Add support for validating a sip uri in the From and To fields

Add ParsedNumber to provide details about different types of To and From values including SIP URI's

Author: jtwatson

request.go

@@ -9,9 +9,11 @@ import (
 	"net/http"
 	"sort"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/pkg/errors"
+	"github.com/ttacon/libphonenumber"
 	"go.opencensus.io/trace"
 )
 
@@ -54,6 +56,76 @@ func (r RequestValues) TimestampOrNow() time.Time {
 	return t
 }
 
+// From returns a Number parsed from the raw From value
+func (r RequestValues) From() *ParsedNumber {
+	return ParseNumber(r["From"])
+}
+
+// To returns a Number parsed from the raw To value
+func (r RequestValues) To() *ParsedNumber {
+	return ParseNumber(r["To"])
+}
+
+// ParseNumber parses ether a E164 number or a SIP URI returning a ParsedNumber
+func ParseNumber(v string) *ParsedNumber {
+	number := &ParsedNumber{
+		Number: v,
+		Raw:    v,
+	}
+
+	if err := validPhoneNumber(v, ""); err == nil {
+		number.Valid = true
+		return number
+	}
+
+	u, err := parseSipURI(v)
+	if err != nil {
+		return number
+	}
+
+	parts := strings.Split(u.Hostname(), ".")
+	l := len(parts)
+
+	if l < 5 || strings.Join(parts[l-2:], ".") != "twilio.com" || parts[l-4] != "sip" {
+		return number
+	}
+
+	num, err := FormatNumber(u.User.Username())
+	if err != nil {
+		return number
+	}
+
+	number.Valid = true
+	number.Sip = true
+	number.Number = num
+	number.SipDomain = strings.Join(parts[:l-4], ".")
+	number.Region = parts[l-4]
+
+	return number
+}
+
+type ParsedNumber struct {
+	Valid     bool
+	Number    string
+	Sip       bool
+	SipDomain string
+	Region    string
+	Raw       string
+}
+
+// FormatNumber formates a number to E164 format
+func FormatNumber(number string) (string, error) {
+	num, err := libphonenumber.Parse(number, "US")
+	if err != nil {
+		return number, errors.WithMessagef(errors.New("Invalid phone number"), "twiml.FormatNumber(): %s", err)
+	}
+	if !libphonenumber.IsValidNumber(num) {
+		return number, errors.WithMessage(errors.New("Invalid phone number"), "twiml.FormatNumber()")
+	}
+
+	return libphonenumber.Format(num, libphonenumber.E164), nil
+}
+
 // Request is a twillio request expecting a TwiML response
 type Request struct {
 	host   string
@@ -75,7 +147,7 @@ func (req *Request) ValidatePost(ctx context.Context, authToken string) error {
 	span.AddAttributes(trace.StringAttribute("url", url))
 
 	if req.r.Method != "POST" {
-		return fmt.Errorf("twiml.Request.ValidatePost(): Expected a POST request, received %s", req.r.Method)
+		return errors.WithMessage(fmt.Errorf("Expected a POST request, received %s", req.r.Method), "twiml.Request.ValidatePost()")
 	}
 
 	if err := req.r.ParseForm(); err != nil {
@@ -86,7 +158,7 @@ func (req *Request) ValidatePost(ctx context.Context, authToken string) error {
 	for p := range req.r.PostForm {
 		params = append(params, p)
 	}
-	sort.Sort(sort.StringSlice(params))
+	sort.Strings(params)
 
 	message := url
 	for _, p := range params {
@@ -110,7 +182,7 @@ func (req *Request) ValidatePost(ctx context.Context, authToken string) error {
 		if len(xTwilioSigHdr) == 1 {
 			xTwilioSig = xTwilioSigHdr[0]
 		}
-		return fmt.Errorf("twiml.Request.ValidatePost(): Calculated Signature: %s, failed to match X-Twilio-Signature: %s", sig, xTwilioSig)
+		return errors.WithMessage(fmt.Errorf("Calculated Signature: %s, failed to match X-Twilio-Signature: %s", sig, xTwilioSig), "twiml.Request.ValidatePost()")
 	}
 
