Add Last.FM Authentication methods

core/agents/lastfm/client.go

@@ -2,12 +2,17 @@ package lastfm
 
 import (
 	"context"
+	"crypto/md5"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/url"
+	"sort"
 	"strconv"
+	"strings"
+
+	"github.com/navidrome/navidrome/utils"
 )
 
 const (
@@ -27,52 +32,17 @@ type httpDoer interface {
 	Do(req *http.Request) (*http.Response, error)
 }
 
-func NewClient(apiKey string, lang string, hc httpDoer) *Client {
+func NewClient(apiKey string, secret string, lang string, hc httpDoer) *Client {
-	return &Client{apiKey, lang, hc}
+	return &Client{apiKey, secret, lang, hc}
 }
 
 type Client struct {
 	apiKey string
+	secret string
 	lang   string
 	hc     httpDoer
 }
 
-func (c *Client) makeRequest(params url.Values) (*Response, error) {
-	params.Add("format", "json")
-	params.Add("api_key", c.apiKey)
-
-	req, _ := http.NewRequest("GET", apiBaseUrl, nil)
-	req.URL.RawQuery = params.Encode()
-
-	resp, err := c.hc.Do(req)
-	if err != nil {
-		return nil, err
-	}
-
-	defer resp.Body.Close()
-	data, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return nil, err
-	}
-
-	var response Response
-	jsonErr := json.Unmarshal(data, &response)
-
-	if resp.StatusCode != 200 && jsonErr != nil {
-		return nil, fmt.Errorf("last.fm http status: (%d)", resp.StatusCode)
-	}
-
-	if jsonErr != nil {
-		return nil, jsonErr
-	}
-
-	if response.Error != 0 {
-		return &response, &lastFMError{Code: response.Error, Message: response.Message}
-	}
-
-	return &response, nil
-}
-
 func (c *Client) ArtistGetInfo(ctx context.Context, name string, mbid string) (*Artist, error) {
 	params := url.Values{}
 	params.Add("method", "artist.getInfo")
@@ -111,3 +81,76 @@ func (c *Client) ArtistGetTopTracks(ctx context.Context, name string, mbid strin
 	}
 	return &response.TopTracks, nil
 }
+
+func (c *Client) GetToken(ctx context.Context) (string, error) {
+	params := url.Values{}
+	params.Add("method", "auth.getToken")
+	c.sign(params)
+	response, err := c.makeRequest(params)
+	if err != nil {
+		return "", err
+	}
+	return response.Token, nil
+}
+
+func (c *Client) GetSession(ctx context.Context, token string) (string, error) {
+	params := url.Values{}
+	params.Add("method", "auth.getSession")
+	params.Add("token", token)
+	c.sign(params)
+	response, err := c.makeRequest(params)
+	if err != nil {
+		return "", err
+	}
+	return response.Session.Key, nil
+}
+
+func (c *Client) makeRequest(params url.Values) (*Response, error) {
+	params.Add("format", "json")
+	params.Add("api_key", c.apiKey)
+
+	req, _ := http.NewRequest("GET", apiBaseUrl, nil)
+	req.URL.RawQuery = params.Encode()
+
+	resp, err := c.hc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+	decoder := json.NewDecoder(resp.Body)
+
+	var response Response
+	jsonErr := decoder.Decode(&response)
+	if resp.StatusCode != 200 && jsonErr != nil {
+		return nil, fmt.Errorf("last.fm http status: (%d)", resp.StatusCode)
+	}
+	if jsonErr != nil {
+		return nil, jsonErr
+	}
+	if response.Error != 0 {
+		return &response, &lastFMError{Code: response.Error, Message: response.Message}
+	}
+
+	return &response, nil
+}
+
+func (c *Client) sign(params url.Values) {
+	// the parameters must be in order before hashing
+	keys := make([]string, 0, len(params))
+	for k := range params {
+		if utils.StringInSlice(k, []string{"format", "callback"}) {
+			continue
+		}
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	msg := strings.Builder{}
+	for _, k := range keys {
+		msg.WriteString(k)
+		msg.WriteString(params[k][0])
+	}
+	msg.WriteString(c.secret)
+	hash := md5.Sum([]byte(msg.String()))
+	params.Add("api_sig", hex.EncodeToString(hash[:]))
+}

core/agents/lastfm/client_test.go

@@ -3,9 +3,12 @@ package lastfm
 import (
 	"bytes"
 	"context"
+	"crypto/md5"
 	"errors"
+	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"os"
 
 	"github.com/navidrome/navidrome/tests"
@@ -19,7 +22,7 @@ var _ = Describe("Client", func() {
 
 	BeforeEach(func() {
 		httpClient = &tests.FakeHttpClient{}
-		client = NewClient("API_KEY", "pt", httpClient)
+		client = NewClient("API_KEY", "SECRET", "pt", httpClient)
 	})
 
