C++

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 C++ Downloads

Download Chilkat for C++

C++

#include <CkFtp2.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkFtp2 ftp;

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("myFtpLogin");

    ftp.put_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.put_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.put_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.put_TlsPinSet("sha256//YLh1dUR9y6Kja30RrAn7JKnbQG/uEtLMkBgFF2Fuihg=");

    success = ftp.Connect();
    if (success == false) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }

    //  SslServerCertVerified reports whether the certificate chain was successfully verified.
    if (ftp.get_SslServerCertVerified()) {
        std::cout << "The server certificate was verified." << "\r\n";
    }

    success = ftp.Disconnect();
    if (success == false) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }
    }