diff --git a/activitypub/keys.go b/activitypub/keys.go
index 7dbddfc..9540668 100644
--- a/activitypub/keys.go
+++ b/activitypub/keys.go
@@ -1,61 +1,91 @@
 package activitypub
 
 import (
 	"crypto"
 	"crypto/rsa"
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
 	"github.com/writeas/openssl-go"
 	"log"
 )
 
 const keyBitSize = 2048
 
 // GenerateKeys creates an RSA keypair and returns the public and private key,
 // in that order.
 func GenerateKeys() (pubPEM []byte, privPEM []byte) {
 	var err error
 	privPEM, err = openssl.Call(nil, "genrsa", fmt.Sprintf("%d", keyBitSize))
 	if err != nil {
 		log.Printf("Unable to generate private key: %v", err)
 		return nil, nil
 	}
 
 	pubPEM, err = openssl.Call(privPEM, "rsa", "-in", "/dev/stdin", "-pubout")
 	if err != nil {
 		log.Printf("Unable to get public key: %v", err)
 		return nil, nil
 	}
 	return
 }
 
 func parsePrivateKey(der []byte) (crypto.PrivateKey, error) {
 	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
 		return key, nil
 	}
 	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
 		switch key := key.(type) {
 		case *rsa.PrivateKey:
 			return key, nil
 		default:
 			return nil, fmt.Errorf("found unknown private key type in PKCS#8 wrapping")
 		}
 	}
 	if key, err := x509.ParseECPrivateKey(der); err == nil {
 		return key, nil
 	}
 
 	return nil, fmt.Errorf("failed to parse private key")
 }
 
+func parsePublicKey(der []byte) (crypto.PublicKey, error) {
+	if key, err := x509.ParsePKCS1PublicKey(der); err == nil {
+		return key, nil
+	}
+	if key, err := x509.ParsePKIXPublicKey(der); err == nil {
+		switch key := key.(type) {
+		case *rsa.PublicKey:
+			return key, nil
+		default:
+			return nil, fmt.Errorf("found unknown public key type in PKIX wrapping")
+		}
+	}
+
+	return nil, fmt.Errorf("failed to parse public key")
+}
+
 // DecodePrivateKey encodes public and private key to PEM format, returning
 // them in that order.
 func DecodePrivateKey(k []byte) (crypto.PrivateKey, error) {
 	block, _ := pem.Decode(k)
 	if block == nil || block.Type != "RSA PRIVATE KEY" {
 		return nil, fmt.Errorf("failed to decode PEM block containing private key")
 	}
 
 	return parsePrivateKey(block.Bytes)
 }
+
+// DecodePublicKey decodes public keys
+func DecodePublicKey(k []byte) (crypto.PublicKey, error) {
+	block, _ := pem.Decode(k)
+	if block == nil || block.Type != "PUBLIC KEY" {
+		if block != nil {
+			return nil, fmt.Errorf("failed to decode PEM block containing public key. type: %v", block.Type)
+		} else {
+			return nil, fmt.Errorf("failed to decode PEM block containing public key.")
+		}
+	}
+
+	return parsePublicKey(block.Bytes)
+}