Implemented jwt generation

Gopkg.lock

@@ -1,6 +1,12 @@
 # This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
 
 
+[[projects]]
+  name = "github.com/SermoDigital/jose"
+  packages = [".","crypto","jws","jwt"]
+  revision = "f6df55f235c24f236d11dbcf665249a59ac2021f"
+  version = "1.1"
+
 [[projects]]
   name = "github.com/assembla/cony"
   packages = ["."]
@@ -55,6 +61,12 @@
   packages = [".","hcl/ast","hcl/parser","hcl/scanner","hcl/strconv","hcl/token","json/parser","json/scanner","json/token"]
   revision = "8f6b1344a92ff8877cf24a5de9177bf7d0a2a187"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/howeyc/gopass"
+  packages = ["."]
+  revision = "bf9dde6d0d2c004a008c27aaee91170c786f6db8"
+
 [[projects]]
   name = "github.com/inconshreveable/mousetrap"
   packages = ["."]
@@ -73,6 +85,12 @@
   packages = ["cluster","pool","redis","util"]
   revision = "d234cfb904a91daafa4e1f92599a893b349cc0c2"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/mitchellh/go-homedir"
+  packages = ["."]
+  revision = "b8bc1bf767474819792c23f32d8286a45736f1c6"
+
 [[projects]]
   branch = "master"
   name = "github.com/mitchellh/mapstructure"
@@ -109,6 +127,12 @@
   revision = "792786c7400a136282c1664665ae0a8db921c6c2"
   version = "v1.0.0"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/segmentio/go-prompt"
+  packages = ["."]
+  revision = "f0d19b6901ade831d5a3204edc0d6a7d6457fbb2"
+
 [[projects]]
   branch = "master"
   name = "github.com/spf13/afero"
@@ -157,10 +181,16 @@
   revision = "69483b4bd14f5845b5a1e55bca19e954e827f1d0"
   version = "v1.1.4"
 
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/crypto"
+  packages = ["ssh/terminal"]
+  revision = "0fcca4842a8d74bfddc2c96a073bd2a4d2a7a2e8"
+
 [[projects]]
   branch = "master"
   name = "golang.org/x/sys"
-  packages = ["unix"]
+  packages = ["unix","windows"]
   revision = "7ddbeae9ae08c6a06a59597f0c9edbc5ff2444ce"
 
 [[projects]]
@@ -184,6 +214,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "11938f85225b2839e4ed7cd4345bed8f44510b6eb50c003b89c8e14e0fd6b6e7"
+  inputs-digest = "a12e681ec671ce8a93256cd754d4e70797476b2d2ce4379c3860df09c4b6a552"
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -23,6 +23,17 @@ ignored = ["elyby/minecraft-skinsystem"]
   name = "github.com/assembla/cony"
   version = "^0.3.2"
 
+[[constraint]]
+  name = "github.com/SermoDigital/jose"
+  version = "~1.1.0"
+
+[[constraint]]
+  name = "github.com/mitchellh/go-homedir"
+
+[[constraint]]
+  name = "github.com/segmentio/go-prompt"
+  branch = "master"
+
 # Testing dependencies
 
 [[constraint]]

