#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes
struct	algo_attr_t
	Parsed algorithm-attribute payload. More...

Enumerations
enum	algo_attr_algo_id_t { ALGO_ATTR_ID_RSA = 0x01 , ALGO_ATTR_ID_ECDH = 0x12 , ALGO_ATTR_ID_ECDSA = 0x13 , ALGO_ATTR_ID_EDDSA = 0x16 }
	OpenPGP algorithm-attribute codec. More...
enum	algo_attr_curve_t { ALGO_ATTR_CURVE_UNKNOWN = 0 , ALGO_ATTR_CURVE_P256 , ALGO_ATTR_CURVE_ED25519 , ALGO_ATTR_CURVE_X25519 }
	Curves the firmware recognises. UNKNOWN flags unsupported OIDs. More...
enum	algo_attr_role_t { ALGO_ATTR_ROLE_SIG = 0 , ALGO_ATTR_ROLE_DEC = 1 , ALGO_ATTR_ROLE_AUT = 2 }
	Key role (selects which DO tag is being parsed / built). More...
enum	algo_attr_status_t { ALGO_ATTR_OK = 0 , ALGO_ATTR_ERR_TOO_SHORT , ALGO_ATTR_ERR_BAD_ALGO , ALGO_ATTR_ERR_BAD_CURVE , ALGO_ATTR_ERR_BAD_RSA , ALGO_ATTR_ERR_ROLE_MISMATCH , ALGO_ATTR_ERR_BUF_TOO_SMALL , ALGO_ATTR_ERR_NULL }
	Outcome of algo-attribute operations. More...

Functions
algo_attr_status_t	algo_attr_parse (const uint8_t bytes, size_t len, algo_attr_t out)
	Parse a raw algorithm-attribute byte sequence into structured form.
algo_attr_status_t	algo_attr_build (const algo_attr_t attr, uint8_t out, size_t out_cap, size_t *out_len)
	Serialise an algorithm-attribute structure to bytes.
algo_attr_status_t	algo_attr_validate_role (const algo_attr_t *attr, algo_attr_role_t role)
	Check whether the parsed attribute is compatible with the key role it will be installed into.
algo_attr_status_t	algo_attr_validate_capability (const algo_attr_t *attr, bool rsa_supported)
	Check whether the badge's secure element / mbedTLS combination can actually execute this algorithm.

Enumeration Type Documentation

◆ algo_attr_algo_id_t

enum algo_attr_algo_id_t

OpenPGP algorithm-attribute codec.

Encodes / decodes / validates the byte sequences carried by Data Objects 0xC1 (SIG), 0xC2 (DEC) and 0xC3 (AUT) per OpenPGP Smart Card Application 3.4.1, §4.4.3.7-9.

Layout:

ECC (algorithm = ECDSA / EdDSA / ECDH): +---—+-------------—+-----—+ | algo | curve OID | format | +---—+-------------—+-----—+ 1B n bytes 1B (optional, 0xFF = standard)

Algorithm IDs come from RFC 4880 §9.1; curve OIDs are the DER-encoded bytes WITHOUT the leading tag/length, exactly as carried in the DO.

The CDC Badge currently honours three ECC choices: Ed25519 (SIG/AUT), P-256 ECDSA (SIG/AUT), P-256 ECDH (DEC). RSA is optional and is treated as a fallback per the plan in plan2.md §10.

RFC 4880 §9.1 algorithm IDs we care about.

Enumerator
ALGO_ATTR_ID_RSA
ALGO_ATTR_ID_ECDH
ALGO_ATTR_ID_ECDSA
ALGO_ATTR_ID_EDDSA

Definition at line 40 of file algo_attr.h.

◆ algo_attr_curve_t

enum algo_attr_curve_t

Curves the firmware recognises. UNKNOWN flags unsupported OIDs.

Enumerator
ALGO_ATTR_CURVE_UNKNOWN
ALGO_ATTR_CURVE_P256
ALGO_ATTR_CURVE_ED25519
ALGO_ATTR_CURVE_X25519	Reserved for future ECDH-X25519 support.

Definition at line 48 of file algo_attr.h.

◆ algo_attr_role_t

enum algo_attr_role_t

Key role (selects which DO tag is being parsed / built).

