feat (config): add support for a http.RoundTripper (#137)

Add support for specifying an optional http.RoundTripper
for a provider config.  If specified the http
client will use the RoundTripper when making
requests to the provider.

oidc/config.go

@@ -12,6 +12,7 @@ import (
  "fmt"
  "hash"
  "hash/fnv"
+ "net/http"
  "net/url"
  "reflect"
  "runtime"
@@ -89,9 +90,15 @@ type Config struct {
 
  // ProviderCA is an optional CA certs (PEM encoded) to use when sending
  // requests to the provider. If you have a list of *x509.Certificates, then
- // see EncodeCertificates(...) to PEM encode them.
+ // see EncodeCertificates(...) to PEM encode them. Note: specifying both
+ // ProviderCA and RoundTripper is an error.
  ProviderCA string
 
+ // RoundTripper is an optional http.RoundTripper to use when sending requests
+ // to the provider. Note: specifying both ProviderCA and RoundTripper is an
+ // error.
+ RoundTripper http.RoundTripper
+
  // NowFunc is a time func that returns the current time.
  NowFunc func() time.Time `json:"-"`
 
@@ -118,6 +125,7 @@ func NewConfig(issuer string, clientID string, clientSecret ClientSecret, suppor
  SupportedSigningAlgs: supported,
  Scopes: opts.withScopes,
  ProviderCA: opts.withProviderCA,
+ RoundTripper: opts.withRoundTripper,
  Audiences: opts.withAudiences,
  NowFunc: opts.withNowFunc,
  AllowedRedirectURLs: allowedRedirectURLs,
@@ -168,6 +176,16 @@ func (c *Config) Hash() (uint64, error) {
  args = append(args, audiences...)
  args = append(args, redirects...)
 
+ if c.RoundTripper != nil {
+ v := reflect.ValueOf(c.RoundTripper)
+ switch {
+ case v.CanAddr():
+ args = append(args, v.Addr().String())
+ default:
+ args = append(args, v.String())
+ }
+ }
+
  if c.ProviderConfig != nil {
  args = append(
  args,
@@ -269,6 +287,9 @@ func (c *Config) Validate() error {
  return fmt.Errorf("%s: %w", op, ErrInvalidCACert)
  }
  }
+ if c.ProviderCA != "" && c.RoundTripper != nil {
+ return fmt.Errorf("%s: you cannot specify both a ProviderCA and RoundTripper: %w", op, ErrInvalidParameter)
+ }
 
  if c.ProviderConfig != nil {
  switch {
@@ -300,6 +321,7 @@ type configOptions struct {
  withProviderCA string
  withNowFunc func() time.Time
  withProviderConfig *ProviderConfig
+ withRoundTripper http.RoundTripper
 }
 
 // configDefaults is a handy way to get the defaults at runtime and
@@ -319,12 +341,14 @@ func getConfigOpts(opt ...Option) configOptions {
 }
 
 // WithProviderCA provides optional CA certs (PEM encoded) for the provider's
-// config. These certs will can be used when making http requests to the
+// config. These certs will be used when making http requests to the
 // provider.
 //
 // Valid for: Config
 //
 // See EncodeCertificates(...) to PEM encode a number of certs.
+//
+// Note: specifying both WithProviderCA and WithRoundTripper is a error.
 func WithProviderCA(cert string) Option {
  return func(o interface{}) {
  if o, ok := o.(*configOptions); ok {
@@ -333,6 +357,18 @@ func WithProviderCA(cert string) Option {
  }
 }
 
+// WithRoundTripper provides and optional RoundTripper for the provider's
+// config. This RoundTripper will be used when making http requests to the
+// provider. Note: specifying both WithProviderCA and WithRoundTripper is a
+// error.
+func WithRoundTripper(rt http.RoundTripper) Option {
+ return func(o interface{}) {
+ if o, ok := o.(*configOptions); ok {
+ o.withRoundTripper = rt
+ }
+ }
+}
+
 // EncodeCertificates will encode a number of x509 certificates to PEM. It will
 // help encode certs for use with the WithProviderCA(...) option.
 func EncodeCertificates(certs ...*x509.Certificate) (string, error) {

oidc/config_test.go

@@ -7,6 +7,7 @@ import (
  "crypto/x509"
  "errors"
  "fmt"
+ "net/http"
  "testing"
  "time"
 
@@ -44,6 +45,8 @@ func TestNewConfig(t *testing.T) {
  return time.Now().Add(-1 * time.Minute)
  }
 
