Move GetPublicKey to the shared `lib` package

3 files changed, 28 insertions, 4 deletions

diff --git a/lib/const.go b/lib/proto.go
index 1ba2749..f3d7115 100644
--- a/lib/const.go
+++ b/lib/proto.go
@@ -9,9 +9,7 @@ type SignRequest struct {
 }
 
 // SignResponse is sent by the server.
-// `Status' is "ok" or "error".
-// `Response' contains a signed certificate or an error message.
 type SignResponse struct {
-	Status   string `json:"status"`
-	Response string `json:"response"`
+	Status   string `json:"status"`   // Status will be "ok" or "error".
+	Response string `json:"response"` // Response will contain either the signed certificate or the error message.
 }
diff --git a/lib/util.go b/lib/util.go
new file mode 100644
index 0000000..b1c7b87
--- /dev/null
+++ b/lib/util.go
@@ -0,0 +1,10 @@
+package lib
+
+import "golang.org/x/crypto/ssh"
+
+// GetPublicKey marshals a ssh certificate to a string.
+func GetPublicKey(pub ssh.PublicKey) string {
+	marshaled := ssh.MarshalAuthorizedKey(pub)
+	// Strip trailing newline
+	return string(marshaled[:len(marshaled)-1])
+}
diff --git a/lib/util_test.go b/lib/util_test.go
new file mode 100644
index 0000000..9e89297
--- /dev/null
+++ b/lib/util_test.go
@@ -0,0 +1,16 @@
+package lib
+
+import (
+	"testing"
+
+	"github.com/nsheridan/cashier/testdata"
+	"golang.org/x/crypto/ssh"
+)
+
+func TestGetPublicKey(t *testing.T) {
+	t.Parallel()
+	c, _, _, _, _ := ssh.ParseAuthorizedKey(testdata.Cert)
+	if GetPublicKey(c.(*ssh.Certificate)) != string(testdata.Cert) {
+		t.Fail()
+	}
+}