object

jwt_jwa

JSON Web Algorithm metadata and header helpers.

Availability:
logtalk_load(jwt(loader))
Author: Paulo Moura
Version: 1:0:0
Date: 2026-07-06
Compilation flags:
static, context_switching_calls
Imports:
public jwt_helpers
Uses:
list
Remarks:
(none)
Inherited public predicates:
 check_option/1  check_options/1  default_option/1  default_options/1  option/2  option/3  valid_option/1  valid_options/1

Public predicates

header_algorithm/2

Extracts and validates the JWT header algorithm.

Compilation flags:
static
Template:
header_algorithm(Header,Algorithm)
Mode and number of proofs:
header_algorithm(+term,-atom) - one_or_error
Exceptions:
Header does not contain a valid alg member:
domain_error(jwt_header,Header)

header_key_id/2

Extracts the optional key identifier from a JWT header.

Compilation flags:
static
Template:
header_key_id(Header,KeyId)
Mode and number of proofs:
header_key_id(+term,-atom) - zero_or_one

validate_header/1

Validates a JWT header object and rejects unsupported critical header parameters.

Compilation flags:
static
Template:
validate_header(Header)
Mode and number of proofs:
validate_header(+term) - one_or_error
Exceptions:
Header is not a JSON object, contains duplicate member names, or contains unsupported critical header parameters:
domain_error(jwt_header,Header)

allowed_algorithm/2

Validates that an algorithm is supported and allowed by the options.

Compilation flags:
static
Template:
allowed_algorithm(Algorithm,Options)
Mode and number of proofs:
allowed_algorithm(+atom,+list(compound)) - one_or_error
Exceptions:
Algorithm is unsupported or disallowed by Options:
domain_error(jwt_algorithm,Algorithm)

supported_algorithm/1

Succeeds when the algorithm is supported by this library.

Compilation flags:
static
Template:
supported_algorithm(Algorithm)
Mode and number of proofs:
supported_algorithm(+atom) - zero_or_one

key_type/2

Maps a supported algorithm to the required JWK key type.

Compilation flags:
static
Template:
key_type(Algorithm,KeyType)
Mode and number of proofs:
key_type(+atom,-atom) - zero_or_one

hmac_hash/2

Maps a supported HMAC algorithm to its hash object.

Compilation flags:
static
Template:
hmac_hash(Algorithm,Hash)
Mode and number of proofs:
hmac_hash(+atom,-object_identifier) - zero_or_one

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)