Rust Requires Chilkat v11.0.0+

RSA-OAEP with SHA256 hashing

See more RSA Examples

RSA encrypt a SHA256 hash with OAEP padding. Rust

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

let pubkey = chilkat::PublicKey::new();

let sb_pem = chilkat::StringBuilder::new();
let b_crlf = true;
let _ = sb_pem.append_line("-----BEGIN PUBLIC KEY-----", b_crlf);
let _ = sb_pem.append_line("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF", b_crlf);
let _ = sb_pem.append_line("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA", b_crlf);
let _ = sb_pem.append_line("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s", b_crlf);
let _ = sb_pem.append_line("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF", b_crlf);
let _ = sb_pem.append_line("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE", b_crlf);
let _ = sb_pem.append_line("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W", b_crlf);
let _ = sb_pem.append_line("SwIDAQAB", b_crlf);
let _ = sb_pem.append_line("-----END PUBLIC KEY-----", b_crlf);

// Load the public key object from the PEM. 
if pubkey.load_from_string(&sb_pem.get_as_string().unwrap_or_default()).is_err() {
    println!("{}", pubkey.last_error_text());
    return;
}

// Build a small string to encrypt
let json = chilkat::JsonObject::new();
let _ = json.update_string("example", "123");
let _ = json.update_string("hello", "world");
println!("{}", json.emit().unwrap_or_default());

// This is the JSON to be RSA encrypted:  {"example":"123","hello":"world"}

// IMPORTANT: RSA encryption is only used to encrypt small amounts of data.
// RSA is only able to encrypt data to a maximum amount of your key size (2048 bits = 256 bytes) 
// minus padding / header data (11 bytes for PKCS#1 v1.5 padding, 42 bytes for OAEP).
// As a result it is often not possible to encrypt files with RSA directly. 
// RSA is also not meant for this purpose. 
// 
// If you want to encrypt more data, you can use something like:
// 1) Generate a 256-bit random keystring K
// 2) Encrypt your data with AES-CBC with K
// 3) Encrypt K with RSA
// 4) Send both to the other side 

let rsa = chilkat::Rsa::new();
rsa.set_pkcs_padding(false);
rsa.set_oaep_hash("SHA-256");
let _ = rsa.use_public_key(&pubkey);
rsa.set_encoding_mode("base64");

// Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
// even using the same data and key, the result will be different --  but still valid.  One should not expect
// to get the same output.
let b_use_private_key = false;
let Ok(encrypted_str) = rsa.encrypt_string_enc(&json.emit().unwrap_or_default(), b_use_private_key) else {
    println!("{}", rsa.last_error_text());
    return;
};

println!("Result: {}", encrypted_str);