address_book_crypto.c File Reference

HMAC Proof of Registration for Address Book contacts. More...

#include <string.h>
#include "address_book_crypto.h"
#include "ledger_account.h"
#include "identity.h"
#include "lcx_sha256.h"
#include "lcx_hmac.h"
#include "lcx_rng.h"
#include "os_utils.h"
#include "io.h"
#include "crypto_helpers.h"

Include dependency graph for address_book_crypto.c:

Go to the source code of this file.

Detailed Description

HMAC Proof of Registration for Address Book contacts.

Provides HMAC-SHA256 based proofs that bind a registered contact to this specific device. Two independent key derivations are used, one per feature:

• Identity KDF: SHA256("AddressBook-Identity" || privkey.d)
• Ledger Account KDF: SHA256("AddressBook-LedgerAccount" || privkey.d)

HMAC messages:

• Group KDF: SHA256("AddressBook-Group" || privkey.d)
• Identity HMAC_PROOF: gid(32) | name_len(1) | name
• Identity HMAC_REST: gid(32) | scope_len(1) | scope | id_len(1) | identifier | family(1) [| chain_id(8) for FAMILY_ETHEREUM]
• Ledger Account: name_len(1) | name | family(1) [| chain_id(8) for FAMILY_ETHEREUM]

The proof is stored by the host and re-verified during Rename operations to confirm that the contact was registered on this device.

Definition in file address_book_crypto.c.