 	Describe("ArtistGetInfo", func() {
@@ -27,7 +30,7 @@ var _ = Describe("Client", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 
-			artist, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			artist, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(BeNil())
 			Expect(artist.Name).To(Equal("U2"))
 			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?api_key=API_KEY&artist=U2&format=json&lang=pt&mbid=123&method=artist.getInfo"))
@@ -39,7 +42,7 @@ var _ = Describe("Client", func() {
 				StatusCode: 500,
 			}
 
-			_, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			_, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(MatchError("last.fm http status: (500)"))
 		})
 
@@ -49,7 +52,7 @@ var _ = Describe("Client", func() {
 				StatusCode: 400,
 			}
 
-			_, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			_, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(MatchError(&lastFMError{Code: 3, Message: "Invalid Method - No method with that name in this package"}))
 		})
 
@@ -59,14 +62,14 @@ var _ = Describe("Client", func() {
 				StatusCode: 200,
 			}
 
-			_, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			_, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(MatchError(&lastFMError{Code: 6, Message: "The artist you supplied could not be found"}))
 		})
 
 		It("fails if HttpClient.Do() returns error", func() {
 			httpClient.Err = errors.New("generic error")
 
-			_, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			_, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(MatchError("generic error"))
 		})
 
@@ -76,7 +79,7 @@ var _ = Describe("Client", func() {
 				StatusCode: 200,
 			}
 
-			_, err := client.ArtistGetInfo(context.TODO(), "U2", "123")
+			_, err := client.ArtistGetInfo(context.Background(), "U2", "123")
 			Expect(err).To(MatchError("invalid character '<' looking for beginning of value"))
 		})
 
@@ -87,7 +90,7 @@ var _ = Describe("Client", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.artist.getsimilar.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 
-			similar, err := client.ArtistGetSimilar(context.TODO(), "U2", "123", 2)
+			similar, err := client.ArtistGetSimilar(context.Background(), "U2", "123", 2)
 			Expect(err).To(BeNil())
 			Expect(len(similar.Artists)).To(Equal(2))
 			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?api_key=API_KEY&artist=U2&format=json&limit=2&mbid=123&method=artist.getSimilar"))
@@ -99,10 +102,60 @@ var _ = Describe("Client", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.artist.gettoptracks.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 
-			top, err := client.ArtistGetTopTracks(context.TODO(), "U2", "123", 2)
+			top, err := client.ArtistGetTopTracks(context.Background(), "U2", "123", 2)
 			Expect(err).To(BeNil())
 			Expect(len(top.Track)).To(Equal(2))
 			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?api_key=API_KEY&artist=U2&format=json&limit=2&mbid=123&method=artist.getTopTracks"))
 		})
 	})
+
+	Describe("GetToken", func() {
+		It("returns a token when the request is successful", func() {
+			httpClient.Res = http.Response{
+				Body:       ioutil.NopCloser(bytes.NewBufferString(`{"token":"TOKEN"}`)),
+				StatusCode: 200,
+			}
+
+			Expect(client.GetToken(context.Background())).To(Equal("TOKEN"))
+			queryParams := httpClient.SavedRequest.URL.Query()
+			Expect(queryParams.Get("method")).To(Equal("auth.getToken"))
+			Expect(queryParams.Get("format")).To(Equal("json"))
+			Expect(queryParams.Get("api_key")).To(Equal("API_KEY"))
+			Expect(queryParams.Get("api_sig")).ToNot(BeEmpty())
+		})
+	})
+
+	Describe("GetSession", func() {
+		It("returns a session key when the request is successful", func() {
+			httpClient.Res = http.Response{
+				Body:       ioutil.NopCloser(bytes.NewBufferString(`{"session":{"name":"Navidrome","key":"SESSION_KEY","subscriber":0}}`)),
+				StatusCode: 200,
+			}
+
+			Expect(client.GetSession(context.Background(), "TOKEN")).To(Equal("SESSION_KEY"))
+			queryParams := httpClient.SavedRequest.URL.Query()
+			Expect(queryParams.Get("method")).To(Equal("auth.getSession"))
+			Expect(queryParams.Get("format")).To(Equal("json"))
+			Expect(queryParams.Get("token")).To(Equal("TOKEN"))
+			Expect(queryParams.Get("api_key")).To(Equal("API_KEY"))
+			Expect(queryParams.Get("api_sig")).ToNot(BeEmpty())
+		})
+	})
+
+	Describe("sign", func() {
+		It("adds an api_sig param with the signature", func() {
+			params := url.Values{}
+			params.Add("d", "444")
+			params.Add("callback", "https://myserver.com")
+			params.Add("a", "111")
+			params.Add("format", "json")
+			params.Add("c", "333")
+			params.Add("b", "222")
+			client.sign(params)
+			Expect(params).To(HaveKey("api_sig"))
+			sig := params.Get("api_sig")
+			expected := fmt.Sprintf("%x", md5.Sum([]byte("a111b222c333d444SECRET")))
+			Expect(sig).To(Equal(expected))
+		})
+	})
 })

