Remove swfextract dependency

README.md

@@ -36,32 +36,14 @@ fmt.Printf("%v", stations)
 
 ### ■ Get & Set authentication token
 
-- swftools is required.
-
 ```go
-// 1. Download a swf player.
-swfPath := path.Join(dir, "myplayer.swf")
-if err := radiko.DownloadPlayer(swfPath); err != nil {
-	log.Fatalf("Failed to download swf player. %s", err)
-}
-
-// 2. Using swfextract, create an authkey file from a swf player.
-cmdPath, err := exec.LookPath("swfextract")
-if err != nil {
-	log.Fatal(err)
-}
-authKeyPath := path.Join(dir, "authkey.png")
-if c := exec.Command(cmdPath, "-b", "12", swfPath, "-o", authKeyPath); err != c.Run() {
-	log.Fatalf("Failed to execute swfextract. %s", err)
-}
-
-// 3. Create a new Client.
+// 1. Create a new Client.
 client, err := radiko.New("")
 if err != nil {
 	panic(err)
 }
 
-// 4. Enables and sets the auth_token.
+// 2. Enables and sets the auth_token.
 // After client.AuthorizeToken() has succeeded,
 // the client has the enabled auth_token internally.
 authToken, err := client.AuthorizeToken(context.Background(), authKeyPath)
@@ -72,16 +54,14 @@ if err != nil {
 
 #### Premium member (Enable to use the [area free](http://radiko.jp/rg/premium/).)
 
-Step 1,2 are the same as above.
-
 ```go
-// 3. Create a new Client.
+// 1. Create a new Client.
 client, err := radiko.New("")
 if err != nil {
 	panic(err)
 }
 
-// 4. Login as the premium member
+// 2. Login as the premium member
 // After client.Login() has succeeded,
 // the client has the valid cookie internally.
 ctx := context.Background()
@@ -94,7 +74,7 @@ if login.StatusCode() != 200 {
 		login.StatusCode())
 }
 
-// 5. Enables and sets the auth_token.
+// 3. Enables and sets the auth_token.
 // After client.AuthorizeToken() has succeeded,
 // the client has the enabled auth_token internally.
 authToken, err := client.AuthorizeToken(context.Background(), authKeyPath)

auth.go

@@ -1,32 +1,36 @@
 package radiko
 
 import (
+	"bytes"
 	"context"
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
-	"os"
 	"strconv"
 	"strings"
 )
 
 // AuthorizeToken returns an enables auth_token and error,
 // and sets auth_token in Client.
 // Is is a alias function that wraps Auth1Fms and Auth2Fms.
-func (c *Client) AuthorizeToken(ctx context.Context, pngFile string) (string, error) {
-	authToken, length, offset, err := c.Auth1Fms(ctx)
+func (c *Client) AuthorizeToken(ctx context.Context) (string, error) {
+	bin, err := downloadBinary()
 	if err != nil {
 		return "", err
 	}
 
-	f, err := os.Open(pngFile)
+	f := bytes.NewReader(bin)
+
+	authToken, length, offset, err := c.Auth1Fms(ctx)
 	if err != nil {
 		return "", err
 	}
 
 	b := make([]byte, length)
-	if _, err = f.ReadAt(b, offset); err != nil {
+	io.CopyN(ioutil.Discard, f, offset)
+	if _, err = f.Read(b); err != nil {
 		return "", err
 	}
 	partialKey := base64.StdEncoding.EncodeToString(b)

auth_test.go

@@ -19,8 +19,7 @@ func TestAuthorizeToken(t *testing.T) {
 	}
 
 	ctx := context.Background()
-	pngPath := path.Join(testdataDir, "authkey.png")
-	authToken, err := c.AuthorizeToken(ctx, pngPath)
+	authToken, err := c.AuthorizeToken(ctx)
 	if err != nil {
 		t.Error(err)
 	}
@@ -29,20 +28,6 @@ func TestAuthorizeToken(t *testing.T) {
 	}
 }
 
-func TestAuthorizeToken_NotExistAuthkeyFile(t *testing.T) {
-	c, err := New("")
-	if err != nil {
-		t.Fatalf("Failed to construct client: %s", err)
-	}
-
-	ctx := context.Background()
-	pngFile := path.Join(testdataDir, "not_exist_authkey.png")
-	_, err = c.AuthorizeToken(ctx, pngFile)
-	if err == nil {
-		t.Error(err)
-	}
-}
-
 func TestAuth1Fms(t *testing.T) {
 	c, err := New("")
 	if err != nil {

examples/auth/main.go

@@ -6,42 +6,21 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"os/exec"
-	"path"
 
 	radiko "github.com/yyoshiki41/go-radiko"
 )
 
