Initial commit

1 files changed, 64 insertions, 0 deletions

diff --git a/client/keys.go b/client/keys.go
new file mode 100644
index 0000000..4acfbb9
--- /dev/null
+++ b/client/keys.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"fmt"
+
+	"golang.org/x/crypto/ssh"
+)
+
+const (
+	rsaKey   = "rsa"
+	ecdsaKey = "ecdsa"
+)
+
+type key interface{}
+
+func generateRSAKey(bits int) (*rsa.PrivateKey, ssh.PublicKey, error) {
+	k, err := rsa.GenerateKey(rand.Reader, bits)
+	if err != nil {
+		return nil, nil, err
+	}
+	pub, err := ssh.NewPublicKey(&k.PublicKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	return k, pub, nil
+}
+
+func generateECDSAKey(bits int) (*ecdsa.PrivateKey, ssh.PublicKey, error) {
+	var curve elliptic.Curve
+	switch bits {
+	case 256:
+		curve = elliptic.P256()
+	case 384:
+		curve = elliptic.P384()
+	case 521:
+		curve = elliptic.P521()
+	default:
+		return nil, nil, fmt.Errorf("Unsupported key size. Valid sizes are '256', '384', '521'")
+	}
+	k, err := ecdsa.GenerateKey(curve, rand.Reader)
+	if err != nil {
+		return nil, nil, err
+	}
+	pub, err := ssh.NewPublicKey(&k.PublicKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	return k, pub, nil
+}
+
+func generateKey(keytype string, bits int) (key, ssh.PublicKey, error) {
+	switch keytype {
+	case rsaKey:
+		return generateRSAKey(bits)
+	case ecdsaKey:
+		return generateECDSAKey(bits)
+	default:
+		return nil, nil, fmt.Errorf("Unsupported key type %s. Valid choices are [%s, %s]", keytype, rsaKey, ecdsaKey)
+	}
+}