Allow noncer to be configured (#45)

* Add a Noncer interface to allow custom noncers
* Default to Base64Noncer (no change, recommended)
* Add HexNoncer for providers that don't accept non-alphanumeric nonces

auther.go

@@ -2,8 +2,6 @@ package oauth1
 
 import (
 	"bytes"
-	"crypto/rand"
-	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -38,19 +36,19 @@ type clock interface {
 	Now() time.Time
 }
 
-// A noncer provides random nonce strings.
-type noncer interface {
-	Nonce() string
-}
-
 // auther adds an "OAuth" Authorization header field to requests.
 type auther struct {
 	config *Config
 	clock  clock
-	noncer noncer
 }
 
 func newAuther(config *Config) *auther {
+	if config == nil {
+		config = &Config{}
+	}
+	if config.Noncer == nil {
+		config.Noncer = Base64Noncer{}
+	}
 	return &auther{
 		config: config,
 	}
@@ -135,14 +133,9 @@ func (a *auther) commonOAuthParams() map[string]string {
 	return params
 }
 
-// Returns a base64 encoded random 32 byte string.
+// Returns a nonce using the configured Noncer.
 func (a *auther) nonce() string {
-	if a.noncer != nil {
-		return a.noncer.Nonce()
-	}
-	b := make([]byte, 32)
-	rand.Read(b)
-	return base64.StdEncoding.EncodeToString(b)
+	return a.config.Noncer.Nonce()
 }
 
 // Returns the Unix epoch seconds.

auther_test.go

@@ -17,9 +17,11 @@ func TestCommonOAuthParams(t *testing.T) {
 	}{
 		{
 			&auther{
-				&Config{ConsumerKey: "some_consumer_key"},
+				&Config{
+					ConsumerKey: "some_consumer_key",
+					Noncer:      &fixedNoncer{"some_nonce"},
+				},
 				&fixedClock{time.Unix(50037133, 0)},
-				&fixedNoncer{"some_nonce"},
 			},
 			map[string]string{
 				"oauth_consumer_key":     "some_consumer_key",
@@ -31,9 +33,12 @@ func TestCommonOAuthParams(t *testing.T) {
 		},
 		{
 			&auther{
-				&Config{ConsumerKey: "some_consumer_key", Realm: "photos"},
+				&Config{
+					ConsumerKey: "some_consumer_key",
+					Realm:       "photos",
+					Noncer:      &fixedNoncer{"some_nonce"},
+				},
 				&fixedClock{time.Unix(50037133, 0)},
-				&fixedNoncer{"some_nonce"},
 			},
 			map[string]string{
 				"oauth_consumer_key":     "some_consumer_key",
@@ -52,7 +57,7 @@ func TestCommonOAuthParams(t *testing.T) {
 }
 
 func TestNonce(t *testing.T) {
-	auther := &auther{}
+	auther := newAuther(nil)
 	nonce := auther.nonce()
 	// assert that 32 bytes (256 bites) become 44 bytes since a base64 byte
 	// zeros the 2 high bits. 3 bytes convert to 4 base64 bytes, 40 base64 bytes
@@ -62,7 +67,7 @@ func TestNonce(t *testing.T) {
 }
 
 func TestEpoch(t *testing.T) {
-	a := &auther{}
+	a := newAuther(nil)
 	// assert that a real time is used by default
 	assert.InEpsilon(t, time.Now().Unix(), a.epoch(), 1)
 	// assert that the fixed clock can be used for testing

config.go

@@ -29,6 +29,8 @@ type Config struct {
 	Realm string
 	// OAuth1 Signer (defaults to HMAC-SHA1)
 	Signer Signer
+	// Noncer creates request nonces (defaults to DefaultNoncer)
+	Noncer Noncer
 }
 
 // NewConfig returns a new Config with the given consumer key and secret.

noncer.go

@@ -0,0 +1,34 @@
+package oauth1
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/hex"
+)
+
+// Noncer provides random nonce strings.
+type Noncer interface {
+	Nonce() string
+}
+
+// Base64Noncer reads 32 bytes from crypto/rand and
+// returns those bytes as a base64 encoded string.
+type Base64Noncer struct{}
+
+// Nonce provides a random nonce string.
+func (n Base64Noncer) Nonce() string {
+	b := make([]byte, 32)
+	rand.Read(b)
+	return base64.StdEncoding.EncodeToString(b)
+}
+
+// HexNoncer reads 32 bytes from crypto/rand and
+// returns those bytes as a base64 encoded string.
+type HexNoncer struct{}
+
+// Nonce provides a random nonce string.
+func (n HexNoncer) Nonce() string {
+	b := make([]byte, 32)
+	rand.Read(b)
+	return hex.EncodeToString(b)
+}

reference_test.go

@@ -33,9 +33,10 @@ func TestTwitterRequestTokenAuthHeader(t *testing.T) {
 			AuthorizeURL:    "https://api.twitter.com/oauth/authorize",
 			AccessTokenURL:  "https://api.twitter.com/oauth/access_token",
 		},
+		Noncer: &fixedNoncer{expectedNonce},
 	}
 
