Deep inspection firewalls, also known as deep packet inspection (DPI) firewalls, analyze the content of network traffic beyond basic header information, inspecting the payload of packets to enforce security policies, detect anomalies, and filter out malicious data. While this provides enhanced security, deep inspection can interfere with FTP uploads and downloads due to the unique characteristics of the FTP protocol. […]
How SFTP and FTP Are Different Protocols SFTP (Secure File Transfer Protocol) and FTP (File Transfer Protocol) may both be used for file transfers, but they are fundamentally different protocols in their design, security mechanisms, and underlying technologies. 1. SFTP (Secure File Transfer Protocol): Not an Extension of FTP: SFTP is not related to FTP. It’s a completely different protocol […]
Question: Can you please confirm when downloading file(s) from FTP using Chilkat component, the date/time stamp of the file (creation/modified date) is communicated after download? For example, a PC where the file is being downloaded is at EST while the server where the file was located is on PST timezone. Server time for example, was 4:00 AM, while PC where […]
Question: I updated from an older version of Chilkat to the latest version, and the following CkFtp2 (C++) methods no longer exist: GetLastAccessDt and GetLastAccessDtByName. What happened to them? Answer: These methods were deprecated a while ago, and were finally removed. I’ll explain. (The methods still exist in the ActiveX because it’s not possible to remove methods in the ActiveX […]
Question: We are about using Chilkat C++ library for an FTPS connection. I read on online documentation that there is method CkFtp2::put_AuthTls which allows setting TLS connection. Some questions about client behavior according to this method: if we don’t call this method, transmission is in clear text? Is it equivalent to CkFtp2::put_AuthTls(false)? If we call this method with parameter true […]
This post clarifies the topic of binary vs. ascii uploads/downloads for SFTP (Secure File Transfer over SSH) and FTP. Binary mode transmits bytes exactly as-is. Text mode (also known as “ascii” mode) can modify line endings (CR’s and LF’s) to the canonical convention used on the remote system. For example, Linux systems typically use bare LF line-endings, whereas text […]
One particular cause of the following error is finally known: sockRecv(47ms): WindowsError: An existing connection was forcibly closed by the remote host. WindowsErrorCode: 0x2746 numBytesRequested: 5 Failed to receive data on the TCP socket –sockRecv sockRecv failed. sockRecvN_buf: Did not receive the exact number of bytes desired. numBytesToReceive: 5 This error was caused by the Windows Firewall doing stateful FTP […]
A security-related bug was fixed in FTP2. If the KeepSessionLog property was turned on, the password used for authentication was logged to the in-memory SessionLog property. The fix is to instead log “****” in place of the password.
Fixed an FTP2 XCRC issue. If the AutoXcrc property was turned on, Chilkat FTP2 was not computing the CRC of the local file (or data) uploaded to the server. This caused the CRC comparison to fail after the XCRC command was issued. Note: This fix only applies when using AutoXcrc in conjunction with a server that actually supports XCRC. This […]
If an FTP server supports the RFC 3659 extension, which includes the MLSD command, then it is automatically known to Chilkat FTP2 because the FTP server’s response to the FEAT command will include MLSD in the list. (Chilkat automatically sends a FEAT command after connecting so that it knows the capabilities of the FTP server.) When Chilkat FTP2 recognizes that […]