modules/woz_matter/src/matter

Overview

PBKDF2, the SPAKE2+ transcript and confirmations.

depends on aliro_hash.h matter_spake2p.h

API

F`int matter_pbkdf2_sha256(const uint8_t password, size_t password_len, const uint8_t salt, size_t salt_len, uint32_t iterations, uint8_t *out, size_t out_len)`

modules/woz_matter/src/matter_spake2p.c:49

Derive an output key using PBKDF2-SHA256 with the given password, salt, and iteration count; returns MATTER_E_INVAL if parameters are invalid or MATTER_E_NOSPACE if the salt is too long.

called by matter_spake2p_w0w1

F`int matter_spake2p_w0w1(uint32_t passcode, const uint8_t *salt, size_t salt_len, uint32_t iterations, uint8_t w0[MATTER_SPAKE_SCALAR_LEN], uint8_t w1[MATTER_SPAKE_SCALAR_LEN])`

modules/woz_matter/src/matter_spake2p.c:113

Derive SPAKE2+ w0 and w1 scalars from a 32-bit passcode using PBKDF2-SHA256 with salt and iterations. Passcode is encoded little-endian; each result is reduced modulo the P-256 order using 40 bytes of derived material (8 bytes extra for negligible bias). Returns MATTER_OK on success.

calls matter_pbkdf2_sha256

F`int matter_spake2p_context(const uint8_t req, size_t req_len, const uint8_t resp, size_t resp_len, uint8_t out[MATTER_SPAKE_HASH_LEN])`

modules/woz_matter/src/matter_spake2p.c:154

Hash the SPAKE2+ context from optional request and response payloads; context is always hashed but payloads are only included if present.

F`static void tt_put(uint8_t out, size_t off, const uint8_t *data, size_t len)`

modules/woz_matter/src/matter_spake2p.c:180

Append one length-prefixed transcript element.

called by matter_spake2p_transcript

F`int matter_spake2p_transcript(const uint8_t context[MATTER_SPAKE_HASH_LEN], const uint8_t pa[MATTER_SPAKE_POINT_LEN], const uint8_t pb[MATTER_SPAKE_POINT_LEN], const uint8_t z[MATTER_SPAKE_POINT_LEN], const uint8_t v[MATTER_SPAKE_POINT_LEN], const uint8_t w0[MATTER_SPAKE_SCALAR_LEN], uint8_t out, size_t out_len)`

modules/woz_matter/src/matter_spake2p.c:201

Assemble the SPAKE2+ transcript from context, identity empty strings, M, N, exchange points, shared secret Z, ephemeral V, and w0 scalar; returns MATTER_E_NOSPACE if output buffer is too small.

calls tt_put

F`int matter_spake2p_p2(const uint8_t tt, size_t tt_len, const uint8_t pa[MATTER_SPAKE_POINT_LEN], const uint8_t pb[MATTER_SPAKE_POINT_LEN], struct matter_spake2p_result out)`

modules/woz_matter/src/matter_spake2p.c:243

Derive confirmation and session keys from the SPAKE2+ transcript and exchange points; swaps Ka and Ke derivation order and produces confirmation codes Ca over peer's point and Cb over own point.

F`bool matter_spake2p_verify(const uint8_t expected[MATTER_SPAKE_HASH_LEN], const uint8_t got[MATTER_SPAKE_HASH_LEN])`

modules/woz_matter/src/matter_spake2p.c:279

Compare two SPAKE2+ hash values in constant time; returns true if they match exactly.

Overview

API

Fint matter_pbkdf2_sha256(const uint8_t *password, size_t password_len, const uint8_t *salt, size_t salt_len, uint32_t iterations, uint8_t *out, size_t out_len)

Fint matter_spake2p_w0w1(uint32_t passcode, const uint8_t *salt, size_t salt_len, uint32_t iterations, uint8_t w0[MATTER_SPAKE_SCALAR_LEN], uint8_t w1[MATTER_SPAKE_SCALAR_LEN])

Fint matter_spake2p_context(const uint8_t *req, size_t req_len, const uint8_t *resp, size_t resp_len, uint8_t out[MATTER_SPAKE_HASH_LEN])

Fstatic void tt_put(uint8_t *out, size_t *off, const uint8_t *data, size_t len)