Rust

JWE using "dir" Direct use of Shared Symmetric Key

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create a JWE using the "dir" alg -- which is to directly use a shared symmetric key.

Note: This example requires Chilkat v9.5.0.66 or greater.

Rust

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Note: This example requires Chilkat v9.5.0.66 or greater.

let plaintext = "Live long and prosper.".to_string();

let jwe = chilkat::Jwe::new();

// First build the JWE Protected Header..
let jwe_prot_hdr = chilkat::JsonObject::new();
let _ = jwe_prot_hdr.append_string("alg", "dir");
let _ = jwe_prot_hdr.append_string("enc", "A128GCM");

// Don't forget to actually provide the protected header to the JWE object:
let _ = jwe.set_protected_header(&jwe_prot_hdr);

// The JWE is to use 128-bit AES GCM encryption as specified by the "enc" parameter.
// Given that the "alg" = "dir", we are to directly specify the AES GCM key.
// (It is assumed that the decrypting side also has knowledge of the direct key to be used..)

// Our key will be these 16 hex bytes: 000102030405060708090A0B0C0D0E0F

// The SetWrappingKey method is also used for "dir" direct keys.
// However, if there are multiple recipients, they must all share the same CEK (Content Encryption Key),
// which is specified by calling SetWrappingKey with an index of 0.

let recipient_index = 0;
let _ = jwe.set_wrapping_key(recipient_index, "000102030405060708090A0B0C0D0E0F", "hex");

// Encrypt and return the JWE:
let Ok(str_jwe) = jwe.encrypt(&plaintext, "utf-8") else {
    println!("{}", jwe.last_error_text());
    return;
};

// Show the JWE we just created:
println!("{}", str_jwe);

// Decrypt the JWE.
let jwe2 = chilkat::Jwe::new();
if jwe2.load_jwe(&str_jwe).is_err() {
    println!("{}", jwe2.last_error_text());
    return;
}

let _ = jwe2.set_wrapping_key(0, "000102030405060708090A0B0C0D0E0F", "hex");

// Decrypt.
let Ok(original_plaintext) = jwe2.decrypt(0, "utf-8") else {
    println!("{}", jwe2.last_error_text());
    return;
};

println!("original text: ");
println!("{}", original_plaintext);

// Sample output:
// eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..20HX5Huc7f1nQC4pBUtiCQ.axFZIxtZy5j0ifJQUzGXLKIpsBuxJA.eBrOC-NrsreN6JeGuOPk1g
// original text: 
// Live long and prosper.