core/agents/lastfm/lastfm.go

@@ -14,12 +14,13 @@ import (
 const (
 	lastFMAgentName = "lastfm"
 	lastFMAPIKey    = "9b94a5515ea66b2da3ec03c12300327e"
-	//lastFMAPISecret = "74cb6557cec7171d921af5d7d887c587" // Will be needed when implementing Scrobbling
+	lastFMAPISecret = "74cb6557cec7171d921af5d7d887c587" // nolint:gosec
 )
 
 type lastfmAgent struct {
 	ctx    context.Context
 	apiKey string
+	secret string
 	lang   string
 	client *Client
 }
@@ -28,14 +29,15 @@ func lastFMConstructor(ctx context.Context) agents.Interface {
 	l := &lastfmAgent{
 		ctx:    ctx,
 		lang:   conf.Server.LastFM.Language,
+		apiKey: lastFMAPIKey,
+		secret: lastFMAPISecret,
 	}
 	if conf.Server.LastFM.ApiKey != "" {
 		l.apiKey = conf.Server.LastFM.ApiKey
-	} else {
+		l.secret = conf.Server.LastFM.Secret
-		l.apiKey = lastFMAPIKey
 	}
 	hc := utils.NewCachedHTTPClient(http.DefaultClient, consts.DefaultCachedHttpClientTTL)
-	l.client = NewClient(l.apiKey, l.lang, hc)
+	l.client = NewClient(l.apiKey, l.secret, l.lang, hc)
 	return l
 }
 

core/agents/lastfm/lastfm_test.go

@@ -24,7 +24,7 @@ var _ = Describe("lastfmAgent", func() {
 	Describe("lastFMConstructor", func() {
 		It("uses default api key and language if not configured", func() {
 			conf.Server.LastFM.ApiKey = ""
-			agent := lastFMConstructor(context.TODO())
+			agent := lastFMConstructor(context.Background())
 			Expect(agent.(*lastfmAgent).apiKey).To(Equal(lastFMAPIKey))
 			Expect(agent.(*lastfmAgent).lang).To(Equal("en"))
 		})
@@ -32,7 +32,7 @@ var _ = Describe("lastfmAgent", func() {
 		It("uses configured api key and language", func() {
 			conf.Server.LastFM.ApiKey = "123"
 			conf.Server.LastFM.Language = "pt"
-			agent := lastFMConstructor(context.TODO())
+			agent := lastFMConstructor(context.Background())
 			Expect(agent.(*lastfmAgent).apiKey).To(Equal("123"))
 			Expect(agent.(*lastfmAgent).lang).To(Equal("pt"))
 		})
@@ -43,8 +43,8 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := NewClient("API_KEY", "pt", httpClient)
+			client := NewClient("API_KEY", "SECRET", "pt", httpClient)
-			agent = lastFMConstructor(context.TODO()).(*lastfmAgent)
+			agent = lastFMConstructor(context.Background()).(*lastfmAgent)
 			agent.client = client
 		})
 
@@ -101,8 +101,8 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := NewClient("API_KEY", "pt", httpClient)
+			client := NewClient("API_KEY", "SECRET", "pt", httpClient)
-			agent = lastFMConstructor(context.TODO()).(*lastfmAgent)
+			agent = lastFMConstructor(context.Background()).(*lastfmAgent)
 			agent.client = client
 		})
 
@@ -162,8 +162,8 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := NewClient("API_KEY", "pt", httpClient)
+			client := NewClient("API_KEY", "SECRET", "pt", httpClient)
-			agent = lastFMConstructor(context.TODO()).(*lastfmAgent)
+			agent = lastFMConstructor(context.Background()).(*lastfmAgent)
 			agent.client = client
 		})
 

core/agents/lastfm/responses.go

@@ -6,6 +6,8 @@ type Response struct {
 	TopTracks      TopTracks      `json:"toptracks"`
 	Error          int            `json:"error"`
 	Message        string         `json:"message"`
+	Token          string         `json:"token"`
+	Session        Session        `json:"session"`
 }
 
 type Artist struct {
@@ -59,3 +61,9 @@ type TopTracks struct {
 	Track []Track `json:"track"`
 	Attr  Attr    `json:"@attr"`
 }
+
+type Session struct {
+	Name       string `json:"name"`
+	Key        string `json:"key"`
+	Subscriber int    `json:"subscriber"`
+}