nip96: http file storage

nip96/nip96.go

@@ -0,0 +1,127 @@
+package nip96
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"strconv"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+// Upload uploads a file to the provided req.Host.
+func Upload(ctx context.Context, req UploadRequest) (*UploadResponse, error) {
+	if err := req.Validate(); err != nil {
+		return nil, err
+	}
+
+	client := http.DefaultClient
+	if req.HTTPClient != nil {
+		client = req.HTTPClient
+	}
+
+	var requestBody bytes.Buffer
+	writer := multipart.NewWriter(&requestBody)
+	{
+		// Add the file
+		fileWriter, err := writer.CreateFormFile("file", req.Filename)
+		if err != nil {
+			return nil, fmt.Errorf("multipartWriter.CreateFormFile: %w", err)
+		}
+		if _, err := io.Copy(fileWriter, req.File); err != nil {
+			return nil, fmt.Errorf("io.Copy: %w", err)
+		}
+
+		// Add the other fields
+		writer.WriteField("caption", req.Caption)
+		writer.WriteField("alt", req.Alt)
+		writer.WriteField("media_type", req.MediaType)
+		writer.WriteField("content_type", req.ContentType)
+		writer.WriteField("no_transform", fmt.Sprintf("%t", req.NoTransform))
+		if req.Expiration == 0 {
+			writer.WriteField("expiration", "")
+		} else {
+			writer.WriteField("expiration", strconv.FormatInt(int64(req.Expiration), 10))
+		}
+
+		if err := writer.Close(); err != nil {
+			return nil, fmt.Errorf("multipartWriter.Close: %w", err)
+		}
+	}
+
+	uploadReq, err := http.NewRequest("POST", req.Host, &requestBody)
+	if err != nil {
+		return nil, fmt.Errorf("http.NewRequest: %w", err)
+	}
+	uploadReq.Header.Set("Content-Type", writer.FormDataContentType())
+
+	if req.SK != "" {
+		auth, err := generateAuthHeader(req.SK, req.Host)
+		if err != nil {
+			return nil, fmt.Errorf("generateAuthHeader: %w", err)
+		}
+		uploadReq.Header.Set("Authorization", auth)
+	}
+
+	resp, err := client.Do(uploadReq)
+	if err != nil {
+		return nil, fmt.Errorf("httpclient.Do: %w", err)
+	}
+	defer resp.Body.Close()
+
+	switch resp.StatusCode {
+	case http.StatusRequestEntityTooLarge:
+		return nil, fmt.Errorf("File is too large")
+
+	case http.StatusBadRequest:
+		return nil, fmt.Errorf("Bad request")
+
+	case http.StatusForbidden:
+		return nil, fmt.Errorf("Unauthorized")
+
+	case http.StatusPaymentRequired:
+		return nil, fmt.Errorf("Payment required")
+
+	case http.StatusOK, http.StatusCreated, http.StatusAccepted:
+		var uploadResp UploadResponse
+		if err := json.NewDecoder(resp.Body).Decode(&uploadResp); err != nil {
+			return nil, fmt.Errorf("Error decoding JSON: %w", err)
+		}
+		return &uploadResp, nil
+
+	default:
+		return nil, fmt.Errorf("Unexpected error %v", resp.Status)
+	}
+}
+
+func generateAuthHeader(sk, host string) (string, error) {
+	pk, err := nostr.GetPublicKey(sk)
+	if err != nil {
+		return "", fmt.Errorf("nostr.GetPublicKey: %w", err)
+	}
+
+	event := nostr.Event{
+		Kind:      27235,
+		PubKey:    pk,
+		CreatedAt: nostr.Now(),
+		Tags: nostr.Tags{
+			nostr.Tag{"u", host},
+			nostr.Tag{"method", "POST"},
+		},
+	}
+	event.Sign(sk)
+
+	b, err := json.Marshal(event)
+	if err != nil {
+		return "", fmt.Errorf("json.Marshal: %w", err)
+	}
+
+	payload := base64.StdEncoding.EncodeToString(b)
+
+	return fmt.Sprintf("Nostr %s", payload), nil
+}