Enumerator
ALGO_ATTR_ROLE_SIG
ALGO_ATTR_ROLE_DEC
ALGO_ATTR_ROLE_AUT

Definition at line 56 of file algo_attr.h.

◆ algo_attr_status_t

enum algo_attr_status_t

Outcome of algo-attribute operations.

Enumerator
ALGO_ATTR_OK
ALGO_ATTR_ERR_TOO_SHORT
ALGO_ATTR_ERR_BAD_ALGO
ALGO_ATTR_ERR_BAD_CURVE
ALGO_ATTR_ERR_BAD_RSA
ALGO_ATTR_ERR_ROLE_MISMATCH
ALGO_ATTR_ERR_BUF_TOO_SMALL
ALGO_ATTR_ERR_NULL

Definition at line 77 of file algo_attr.h.

Function Documentation

◆ algo_attr_build()

algo_attr_status_t algo_attr_build	(	const algo_attr_t *	attr,
		uint8_t *	out,
		size_t	out_cap,
		size_t *	out_len )

Serialise an algorithm-attribute structure to bytes.

The trailing 0xFF "import format" byte for ECC is emitted only when attr->has_import_format is set. RSA values are encoded in network byte order (big-endian) per spec.

Definition at line 86 of file algo_attr.cpp.

References ALGO_ATTR_ERR_BAD_ALGO, ALGO_ATTR_ERR_BAD_CURVE, ALGO_ATTR_ERR_BAD_RSA, ALGO_ATTR_ERR_BUF_TOO_SMALL, ALGO_ATTR_ERR_NULL, ALGO_ATTR_ID_RSA, ALGO_ATTR_OK, algo_attr_t::algo_id, algo_attr_t::curve, algo_attr_t::has_import_format, algo_attr_t::import_format, algo_attr_t::rsa_e_bits, algo_attr_t::rsa_import_fmt, and algo_attr_t::rsa_n_bits.

◆ algo_attr_parse()

algo_attr_status_t algo_attr_parse	(	const uint8_t *	bytes,
		size_t	len,
		algo_attr_t *	out )

Parse a raw algorithm-attribute byte sequence into structured form.

The function recognises the three supported curves by OID match. Any other OID lands as ALGO_ATTR_CURVE_UNKNOWN with the call still succeeding so the caller can choose between rejection (6A80) and a permissive accept.

Definition at line 53 of file algo_attr.cpp.

References ALGO_ATTR_ERR_BAD_ALGO, ALGO_ATTR_ERR_BAD_RSA, ALGO_ATTR_ERR_NULL, ALGO_ATTR_ERR_TOO_SHORT, ALGO_ATTR_ID_RSA, ALGO_ATTR_OK, algo_attr_t::algo_id, algo_attr_t::curve, algo_attr_t::has_import_format, algo_attr_t::import_format, algo_attr_t::is_rsa, algo_attr_t::rsa_e_bits, algo_attr_t::rsa_import_fmt, and algo_attr_t::rsa_n_bits.

Referenced by put_data_algo_attr().

◆ algo_attr_validate_capability()

algo_attr_status_t algo_attr_validate_capability	(	const algo_attr_t *	attr,
		bool	rsa_supported )

Check whether the badge's secure element / mbedTLS combination can actually execute this algorithm.

Returns ALGO_ATTR_OK for Ed25519, P-256 ECDSA, P-256 ECDH, and (if rsa_supported is true) RSA 2048/3072/4096. Anything else yields ALGO_ATTR_ERR_BAD_CURVE or ALGO_ATTR_ERR_BAD_RSA.

Definition at line 138 of file algo_attr.cpp.

References ALGO_ATTR_CURVE_ED25519, ALGO_ATTR_CURVE_P256, ALGO_ATTR_CURVE_UNKNOWN, ALGO_ATTR_CURVE_X25519, ALGO_ATTR_ERR_BAD_CURVE, ALGO_ATTR_ERR_BAD_RSA, ALGO_ATTR_ERR_NULL, ALGO_ATTR_ID_ECDH, ALGO_ATTR_ID_ECDSA, ALGO_ATTR_ID_EDDSA, ALGO_ATTR_OK, algo_attr_t::algo_id, algo_attr_t::curve, and algo_attr_t::is_rsa.