auth/jwt.go

@@ -0,0 +1,124 @@
+package auth
+
+import (
+	"encoding/base64"
+	"io/ioutil"
+	"math"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/SermoDigital/jose/crypto"
+	"github.com/SermoDigital/jose/jws"
+	"github.com/mitchellh/go-homedir"
+)
+
+var hashAlg = crypto.SigningMethodHS256
+
+const appHomeDirName = ".minecraft-skinsystem"
+const scopesClaim = "scopes"
+
+type Scope string
+
+var (
+	SkinScope = Scope("skin")
+)
+
+type JwtAuth struct {
+	signingKey []byte
+}
+
+func (t *JwtAuth) NewToken(scopes ...Scope) ([]byte, error) {
+	key, err := t.getSigningKey()
+	if err != nil {
+		return nil, err
+	}
+
+	claims := jws.Claims{}
+	claims.Set(scopesClaim, scopes)
+	claims.SetIssuedAt(time.Now())
+	encoder := jws.NewJWT(claims, hashAlg)
+	token, err := encoder.Serialize(key)
+	if err != nil {
+		return nil, err
+	}
+
+	return token, nil
+}
+
+func (t *JwtAuth) GenerateSigningKey() error {
+	if err := createAppHomeDir(); err != nil {
+		return err
+	}
+
+	key := generateRandomBytes(64)
+	if err := ioutil.WriteFile(getKeyPath(), key, 0600); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (t *JwtAuth) getSigningKey() ([]byte, error) {
+	if t.signingKey != nil {
+		return t.signingKey, nil
+	}
+
+	path := getKeyPath()
+	if _, err := os.Stat(path); err != nil {
+		if os.IsNotExist(err) {
+			return nil, &SigningKeyNotAvailable{}
+		}
+
+		return nil, err
+	}
+
+	key, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	return key, nil
+}
+
+func createAppHomeDir() error {
+	path := getAppHomeDirPath()
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		err := os.Mkdir(path, 0755) // rwx r-x r-x
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func getAppHomeDirPath() string {
+	path, err := homedir.Expand("~/" + appHomeDirName)
+	if err != nil {
+		panic(err)
+	}
+
+	return path
+}
+
+func getKeyPath() string {
+	return getAppHomeDirPath() + "/jwt-key"
+}
+
+func generateRandomBytes(n int) []byte {
+	randLen := int(math.Ceil(float64(n) / 1.37)) // base64 will increase length in 1.37 times
+	randBytes := make([]byte, randLen)
+	rand.Read(randBytes)
+	resBytes := make([]byte, n)
+	base64.URLEncoding.Encode(resBytes, randBytes)
+
+	return resBytes
+}
+
+type SigningKeyNotAvailable struct {
+}
+
+func (*SigningKeyNotAvailable) Error() string {
+	return "Signing key not available"
+}

cmd/root.go

@@ -41,6 +41,7 @@ func initConfig() {
 	viper.AutomaticEnv()
 
 	if err := viper.ReadInConfig(); err == nil {
+		// TODO: show only on verbose mode
 		fmt.Println("Using config file:", viper.ConfigFileUsed())
 	}
 }

cmd/token.go

@@ -0,0 +1,65 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+
+	"elyby/minecraft-skinsystem/auth"
+
+	"github.com/segmentio/go-prompt"
+	"github.com/spf13/cobra"
+)
+
+var tokenCmd = &cobra.Command{
+	Use:   "token",
+	Short: "API tokens operations",
+}
+
+var createCmd = &cobra.Command{
+	Use:   "create",
+	Short: "Create the new token, that allows interacting with Ely.by Skinsystem API",
+	Run: func(cmd *cobra.Command, args []string) {
+		jwtAuth := &auth.JwtAuth{}
+		for {
+			token, err := jwtAuth.NewToken(auth.SkinScope)
+			if err != nil {
+				if _, ok := err.(*auth.SigningKeyNotAvailable); !ok {
+					log.Fatalf("Unable to create new token. The error is %v\n", err)
+				}
+
+				log.Println("Signing key not available. Creating...")
+				err := jwtAuth.GenerateSigningKey()
+				if err != nil {
+					log.Fatalf("Unable to generate new signing key. The error is %v\n", err)
+				}
+
+				continue
+			}
+
+			fmt.Printf("%s\n", token)
+		}
+	},
+}
+
+var resetCmd = &cobra.Command{
+	Use:   "reset",
+	Short: "Regenerate the secret key, that invalidate all tokens",
+	Run: func(cmd *cobra.Command, args []string) {
+		if !prompt.Confirm("Do you really want to invalidate all exists tokens?") {
+			fmt.Println("Aboart.")
+			return
+		}
+
+		jwtAuth := &auth.JwtAuth{}
+		if err := jwtAuth.GenerateSigningKey(); err != nil {
+			log.Fatalf("Unable to generate new signing key. The error is %v\n", err)
+		}
+
+		fmt.Println("Token successfully regenerated.")
+	},
+}
+
+func init() {
+	tokenCmd.AddCommand(createCmd, resetCmd)
+	RootCmd.AddCommand(tokenCmd)
+}