Browser CSR Generator — RSA Private Key and Certificate Request PEM

Developer

A browser CSR generator encodes subject details and SAN names into an ASN.1 PKCS#10 structure, then signs it with the Web Crypto API to produce a certificate request PEM.

What is it

A CSR (Certificate Signing Request) is the public key and subject information submitted to a certificate authority when requesting a certificate. This tool creates an RSA key pair in the browser and generates a PKCS#10 CSR with Common Name and Subject Alternative Name values. It also outputs the private key PEM, so save it immediately in a secure place and avoid using shared devices.

CSR = PEM(SEQUENCE(CertificationRequestInfo, sha256WithRSAEncryption, signature)); private key = PKCS#8 PEM

How to use

  1. 1Enter the Common Name and SAN domains.
  2. 2Fill organization, unit, country, state, and locality if needed.
  3. 3Generate the CSR PEM and private key PEM, then submit only the CSR to your certificate authority.

Reference

Browser CSR Generator — RSA Private Key and Certificate Request PEM Reference
FieldMeaning
CNprimary domain name
SANDNS names included in the certificate
Private Keysecret key to store on the server; do not submit it to the CA

Sources & standards

FAQ

Is the private key sent to a server?

No. Key generation and CSR signing use the browser Web Crypto API; the private key is not sent to or stored on a server.

Which part do I submit to the certificate authority?

Submit only the CSR PEM. Keep the PRIVATE KEY PEM securely on your server and never share it externally.

Can I include wildcard or multiple domains?

You can enter multiple DNS names in SAN with commas or newlines. Check your certificate authority policy for wildcard rules.

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