At One Place

.csr files

.csr file
Certificate Signing Request
The request you send a certificate authority to get an SSL certificate issued.

What opens a .csr file

Windows
Notepad (built in), OpenSSL, Certificate Manager
macOS
TextEdit (built in), OpenSSL, Keychain Access (built in)
Linux
openssl req -text -in file.csr, Text Editor (built in)

What a .csr file is

A CSR contains your public key and the domain and organisation details you want certified, signed with the matching private key to prove you hold it. You generate it on the server, paste it into the certificate authority, and receive a certificate back — the CSR itself has no further use afterwards. It is base64 text in the same PEM wrapper as certificates, so a text editor or openssl req -text will show what it claims.

Converting it

A .csr file is commonly converted to .pem, .der or .crt. It is a plain text format, so any text editor can open and edit it directly.

Details

Extension
.csr
Full name
Certificate Signing Request
Category
Data
MIME type
application/pkcs10
Created by
RSA / IETF (PKCS #10)
Format
Plain text

Common questions

How do I open a .csr file?
On Windows use Notepad (built in); on macOS use TextEdit (built in); on Linux use openssl req -text -in file.csr. The request you send a certificate authority to get an SSL certificate issued.
What is a .csr file?
Certificate Signing Request. A CSR contains your public key and the domain and organisation details you want certified, signed with the matching private key to prove you hold it. You generate it on the server, paste it into the certificate authority, and receive a certificate back — the CSR itself has no further use afterwards.
Can I convert a .csr file?
Yes. It is usually converted to .pem, .der or .crt, either by exporting from one of the programs listed above or with a format converter.

Related pages

Sources

  1. Media Types Registry — IANA
  2. Official vendor product documentation — At One Place

How these figures are compiled and checked