Tag: bytes

smartcard world

APDU Lc and Le encoding

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Standard ISO_IEC_7816-4-2020

https://www.iso.org/obp/ui/#iso:std:iso-iec:7816:-4:ed-4:v1:en

What we want:

  • we want to test 2 byte Le fields, that means the Lc field should give us already the info that the c r apdu pair is extended. means Lc = 00 and 2 bytes of lenght info.
  • then data, means command data,
  • then 2 bytes of Le encoded

eg. extended length apdu

00CB3FFF
04
5C02DF40
09

eg. normal length apdu

00CB3FFF
000004
5C02DF40
0009

https://stackoverflow.com/questions/40663460/use-apdu-commands-to-get-some-information-for-a-card

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