kodflow/kitsune

package certs

import (
    "crypto/tls"
    "fmt"
)

// TLSConfigFor generates a TLS configuration for the given domain and subdomains.
// If the domain is "localhost", it generates a self-signed certificate; otherwise,
// it obtains a remotely signed certificate. This function ensures that the generated
// TLS configuration is appropriate for the specified domain and subdomains.
//
// Parameters:
// - domain: string The primary domain for the TLS configuration.
// - subs: ...string A variadic list of subdomains associated with the domain.
//
// Returns:
// - *tls.Config: The TLS configuration with the appropriate certificate.
func TLSConfigFor(domain string, subs ...string) *tls.Config {
    // Default to "localhost" if the domain is empty
    if domain == "" {
        domain = "localhost"
    }

    // Generate a list of hostnames including the domain and subdomains
    hosts := generateHosts(domain, subs...)

    // Generate a self-signed certificate for localhost, otherwise get a remotely signed certificate
    if domain == "localhost" || domain == "127.0.0.1" {
        return generateSelfSignedCert(hosts)
    }

    return generateRemoteSignedCert(hosts)
}

// generateHosts creates a list of hostnames from a domain and its subdomains.
// It combines the main domain with each subdomain to form complete hostnames.
//
// Parameters:
// - domain: string The main domain.
// - subs: ...string A variadic list of subdomains.
//
// Returns:
// - []string: A list of combined domain and subdomain hostnames.
func generateHosts(domain string, subs ...string) []string {
    var combinations []string
    combinations = append(combinations, domain)
    for _, sub := range subs {
        // Combine each subdomain with the main domain
        combinations = append(combinations, fmt.Sprintf("%s.%s", sub, domain))
    }

    return combinations
}