CompTIA PenTest+ 2025 – 400 Free Practice Questions to Pass the Exam

The file format typically used for certificate signing requests (CSRs) is Base64 ASCII. A CSR contains information that will be included in the certificate such as the public key and the identity of the requester. The data included in a CSR is often encoded in Base64 ASCII to ensure it can be transmitted easily across different systems and applications, as Base64 encoding converts binary data into a text format.

This encoding allows for compatibility and transportability, which is essential when it comes to creating and handling CSRs, as they must be shared securely with the certificate authority (CA) for signing. In contrast, the other file types mentioned, such as TXT, XML, and PDF, do not meet the specific requirements for encoding that are needed for CSRs. TXT files are plain text and lack the necessary encoding specifications; XML might organize data well but isn't the standard format for CSRs; and PDF is a document format that is not suitable for the structured data needed for certificate signing requests. Thus, Base64 ASCII is the correct answer for this context.