Recommand · October 22, 2021 0

Delphi SmardCard response from hexadecimal string to string

I’m working with APDU commands and SmartCard. APDU command that I am sending to SmartCard is:
8813040000004A0000015D79403B6900000000000000000000003032313133313638320000000000000000000000415344333231363534000000000000249F000203000000000084AA0100000000024490 (Data converted to an array of bytes and printed as a hexadecimal string).

Response code is 9000(OK) and response data is:

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

SmardCard is supposed to sign and return data with signature (Certificate). It should be a string that I need for later but when I try to convert it back to string all I’m getting is vC~ÄoÁ;ú¤O³H÷-Ïà÷6§¯±µhТ´6ÑÄk16XHº »¹5 w_ªK©$o_oLL kind of a string that I can’t actually use. Am I doing something wrong or missing any steps in between? How am I supposed to get that string from that hex response? Do I need to reverse bytes maybe (tried)?

Thanks in advance!

You are converting the returned data into a WideString (default string type in modern Delphi versions) but the returned data is actually in AnsiString format.

And if you want to view the returned data in a similar fashion that most browsers show digital certificate key value just add an empty space after every two characters.

For this you can use code like this:

//AStr is of AnsiString type
for I := Length(AStr)div 2 downto 1 do
begin
  Insert(' ',AStr,I*2+1);
end;

The returned result will then be:

00 00 01 5D 79 40 3B 69 00 00 00 00 00 00 00 00 00 00 00 30 32 31 31 33 31 36 38 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 24 9F 00 00 00 00 4D 00 00 00 4D 59 98 43 10 37 5B FA 31 5B D7 D0 67 A4 95 35 28 16 65 DB F0 E7 62 87 A9 A1 D8 E2 23 AE D0 E2 90 8D AE 61 A0 3B 91 FD 96 52 71 B7 98 08 07 E8 26 17 4F 33 D3 E6 56 14 19 17 34 C7 FC BE 5C F1 66 52 30 19 05 CC 9E 93 64 A4 2C CE 2C 59 53 3C 60 42 00 97 D1 72 5E AE EC F8 83 B5 1E 4F 9E 17 FE D1 F7 D6 3B 93 C1 B4 D7 0D 6A 12 27 5E A4 0F 09 C1 32 12 23 BB 76 05 81 DB AF 7C A7 20 C1 EB A7 A4 01 6D 66 B0 2B FB 1C D1 90 2C 46 45 8E E2 25 28 D0 55 64 99 2D 77 E0 DF 2E 1F C6 30 93 D4 5B B8 BC 49 30 76 E6 94 C2 4C 1F C1 A2 99 82 C8 26 74 D2 7D B6 41 51 0E 07 AD E4 8A 58 6F C3 CB 05 E2 87 34 A7 ED 7D 86 CA 3D 9E 66 EB BA E7 B7 8E ED C7 E8 A5 67 DB 39 A3 7D 0B 92 C1 10 54 0C 20 29 00 55 E2 F9 0F C6 74 FB 4E 39 A3 4A 76 A5 31 0A BC 1C 9C F5 E4 8D 49 94 73 EC 0E AA DF 30 5F 66 7E 27 98 73 70 E7 44 15 3D 35 33 FB 6D 93 CE 98 35 36 3D F2 39 86 77 A9 6F E4 A5 CC 0D AE FB 34 43 91 F7 F2 A1 7C 42 E6 CB E9 E3 62 54 94 5A 38 A0 EB D4 B1 D0 A2 16 7A 8D D1 D8 B5 93 F6 EE C5 C9 2D 86 6D 14 23 EC 3E D8 98 93 F1 23 D1 92 3A 3A D3 E1 AE DA 42 42 32 D0 C9 B3 A6 0C 9E 17 9B 02 BD F2 DA FD 00 B8 10 F3 5E 60 83 22 61 9E F9 D9 D9 0B 25 12 E3 21 6B 0E C4 D3 D3 6C E6 65 05 A1 45 77 67 DA 5D 55 42 BE F5 7B 2B B1 5B 12 A9 F1 94 95 C7 4A 96 33 39 5A DE 2F D4 A1 63 9E 1A 53 33 4B CE 88 D5 19 37 A7 86 F0 02 ED EE B9 6B A5 24 C6 0D 26 23 39 0D 76 43 7E C4 6F 99 C1 3B FA 91 A4 4F B3 48 F7 2D CF 8C 02 0E E0 F7 36 07 A7 AF B1 B5 68 D0 9C 05 9B A2 B4 36 1B 02 D1 C4 6B 1D 31 36 9D 58 48 81 18 BA 20 BB B9 9C 35 93 A0 77 5F 9F AA 4B A9 24 1C 6F 5F 6F 4C 4C 84

Is this the result you are looking for?