1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package activitypub

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
)

const rsaBits = 2048

// GenerateKeyPair generates a public and private keypair for signing actions by users for activitypub purposes
func GenerateKeyPair() (string, string, error) {
	priv, _ := rsa.GenerateKey(rand.Reader, rsaBits)
	privPem, err := pemBlockForPriv(priv)
	if err != nil {
		return "", "", err
	}
	pubPem, err := pemBlockForPub(&priv.PublicKey)
	if err != nil {
		return "", "", err
	}
	return privPem, pubPem, nil
}

func pemBlockForPriv(priv *rsa.PrivateKey) (string, error) {
	privBytes := pem.EncodeToMemory(&pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(priv),
	})
	return string(privBytes), nil
}

func pemBlockForPub(pub *rsa.PublicKey) (string, error) {
	pubASN1, err := x509.MarshalPKIXPublicKey(pub)
	if err != nil {
		return "", err
	}
	pubBytes := pem.EncodeToMemory(&pem.Block{
		Type:  "PUBLIC KEY",
		Bytes: pubASN1,
	})
	return string(pubBytes), nil
}