diff --git a/go.mod b/go.mod
index cd88f3b..093567b 100644
--- a/go.mod
+++ b/go.mod
@@ -1,22 +1,22 @@
 module github.com/luthersystems/lutherauth-sdk-go
 
-go 1.20
+go 1.21
 
 require (
 	github.com/golang-jwt/jwt/v4 v4.5.0
 	github.com/mendsley/gojwk v0.0.0-20141217222730-4d5ec6e58103
 	github.com/sirupsen/logrus v1.9.3
-	github.com/stretchr/testify v1.8.1
-	google.golang.org/grpc v1.57.0
+	github.com/stretchr/testify v1.8.4
+	google.golang.org/grpc v1.60.1
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/sys v0.11.0 // indirect
-	google.golang.org/genproto v0.0.0-20230803162519-f966b187b2e5 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20230807174057-1744710a1577 // indirect
+	golang.org/x/net v0.19.0 // indirect
+	golang.org/x/sys v0.15.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20231212172506-995d672761c0 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 993cefe..5b2d348 100644
--- a/go.sum
+++ b/go.sum
@@ -1,56 +1,38 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/golang-jwt/jwt/v4 v4.4.3 h1:Hxl6lhQFj4AnOX6MLrsCb/+7tCj7DxP7VA+2rDIq5AU=
-github.com/golang-jwt/jwt/v4 v4.4.3/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
 github.com/golang-jwt/jwt/v4 v4.5.0 h1:7cYmW1XlMY7h7ii7UhUyChSgS5wUJEnm9uZVTGqOWzg=
 github.com/golang-jwt/jwt/v4 v4.5.0/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw=
-github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
 github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/mendsley/gojwk v0.0.0-20141217222730-4d5ec6e58103 h1:Z/i1e+gTZrmcGeZyWckaLfucYG6KYOXLWo4co8pZYNY=
 github.com/mendsley/gojwk v0.0.0-20141217222730-4d5ec6e58103/go.mod h1:o9YPB5aGP8ob35Vy6+vyq3P3bWe7NQWzf+JLiXCiMaE=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sirupsen/logrus v1.9.0 h1:trlNQbNUG3OdDrDil03MCb1H2o9nJ1x4/5LYw7byDE0=
-github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-golang.org/x/net v0.5.0 h1:GyT4nK/YDHSqa1c4753ouYCDajOYKTja9Xb/OHtgvSw=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/net v0.19.0 h1:zTwKpTd2XuCqf8huc7Fo2iSy+4RHPd10s4KzeTnVr1c=
+golang.org/x/net v0.19.0/go.mod h1:CfAk/cbD4CthTvqiEl8NpboMuiuOYsAr/7NOjZJtv1U=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
-golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
-golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/text v0.6.0 h1:3XmdazWV+ubf7QgHSTWeykHOci5oeekaGJBLkrkaw4k=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f h1:BWUVssLB0HVOSY78gIdvk1dTVYtT1y8SBWtPYuTJ/6w=
-google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f/go.mod h1:RGgjbofJ8xD9Sq1VVhDM1Vok1vRONV+rg+CjzG4SZKM=
-google.golang.org/genproto v0.0.0-20230803162519-f966b187b2e5 h1:L6iMMGrtzgHsWofoFcihmDEMYeDR9KN/ThbPWGrh++g=
-google.golang.org/genproto v0.0.0-20230803162519-f966b187b2e5/go.mod h1:oH/ZOT02u4kWEp7oYBGYFFkCdKS/uYR9Z7+0/xuuFp8=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20230807174057-1744710a1577 h1:wukfNtZmZUurLN/atp2hiIeTKn7QJWIQdHzqmsOnAOk=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20230807174057-1744710a1577/go.mod h1:+Bk1OCOj40wS2hwAMA+aCW9ypzm63QTBBHp6lQ3p+9M=
-google.golang.org/grpc v1.53.0 h1:LAv2ds7cmFV/XTS3XG1NneeENYrXGmorPxsBbptIjNc=
-google.golang.org/grpc v1.53.0/go.mod h1:OnIrk0ipVdj4N5d9IUoFUx72/VlD7+jUsHwZgwSMQpw=
-google.golang.org/grpc v1.57.0 h1:kfzNeI/klCGD2YPMUlaGNT3pxvYfga7smW3Vth8Zsiw=
-google.golang.org/grpc v1.57.0/go.mod h1:Sd+9RMTACXwmub0zcNY2c4arhtrbBYD1AUHI/dt16Mo=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20231212172506-995d672761c0 h1:/jFB8jK5R3Sq3i/lmeZO0cATSzFfZaJq1J2Euan3XKU=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20231212172506-995d672761c0/go.mod h1:FUoWkonphQm3RhTS+kOEhF8h0iDpm4tdXolVCeZ9KKA=
+google.golang.org/grpc v1.60.1 h1:26+wFr+cNqSGFcOXcabYC0lUVJVRa2Sb2ortSK7VrEU=
+google.golang.org/grpc v1.60.1/go.mod h1:OlCHIeLYqSSsLi6i49B5QGdzaMZK9+M7LXN2FKz4eGM=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
-google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
-google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
 google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
diff --git a/jwk/rs256.go b/jwk/rs256.go
index 32e2cab..c9a82d9 100644
--- a/jwk/rs256.go
+++ b/jwk/rs256.go
@@ -247,37 +247,39 @@ func (s *Settings) putKey(issuer string, kid string, key *rsa.PublicKey) {
 	s.cache.putKey(issuer, kid, key)
 }
 
