Eureka!
After spending all day working on it, I finally did it! The pseudo steps
are here:
http://en.wikipedia.org/wiki/Hash-based_message_authentication_code
And, this is the final code (please improves it please):
uses
SHA1;
function SHA1Raw(const ABuffer; const ABufferLength: PtrUInt): string;
var
I: Byte;
VBytes : TBytes;
VDigest: TSHA1Digest;
VContext: TSHA1Context;
begin
Result := '';
SHA1Init(VContext);
SHA1Update(VContext, ABuffer, ABufferLength);
SHA1Final(VContext, VDigest);
SetLength(VBytes, 20);
Move(VDigest, VBytes[0], 20);
for I := 0 to 19 do
Result := Result + Char(VBytes[I]);
end;
function HMACSHA1(const AKey, AMessage: string): string;
const
BLOCK_SIZE = 64;
var
I: Byte;
VKey: string;
VLenght: PtrUInt;
VOPadStr, VIPadStr: string;
VOPad, VIPad: array[1..BLOCK_SIZE] of Byte;
begin
VLenght := Length(AKey);
if VLenght > BLOCK_SIZE then
begin
SetLength(VKey, BLOCK_SIZE);
FillChar(Pointer(VKey)^, BLOCK_SIZE, #0);
VKey := SHA1Raw(Pointer(AKey)^, VLenght) + VKey;
end
else
begin
SetLength(VKey, BLOCK_SIZE - VLenght);
FillChar(Pointer(VKey)^, BLOCK_SIZE - VLenght, #0);
VKey := AKey + VKey;
end;
FillChar(VOPad, BLOCK_SIZE, $5c);
FillChar(VIPad, BLOCK_SIZE, $36);
for I := 1 to BLOCK_SIZE do
begin
VOPad[I] := VOPad[I] xor Byte(VKey[I]);
VIPad[I] := VIPad[I] xor Byte(VKey[I]);
end;
SetLength(VOPadStr, BLOCK_SIZE);
Move(VOPad, Pointer(VOPadStr)^, BLOCK_SIZE);
SetLength(VIPadStr, BLOCK_SIZE);
Move(VIPad, Pointer(VIPadStr)^, BLOCK_SIZE);
VIPadStr := VIPadStr + AMessage;
Result := SHA1Print(SHA1String(VOPadStr +
SHA1Raw(Pointer(VIPadStr)^, Length(VIPadStr))));
end;
Usage:
WriteLn(HMACSHA1('key', 'The quick brown fox jumped over the lazy dog.')).
Result: 0b7252985d63555b31db4755f37efe218c509711 (same result in PHP, JS
and Phyton! ;) )
So, can you add this code (I'll make HMACMD5 too) in FCL hashes?
(>fpc\VER\source\packages\hash\src)
Thank you very much buddies! :)
--
Silvio Clécio
My public projects - github.com/silvioprog
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