[SOLVED] Failed to decrypt string

[artem101]

I need to encrypt and decrypt string with key. I made two methods used blowfish and base64.

Code: Pascal  [Select][+][-]

1. function Encrypt(AKey, ANormalStr: string): string;
2. var
3.   EncrStream: TBlowFishEncryptStream;
4.   StrStream: TStringStream;
5. begin
6.   Result := '';
7.  
8.   StrStream := TStringStream.Create('');
9.   try
10.     EncrStream := TBlowFishEncryptStream.Create(AKey, StrStream);
11.     try
12.       EncrStream.WriteAnsiString(ANormalStr);
13.       Result := EncodeStringBase64(StrStream.DataString);
14.     finally
15.       EncrStream.Free;
16.     end;
17.   finally
18.     StrStream.Free;
19.   end;
20. end;
21.  
22. function Decrypt(AKey, AEncryptedStr: string): string;
23. var
24.   DecrStream: TBlowFishDeCryptStream;
25.   StrStream: TStringStream;
26. begin
27.   Result := '';
28.  
29.   StrStream := TStringStream.Create(DecodeStringBase64(AEncryptedStr));
30.   try
31.     DecrStream := TBlowFishDecryptStream.Create(AKey, StrStream);
32.     try
33.       Result := DecrStream.ReadAnsiString;
34.     finally
35.       DecrStream.Free;
36.     end;
37.   finally
38.     StrStream.Free;
39.   end;
40. end;        

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button3Click(Sender: TObject);
2. var
3.   s: string;
4. begin
5.   s:= 'hellow';
6.   s := Encrypt('123', s);
7.   writeln(s); // 0/6+UPi7OPI=
8.   s := Decrypt('123',s);
9.   writeln(s);
10. end;      

Encryption works, but decryption failed with stream read error. What's wrong?

[cdbc]

Hi
I once saw an error like that, when I erroneously called "EncryptString" on an encrypted string, instead of calling the right one "DecryptString"...
So I learned the hard way:
Encrypt -> Encrypt = Crashing with streamerrors...!
Just FYI
Regards Benny

[Handoko]

Bug fixed:

Code: Pascal  [Select][+][-]

1. function Encrypt(AKey, ANormalStr: string): string;
2. var
3.   EncrStream: TBlowFishEncryptStream;
4.   StrStream: TStringStream;
5. begin
6.   Result := '';
7.  
8.   StrStream := TStringStream.Create('');
9.   try
10.     EncrStream := TBlowFishEncryptStream.Create(AKey, StrStream);
11.     try
12.       EncrStream.WriteAnsiString(ANormalStr);
13.     finally
14.       EncrStream.Free;
15.       Result := EncodeStringBase64(StrStream.DataString);
16.     end;
17.   finally
18.     StrStream.Free;
19.   end;
20. end;

Alternatively:

Code: Pascal  [Select][+][-]

1. function Encrypt(AKey, ANormalStr: string): string;
2. var
3.   EncrStream: TBlowFishEncryptStream;
4.   StrStream: TStringStream;
5. begin
6.   Result := '';
7.  
8.   StrStream := TStringStream.Create('');
9.   try
10.     EncrStream := TBlowFishEncryptStream.Create(AKey, StrStream);
11.     try
12.       EncrStream.WriteAnsiString(ANormalStr);
13.       EncrStream.Flush;
14.       Result := EncodeStringBase64(StrStream.DataString);
15.     finally
16.       EncrStream.Free;
17.     end;
18.   finally
19.     StrStream.Free;
20.   end;
21. end;

[Thaddy]

Stream.position := 0;

[artem101]

Bug fixed

Thank you!