 	// Validate data
@@ -121,7 +193,7 @@ func (req *Request) ValidatePost(ctx context.Context, authToken string) error {
 		}
 		if valParam, ok := fieldValidators[p]; ok {
 			if err := valParam.valFunc(val, valParam.valParam); err != nil {
-				return fmt.Errorf("twiml.Request.ValidatePost(): Invalid form value: %s=%s, err: %s", p, val, err)
+				return errors.WithMessage(fmt.Errorf("Invalid form value: %s=%s, err: %s", p, val, err), "twiml.Request.ValidatePost()")
 			}
 		}
 		req.Values[p] = val
@@ -138,8 +210,8 @@ type valCfg struct {
 var fieldValidators = map[string]valCfg{
 	// "CallSid":       "CallSid",
 	// "AccountSid":    "AccountSid",
-	"From": valCfg{valFunc: validPhoneNumber},
-	"To":   valCfg{valFunc: validPhoneNumber},
+	"From": valCfg{valFunc: validFromOrTo},
+	"To":   valCfg{valFunc: validFromOrTo},
 	// "CallStatus":    "CallStatus",
 	// "ApiVersion":    "ApiVersion",
 	// "ForwardedFrom": "ForwardedFrom",

request_test.go

@@ -1,6 +1,9 @@
 package twiml
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestRequestValues_Duration(t *testing.T) {
 	tests := []struct {
@@ -25,3 +28,28 @@ func TestRequestValues_Duration(t *testing.T) {
 		})
 	}
 }
+
+func TestParseNumber(t *testing.T) {
+	type args struct {
+		v string
+	}
+	tests := []struct {
+		name string
+		args args
+		want *ParsedNumber
+	}{
+		{name: "Valid Number", args: args{v: "+18005642365"}, want: &ParsedNumber{Valid: true, Number: "+18005642365", Raw: "+18005642365"}},
+		{name: "Valid SIP us1", args: args{v: "sips:[email protected]:5061"}, want: &ParsedNumber{Valid: true, Number: "+18005642365", Sip: true, SipDomain: "domain", Region: "sip", Raw: "sips:[email protected]:5061"}},
+		{name: "Valid SIP us2", args: args{v: "sips:[email protected]:5061"}, want: &ParsedNumber{Valid: true, Number: "+18005642365", Sip: true, SipDomain: "domain", Region: "sip", Raw: "sips:[email protected]:5061"}},
+		{name: "Invalid SIP sip.domain.com", args: args{v: "sips:[email protected]:5061"}, want: &ParsedNumber{Number: "sips:[email protected]:5061", Raw: "sips:[email protected]:5061"}},
+		{name: "Invalid SIP sip2.twilio.com", args: args{v: "sips:[email protected]:5061"}, want: &ParsedNumber{Number: "sips:[email protected]:5061", Raw: "sips:[email protected]:5061"}},
+		{name: "Invalid SIP twilio.com", args: args{v: "sips:[email protected]:5061"}, want: &ParsedNumber{Number: "sips:[email protected]:5061", Raw: "sips:[email protected]:5061"}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ParseNumber(tt.args.v); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("ParseNumber() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

validators.go

@@ -3,11 +3,27 @@ package twiml
 import (
 	"errors"
 	"fmt"
+	"net/url"
 	"strings"
 
 	"github.com/ttacon/libphonenumber"
 )
 
+// validFromOrTo checks that a valid phone number or sip uri is provided
+// param of "allowempty" will allow a nil value
+func validFromOrTo(v interface{}, param string) error {
+	err := validPhoneNumber(v, param)
+	if err == nil {
+		return nil
+	}
+
+	if err := validSipURI(v, param); err == nil {
+		return nil
+	}
+
+	return err
+}
+
 // validPhoneNumber checks that a valid phone number is provided
 // param of "allowempty" will allow a nil value
 func validPhoneNumber(v interface{}, param string) error {
@@ -29,7 +45,7 @@ func validPhoneNumber(v interface{}, param string) error {
 		}
 		return validatePhoneNumber(*num)
 	default:
-		return fmt.Errorf("validDatastoreKey: Unexpected type %T", num)
+		return fmt.Errorf("validPhoneNumber: Unexpected type %T", num)
 	}
 }
 
