The release of Chrony 4.2 has been published, providing an independent implementation of the NTP client and server used for synchronizing accurate time across various Linux distributions, including Fedora, Ubuntu, SUSE/openSUSE, and RHEL/CentOS. The program supports the NTPv4 specification (RFC 5905) and the NTS (Network Time Security) protocol, which utilizes elements of public key infrastructure (PKI) and allows for the application of TLS and authenticated encryption AEAD (Authenticated Encryption with Associated Data) for cryptographic protection of time synchronization. The code is written in C and distributed under the GPLv2 license.
For accurate time data, both external NTP servers and reference clocks, such as those based on GPS receivers, can be utilized, achieving accuracy in the range of microseconds. The project was originally designed to operate correctly in unstable environments, including unreliable networks with connection drops, high latency, and packet loss, working in virtual machines systems with changing temperature regimes (the operation of hardware clocks is affected by temperature).
In the new release:
- Experimental support has been added for a field that extends the capabilities of the NTPv4 protocol and is used to enhance synchronization stability, as well as reduce latency and value dispersion.
- Experimental support for NTP tunneling over the PTP (Precision Time Protocol) has been added.
- Support for the AES-CMAC encryption algorithm has been added to the NTS implementation, along with the ability to use hash functions from GnuTLS.
- Improvements have been made to the alternating mode servers to enhance reliability. The serverstats report now includes statistics on the alternating mode.
- Improved support for multiple clients behind a single address translator (NAT).
- The syscall filter has been updated based on the seccomp mechanism.
- Support for the Solaris OS has been transitioned to use the Illumos project as a reference, which continues the development of the kernel, networking stack, file systems, drivers, libraries, and the basic set of system utilities from OpenSolaris. In Illumos, the ability to disable the correction of system clocks by the kernel has been implemented.
Source: opennet.ru
