Rust

Check if an Email Was Received Digitally Signed

Demonstrates the read-only Chilkat Email.ReceivedSigned property, which is true if the email was originally received carrying one or more digital signatures. Knowing a message was signed is separate from knowing the signature checked out, so this example also reads SignaturesValid to report whether the signed content verified.

Background: A digital signature on an email (S/MIME) provides two things: authenticity (it was really sent by the holder of a particular certificate) and integrity (the content was not altered in transit). The sender signs a hash of the message with their private key; the recipient verifies it with the sender's public certificate. ReceivedSigned simply tells you a signature is present — verifying it is a separate step exposed through SignaturesValid.

Chilkat Rust Downloads

Download Chilkat for Rust

Rust


// Demonstrates the read-only Email.ReceivedSigned property, which is true if this
// email was originally received with a digital signature.  Use SignaturesValid to
// determine whether the signed content actually verified.

let email = chilkat::Email::new();

if email.load_eml("qa_data/eml/signed.eml").is_err() {
    println!("{}", email.last_error_text());
    return;
}

if email.received_signed() {
    println!("This email was received with a digital signature.");
    if email.signatures_valid() {
        println!("All signatures are valid.");
    } else {
        println!("One or more signatures are NOT valid.");
    }

} else {
    println!("This email was not signed.");
}

// Note: Paths such as "qa_data/..." are relative local filesystem paths,
// relative to the current working directory of the running application.