What Are the Reasons for Algorithm Negotiation Failure Error?

Question

Why are syncs failing with the Algorithm Negotiation Failure error?

Environment

SFTP connectors

Resolution

To resolve the Algorithm Negotiation Failure error, you must investigate and address the configuration settings, encryption algorithm support, and compatibility between the communicating parties. The resolution may involve updating software, configuring the encryption settings correctly, and ensuring that both parties support the same set of encryption algorithms and protocols.

Context

Algorithm negotiation failure in SFTP (SSH File Transfer Protocol) can occur for various reasons. It occurs in the context of network communication or encryption protocols. The error indicates that two parties attempting to establish a connection or exchange data are unable to agree on the encryption algorithms or other parameters to use for secure communications.

The Algorithm Negotiation Failure error may occur in the following scenarios:

• SSL/TLS handshake: When clients connect to a secure server using the SSL/TLS protocol, they go through a handshake process. During this handshake, the client and server negotiate the encryption algorithms and protocols to use for secure communications. The handshake can fail with an Algorithm Negotiation Failure error if they can't agree on a common or standard set of algorithms or if there's a configuration issue on either side.

• SSH connection: In Secure Shell (SSH) communication, the client and server negotiate encryption algorithms and other settings to establish a secure connection. You may encounter this error if the client and server can't agree on the encryption algorithms.

• Expired certificates or keys: The SFTP negotiation may fail if certificates or keys used for authentication or encryption have expired.

• Network issues: Connectivity issues, such as network delays or packet loss, can lead to timeouts during algorithm negotiation, causing a failure.

• Server policy: The server may have a strict security policy that enforces specific algorithm requirements. If the client does not meet these requirements, the negotiation will fail.

• VPN setup: Virtual Private Networks (VPNs) also involve the negotiation of encryption algorithms and settings between the client and the VPN server. You may face this error if there's a mismatch or a problem in the negotiation.

• API communication: The Algorithm Negotiation Failure error may occur if two software systems or APIs that communicate over a network have different expectations regarding encryption algorithms or other security settings

• Old or incompatible software: In some cases, older software or devices may not support the encryption algorithms the newer ones support. This incompatibility can lead to negotiation failures if they can't agree on a mutually acceptable set of algorithms.