LR1110
User Manual Rev.1.0
UM.LR1110.W.APP March 2020
109 of 130
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• DecKeyID and VerKeyID are defined in Table 12-1: Cryptographic Keys Usage and Derivation:
DecKeyID specifies the key used for decryption of the message.
VerKeyID specifies the key used for the MIC verification.
• Depending on the LoRaWanVer, the expected Header size N is 1 byte (v1.0) or 12 bytes (v1.1).
LoRaWanVer=0: LoRaWAN verison 1.0
LoRaWanVer=1: LoRaWAN verison 1.1
...
• Header1, ... ,HeaderN: Header
• Data1, ... ,DataN: Data. Data size M is either 16 Bytes or 32 Bytes. Data must include the encrypted MIC.
• CEStatus is defined in section CEStatus on page 107.
12.3.5 CryptoComputeAesCmac
The command CryptoComputeAesCmac( ) will compute the AES CMAC of the provided data using the specified Key and
return the MIC.
• KeyID: specified Key ID, as defined in Table 12-1: Cryptographic Keys Usage and Derivation. Goes from 0 to 27.
• Data1, Data2, ... , DataN: Provided data, considered as Byte buffers.
• CEStatus: defined in section CEStatus on page 107.
• MIC: Message Integrity Check (first 4 bytes of the CMAC).
Table 12-7: CryptoProcessJoinAccept Response
Byte 0 1 2 ... M+3
Data from Host 0x00 0x00 0x00 ... 0x00
Data to Host Stat1 CEStatus Data1 ... DataM
Table 12-8: CryptoComputeAesCmac Command
Byte 0 1 2 3 4 5 … N+3
Data from Host 0x05 0x05
KeyID
(7:0)
Data1 Data2 Data3 … DataN
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
… 0x00
Table 12-9: CryptoComputeAesCmac Response
Byte 0 1 2 3 4 5
Data from Host 0x00 0x00 0x00 0x00 0x00 0x00
Data to Host Stat1 CEStatus MIC1 MIC2 MIC3 MIC4