internal/config: refactor option parsing

- authorize: build whitelist from policy's URLs instead of strings.
- internal/httputil: merged httputil and https package.
- internal/config: merged config and policy packages.
- internal/metrics: removed unused measure struct.
- proxy/clients: refactor Addr fields to be urls.
- proxy: remove unused extend deadline function.
- proxy: use handler middleware for reverse proxy leg.
- proxy: change the way websocket requests are made (route based).

General improvements
- omitted value from range in several cases where for loop could be simplified.
- added error checking to many tests.
- standardize url parsing.
- remove unnecessary return statements.

- proxy: add self-signed certificate support. #179
- proxy: add skip tls certificate verification. #179
- proxy: Refactor websocket support to be route based. #204

internal/cryptutil/encrypt.go

@@ -13,14 +13,32 @@ import (
 	"golang.org/x/crypto/chacha20poly1305"
 )
 
+const DefaultKeySize = 32
+
 // GenerateKey generates a random 32-byte key.
+//
 // Panics if source of randomness fails.
 func GenerateKey() []byte {
-	key := make([]byte, 32)
-	if _, err := rand.Read(key); err != nil {
+	return randomBytes(DefaultKeySize)
+}
+
+// GenerateRandomString returns base64 encoded securely generated random string
+// of a given set of bytes.
+//
+// Panics if source of randomness fails.
+func GenerateRandomString(c int) string {
+	return base64.StdEncoding.EncodeToString(randomBytes(c))
+}
+
+func randomBytes(c int) []byte {
+	if c < 0 {
+		c = DefaultKeySize
+	}
+	b := make([]byte, c)
+	if _, err := rand.Read(b); err != nil {
 		panic(err)
 	}
-	return key
+	return b
 }
 
 // Cipher provides methods to encrypt and decrypt values.

internal/cryptutil/encrypt_test.go

@@ -1,8 +1,9 @@
-package cryptutil // import "github.com/pomerium/pomerium/internal/cryptutil"
+package cryptutil
 
 import (
 	"crypto/rand"
 	"crypto/sha1"
+	"encoding/base64"
 	"fmt"
 	"reflect"
 	"sync"
@@ -162,3 +163,29 @@ func TestCipherDataRace(t *testing.T) {
 	}
 	wg.Wait()
 }
+
+func TestGenerateRandomString(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name string
+		c    int
+		want int
+	}{
+		{"simple", 32, 32},
+		{"zero", 0, 0},
+		{"negative", -1, 32},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			o := GenerateRandomString(tt.c)
+			b, err := base64.StdEncoding.DecodeString(o)
+			if err != nil {
+				t.Error(err)
+			}
+			got := len(b)
+			if got != tt.want {
+				t.Errorf("GenerateRandomString() = %d, want %d", got, tt.want)
+			}
+		})
+	}
+}