Xbase++

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.

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LOCAL nSuccess
LOCAL oFtp

nSuccess := 0

oFtp := CreateObject("Chilkat.Ftp2")

oFtp:Hostname := "ftp.example.com"
oFtp:Username := "myFtpLogin"

oFtp:AuthTls := 1

//  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.
oFtp:Password := "myPassword"

//  Reject the connection if the server certificate cannot be verified (expired, bad signature,
//  untrusted chain, etc.).  The default is 0, which does not reject on verification
//  failure -- set 1 for security.
oFtp:RequireSslCertVerify := 1

//  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.
oFtp:TlsPinSet := "sha256//YLh1dUR9y6Kja30RrAn7JKnbQG/uEtLMkBgFF2Fuihg="

nSuccess := oFtp:Connect()
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

//  SslServerCertVerified reports whether the certificate chain was successfully verified.
IF (oFtp:SslServerCertVerified)
    ? "The server certificate was verified."
ENDIF

nSuccess := oFtp:Disconnect()
IF (nSuccess == 0)
    ? oFtp:LastErrorText
    oFtp:destroy()
    RETURN
ENDIF

oFtp:destroy()