Cryptographic Test Cases

This page describes tests a provider can write to verify the cryptographic components of their provider implementation.

Google recommends implementing these tests early to ease Fast Pair integration.

Test Cases

These cases cover:

Hashing
The Bloom Filter
AES Encryption and Public Key Exchange
Message enciphering and deciphering

SHA-256 Hashing

Input value:

Hashed result:

AES Encryption

Input value:

Secret key:

Encrypted output:

ECDH Key Exchange

Bob's private key:

Bob's public key:

Alice's private key:

Alice's public key:

Generated shared key (either Alice's public + Bob's private or Bob's public + Alice's private):

AES Key from ECDH Shared Secret

This is step 1b (AES key generation) in the GATT procedure .

ECDH shared key:

Generated AES key:

Bloom Filter

Random salt:

  0 
 xC7C8

First account key added to the filter (combine with the above random salt):

Resulting bloom filter:

Battery data (if it is contained in the advertisement):

  0 
 b00110011 
 , 
  
 // 
  
 len 
 gth 
  
 = 
  
 3 
 , 
  
 show 
  
 UI 
  
 indication 
 . 
 0 
 b01000000 
 , 
  
 // 
  
 left 
  
 bud 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64. 
 0 
 b01000000 
 , 
  
 // 
  
 right 
  
 bud 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64. 
 0 
 b01000000 
  
 // 
  
 case 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64.

Resulting bloom filter with battery data:

Second account key added to the filter (combine with the above random salt):

Resulting bloom filter from both added account keys:

Battery data (if it is contained in the advertisement):

  0 
 b00110011 
 , 
  
 // 
  
 len 
 gth 
  
 = 
  
 3 
 , 
  
 show 
  
 UI 
  
 indication 
 . 
 0 
 b01000000 
 , 
  
 // 
  
 left 
  
 bud 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64. 
 0 
 b01000000 
 , 
  
 // 
  
 right 
  
 bud 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64. 
 0 
 b01000000 
  
 // 
  
 case 
 : 
  
 not 
  
 charging 
 , 
  
 battery 
  
 level 
  
 = 
  
 64.

Resulting bloom filter from both added account keys with battery data:

AES-CTR Encryption

Input data: "Someone's Google Headphone" with utf-8 encoding

Secret key:

Nonce:

Expected encryption result:

HMAC-SHA256

Input data:

Secret key:

Expected HMAC-SHA256 result:

Encode personalized name to additional data packet

Input data: "Someone's Google Headphone" with utf-8 encoding

Secret key:

Nonce:

Expected additional data packet:

Decode additional data packet to get personalized name

Input data:

Secret key:

Expected name: "Someone's Google Headphone" with utf-8 encoding

Encrypted connection status field

Field length and type:

  0 
 b001100101 
  
 ( 
 len 
 gth 
  
 = 
  
 3 
 , 
  
 type 
  
 = 
  
 connection 
  
 status 
  
 field 
 )

Connection state:

  0 
 b10000101 
 : 
 * 
  
 on 
  
 head 
  
 detection 
  
 = 
  
 1 
 * 
  
 connection 
  
 availability 
  
 = 
  
 0 
 * 
  
 focus 
  
 mode 
  
 = 
  
 0 
 * 
  
 auto 
 - 
 reconnected 
  
 = 
  
 0 
 * 
  
 connection 
  
 state 
  
 = 
  
 0 
 x5 
  
 ( 
 A2DP 
  
 with 
  
 AVRCP 
 )

Custom data:

  0 
 x38

Connected devices bitmap:

  0 
 b00001001

Connection status field raw data (combine above 4 bytes):

  0 
 x35853809

In use account key (this is the Key):

Non-in use account key:

Random salt:

  0 
 xC7C8

Account key filter (this is IV): this is generated by changing the first byte of in use account key from 0b00000100 to 0b00000110.

Encrypted connection status field:

Cryptographic Test Cases Stay organized with collections Save and categorize content based on your preferences.

Test Cases

SHA-256 Hashing

AES Encryption

ECDH Key Exchange

AES Key from ECDH Shared Secret

Bloom Filter

AES-CTR Encryption

HMAC-SHA256

Encode personalized name to additional data packet

Decode additional data packet to get personalized name

Encrypted connection status field

Cryptographic Test Cases