MF2DL1000DA4SLASH02 datasheet(25/132 Pages) NXP

25 / 132 page

NXP Semiconductors

MF2DL(H)x0

MIFARE DESFire Light contactless application IC

MF2DL_H_x0

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 3.3 — 5 April 2019

COMPANY PUBLIC

430733

25 / 132

9.1 AES Secure Messaging

The AES Secure Messaging is managed by AuthenticateEV2First and

AuthenticateEV2NonFirst.

Note that AuthenticateEV2First and AuthenticateEV2NonFirst can also be used to start

LRP Secure Messaging, as defined in Section 9.2. This is done with the PCDCap2 sent

in First Authentication and the return code, see Section 9 and Section 9.2.5 for details.

9.1.1 Transaction Identifier

In order to avoid interleaving of transactions from multiple PCDs toward one PICC, the

Transaction Identifier (TI) is included in each MAC that is calculated over commands

or responses. The TI is generated by the PICC and communicated to the PCD with a

successful execution of an AuthenticateEV2First command, see Section 11.4.1. The size

is 4 bytes and these 4 bytes can hold any value. The TI is treated as a byte array, so

there is no notion of MSB and LSB.

9.1.2 Command Counter

A command counter is included in the MAC calculation for commands and responses in

order to prevent e.g. replay attacks. It is also used to construct the Initialization Vector

(IV) for encryption and decryption.

Each command, besides few exceptions, see below, is counted by the command counter

CmdCtr which is a 16-bit unsigned integer. Both sides count commands, so the actual

value of the CmdCtr is never transmitted. The CmdCtr is reset to 0000h at PCD and

PICC after a successful AuthenticateEV2First authentication and it is maintained as

long as the PICC remains authenticated. In cryptographic calculations, the CmdCtr is

represented LSB first. Subsequent authentications using AuthenticateEV2NonFirst do not

affect the CmdCtr. Subsequent authentications using the AuthenticateEV2First will reset

the CmdCtr to 0000h. The CmdCtr is increased between the command and response, for

all communication modes.

When a MAC on a command is calculated at PCD side that includes the CmdCtr, it uses

the current CmdCtr. The CmdCtr is afterwards incremented by 1. At PICC side, a MAC

appended at received commands is checked using the current value of CmdCtr. If the

MAC matches, CmdCtr is incremented by 1 after successful reception of the command,

and before sending a response.

For CommMode.Full, the same holds for both the MAC and encryption IV calculation, i.e.

the non-increased value is used for the command calculations while the increased value

is used for the response calculations.

If the CmdCtr holds the value FFFFh and a command maintaining the active

authentication arrives at the PICC, this leads to an error response and the command is

handled like the MAC was wrong.

Command chaining, see Section 8.5, does not affect the counter. The chained command

is considered as a single command, just as for the other aspects of secure messaging,

and thus the related counter is increased only once.

9.1.3 MAC Calculation

MACs are calculated using the underlying block cipher according to the CMAC standard

described in [6]. Padding is applied according to the standard.

MF2DL1000DA4/02 Datasheet(PDF) 25 Page - NXP Semiconductors

MF2DL1000DA4/02 Datasheet(HTML) 25 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL