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:
0x11, 0x22, 0x33, 0x44, 0x55, 0x66
Hashed result:
0xBB, 0x00, 0x0D, 0xDD, 0x92, 0xA0, 0xA2, 0xA3, 0x46, 0xF0, 0xB5, 0x31,
0xF2, 0x78, 0xAF, 0x06, 0xE3, 0x70, 0xF8, 0x69, 0x32, 0xCC, 0xAF, 0xCC,
0xC8, 0x92, 0xD6, 0x8D, 0x35, 0x0F, 0x80, 0xF8
AES Encryption
Input value:
0xF3, 0x0F, 0x4E, 0x78, 0x6C, 0x59, 0xA7, 0xBB, 0xF3, 0x87, 0x3B, 0x5A,
0x49, 0xBA, 0x97, 0xEA
Secret key:
0xA0, 0xBA, 0xF0, 0xBB, 0x95, 0x1F, 0xF7, 0xB6, 0xCF, 0x5E, 0x3F, 0x45,
0x61, 0xC3, 0x32, 0x1D
Encrypted output:
0xAC, 0x9A, 0x16, 0xF0, 0x95, 0x3A, 0x3F, 0x22, 0x3D, 0xD1, 0x0C, 0xF5,
0x36, 0xE0, 0x9E, 0x9C
ECDH Key Exchange
Bob's private key:
0x02, 0xB4, 0x37, 0xB0, 0xED, 0xD6, 0xBB, 0xD4, 0x29, 0x06, 0x4A, 0x4E,
0x52, 0x9F, 0xCB, 0xF1, 0xC4, 0x8D, 0x0D, 0x62, 0x49, 0x24, 0xD5, 0x92,
0x27, 0x4B, 0x7E, 0xD8, 0x11, 0x93, 0xD7, 0x63
Bob's public key:
0xF7, 0xD4, 0x96, 0xA6, 0x2E, 0xCA, 0x41, 0x63, 0x51, 0x54, 0x0A, 0xA3,
0x43, 0xBC, 0x69, 0x0A, 0x61, 0x09, 0xF5, 0x51, 0x50, 0x06, 0x66, 0xB8,
0x3B, 0x12, 0x51, 0xFB, 0x84, 0xFA, 0x28, 0x60, 0x79, 0x5E, 0xBD, 0x63,
0xD3, 0xB8, 0x83, 0x6F, 0x44, 0xA9, 0xA3, 0xE2, 0x8B, 0xB3, 0x40, 0x17,
0xE0, 0x15, 0xF5, 0x97, 0x93, 0x05, 0xD8, 0x49, 0xFD, 0xF8, 0xDE, 0x10,
0x12, 0x3B, 0x61, 0xD2
Alice's private key:
0xD7, 0x5E, 0x54, 0xC7, 0x7D, 0x76, 0x24, 0x89, 0xE5, 0x7C, 0xFA, 0x92,
0x37, 0x43, 0xF1, 0x67, 0x77, 0xA4, 0x28, 0x3D, 0x99, 0x80, 0x0B, 0xAC,
0x55, 0x58, 0x48, 0x38, 0x93, 0xE5, 0xB0, 0x6D
Alice's public key:
0x36, 0xAC, 0x68, 0x2C, 0x50, 0x82, 0x15, 0x66, 0x8F, 0xBE, 0xFE, 0x24,
0x7D, 0x01, 0xD5, 0xEB, 0x96, 0xE6, 0x31, 0x8E, 0x85, 0x5B, 0x2D, 0x64,
0xB5, 0x19, 0x5D, 0x38, 0xEE, 0x7E, 0x37, 0xBE, 0x18, 0x38, 0xC0, 0xB9,
0x48, 0xC3, 0xF7, 0x55, 0x20, 0xE0, 0x7E, 0x70, 0xF0, 0x72, 0x91, 0x41,
0x9A, 0xCE, 0x2D, 0x28, 0x14, 0x3C, 0x5A, 0xDB, 0x2D, 0xBD, 0x98, 0xEE,
0x3C, 0x8E, 0x4F, 0xBF
Generated shared key (either Alice's public + Bob's private or Bob's public + Alice's private):
0x9D, 0xAD, 0xE4, 0xF8, 0x6A, 0xC3, 0x48, 0x8B, 0xBA, 0xC2, 0xAC, 0x34,
0xB5, 0xFE, 0x68, 0xA0, 0xEE, 0x5A, 0x67, 0x06, 0xF5, 0x43, 0xD9, 0x06,
0x1A, 0xD5, 0x78, 0x89, 0x49, 0x8A, 0xE6, 0xBA
AES Key from ECDH Shared Secret
This is step 1b (AES key generation) in the GATT procedure.
ECDH shared key:
0x9D, 0xAD, 0xE4, 0xF8, 0x6A, 0xC3, 0x48, 0x8B, 0xBA, 0xC2, 0xAC, 0x34,
0xB5, 0xFE, 0x68, 0xA0, 0xEE, 0x5A, 0x67, 0x06, 0xF5, 0x43, 0xD9, 0x06,
0x1A, 0xD5, 0x78, 0x89, 0x49, 0x8A, 0xE6, 0xBA
Generated AES key:
0xB0, 0x7F, 0x1F, 0x17, 0xC2, 0x36, 0xCB, 0xD3, 0x35, 0x23, 0xC5, 0x15,
0xF3, 0x50, 0xAE, 0x57
Bloom Filter
Random salt:
0xC7C8
First account key added to the filter (combine with the above random salt):
0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0x00, 0xAA, 0xBB,
0xCC, 0xDD, 0xEE, 0xFF
Resulting bloom filter:
0x02, 0x0C, 0x80, 0x2A
Battery data (if it is contained in the advertisement):
0b00110011, // length = 3, show UI indication.
0b01000000, // left bud: not charging, battery level = 64.
0b01000000, // right bud: not charging, battery level = 64.
0b01000000 // case: not charging, battery level = 64.
Resulting bloom filter with battery data:
0x01, 0x01, 0x46, 0x0A
Second account key added to the filter (combine with the above random salt):
0x11, 0x11, 0x22, 0x22, 0x33, 0x33, 0x44, 0x44, 0x55, 0x55, 0x66, 0x66,
0x77, 0x77, 0x88, 0x88
Resulting bloom filter from both added account keys:
0x84, 0x4A, 0x62, 0x20, 0x8B
Battery data (if it is contained in the advertisement):
0b00110011, // length = 3, show UI indication.
0b01000000, // left bud: not charging, battery level = 64.
0b01000000, // right bud: not charging, battery level = 64.
0b01000000 // case: not charging, battery level = 64.
Resulting bloom filter from both added account keys with battery data:
0x46, 0x15, 0x24, 0xD0, 0x08
AES-CTR Encryption
Input data: "Someone's Google Headphone" with utf-8 encoding
0x53, 0x6F, 0x6D, 0x65, 0x6F, 0x6E, 0x65, 0x27, 0x73, 0x20, 0x47, 0x6F,
0x6F, 0x67, 0x6C, 0x65, 0x20, 0x48, 0x65, 0x61, 0x64, 0x70, 0x68, 0x6F,
0x6E, 0x65
Secret key:
0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67,
0x89, 0xAB, 0xCD, 0xEF
Nonce:
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07
Expected encryption result:
0xEE, 0x4A, 0x24, 0x83, 0x73, 0x80, 0x52, 0xE4, 0x4E, 0x9B, 0x2A, 0x14,
0x5E, 0x5D, 0xDF, 0xAA, 0x44, 0xB9, 0xE5, 0x53, 0x6A, 0xF4, 0x38, 0xE1,
0xE5, 0xC6
HMAC-SHA256
Input data:
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xEE, 0x4A, 0x24, 0x83,
0x73, 0x80, 0x52, 0xE4, 0x4E, 0x9B, 0x2A, 0x14, 0x5E, 0x5D, 0xDF, 0xAA,
0x44, 0xB9, 0xE5, 0x53, 0x6A, 0xF4, 0x38, 0xE1, 0xE5, 0xC6
Secret key:
0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67,
0x89, 0xAB, 0xCD, 0xEF
