[CLOSED] Improvements to TSHA256's Stream, StreamHexa and StreamBase64 routines

[lagprogramming]

packages/fcl-hash/src/fpsha256.pp has the following routines:
1/3

Code: Pascal  [Select][+][-]

1. class procedure TSHA256.Stream(aStream: TStream; out aDigest: TSHA256Digest);
2.  
3. const
4.   BUFFER_SIZE = 64*1024;
5.  
6. var
7.   aLen : LongInt;
8.   Buffer: TBytes;
9.   SHA256: TSHA256;
10.  
11. begin
12.   Buffer:=Nil;
13.   SHA256.Init;
14.   SetLength(Buffer,BUFFER_SIZE);
15.   repeat
16.      aLen:=aStream.Read(Buffer, BUFFER_SIZE);
17.      if aLen = 0 then
18.        Break;
19.      SHA256.Update(PByte(Buffer),aLen);
20.   until aLen=0;
21.   SHA256.Final;
22.   aDigest:=SHA256.Digest;
23. end;

The condition of the repeat loop regarding the value of aLen is always fulfilled because if the assigned value is 0 then we have an immediate break and later the declared procedure Update(PBuf: PByte; Size: UInt32); overload; receives the aLen parameter by value.
The proposed patch replaces until aLen=0; with until false;

2/3

Code: Pascal  [Select][+][-]

1. class function TSHA256.StreamHexa(aStream: TStream): AnsiString;
2.  
3. begin
4.   Result:='';
5.   StreamHexa(aStream,Result);
6. end;

The file contains the following declaration: class procedure StreamHexa(aStream: TStream; out Result: AnsiString); static; overload;
According to the above declaration, the proposed patch removes the line Result:='';

3/3

Code: Pascal  [Select][+][-]

1. class Function TSHA256.StreamBase64(aStream: TStream; isURL : Boolean): AnsiString;
2.  
3. begin
4.   Result:='';
5.   StreamBase64(aStream,isURL,Result);
6. end;

The file contains the following declaration: class procedure StreamBase64(aStream: TStream; isURL : Boolean; out Result: AnsiString); static; overload;
According to the above declaration, the proposed patch removes the line Result:='';
Here is the patch:

Code: Pascal  [Select][+][-]

1. diff --git a/packages/fcl-hash/src/fpsha256.pp b/packages/fcl-hash/src/fpsha256.pp
2. index 7cb3c8b2d6..80cab79351 100644
3. --- a/packages/fcl-hash/src/fpsha256.pp
4. +++ b/packages/fcl-hash/src/fpsha256.pp
5. @@ -361,7 +361,7 @@ class procedure TSHA256.Stream(aStream: TStream; out aDigest: TSHA256Digest);
6.       if aLen = 0 then
7.         Break;
8.       SHA256.Update(PByte(Buffer),aLen);
9. -  until aLen=0;
10. +  until false;
11.    SHA256.Final;
12.    aDigest:=SHA256.Digest;
13.  end;
14. @@ -388,7 +388,6 @@ class procedure TSHA256.StreamHexa(aStream: TStream; out Result: AnsiString);
15.  class function TSHA256.StreamHexa(aStream: TStream): AnsiString;
16.  
17.  begin
18. -  Result:='';
19.    StreamHexa(aStream,Result);
20.  end;
21.  
22. @@ -408,7 +407,6 @@ class procedure TSHA256.StreamBase64(aStream: TStream; isURL : Boolean; out Resu
23.  class Function TSHA256.StreamBase64(aStream: TStream; isURL : Boolean): AnsiString;
24.  
25.  begin
26. -  Result:='';
27.    StreamBase64(aStream,isURL,Result);
28.  end;
29.  

[AlexTP]

Posted to https://gitlab.com/freepascal.org/fpc/source/-/issues/40386