-	auther := &auther{config, &fixedClock{time.Unix(unixTimestamp, 0)}, &fixedNoncer{expectedNonce}}
+	auther := &auther{config, &fixedClock{time.Unix(unixTimestamp, 0)}}
 	req, err := http.NewRequest("POST", config.Endpoint.RequestTokenURL, nil)
 	assert.Nil(t, err)
 	err = auther.setRequestTokenAuthHeader(req)
@@ -70,9 +71,10 @@ func TestTwitterAccessTokenAuthHeader(t *testing.T) {
 			AuthorizeURL:    "https://api.twitter.com/oauth/authorize",
 			AccessTokenURL:  "https://api.twitter.com/oauth/access_token",
 		},
+		Noncer: &fixedNoncer{expectedNonce},
 	}
 
-	auther := &auther{config, &fixedClock{time.Unix(unixTimestamp, 0)}, &fixedNoncer{expectedNonce}}
+	auther := &auther{config, &fixedClock{time.Unix(unixTimestamp, 0)}}
 	req, err := http.NewRequest("POST", config.Endpoint.AccessTokenURL, nil)
 	assert.Nil(t, err)
 	err = auther.setAccessTokenAuthHeader(req, expectedRequestToken, requestTokenSecret, expectedVerifier)
@@ -105,10 +107,11 @@ var twitterConfig = &Config{
 		AuthorizeURL:    "https://api.twitter.com/oauth/authorize",
 		AccessTokenURL:  "https://api.twitter.com/oauth/access_token",
 	},
+	Noncer: &fixedNoncer{expectedNonce},
 }
 
 func TestTwitterParameterString(t *testing.T) {
-	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}, &fixedNoncer{expectedNonce}}
+	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}}
 	values := url.Values{}
 	values.Add("status", "Hello Ladies + Gentlemen, a signed OAuth request!")
 	// note: the reference example is old and uses api v1 in the URL
@@ -125,7 +128,7 @@ func TestTwitterParameterString(t *testing.T) {
 }
 
 func TestTwitterSignatureBase(t *testing.T) {
-	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}, &fixedNoncer{expectedNonce}}
+	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}}
 	values := url.Values{}
 	values.Add("status", "Hello Ladies + Gentlemen, a signed OAuth request!")
 	// note: the reference example is old and uses api v1 in the URL
@@ -148,7 +151,7 @@ func TestTwitterRequestAuthHeader(t *testing.T) {
 	expectedSignature := PercentEncode("tnnArxj06cWHq44gCs1OSKk/jLY=")
 	expectedTimestamp := "1318622958"
 
-	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}, &fixedNoncer{expectedNonce}}
+	auther := &auther{twitterConfig, &fixedClock{time.Unix(unixTimestampOfRequest, 0)}}
 	values := url.Values{}
 	values.Add("status", "Hello Ladies + Gentlemen, a signed OAuth request!")
 

transport_test.go

@@ -32,11 +32,11 @@ func TestTransport(t *testing.T) {
 	config := &Config{
 		ConsumerKey:    expectedConsumerKey,
 		ConsumerSecret: "consumer_secret",
+		Noncer:         &fixedNoncer{expectedNonce},
 	}
 	auther := &auther{
 		config: config,
 		clock:  &fixedClock{time.Unix(123456789, 0)},
-		noncer: &fixedNoncer{expectedNonce},
 	}
 	tr := &Transport{
 		source: StaticTokenSource(NewToken(expectedToken, "some_secret")),
@@ -69,9 +69,8 @@ func TestTransport_nilSource(t *testing.T) {
 	tr := &Transport{
 		source: nil,
 		auther: &auther{
-			config: &Config{},
+			config: &Config{Noncer: &fixedNoncer{"any_nonce"}},
 			clock:  &fixedClock{time.Unix(123456789, 0)},
-			noncer: &fixedNoncer{"any_nonce"},
 		},
 	}
 	client := &http.Client{Transport: tr}
@@ -86,9 +85,8 @@ func TestTransport_emptySource(t *testing.T) {
 	tr := &Transport{
 		source: StaticTokenSource(nil),
 		auther: &auther{
-			config: &Config{},
+			config: &Config{Noncer: &fixedNoncer{"any_nonce"}},
 			clock:  &fixedClock{time.Unix(123456789, 0)},
-			noncer: &fixedNoncer{"any_nonce"},
 		},
 	}
 	client := &http.Client{Transport: tr}