+ testRt := newTestRoundTripper(t)
+
  type args struct {
  issuer string
  clientID string
@@ -61,7 +64,7 @@ func TestNewConfig(t *testing.T) {
  wantErrContains string
  }{
  {
- name: "valid-with-all-valid-opts",
+ name: "valid-with-all-valid-opts-except-with-round-tripper",
  args: args{
  issuer: "http://your_issuer/",
  clientID: "your_client_id",
@@ -103,6 +106,49 @@ func TestNewConfig(t *testing.T) {
  },
  },
  },
+ {
+ name: "with-round-tripper",
+ args: args{
+ issuer: "http://your_issuer/",
+ clientID: "your_client_id",
+ clientSecret: "your_client_secret",
+ supported: []Alg{RS512},
+ allowedRedirectURLs: []string{"http://your_redirect_url", "http://redirect_url_two", "http://redirect_url_three"},
+ opt: []Option{
+ WithAudiences("your_aud1", "your_aud2"),
+ WithScopes("email", "profile"),
+ WithRoundTripper(testRt),
+ WithNow(testNow),
+ WithProviderConfig(&ProviderConfig{
+ AuthURL: "https://auth-endpoint",
+ JWKSURL: "https://jwks-endpoint",
+ TokenURL: "https://token-endpoint",
+ UserInfoURL: "https://userinfo-endpoint",
+ }),
+ },
+ },
+ want: &Config{
+ Issuer: "http://your_issuer/",
+ ClientID: "your_client_id",
+ ClientSecret: "your_client_secret",
+ SupportedSigningAlgs: []Alg{RS512},
+ Audiences: []string{"your_aud1", "your_aud2"},
+ Scopes: []string{oidc.ScopeOpenID, "email", "profile"},
+ RoundTripper: testRt,
+ NowFunc: testNow,
+ AllowedRedirectURLs: []string{
+ "http://your_redirect_url",
+ "http://redirect_url_two",
+ "http://redirect_url_three",
+ },
+ ProviderConfig: &ProviderConfig{
+ AuthURL: "https://auth-endpoint",
+ JWKSURL: "https://jwks-endpoint",
+ TokenURL: "https://token-endpoint",
+ UserInfoURL: "https://userinfo-endpoint",
+ },
+ },
+ },
  {
  name: "missing-provider-config-auth-url",
  args: args{
@@ -282,6 +328,22 @@ func TestNewConfig(t *testing.T) {
  wantErr: true,
  wantIsErr: ErrInvalidCACert,
  },
+ {
+ name: "invalid-both-cert-and-round-tripper",
+ args: args{
+ issuer: "http://your_issuer/",
+ clientID: "your_client_id",
+ clientSecret: "your_client_secret",
+ supported: []Alg{RS512},
+ allowedRedirectURLs: []string{"http://your_redirect_url"},
+ opt: []Option{
+ WithProviderCA(testCaPem),
+ WithRoundTripper(testRt),
+ },
+ },
+ wantErr: true,
+ wantIsErr: ErrInvalidParameter,
+ },
  {
  name: "invalid-alg",
  args: args{
@@ -430,6 +492,7 @@ func TestConfig_Hash(t *testing.T) {
  require.NoError(t, err)
  return c
  }
+ testRt := newTestRoundTripper(t)
  tests := []struct {
  name string
  c1 *Config
@@ -473,6 +536,42 @@ func TestConfig_Hash(t *testing.T) {
  ),
  wantEqual: true,
  },
+ {
+ name: "equal-with-round-tripper",
+ c1: newCfg(
+ "https://www.alice.com",
+ "client-id", "client-secret",
+ []Alg{RS256},
+ []string{"www.alice.com/callback", "www.bob.com/callback"},
+ WithScopes("email", "profile"),
+ WithAudiences("alice.com", "bob.com"),
+ WithRoundTripper(testRt),
+ WithNow(time.Now),
+ WithProviderConfig(&ProviderConfig{
+ AuthURL: "https://auth-endpoint",
+ JWKSURL: "https://jwks-endpoint",
+ TokenURL: "https://token-endpoint",
+ UserInfoURL: "https://userinfo-endpoint",
+ }),
+ ),
+ c2: newCfg(
+ "https://www.alice.com",
+ "client-id", "client-secret",
+ []Alg{RS256},
+ []string{"www.bob.com/callback", "www.alice.com/callback"},
+ WithScopes("profile", "email"),
+ WithAudiences("bob.com", "alice.com"),
+ WithRoundTripper(testRt),
+ WithNow(time.Now),
+ WithProviderConfig(&ProviderConfig{
+ AuthURL: "https://auth-endpoint",
+ JWKSURL: "https://jwks-endpoint",
+ TokenURL: "https://token-endpoint",
+ UserInfoURL: "https://userinfo-endpoint",
+ }),
+ ),
+ wantEqual: true,
+ },
  {
  name: "diff-issuer",
  c1: newCfg(
@@ -664,6 +763,29 @@ func TestConfig_Hash(t *testing.T) {
  ),
  wantEqual: false,
  },
+ {
+ name: "diff-round-trippers",
+ c1: newCfg(
+ "https://www.alice.com",
+ "client-id", "client-secret",
+ []Alg{RS256},
+ []string{"www.alice.com/callback"},
+ WithScopes("email", "profile"),
+ WithAudiences("alice.com", "bob.com"),
+ WithRoundTripper(newTestRoundTripper(t)),
+ WithNow(time.Now),
+ ),
+ c2: newCfg(
+ "https://www.alice.com",
+ "client-id", "client-secret",
+ []Alg{RS256},
+ []string{"www.alice.com/callback"},
+ WithScopes("email", "profile"),
+ WithAudiences("alice.com", "bob.com"),
+ WithNow(time.Now),
+ ),
+ wantEqual: false,
+ },
  {
  name: "diff-now-func",
  c1: newCfg(
@@ -855,3 +977,20 @@ func TestConfig_Hash(t *testing.T) {
  })
  }
 }
+
+type testRoundTripper struct {
+ transport http.RoundTripper
+ called int
+}
+
+func newTestRoundTripper(t *testing.T) *testRoundTripper {
+ t.Helper()
+ return &testRoundTripper{
+ transport: http.DefaultTransport,
+ }
+}
+
+func (rt *testRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+ rt.called++
+ return rt.transport.RoundTrip(req)
+}

