);
    Round3(C, D, A, B, Data[ 3] + LongInt($d4ef3085), 16);
    Round3(B, C, D, A, Data[ 6] + LongInt($04881d05), 23);
    Round3(A, B, C, D, Data[ 9] + LongInt($d9d4d039),  4);
    Round3(D, A, B, C, Data[12] + LongInt($e6db99e5), 11);
    Round3(C, D, A, B, Data[15] + LongInt($1fa27cf8), 16);
    Round3(B, C, D, A, Data[ 2] + LongInt($c4ac5665), 23);

    Round4(A, B, C, D, Data[ 0] + LongInt($f4292244),  6);
    Round4(D, A, B, C, Data[ 7] + LongInt($432aff97), 10);
    Round4(C, D, A, B, Data[14] + LongInt($ab9423a7), 15);
    Round4(B, C, D, A, Data[ 5] + LongInt($fc93a039), 21);
    Round4(A, B, C, D, Data[12] + LongInt($655b59c3),  6);
    Round4(D, A, B, C, Data[ 3] + LongInt($8f0ccc92), 10);
    Round4(C, D, A, B, Data[10] + LongInt($ffeff47d), 15);
    Round4(B, C, D, A, Data[ 1] + LongInt($85845dd1), 21);
    Round4(A, B, C, D, Data[ 8] + LongInt($6fa87e4f),  6);
    Round4(D, A, B, C, Data[15] + LongInt($fe2ce6e0), 10);
    Round4(C, D, A, B, Data[ 6] + LongInt($a3014314), 15);
    Round4(B, C, D, A, Data[13] + LongInt($4e0811a1), 21);
    Round4(A, B, C, D, Data[ 4] + LongInt($f7537e82),  6);
    Round4(D, A, B, C, Data[11] + LongInt($bd3af235), 10);
    Round4(C, D, A, B, Data[ 2] + LongInt($2ad7d2bb), 15);
    Round4(B, C, D, A, Data[ 9] + LongInt($eb86d391), 21);

    Inc(Buf[0], A);
    Inc(Buf[1], B);
    Inc(Buf[2], C);
    Inc(Buf[3], D);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure MD5UpdateBuffer(
    var MD5Context: TMD5Context;
    Buffer: Pointer;
    BufSize: Integer);
var
    BufTmp : PMD5Buffer;
    BufPtr : PChar;
    Bytes  : Word;
begin
    New(BufTmp);
    BufPtr := Buffer;
    try
        repeat
            if BufSize > MaxBufSize then
                Bytes := MaxBufSize
            else
                Bytes := BufSize;
            Move(BufPtr^, BufTmp^, Bytes);
            Inc(BufPtr, Bytes);
            Dec(BufSize, Bytes);
            if Bytes > 0 then
                MD5Update(MD5Context, BufTmp^, Bytes);
        until Bytes < MaxBufSize;
    finally
        Dispose(BufTmp);
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function GetMD5(Buffer: Pointer; BufSize: Integer): string;
var
    I          : Integer;
    MD5Digest  : TMD5Digest;
    MD5Context : TMD5Context;
begin
    for I := 0 to 15 do
        Byte(MD5Digest[I]) := I + 1;
    MD5Init(MD5Context);
    MD5UpdateBuffer(MD5Context, Buffer, BufSize);
    MD5Final(MD5Digest, MD5Context);
    Result := '';
    for I := 0 to 15 do
        Result := Result + IntToHex(Byte(MD5Digest[I]), 2);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function StrMD5(Buffer : String): string;
begin
    Result := GetMD5(@Buffer[1], Length(Buffer));
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function FileMD5(const Filename: String) : String;
const
{$IFDEF VER80}
    ChunkSize : Cardinal = 1024 * 31;
{$ELSE}
    ChunkSize : Cardinal = 102400;
{$ENDIF}
var
    I          : Integer;
    J          : Integer;
    Num        : Integer;
    Rest       : Integer;
    MD5Digest  : TMD5Digest;
    MD5Context : TMD5Context;
    Buf        : ^Byte;
    Stream     : TFileStream;
begin
    Result := '';

    { Open file }
    Stream := TFileStream.Create(Filename, fmOpenRead or fmShareDenyWrite);
    try
        { Allocate buffer to read file }
        GetMem(Buf, ChunkSize);
        try
            { Initialize MD5 engine }
            for I := 0 to 15 do
                Byte(MD5Digest[I]) := I + 1;
            MD5Init(MD5Context);

            { Calculate number of full chunks that will fit into the buffer }
            Num  := Cardinal(Stream.Size) div ChunkSize;
            { Calculate remaining bytes }
            Rest := Cardinal(Stream.Size) mod ChunkSize;

            { Set the stream to the beginning of the file }
            Stream.Position := 0;

            { Process full chunks }
            for J := 0 to Num-1 do begin
                Stream.Read(buf^, ChunkSize);
                MD5UpdateBuffer(MD5Context, buf, ChunkSize);
            end;

            { Process remaining bytes }
            if Rest > 0 then begin
                Stream.Read(buf^, Rest);
                MD5UpdateBuffer(MD5Context, buf, Rest);
            end;

        finally
            FreeMem(Buf, ChunkSize);
        end;

        { Finalize MD5 calculation }
        MD5Final(MD5Digest, MD5Context);
        for I := 0 to 15 do
            Result := Result + IntToHex(Byte(MD5Digest[I]), 2);
    finally
        { Free the file }
        Stream.Free;
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}


end.