v7.1.8

backend/community_apikey.go

@@ -0,0 +1,97 @@
+package backend
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"fmt"
+	"net/http"
+	"strings"
+	"sync"
+)
+
+var (
+	communityAPIKeyOnce sync.Once
+	communityAPIKey     string
+	communityAPIKeyErr  error
+)
+
+var communityAPIKeySeedParts = [][]byte{
+	[]byte("spotif"),
+	[]byte("lac:co"),
+	[]byte("mmunity:apikey:v1"),
+}
+
+var communityAPIKeyAAD = []byte("spotiflac|community|apikey|v1")
+
+var communityAPIKeyNonce = []byte{
+	0x20, 0x5c, 0x92, 0x4b, 0x61, 0xc2, 0x79, 0xd3, 0xea, 0x5d, 0xdd, 0xd4,
+}
+
+var communityAPIKeyCiphertext = []byte{
+	0x51, 0x0b, 0x26, 0xaf, 0xac, 0x6f, 0xf6, 0x41, 0x79, 0xde, 0x8d, 0x36,
+	0x83, 0x46, 0xb5, 0xd5, 0x96, 0xef, 0xad, 0xed, 0xe0, 0xd0, 0xc7, 0xc2,
+	0x90, 0x01, 0x50, 0x5f, 0x55, 0x59, 0x9f, 0xac, 0x1f, 0xd0, 0x70, 0x18,
+	0x91, 0x4f, 0x7a, 0x32,
+}
+
+var communityAPIKeyTag = []byte{
+	0x56, 0xb0, 0x28, 0x68, 0x9f, 0x39, 0x0d, 0xbc, 0xc0, 0x8e, 0xfb, 0x52,
+	0x3a, 0xd6, 0x18, 0xae,
+}
+
+func getCommunityAPIKey() (string, error) {
+	communityAPIKeyOnce.Do(func() {
+		hasher := sha256.New()
+		for _, part := range communityAPIKeySeedParts {
+			hasher.Write(part)
+		}
+
+		block, err := aes.NewCipher(hasher.Sum(nil))
+		if err != nil {
+			communityAPIKeyErr = err
+			return
+		}
+
+		gcm, err := cipher.NewGCM(block)
+		if err != nil {
+			communityAPIKeyErr = err
+			return
+		}
+
+		sealed := make([]byte, 0, len(communityAPIKeyCiphertext)+len(communityAPIKeyTag))
+		sealed = append(sealed, communityAPIKeyCiphertext...)
+		sealed = append(sealed, communityAPIKeyTag...)
+
+		plaintext, err := gcm.Open(nil, communityAPIKeyNonce, sealed, communityAPIKeyAAD)
+		if err != nil {
+			communityAPIKeyErr = err
+			return
+		}
+
+		communityAPIKey = string(plaintext)
+	})
+
+	if communityAPIKeyErr != nil {
+		return "", communityAPIKeyErr
+	}
+	return communityAPIKey, nil
+}
+
+func communityUserAgent() string {
+	version := strings.TrimSpace(AppVersion)
+	if version == "" || version == "Unknown" {
+		return "SpotiFLAC"
+	}
+	return "SpotiFLAC/" + version
+}
+
+func setCommunityRequestHeaders(req *http.Request) error {
+	apiKey, err := getCommunityAPIKey()
+	if err != nil {
+		return fmt.Errorf("failed to prepare community API key: %w", err)
+	}
+	req.Header.Set("x-api-key", apiKey)
+	req.Header.Set("User-Agent", communityUserAgent())
+	return nil
+}