SHA-256 Merkle tree: Difference between revisions
Added Delphi example
(Added Wren) |
MaiconSoft (talk | contribs) (Added Delphi example) |
||
Line 193:
a4f902cf9d51fe51eda156a6792e1445dff65edf3a217a1f3334cc9cf1495c2c
</pre>
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
{{libheader| System.Classes}}
{{libheader| DCPsha256}}
{{Trans|Go}}
<lang Delphi>
program SHA256_Merkle_tree;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Classes,
DCPsha256;
function SHA256(const Input: TArray<Byte>; Len: Integer = -1): TArray<Byte>;
var
Hasher: TDCP_sha256;
l: Integer;
begin
if Len < 0 then
l := length(Input)
else
l := Len;
Hasher := TDCP_sha256.Create(nil);
try
Hasher.Init;
Hasher.Update(Input[0], l);
SetLength(Result, Hasher.HashSize div 8);
Hasher.final(Result[0]);
finally
Hasher.Free;
end;
end;
function Merkle_tree(FileName: TFileName): string;
const
blockSize = 1024;
var
f: TMemoryStream;
hashes: TArray<TArray<byte>>;
bytesRead: Cardinal;
buffer: TArray<byte>;
i, index: Integer;
begin
Result := '';
if not FileExists(FileName) then
exit;
SetLength(buffer, blockSize);
FillChar(buffer[0], blockSize, 0);
f := TMemoryStream.Create;
f.LoadFromFile(FileName);
index := 0;
repeat
bytesRead := f.Read(buffer, blockSize);
if 0 = bytesRead then
Break;
Insert(SHA256(buffer, bytesRead), hashes, index);
inc(index);
until false;
f.Free;
SetLength(buffer, 64);
while Length(hashes) > 1 do
begin
var hashes2: TArray<TArray<byte>>;
index := 0;
i := 0;
while i < length(hashes) do
begin
if i < length(hashes) - 1 then
begin
buffer := copy(hashes[i], 0, length(hashes[i]));
buffer := concat(buffer, copy(hashes[i + 1], 0, length(hashes[i])));
Insert(SHA256(buffer), hashes2, index);
inc(index);
end
else
begin
Insert(hashes[i], hashes2, index);
inc(index);
end;
inc(i, 2);
end;
hashes := hashes2;
end;
Result := '';
for var b in hashes[0] do
begin
Result := Result + b.ToHexString(2);
end;
end;
begin
writeln(Merkle_tree('title.png'));
readln;
end.</lang>
{{out}}
<pre>A4F902CF9D51FE51EDA156A6792E1445DFF65EDF3A217A1F3334CC9CF1495C2C</pre>
=={{header|Factor}}==
| |||