Add SSL certificate checker

Implement SSL certificate checking functionality

server/service-operation/operations/ssl_extractor.go

@@ -0,0 +1,57 @@
+
+package operations
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/x509"
+	"fmt"
+	"net"
+)
+
+// extractSANs extracts Subject Alternative Names from certificate
+func (op *SSLOperation) extractSANs(cert *x509.Certificate) []string {
+	sans := make([]string, 0)
+	
+	// Add DNS names
+	sans = append(sans, cert.DNSNames...)
+	
+	// Add IP addresses
+	for _, ip := range cert.IPAddresses {
+		sans = append(sans, ip.String())
+	}
+	
+	// Add email addresses
+	sans = append(sans, cert.EmailAddresses...)
+	
+	// Add URIs
+	for _, uri := range cert.URIs {
+		sans = append(sans, uri.String())
+	}
+	
+	return sans
+}
+
+// getResolvedIP resolves the domain to its IP address
+func (op *SSLOperation) getResolvedIP(hostname string) string {
+	ips, err := net.LookupIP(hostname)
+	if err != nil || len(ips) == 0 {
+		return ""
+	}
+	return ips[0].String()
+}
+
+// getCertificateAlgorithm returns detailed algorithm information
+func (op *SSLOperation) getCertificateAlgorithm(cert *x509.Certificate) string {
+	algorithm := cert.SignatureAlgorithm.String()
+	
+	// Add key size information if available
+	switch pub := cert.PublicKey.(type) {
+	case *rsa.PublicKey:
+		algorithm += fmt.Sprintf(" (RSA %d-bit)", pub.N.BitLen())
+	case *ecdsa.PublicKey:
+		algorithm += fmt.Sprintf(" (ECDSA %d-bit)", pub.Curve.Params().BitSize)
+	}
+	
+	return algorithm
+}