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Self-signed certificates

A self-signed certificate is a Digital Certificate that is signed by the same entity whose identity it certifies, rather than by a [[Certificate Authority|CA]]. In this arrangement, the entity acts as its own CA, functioning as both the creator and the subject of the certificate.^[600-developer-tools-security-openssl.md]

Purpose and Usage

Self-signed certificates are typically utilized for development and testing purposes where the full validation chain of a commercial CA is not required.^[600-developer-tools-security-openssl.md] They allow developers to implement secure protocols (such as SSL/TLS) locally or in isolated environments without incurring the costs or processing time associated with external certificate authorities.

Trust and Verification

Because the certificate is not signed by a trusted third-party root CA, operating systems and browsers do not automatically trust self-signed certificates.^[600-developer-tools-security-openssl.md] To establish trust in a local environment, the user must explicitly import the generated certificate into the "Trusted Root Certification Authorities" store on their system.^[600-developer-tools-security-openssl.md]

Creation with OpenSSL

The openssl command-line tool is frequently used to generate self-signed certificates.

  • Generate Private Key: The first step is to create a private key (e.g., rootCA.key) using a strong encryption algorithm (e.g., 4096-bit RSA) and a password.^[600-developer-tools-security-openssl.md]
  • Generate Certificate: A certificate signing request is combined with the private key to generate the final certificate file (e.g., rootCA.crt). This command typically includes parameters for the hashing algorithm (SHA-256) and the validity period (e.g., 36,500 days).^[600-developer-tools-security-openssl.md]

Sources

  • 600-developer-tools-security-openssl.md