 func main() {
-	dir, f := createTempDir()
-	defer f()
-
-	// 1. Download a swf player
-	swfPath := path.Join(dir, "myplayer.swf")
-	if err := radiko.DownloadPlayer(swfPath); err != nil {
-		log.Fatalf("Failed to download swf player. %s", err)
-	}
-
-	// 2. Using swfextract, create an authkey file from a swf player.
-	cmdPath, err := exec.LookPath("swfextract")
-	if err != nil {
-		log.Fatal(err)
-	}
-	authKeyPath := path.Join(dir, "authkey.png")
-	if c := exec.Command(cmdPath, "-b", "12", swfPath, "-o", authKeyPath); err != c.Run() {
-		log.Fatalf("Failed to execute swfextract. %s", err)
-	}
-
-	// 3. Create a new Client.
+	// 1. Create a new Client.
 	client, err := radiko.New("")
 	if err != nil {
 		log.Fatalf("Failed to construct a radiko Client. %s", err)
 	}
 
-	// 4. Enables and sets the auth_token.
+	// 2. Enables and sets the auth_token.
 	// After client.AuthorizeToken() has succeeded,
 	// the client has the enabled auth_token internally.
-	authToken, err := client.AuthorizeToken(context.Background(), authKeyPath)
+	authToken, err := client.AuthorizeToken(context.Background())
 	if err != nil {
 		log.Fatal(err)
 	}

player.go

@@ -1,31 +1,92 @@
 package radiko
 
 import (
+	"compress/zlib"
+	"errors"
 	"io"
+	"io/ioutil"
 	"net/http"
-	"os"
 )
 
 const (
 	playerURL = "http://radiko.jp/apps/js/flash/myplayer-release.swf"
 )
 
-// DownloadPlayer downloads a swf player file.
-func DownloadPlayer(path string) error {
+func downloadBinary() ([]byte, error) {
 	resp, err := http.Get(playerURL)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	defer resp.Body.Close()
 
-	f, err := os.Create(path)
+	return swfExtract(resp.Body)
+}
+
+const targetID = 12   // swfextract -b "12"
+const targetCode = 87 // swfextract "-b" 12
+
+const headerCWS = 8
+const headerRect = 5
+const rectNum = 4
+const headerRest = 2 + 2
+const binaryOffset = 6
+
+func swfExtract(body io.Reader) ([]byte, error) {
+	io.CopyN(ioutil.Discard, body, headerCWS)
+	zf, err := zlib.NewReader(body)
 	if err != nil {
-		return err
+		return nil, err
 	}
+	buf, err := ioutil.ReadAll(zf)
+	if err != nil {
+		return nil, err
+	}
+
+	offset := 0
+
+	// Skip Rect
+	rectSize := int(buf[offset] >> 3)
+	rectOffset := (headerRect + rectNum*rectSize + 7) / 8
+
+	offset += rectOffset
+
+	// Skip the rest header
+	offset += headerRest
+
+	// Read tags
+	for i := 0; ; i++ {
+		// tag code
+		code := int(buf[offset+1])<<2 + int(buf[offset])>>6
+
+		// tag length
+		len := int(buf[offset] & 0x3f)
+
+		// Skip tag header
+		offset += 2
+
+		// tag length (if long version)
+		if len == 0x3f {
+			len = int(buf[offset])
+			len += int(buf[offset+1]) << 8
+			len += int(buf[offset+2]) << 16
+			len += int(buf[offset+3]) << 24
+
+			// skip tag lentgh header
+			offset += 4
+		}
+
+		// Not found...
+		if code == 0 {
+			return nil, errors.New("swf extract failed")
+		}
+		// tag ID
+		id := int(buf[offset]) + int(buf[offset+1])<<8
+
+		// Found?
+		if code == targetCode && id == targetID {
+			return buf[offset+binaryOffset : offset+len], nil
+		}
 
-	_, err = io.Copy(f, resp.Body)
-	if closeErr := f.Close(); err == nil {
-		err = closeErr
+		offset += len
 	}
-	return err
 }

player_test.go

@@ -1,17 +1,10 @@
 package radiko
 
-import (
-	"path"
-	"testing"
-)
+import "testing"
 
-func TestDownloadPlayer(t *testing.T) {
-	dir, removeDir := createTestTempDir(t)
-	defer removeDir() // clean up
-
-	playerPath := path.Join(dir, "myplayer.swf")
-	err := DownloadPlayer(playerPath)
+func TestDownloadBinary(t *testing.T) {
+	_, err := downloadBinary()
 	if err != nil {
-		t.Errorf("Failed to download player.swf: %s", err)
+		t.Errorf("Failed to download binary: %s", err)
 	}
 }