@@ -63,7 +79,7 @@ func validateKeyPadEntry(v interface{}, param string) error {
 		}
 		return validateNumericPoundStar(*num)
 	default:
-		return fmt.Errorf("validDatastoreKey: Unexpected type %T", num)
+		return fmt.Errorf("validateKeyPadEntry: Unexpected type %T", num)
 	}
 }
 
@@ -75,9 +91,73 @@ func validateNumericPoundStar(v string) error {
 // returns an erro if a character is found which is not in charList
 func characterList(s string, charList string) error {
 	for _, c := range s {
-		if strings.Index(charList, string(c)) == -1 {
+		if !strings.Contains(charList, string(c)) {
 			return fmt.Errorf("Invalid: character '%s' is not allowed", string(c))
 		}
 	}
 	return nil
 }
+
+// validSipURI checks that a valid sip uri is provided
+// param of "allowempty" will allow a nil value
+func validSipURI(v interface{}, param string) error {
+	switch num := v.(type) {
+	case string:
+		if num == "" {
+			if param == "allowempty" {
+				return nil
+			}
+			return errors.New("Required")
+		}
+		_, err := parseSipURI(num)
+		return err
+	case *string:
+		if num == nil {
+			if param == "allowempty" {
+				return nil
+			}
+			return errors.New("Required")
+		}
+		_, err := parseSipURI(*num)
+		return err
+	default:
+		return fmt.Errorf("validPhoneNumber: Unexpected type %T", num)
+	}
+}
+
+func parseSipURI(uri string) (*url.URL, error) {
+	uri = strings.ToLower(uri)
+
+	if !strings.HasPrefix(uri, "sip") {
+		return nil, errors.New("Invalid SIP URI")
+	}
+
+	// Insert the // after the Schema to enable full parsing and avoid Opaque
+	if strings.HasPrefix(uri, "sips:") {
+		uri = strings.Replace(uri, "sips:", "sips://", 1)
+	} else if strings.HasPrefix(uri, "sip:") {
+		uri = strings.Replace(uri, "sip:", "sip://", 1)
+	}
+
+	u, err := url.Parse(uri)
+	if err != nil {
+		return nil, errors.New("Invalid SIP URI")
+	}
+
+	// Schema should be valid
+	if u.Scheme != "sip" && u.Scheme != "sips" {
+		return u, errors.New("Invalid SIP URI")
+	}
+
+	// Path and Opaque should be empty
+	if u.Path != "" || u.Opaque != "" {
+		return u, errors.New("Invalid SIP URI")
+	}
+
+	// Host and User should be provided
+	if u.Host == "" || u.User.String() == "" {
+		return u, errors.New("Invalid SIP URI")
+	}
+
+	return u, nil
+}

validators_test.go

@@ -0,0 +1,29 @@
+package twiml
+
+import "testing"
+
+func Test_validSipURI(t *testing.T) {
+	type args struct {
+		v     interface{}
+		param string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{name: "Valid SIPS URI", args: args{v: "sips:[email protected]:5061", param: ""}, wantErr: false},
+		{name: "Valid SIP  URI", args: args{v: "sip:[email protected]:5061", param: ""}, wantErr: false},
+		{name: "Valid", args: args{v: "", param: "allowempty"}, wantErr: false},
+		{name: "Invaid", args: args{v: "", param: ""}, wantErr: true},
+		{name: "Invalid SIP URI", args: args{v: "+18002368945", param: ""}, wantErr: true},
+		{name: "Invalid URL", args: args{v: "https://[email protected]:5061", param: ""}, wantErr: true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := validSipURI(tt.args.v, tt.args.param); (err != nil) != tt.wantErr {
+				t.Errorf("validSipURI() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}