oidc/docs_test.go

@@ -95,7 +95,7 @@ func ExampleNewConfig() {
  fmt.Println(pc)
 
  // Output:
- // &{your_client_id [REDACTED: client secret] [openid] http://your_issuer/ [RS256] [http://your_redirect_url/callback] [] <nil> <nil>}
+ // &{your_client_id [REDACTED: client secret] [openid] http://your_issuer/ [RS256] [http://your_redirect_url/callback] [] <nil> <nil> <nil>}
 }
 
 func ExampleWithProviderConfig() {
@@ -120,7 +120,7 @@ func ExampleWithProviderConfig() {
  fmt.Println(string(val))
 
  // Output:
- // {"ClientID":"your_client_id","ClientSecret":"[REDACTED: client secret]","Scopes":["openid"],"Issuer":"https://your_issuer/","SupportedSigningAlgs":["RS256"],"AllowedRedirectURLs":["https://your_redirect_url/callback"],"Audiences":null,"ProviderCA":"","ProviderConfig":{"AuthURL":"https://your_issuer/authorize","TokenURL":"https://your_issuer/token","UserInfoURL":"https://your_issuer/userinfo","JWKSURL":"https://your_issuer/.well-known/jwks.json"}}
+ // {"ClientID":"your_client_id","ClientSecret":"[REDACTED: client secret]","Scopes":["openid"],"Issuer":"https://your_issuer/","SupportedSigningAlgs":["RS256"],"AllowedRedirectURLs":["https://your_redirect_url/callback"],"Audiences":null,"ProviderCA":"","RoundTripper":null,"ProviderConfig":{"AuthURL":"https://your_issuer/authorize","TokenURL":"https://your_issuer/token","UserInfoURL":"https://your_issuer/userinfo","JWKSURL":"https://your_issuer/.well-known/jwks.json"}}
 }
 
 func ExampleNewProvider() {

oidc/provider.go

@@ -635,17 +635,22 @@ func (p *Provider) HTTPClient() (*http.Client, error) {
  // to the same host. On the downside, this transport can leak file
  // descriptors over time, so we'll be sure to call
  // client.CloseIdleConnections() in the Provider.Done() to stave that off.
- tr := cleanhttp.DefaultPooledTransport()
+ var tr http.RoundTripper
 
- if p.config.ProviderCA != "" {
+ switch {
+ case p.config.RoundTripper != nil && p.config.ProviderCA != "":
+ return nil, fmt.Errorf("%s: you cannot specify config for both a ProviderCA and RoundTripper: %w", op, ErrInvalidParameter)
+ case p.config.ProviderCA != "":
  certPool := x509.NewCertPool()
  if ok := certPool.AppendCertsFromPEM([]byte(p.config.ProviderCA)); !ok {
  return nil, fmt.Errorf("%s: %w", op, ErrInvalidCACert)
  }
-
- tr.TLSClientConfig = &tls.Config{
+ tr = cleanhttp.DefaultPooledTransport()
+ tr.(*http.Transport).TLSClientConfig = &tls.Config{
  RootCAs: certPool,
  }
+ case p.config.RoundTripper != nil:
+ tr = p.config.RoundTripper
  }
 
  c := &http.Client{

oidc/provider_test.go

@@ -714,6 +714,31 @@ func TestHTTPClient(t *testing.T) {
  require.NoError(t, err)
  assert.Equal(t, c.Transport, p.client.Transport)
  })
+ t.Run("check-transport-with-round-tripper", func(t *testing.T) {
+ testRt := newTestRoundTripper(t)
+ p := &Provider{
+ config: &Config{
+ RoundTripper: testRt,
+ },
+ }
+ c, err := p.HTTPClient()
+ require.NoError(t, err)
+ assert.Equal(t, c.Transport, p.client.Transport)
+ })
+ t.Run("err-both-ca-and-round-trippe", func(t *testing.T) {
+ _, testCaPem := TestGenerateCA(t, []string{"localhost"})
+
+ p := &Provider{
+ config: &Config{
+ ProviderCA: testCaPem,
+ RoundTripper: newTestRoundTripper(t),
+ },
+ }
+ _, err := p.HTTPClient()
+ require.Error(t, err)
+ assert.ErrorIs(t, err, ErrInvalidParameter)
+ assert.ErrorContains(t, err, "you cannot specify config for both a ProviderCA and RoundTripper")
+ })
 }
 
 func TestProvider_UserInfo(t *testing.T) {