Merge branch 'master' of github.com:stellar/gateway-server

Author: bartekn

src/github.com/stellar/gateway/handlers/address_resolver.go

@@ -0,0 +1,100 @@
+package handlers
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/BurntSushi/toml"
+)
+
+type StellarToml struct {
+	FederationServer *string `toml:"FEDERATION_SERVER"`
+}
+
+type StellarDestination struct {
+	AccountId string  `json:"account_id"`
+	MemoType  *string `json:"memo_type"`
+	Memo      *string `json:"memo"`
+}
+
+type AddressResolverHelperInterface interface {
+	GetStellarToml(domain string) (stellarToml StellarToml, err error)
+	GetDestination(federationUrl, address string) (destination StellarDestination, err error)
+}
+
+type AddressResolver struct {
+	helper AddressResolverHelperInterface
+}
+
+func (ar AddressResolver) Resolve(address string) (destination StellarDestination, err error) {
+	tokens := strings.Split(address, "*")
+	if len(tokens) == 1 {
+		destination.AccountId = address
+	} else if len(tokens) == 2 {
+		var stellarToml StellarToml
+		stellarToml, err = ar.helper.GetStellarToml(tokens[1])
+		if err != nil {
+			return
+		}
+
+		if stellarToml.FederationServer == nil {
+			err = errors.New("stellar.toml does not contain FEDERATION_SERVER value")
+			return
+		}
+
+		destination, err = ar.helper.GetDestination(*stellarToml.FederationServer, address)
+		return
+	} else {
+		err = errors.New("Malformed Stellar address")
+	}
+
+	return
+}
+
+type AddressResolverHelper struct{}
+
+func (ar AddressResolverHelper) GetStellarToml(domain string) (stellarToml StellarToml, err error) {
+	var resp *http.Response
+	resp, err = http.Get("https://www." + domain + "/.well-known/stellar.toml")
+	if err != nil {
+		return
+	}
+	if resp.StatusCode != 200 {
+		err = errors.New("stellar.toml response status code indicates error")
+		return
+	}
+
+	_, err = toml.DecodeReader(resp.Body, &stellarToml)
+	return
+}
+
+func (ar AddressResolverHelper) GetDestination(federationUrl, address string) (destination StellarDestination, err error) {
+	if !strings.HasPrefix(federationUrl, "https://") {
+		err = errors.New("Only HTTPS federation servers allowed")
+		return
+	}
+
+	resp, err := http.Get(federationUrl + "?type=name&q=" + address)
+	if err != nil {
+		return
+	}
+	if resp.StatusCode != 200 {
+		err = errors.New("Federation response status code indicates error")
+		return
+	}
+
+	var bs []byte
+	bs, err = ioutil.ReadAll(resp.Body)
+	err = json.Unmarshal(bs, &destination)
+	if err != nil {
+		return
+	}
+
+	if (destination.MemoType != nil) && (destination.Memo == nil) {
+		err = errors.New("Invalid federation response (memo).")
+	}
+	return
+}