Expected HMAC-SHA256 result:
0x55, 0xEC, 0x5E, 0x60, 0x55, 0xAF, 0x6E, 0x92, 0x61, 0x8B, 0x7D, 0x87,
0x10, 0xD4, 0x41, 0x37, 0x09, 0xAB, 0x5D, 0xA2, 0x7C, 0xA2, 0x6A, 0x66,
0xF5, 0x2E, 0x5A, 0xD4, 0xE8, 0x20, 0x90, 0x52
Encode personalized name to additional data packet
Input data: "Someone's Google Headphone" with utf-8 encoding
0x53, 0x6F, 0x6D, 0x65, 0x6F, 0x6E, 0x65, 0x27, 0x73, 0x20, 0x47, 0x6F,
0x6F, 0x67, 0x6C, 0x65, 0x20, 0x48, 0x65, 0x61, 0x64, 0x70, 0x68, 0x6F,
0x6E, 0x65
Secret key:
0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67,
0x89, 0xAB, 0xCD, 0xEF
Nonce:
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07
Expected additional data packet:
0x55, 0xEC, 0x5E, 0x60, 0x55, 0xAF, 0x6E, 0x92, 0x00, 0x01, 0x02, 0x03,
0x04, 0x05, 0x06, 0x07, 0xEE, 0x4A, 0x24, 0x83, 0x73, 0x80, 0x52, 0xE4,
0x4E, 0x9B, 0x2A, 0x14, 0x5E, 0x5D, 0xDF, 0xAA, 0x44, 0xB9, 0xE5, 0x53,
0x6A, 0xF4, 0x38, 0xE1, 0xE5, 0xC6
Decode additional data packet to get personalized name
Input data:
0x55, 0xEC, 0x5E, 0x60, 0x55, 0xAF, 0x6E, 0x92, 0x00, 0x01, 0x02, 0x03,
0x04, 0x05, 0x06, 0x07, 0xEE, 0x4A, 0x24, 0x83, 0x73, 0x80, 0x52, 0xE4,
0x4E, 0x9B, 0x2A, 0x14, 0x5E, 0x5D, 0xDF, 0xAA, 0x44, 0xB9, 0xE5, 0x53,
0x6A, 0xF4, 0x38, 0xE1, 0xE5, 0xC6
Secret key:
0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67,
0x89, 0xAB, 0xCD, 0xEF
Expected name: "Someone's Google Headphone" with utf-8 encoding
0x53, 0x6F, 0x6D, 0x65, 0x6F, 0x6E, 0x65, 0x27, 0x73, 0x20, 0x47, 0x6F,
0x6F, 0x67, 0x6C, 0x65, 0x20, 0x48, 0x65, 0x61, 0x64, 0x70, 0x68, 0x6F,
0x6E, 0x65
Encrypted connection status field
Field length and type:
0b001100101 (length = 3, type = connection status field)
Connection state:
0b10000101:
* on head detection = 1
* connection availability = 0
* focus mode = 0
* auto-reconnected = 0
* connection state = 0x5 (A2DP with AVRCP)
Custom data:
0x38
Connected devices bitmap:
0b00001001
Connection status field raw data (combine above 4 bytes):
0x35853809
In use account key (this is the Key):
0x04, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0x00, 0xAA, 0xBB,
0xCC, 0xDD, 0xEE, 0xFF
Non-in use account key:
0x04, 0x11, 0x22, 0x22, 0x33, 0x33, 0x44, 0x44, 0x55, 0x55, 0x66, 0x66,
0x77, 0x77, 0x88, 0x88
Random salt:
0xC7C8
Account key filter (this is IV): this is generated by changing the first byte of in use account key from 0b00000100 to 0b00000110.
0x8C, 0xA9, 0x0C, 0x08, 0x1C
Encrypted connection status field:
0xF4, 0xBB, 0x40, 0x6F