+func newHTTPClient() *http.Client {
+	var netTransport = &http.Transport{
+		Dial: (&net.Dialer{
+			Timeout: 5 * time.Second,
+		}).Dial,
+		TLSHandshakeTimeout: 5 * time.Second,
+		Proxy:               http.ProxyFromEnvironment,
+	}
+	return &http.Client{
+		Timeout:   time.Second * 10,
+		Transport: netTransport,
+	}
+}
+
 func (s *Settings) retrieveWebKeys(issuer string) (*gojwk.Key, error) {
 	if issuer == "" {
 		return nil, fmt.Errorf("invalid issuer")
 	}
-	if s.retrieveWebKeysFn != nil {
-		return s.retrieveWebKeysFn(issuer)
+	if s.retrieveWebKeysFn == nil && s.issuerToWebKeyURLFn == nil {
+		return nil, fmt.Errorf("missing all web key fns")
 	}
 	if s.issuerToWebKeyURLFn == nil {
-		// nothing we can do...
-		return nil, fmt.Errorf("cannot map issuer to web key URL")
-	}
-	client := s.httpClient
-	if client == nil {
-		var netTransport = &http.Transport{
-			Dial: (&net.Dialer{
-				Timeout: 5 * time.Second,
-			}).Dial,
-			TLSHandshakeTimeout: 5 * time.Second,
-			Proxy:               http.ProxyFromEnvironment,
-		}
-		client = &http.Client{
-			Timeout:   time.Second * 10,
-			Transport: netTransport,
-		}
+		return s.retrieveWebKeysFn(issuer)
 	}
+
 	webKeyURL, err := s.issuerToWebKeyURLFn(issuer)
-	if err != nil {
-		return nil, err
+	if err != nil || webKeyURL == "" {
+		return s.retrieveWebKeysFn(issuer)
 	}
-	if webKeyURL == "" {
-		return nil, fmt.Errorf("missing web key URL")
+
+	client := s.httpClient
+	if client == nil {
+		client = newHTTPClient()
 	}
 
 	return retrieveWebKeys(client, webKeyURL)
@@ -327,8 +329,8 @@ func WithHardcodedKey(pubKey crypto.PublicKey, kid string) Option {
 }
 
 // WithRetrieveWebKeysFn allows specifying a custom function to retrieve keys.
-// If this function is specified, then it will override WithIssuerToWebKeyURL
-// option.
+// If this function is specified with WithIssuerWebKeyURL, then it will only be
+// called if WithIssuerWebKeyURL cannot resolve the URL.
 func WithRetrieveWebKeysFn(retrieveWebKeysFn func(issuer string) (*gojwk.Key, error)) Option {
 	return func(s *Settings) {
 		s.retrieveWebKeysFn = retrieveWebKeysFn
@@ -337,6 +339,7 @@ func WithRetrieveWebKeysFn(retrieveWebKeysFn func(issuer string) (*gojwk.Key, er
 
 // WithIssuerToWebKeyURL allows specifying a custom function to map an issuer id
 // to a URL that has keys (JWKS).
+// This function handler takes precedence over WithRetrieveWebKeysFn.
 func WithIssuerToWebKeyURL(issuerToWebKeyURLFn func(issuer string) (string, error)) Option {
 	return func(s *Settings) {
 		s.issuerToWebKeyURLFn = issuerToWebKeyURLFn