2 files changed, 60 insertions, 1 deletions
diff --git a/lib/srp.go b/lib/srp.go
index 9fdd594..cdecc4f 100644
--- a/lib/srp.go
+++ b/lib/srp.go
@@ -30,7 +30,7 @@ import "math/big"
 
 // SRP Server.
 type SRPServer struct {
-	users []SRPUser
+	users []*SRPUser
 }
 
 // Registered user on the SRP server.
@@ -90,6 +90,16 @@ type SRPClientSession struct {
 	sk []byte
 }
 
+func (server *SRPServer) RegisterUser(user *SRPUser) error {
+	for _, u := range server.users {
+		if u.ident == user.ident {
+			return CPError{"user already registered"}
+		}
+	}
+	server.users = append(server.users, user)
+	return nil
+}
+
 func NewSRPUser(n, g, k, ident, pass string) (*SRPUser, error) {
 	var err error
 	var ok bool
diff --git a/lib/srp_test.go b/lib/srp_test.go
index edcc588..06d1a27 100644
--- a/lib/srp_test.go
+++ b/lib/srp_test.go
@@ -8,6 +8,55 @@ import (
 	"testing"
 )
 
+func TestSRPServerRegisterUser(t *testing.T) {
+	n := "7"
+	g := "2"
+	k := "3"
+
+	bobIdent := "bob@ricketyspace.net"
+	bobPass := "d59d6c93af0f37f272d924979"
+	bob, err := NewSRPUser(n, g, k, bobIdent, bobPass)
+
+	aliceIdent := "alice@ricketyspace.net"
+	alicePass := "5ae262bcfaf6b4de5a3edc9ae"
+	alice, err := NewSRPUser(n, g, k, aliceIdent, alicePass)
+
+	server := new(SRPServer)
+	err = server.RegisterUser(bob)
+	if err != nil {
+		t.Errorf("registering bob: %v", err)
+	}
+	if len(server.users) != 1 {
+		t.Errorf("server has %v users", len(server.users))
+	}
+	err = server.RegisterUser(alice)
+	if err != nil {
+		t.Errorf("registering alice: %v", err)
+	}
+	if len(server.users) != 2 {
+		t.Errorf("server has %v users", len(server.users))
+	}
+
+	err = server.RegisterUser(bob)
+	if err == nil {
+		t.Errorf("server registered bob again")
+		return
+	}
+	if err.Error() != "user already registered" {
+		t.Errorf("registration message: %v", err)
+		return
+	}
+	err = server.RegisterUser(alice)
+	if err == nil {
+		t.Errorf("server registered alice again")
+		return
+	}
+	if err.Error() != "user already registered" {
+		t.Errorf("registration message: %v", err)
+		return
+	}
+}
+
 func TestNewSRPUser(t *testing.T) {
 	n := StripSpaceChars(
 		`ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024