timoth-y/kicksware-api

package rest

import (
    "bytes"
    "crypto/md5"
    "crypto/rsa"
    "encoding/json"
    "errors"
    "io"
    "io/ioutil"
    "net/http"
    "strings"

    "github.com/golang/glog"

    "go.kicksware.com/api/shared/config"
    "go.kicksware.com/api/shared/core"
    "go.kicksware.com/api/shared/util"
)

type authService struct {
    publicKey *rsa.PublicKey
    authEndpoint string
    accessChecksum []byte
}

func NewAuthService(authConfig config.AuthConfig) core.AuthService {
    return &authService{
        util.GetPublicKey(authConfig.PublicKeyPath),
        authConfig.AuthEndpoint,
        getAccessChecksum(authConfig.AccessKey),
    }
}

func (s *authService) PublicKey() *rsa.PublicKey {
    return s.publicKey
}

func (s *authService) Authenticate() (string, error)  {
    resp, err := http.Get(s.guestEndpoint()); if err != nil {
        return "", errors.New("error has occurred in authenticating service: %q\", err")
    }
    defer resp.Body.Close()

    bytes, err := ioutil.ReadAll(resp.Body); if err != nil {
        return "", err
    }
    token := make(map[string]interface{})
    err = json.Unmarshal(bytes, &token); if err != nil {
        return "", err
    }
    return token["Token"].(string), nil
}

func (s *authService) AccessKey() []byte {
    return s.accessChecksum
}


func (s *authService) VerifyAccessKey(hash []byte) bool {
    ok := bytes.Equal(s.accessChecksum, hash)
    return ok
}

func getAccessChecksum(accessKey string) []byte {
    input := strings.NewReader(accessKey)
    hash := md5.New()
    if _, err := io.Copy(hash, input); err != nil {
        glog.Fatalln(err)
    }
    return hash.Sum(nil)
}

func (s *authService) guestEndpoint() string {
    req, err := http.NewRequest("GET", s.authEndpoint, nil); if err != nil {
        glog.Fatalf("error has occurred in core.AuthService.guestEndpoint(): %q", err)
        return ""
    }
    query := req.URL.Query()
    query.Add("access", string(s.accessChecksum))
    req.URL.RawQuery = query.Encode()
    return req.URL.String()
}