nip96/nip96_test.go

@@ -0,0 +1,33 @@
+package nip96
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func TestUpload(t *testing.T) {
+	img, _ := os.Open("./testdata/image.png")
+	defer img.Close()
+
+	ctx := context.Background()
+	resp, err := Upload(ctx, UploadRequest{
+		Host: "https://nostr.build/api/v2/nip96/upload",
+		//Host:        "https://nostrcheck.me/api/v2/media",
+		//Host:        "https://nostrage.com/api/v2/media",
+		SK:          nostr.GeneratePrivateKey(),
+		File:        img,
+		Filename:    "ostrich.png",
+		Caption:     "nostr ostrich",
+		ContentType: "image/png",
+		NoTransform: true,
+	})
+	if err != nil {
+		t.Fatal(err, "client.Upload")
+	}
+
+	t.Logf("resp: %#v\n", *resp)
+	// nip96_test.go:28: resp: nip96.UploadResponse{Status:"success", Message:"Upload successful.", ProcessingURL:"", Nip94Event:struct { Tags nostr.Tags "json:\"tags\"" }{Tags:nostr.Tags{nostr.Tag{"url", "https://image.nostr.build/4ece05f1d77c9cb97d334ba9c0301b2960640df89bf5d75d6bffadefc4355673.jpg"}, nostr.Tag{"ox", "4ece05f1d77c9cb97d334ba9c0301b2960640df89bf5d75d6bffadefc4355673"}, nostr.Tag{"x", ""}, nostr.Tag{"m", "image/jpeg"}, nostr.Tag{"dim", "1125x750"}, nostr.Tag{"bh", "LLF=kB-;yH-;-;R#t7xKEZWA#_oM"}, nostr.Tag{"blurhash", "LLF=kB-;yH-;-;R#t7xKEZWA#_oM"}, nostr.Tag{"thumb", "https://image.nostr.build/thumb/4ece05f1d77c9cb97d334ba9c0301b2960640df89bf5d75d6bffadefc4355673.jpg"}}}}
+}

nip96/types.go

@@ -0,0 +1,69 @@
+package nip96
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+// UploadRequest is a NIP96 upload request.
+type UploadRequest struct {
+	// Host is the NIP96 server to upload to.
+	Host string
+
+	// SK is a private key used to sign the NIP-98 Auth header. If not set
+	// the auth header will not be included in the upload.
+	SK string
+
+	// File is the file to upload.
+	File io.Reader
+
+	// Filename is the name of the file, e.g. image.png
+	Filename string
+
+	// Caption is a loose description of the file.
+	Caption string
+
+	// Alt is a strict description text for visibility-impaired users.
+	Alt string
+
+	// MediaType is "avatar" or "banner". Informs the server if the file will be
+	// used as an avatar or banner. If absent, the server will interpret it as a
+	// normal upload, without special treatment.
+	MediaType string
+
+	// ContentType is the mime type such as "image/jpeg". This is just a value the
+	// server can use to reject early if the mime type isn't supported.
+	ContentType string
+
+	// NoTransform set to "true" asks server not to transform the file and serve
+	// the uploaded file as is, may be rejected.
+	NoTransform bool
+
+	// Expiration is a UNIX timestamp in seconds. Empty if file should be stored
+	// forever. The server isn't required to honor this.
+	Expiration nostr.Timestamp
+
+	// HTTPClient is an option to provide your own HTTP Client.
+	HTTPClient *http.Client
+}
+
+func (r *UploadRequest) Validate() error {
+	if r.Host == "" {
+		return fmt.Errorf("Host must be set")
+	}
+
+	return nil
+}
+
+// UploadResponse is a NIP96 upload response.
+type UploadResponse struct {
+	Status        string `json:"status"`
+	Message       string `json:"message"`
+	ProcessingURL string `json:"processing_url"`
+	Nip94Event    struct {
+		Tags nostr.Tags `json:"tags"`
+	} `json:"nip94_event"`
+}