KeyFingerprint.cpp File Reference

#include "cdc_core/KeyFingerprint.h"
#include "cdc_hal/ISecureElement.h"
#include "mbedtls/sha256.h"
#include <string.h>

Go to the source code of this file.

Functions
const char *	key_fingerprint_word (uint8_t index)
	Returns alchemical word for 5-bit index.
bool	key_fingerprint_from_pubkey (const uint8_t *pubkey, size_t pubkey_len, char *buf, size_t len)
	Generates human-readable fingerprint from public key bytes.
bool	key_fingerprint_generate (uint8_t slot, char *buf, size_t len)
	Reads public key from secure element slot and generates fingerprint.

Variables
static constexpr size_t	SHA256_DIGEST_SIZE = 32
	Alchemical key fingerprints shared by FIDO and OpenPGP features.
static constexpr size_t	P256_PUBKEY_RAW_SIZE = 64
	Uncompressed P-256 public key length in raw X||Y form (no SEC1 prefix).
static constexpr size_t	ED25519_PUBKEY_SIZE = 32
	Ed25519 public key length in bytes (raw, RFC 8032).
static const char *const	ALCHEMY_WORDS [32]
	Lookup table of 32 alchemical element labels (5-bit index space).

Function Documentation

key_fingerprint_from_pubkey()

bool key_fingerprint_from_pubkey	(	const uint8_t *	pubkey,
		size_t	pubkey_len,
		char *	buf,
		size_t	len )

Generates human-readable fingerprint from public key bytes.

Parameters

pubkey	Public key buffer.
pubkey_len	Length of pubkey.
buf	Output string buffer.
len	Size of output buffer.

Returns

true on success.

Definition at line 49 of file KeyFingerprint.cpp.

References ALCHEMY_WORDS, KEY_FINGERPRINT_MAX_LEN, KEY_FINGERPRINT_WORD_COUNT, and SHA256_DIGEST_SIZE.

Referenced by key_fingerprint_generate(), and cdc::mod_fido2::showDetail().

key_fingerprint_generate()

bool key_fingerprint_generate	(	uint8_t	slot,
		char *	buf,
		size_t	len )

Reads public key from secure element slot and generates fingerprint.

Parameters

slot	Secure-element slot number.
buf	Output string buffer.
len	Size of output buffer.

Returns

true if a key was read and fingerprint generated.

Definition at line 83 of file KeyFingerprint.cpp.

References curve, cdc::hal::ED25519, ED25519_PUBKEY_SIZE, cdc::hal::getSecureElementInstance(), key_fingerprint_from_pubkey(), KEY_FINGERPRINT_MAX_LEN, cdc::hal::OK, cdc::hal::P256, and P256_PUBKEY_RAW_SIZE.

Referenced by gpg_alchemy_fingerprint().

key_fingerprint_word()

const char * key_fingerprint_word

(

uint8_t

index

)

Returns alchemical word for 5-bit index.

Parameters

index

Word index in range [0,31].

Returns

Word string or "?" for invalid index.

Definition at line 36 of file KeyFingerprint.cpp.

References ALCHEMY_WORDS.

Variable Documentation

ALCHEMY_WORDS

const char* const ALCHEMY_WORDS[32]

static

Initial value:

                                      = {
    "Fire",        "Water",      "Earth",      "Air",
    "Aether",      "Sulfur",     "Mercury",    "Salt",
    "Gold",        "Silver",     "Copper",     "Iron",
    "Tin",         "Lead",       "Antimony",   "Arsenic",
    "Bismuth",     "Phosphorus", "Platinum",   "Zinc",
    "Magnesium",   "Potassium",  "Vitriol",    "Aquafortis",
    "Alkahest",    "Azoth",      "Cinnabar",   "Nitre",
    "Calx",        "Regulus",    "Quintessence","Stone"
}

Lookup table of 32 alchemical element labels (5-bit index space).

Definition at line 20 of file KeyFingerprint.cpp.

Referenced by key_fingerprint_from_pubkey(), and key_fingerprint_word().

ED25519_PUBKEY_SIZE

size_t ED25519_PUBKEY_SIZE = 32

staticconstexpr

Ed25519 public key length in bytes (raw, RFC 8032).

Definition at line 15 of file KeyFingerprint.cpp.

P256_PUBKEY_RAW_SIZE

size_t P256_PUBKEY_RAW_SIZE = 64

staticconstexpr

Uncompressed P-256 public key length in raw X||Y form (no SEC1 prefix).

Definition at line 13 of file KeyFingerprint.cpp.

SHA256_DIGEST_SIZE

size_t SHA256_DIGEST_SIZE = 32

staticconstexpr

Alchemical key fingerprints shared by FIDO and OpenPGP features.

Size of a SHA-256 digest in bytes (FIPS 180-4).

Definition at line 11 of file KeyFingerprint.cpp.