Semtech LR1121 - Cryptocomputeaescmac; Table 10-8: Cryptocomputeaescmac Command; Table 10-9: Cryptocomputeaescmac Response; Table 10-10: Cryptocomputeaescmac Command Example

LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
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10.3.5 CryptoComputeAesCmac
Command CryptoComputeAesCmac(...) computes the AES CMAC of the provided data using the specified Key and
returns the MIC.
• KeyID: Specified Key ID, as defined in Table 10-1: Cryptographic Keys Usage and Derivation; 2, 5, 12-17 are supported.
• Data1, Data2, ..., DataN: Provided data, considered as byte buffers.
• CEStatus: Defined in section CEStatus on page 103.
• MIC: Message Integrity Check (first 4 bytes of the CMAC).
For example, when using the test vectors of the RFC4493 example 2, we would have:
• Message: 6BC1BEE2 2E409F96 E93D7E11 7393172A (N=16)
• MIC: 070A16B4
Table 10-8: CryptoComputeAesCmac Command
Byte 0 1 2 3 4 5 … N+2
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 10-9: 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
Table 10-10: CryptoComputeAesCmac Command Example
Byte 0 1 2 3 4 5 … 18
Data from Host 0x05 0x05 KeyID (7:0) 0x6b 0xc1 0xbe ... 0x2a
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
… 0x00
Table 10-11: CryptoComputeAesCmac Response Example
Byte 0 1 2 3 4 5
Data from Host 0x00 0x00 0x00 0x00 0x00 0x00
Data to Host Stat1 CEStatus 0x07 0x0a 0x16 0xb4