64 lines
1.7 KiB
Go
64 lines
1.7 KiB
Go
package tls
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import (
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"crypto/rand"
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"crypto/rsa"
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"crypto/tls"
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"crypto/x509"
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"crypto/x509/pkix"
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"encoding/pem"
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"math/big"
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"net"
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"time"
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)
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func CreateCertificate() (*tls.Certificate, error) {
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// 1. Generate an RSA private key
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privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
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if err != nil {
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return nil, err
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}
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// 2. Define the certificate template
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serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
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serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
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if err != nil {
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return nil, err
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}
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template := x509.Certificate{
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SerialNumber: serialNumber,
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Subject: pkix.Name{
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Organization: []string{"home"},
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CommonName: "localhost",
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},
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NotBefore: time.Now(),
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NotAfter: time.Now().Add(365 * 24 * time.Hour), // Valid for 1 year
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KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
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ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
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BasicConstraintsValid: true,
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// Add localhost as a valid IP and DNS name
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IPAddresses: []net.IP{[]byte{127, 0, 0, 1}},
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DNSNames: []string{"localhost"},
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}
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// 3. Create a self-signed certificate
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// The parent is the template itself, and we use the generated public and private keys.
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derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &privateKey.PublicKey, privateKey)
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if err != nil {
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return nil, err
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}
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derBytes = pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
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keyBytes := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
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cert, err := tls.X509KeyPair(derBytes, keyBytes)
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if err != nil {
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return nil, err
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}
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return &cert, nil
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}
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