CORS support (#73)

This adds per-listener CORS support. Logic is ported from Vault, along with a fully new test suite.

internal/cmd/config/config.go

@@ -40,6 +40,8 @@ listener "tcp" {
 	tls_disable = true
 	proxy_protocol_behavior = "allow_authorized"
 	proxy_protocol_authorized_addrs = "127.0.0.1"
+	cors_enabled = true
+	cors_allowed_origins = ["*"]
 }
 
 listener "tcp" {

internal/cmd/config/config_test.go

@@ -0,0 +1,78 @@
+package config
+
+import (
+	"testing"
+	"time"
+
+	"github.com/hashicorp/go-sockaddr"
+	"github.com/hashicorp/vault/internalshared/configutil"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDevController(t *testing.T) {
+	actual, err := DevController()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	addr, err := sockaddr.NewIPAddr("127.0.0.1")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	exp := &Config{
+		SharedConfig: &configutil.SharedConfig{
+			DisableMlock: true,
+			Listeners: []*configutil.Listener{
+				{
+					Type:                  "tcp",
+					Purpose:               []string{"api"},
+					TLSDisable:            true,
+					ProxyProtocolBehavior: "allow_authorized",
+					ProxyProtocolAuthorizedAddrs: []*sockaddr.SockAddrMarshaler{
+						{SockAddr: addr},
+					},
+					CorsEnabled:        true,
+					CorsAllowedOrigins: []string{"*"},
+				},
+				{
+					Type:                  "tcp",
+					Purpose:               []string{"cluster"},
+					TLSDisable:            true,
+					ProxyProtocolBehavior: "allow_authorized",
+					ProxyProtocolAuthorizedAddrs: []*sockaddr.SockAddrMarshaler{
+						{SockAddr: addr},
+					},
+				},
+			},
+			Seals: []*configutil.KMS{
+				{
+					Type:    "aead",
+					Purpose: []string{"controller"},
+					Config: map[string]string{
+						"aead_type": "aes-gcm",
+					},
+				},
+				{
+					Type:    "aead",
+					Purpose: []string{"worker-auth"},
+					Config: map[string]string{
+						"aead_type": "aes-gcm",
+					},
+				},
+			},
+			Telemetry: &configutil.Telemetry{
+				DisableHostname:         true,
+				PrometheusRetentionTime: time.Hour * 24,
+			},
+		},
+		DevController: true,
+	}
+
+	exp.Listeners[0].RawConfig = actual.Listeners[0].RawConfig
+	exp.Listeners[1].RawConfig = actual.Listeners[1].RawConfig
+	exp.Seals[0].Config["key"] = actual.Seals[0].Config["key"]
+	exp.Seals[1].Config["key"] = actual.Seals[1].Config["key"]
+
+	assert.Equal(t, exp, actual)
+}