Module crypto 

AES-128 primitives, key derivation, cryptograms.

Spec: Annex D.4

Session keys are derived by AES-128 encrypting fixed templates with the SCBK:

• S-ENC = AES_SCBK([0x01, 0x82, RND.A[0..6], 0,0,0,0,0,0,0,0])
• S-MAC1 = AES_SCBK([0x01, 0x01, RND.A[0..6], 0,0,0,0,0,0,0,0])
• S-MAC2 = AES_SCBK([0x01, 0x02, RND.A[0..6], 0,0,0,0,0,0,0,0])

Cryptograms:

• ClientCryptogram = AES_S-ENC(RND.A || RND.B)
• ServerCryptogram = AES_S-ENC(RND.B || RND.A)

Structs

SessionKeys

Derived session keys.

Functions

aes128_decrypt

AES-128 decrypt of a single block.

aes128_encrypt

AES-128 encrypt of a single block.

client_cryptogram

ClientCryptogram = AES_S-ENC(RND.A || RND.B).

diversify_scbk_legacy

Legacy key diversification: SCBK = AES_MK( cUID || ~cUID ).

initial_rmac

Initial R-MAC = AES_S-MAC2( AES_S-MAC1( ServerCryptogram ) ).

server_cryptogram

ServerCryptogram = AES_S-ENC(RND.B || RND.A).

Type Aliases

Block

128-bit AES block.