jsmn_token_get_claim_str¶

Synopsis¶

int jsmn_token_get_claim_str(
    jsmn_token_decode_s* token,
    const char* claim,
    jsmn_value* result);

After you decode a JWT token with jsmn_token_decode you can use this routine to parse the token claims. If the json claim you are parsing is an integer, use jsmn_token_get_claim_int and if the json claim you are parsing is a string use jsmn_token_get_claim_str.

Parameters¶

Parameter	Description
jsmn_token_decode_s *token	A context to manage decoder state
const char *claim	The name of the claim to parse. (IE: “iat”)
jsmn_value * result	A pointer length tuple to the JSON claim

Examples¶

Read the “Subject”, “Name”, and “Issued at” claims of a JWT

const char *jwt = \
   "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9."\
   "eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ."\
   "SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c";

int err;
jsmn_token_decode_s token;

// Decode and validate token
err = jsmn_token_decode(&token, "your-256-bit-secret", JSMN_ALG_HS256, jwt, strlen(jwt));

if (!err) {
  jsmn_value sub, name;
  int iat;

  // Read claims
  jsmn_token_get_claim_str(&token, "sub", &sub);
  jsmn_token_get_claim_str(&token, "name", &name);
  jsmn_token_get_claim_int(&token, "iat", &iat);
  printf("Hello %.*s!", name.len, name.p);
}