certificate signing request (SSL) (CSR)

A certificate signing request(CSR) is a standardized text format for requesting digital certificates from the certification authority. The CSR format is an encrypted text block generated by the server on which the certificate is used.

A certification request contains information that is also in the certificate. Thus, the name of the company or organization, the domain name, the location information and the country. In addition, the public key is part of the certificate. Normally, the private key is also created at the same time as the , Certificate Signing Request.

The Certificate Authority( CA) uses the Certificate Signing Request to create the SSL certificate. It does not need the private key for this purpose. Certificates created with a special Certificate Signing Request can only be decrypted with the private key generated with the Certificate Signing Request.

CSR requests are created in Base64 code and encrypted using Privacy Enhanced Mail( PEM). The CSR format marks the beginning and the end of the CSR encryption with a corresponding note: -----BEGIN CERTIFICATE REQUEST-----, resp -----END CERTIFICATE REQUEST-----.

The key length depends on the security requirements and can be 512 bits, but also 1024 bits or 2048 bits.