formatSignature can not take output of calculateSignature since it already adds ASN.1 lenghts about arduino-optiga-trust-x HOT 2 OPEN

Hi @s00500 , the format signature was intended originally for a different purpose.
The output of the calculateSignature is two DER encoded integers like below

0x000000: 02 20 38 0f 56 c8 90 53 18 9d 8f 58 b4 46 35 a0 . 8.V..S...X.F5.
0x000010: d7 07 63 ef 9f a2 30 64 93 e4 3d bf 7b db 57 a1 ..c...0d..=.{.W.
0x000020: b6 d7 02 20 4f 5e 3a db 6b 1a eb ac 66 9a 15 69 ... O^:.k...f..i
0x000030: 0d 7d 46 5b 44 72 40 06 a5 7b 06 84 0f d7 6e 0f .}F[Dr@..{....n.
0x000040: 4b 45 7f 50                                     KE.P 

In order to let OpenSSL verify it, you need to make it ASN.1. For this as you correctly said adding length and tag should be sufficient.

Meanwhile I treat this issue as a bug in the formatSignature() function. It should be fixed in the next version.

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Great, thanks very much :-)

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