Swift

Verify and Pin the FTPS Server Certificate

Demonstrates the certificate-verification properties RequireSslCertVerify, TlsPinSet, and the read-only SslServerCertVerified.

Background: By default a TLS connection is not rejected merely because certificate-chain verification fails, so RequireSslCertVerify = true is the important hardening step — it makes an expired, unsigned, or untrusted certificate abort the connection. TlsPinSet adds public-key pinning on top: the handshake fails unless the server's SPKI fingerprint matches one you configured, defending against a mis-issued certificate that would otherwise validate. Pinning supplements verification rather than replacing it. SslServerCertVerified reports the outcome.

Chilkat Swift Downloads

Download Chilkat for Swift

Swift


func chilkatTest() {
    var success: Bool = false

    let ftp = CkoFtp2()!

    ftp.hostname = "ftp.example.com"
    ftp.username = "myFtpLogin"

    ftp.authTls = true

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    ftp.password = "myPassword"

    //  Reject the connection if the server certificate cannot be verified (expired, bad signature,
    //  untrusted chain, etc.).  The default is false, which does not reject on verification
    //  failure -- set true for security.
    ftp.requireSslCertVerify = true

    //  Optionally pin the server's public key.  If none of the configured SPKI fingerprints matches,
    //  the TLS handshake fails.  Pinning supplements normal verification; it does not replace it.
    ftp.tlsPinSet = "sha256//YLh1dUR9y6Kja30RrAn7JKnbQG/uEtLMkBgFF2Fuihg="

    success = ftp.connect()
    if success == false {
        print("\(ftp.lastErrorText!)")
        return
    }

    //  SslServerCertVerified reports whether the certificate chain was successfully verified.
    if ftp.sslServerCertVerified {
        print("The server certificate was verified.")
    }

    success = ftp.disconnect()
    if success == false {
        print("\(ftp.lastErrorText!)")
        return
    }


}