|
| 1 | +package dbv1 |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "encoding/json" |
| 6 | + "fmt" |
| 7 | + "math/rand" |
| 8 | + "net/url" |
| 9 | + "strings" |
| 10 | + "time" |
| 11 | + |
| 12 | + "bridgerton.audius.co/config" |
| 13 | + "bridgerton.audius.co/rendezvous" |
| 14 | + "github.com/ethereum/go-ethereum/common/hexutil" |
| 15 | + "github.com/ethereum/go-ethereum/crypto" |
| 16 | +) |
| 17 | + |
| 18 | +type MediaLink struct { |
| 19 | + Url string `json:"url"` |
| 20 | + Mirrors []string `json:"mirrors"` |
| 21 | +} |
| 22 | + |
| 23 | +func mediaLink(cid string, trackId int32, userId int32) *MediaLink { |
| 24 | + ranked := rendezvous.GlobalHasher.Rank(cid) |
| 25 | + randIdx := rand.Intn(3) |
| 26 | + first, rest := ranked[randIdx], append(ranked[:randIdx], ranked[randIdx+1:]...)[:2] |
| 27 | + |
| 28 | + timestamp := time.Now().Unix() * 1000 |
| 29 | + data := map[string]interface{}{ |
| 30 | + "cid": cid, |
| 31 | + "timestamp": timestamp, |
| 32 | + "trackId": trackId, |
| 33 | + "userId": userId, |
| 34 | + } |
| 35 | + |
| 36 | + signature, err := generateSignature(data) |
| 37 | + if err != nil { |
| 38 | + return nil |
| 39 | + } |
| 40 | + |
| 41 | + // Convert the data map to a JSON string |
| 42 | + dataJSON, _ := json.Marshal(data) |
| 43 | + |
| 44 | + signatureData := map[string]interface{}{ |
| 45 | + "signature": signature, |
| 46 | + "data": string(dataJSON), |
| 47 | + } |
| 48 | + signatureJSON, _ := json.Marshal(signatureData) |
| 49 | + queryParams := url.Values{} |
| 50 | + queryParams.Set("signature", string(signatureJSON)) |
| 51 | + |
| 52 | + basePath := fmt.Sprintf("tracks/cidstream/%s", cid) |
| 53 | + path := fmt.Sprintf("%s?%s", basePath, queryParams.Encode()) |
| 54 | + |
| 55 | + return &MediaLink{ |
| 56 | + Url: fmt.Sprintf("%s/%s", first, path), |
| 57 | + Mirrors: rest, |
| 58 | + } |
| 59 | +} |
| 60 | + |
| 61 | +func generateSignature(data map[string]interface{}) (string, error) { |
| 62 | + ecdsaPrivKey, err := crypto.HexToECDSA(config.Cfg.DelegatePrivateKey) |
| 63 | + if err != nil { |
| 64 | + return "", err |
| 65 | + } |
| 66 | + |
| 67 | + // Sort json |
| 68 | + jsonStr := func(data map[string]interface{}) string { |
| 69 | + var b bytes.Buffer |
| 70 | + _ = json.NewEncoder(&b).Encode(data) |
| 71 | + return strings.TrimRight(b.String(), "\n") |
| 72 | + }(data) |
| 73 | + |
| 74 | + // Hash the JSON string, prefix it, and hash again |
| 75 | + messageHash := crypto.Keccak256([]byte(jsonStr)) |
| 76 | + prefix := fmt.Sprintf("\x19Ethereum Signed Message:\n%d", len(messageHash)) |
| 77 | + prefixedMessage := append([]byte(prefix), messageHash...) |
| 78 | + finalHash := crypto.Keccak256(prefixedMessage) |
| 79 | + |
| 80 | + // Sign the hash with the private key |
| 81 | + signature, err := crypto.Sign(finalHash, ecdsaPrivKey) |
| 82 | + if err != nil { |
| 83 | + return "", err |
| 84 | + } |
| 85 | + |
| 86 | + return hexutil.Encode(signature), nil |
| 87 | +} |
0 commit comments