Add support for data URL favicons

reader/icon/finder.go

@@ -5,9 +5,11 @@
 package icon
 
 import (
+	"encoding/base64"
 	"fmt"
 	"io"
 	"io/ioutil"
+	"strings"
 
 	"github.com/miniflux/miniflux/helper"
 	"github.com/miniflux/miniflux/http"
@@ -36,6 +38,10 @@ func FindIcon(websiteURL string) (*model.Icon, error) {
 		return nil, err
 	}
 
+	if strings.HasPrefix(iconURL, "data:") {
+		return parseImageDataURL(iconURL)
+	}
+
 	logger.Debug("[FindIcon] Fetching icon => %s", iconURL)
 	icon, err := downloadIcon(iconURL)
 	if err != nil {
@@ -108,3 +114,42 @@ func downloadIcon(iconURL string) (*model.Icon, error) {
 
 	return icon, nil
 }
+
+func parseImageDataURL(value string) (*model.Icon, error) {
+	colon := strings.Index(value, ":")
+	semicolon := strings.Index(value, ";")
+	comma := strings.Index(value, ",")
+
+	if colon <= 0 || semicolon <= 0 || comma <= 0 {
+		return nil, fmt.Errorf(`icon: invalid data url "%s"`, value)
+	}
+
+	mimeType := value[colon+1 : semicolon]
+	encoding := value[semicolon+1 : comma]
+	data := value[comma+1:]
+
+	if encoding != "base64" {
+		return nil, fmt.Errorf(`icon: unsupported data url encoding "%s"`, value)
+	}
+
+	if !strings.HasPrefix(mimeType, "image/") {
+		return nil, fmt.Errorf(`icon: invalid mime type "%s"`, mimeType)
+	}
+
+	blob, err := base64.StdEncoding.DecodeString(data)
+	if err != nil {
+		return nil, fmt.Errorf(`icon: invalid data "%s" (%v)`, value, err)
+	}
+
+	if len(blob) == 0 {
+		return nil, fmt.Errorf(`icon: empty data "%s"`, value)
+	}
+
+	icon := &model.Icon{
+		Hash:     helper.HashFromBytes(blob),
+		Content:  blob,
+		MimeType: mimeType,
+	}
+
+	return icon, nil
+}

reader/icon/finder_test.go

@@ -0,0 +1,51 @@
+// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package icon
+
+import "testing"
+
+func TestParseImageDataURL(t *testing.T) {
+	iconURL := "data:image/webp;base64,UklGRhQJAABXRUJQVlA4TAcJAAAvv8AvEIU1atuOza3OCSaanSeobUa17T61bdu2bVtRbdvtDmrb7gSTdibJXOG81/d9z/vsX3utCLi1bbuJ3hKeVEymRRuaSnCVSBWIBmwP410h0IHJXDyfZCfRNhklFS/sufGPbPHPjT0vVJRkhE1BwxFZ5EhDQVjkrEjIJokVOVHMhAuyyoUpUUCbDbLLhjbRFkO+kWG+GRLT0+YTWeaTNjEdW2SaLTEtU2SbOTGVnAuyzY0nYgobZJwtMZkxD2ScB2NiEg2yTkOQcULWOZFRIvOU1Mg8FS/IPC8ckHkOXJF5riRknoT/pb1t6iwPetFIH3jNY660i/khw/3dq4W09ZbNIbN1TjOeFD2iB2T1KmIM0x0yuhOxbod81vueWK0GQDa3IuZ1kM2bifkdZPM94s4CuRxN3GUhl2KvC7kUez3I5TjiLge5/Ji4s0AuBxPzO8jmbsS8GrLZ4G9itVoM8nkssW6CjLb3BDFGaoCcdnU/KXxMb8hrnZ18Ttr82UHqILvtrO50j/vOaDKpyY/ecKWNdYJst1MP/7fxHwtYyprWtrGNrG0pfcyqDjI7r22d6V4faCJttfjOa4Y6155WMwuUpsEw5spQjW62d7tvif+H4YapCAkFYkaofB1DNJEaIqFAzAgVdrCTkaS2SCgQM0Jla/uQ1BoJBWJGqKTBTaT2SCgQM0IFfXxMEkBCgZgR/I2MJSkgoUDMCPaWmkkSSCgQM4K7pmaSBhIKxIxgLqCRJIKEAjEjePWGk1SQUCBmBO8kksgoj0BCgZgRrDn8Q+zfDXKkzaxt0gb2coX3SMVNnnG85XSAlAIxI1hXEneEzbWH6fsYpJX4zV52mlXVQ2qBmBGcWY0jXquTdYC21/En8YY7z7q6QoqBmBGc44jXag8o7Ot3Yp0DiQZiRnDeI97FYGyglTj/mgvSDMSMYCxGvG91BWcQsa6BNAMxIxgHEe9gsBbVSpwxekCSgZgRjCHEGqcBvBeJtRckGYgZwfiGWA+CeSixnoAkAzEjFDcQ73AwBxCrST2kGIgZobgP8VYDs4MWYi0LKQZiRihej3izgvsZsfaEFAMxIxRvR6yJ2oP7IrFOhxQDMSMU70+sRrAfIdYNkGIgZoTi/Yn1I9gDiTUQUgzEjFC8P7F+BHsgsQZCioGYEYp3IlYj2A8TayCkGIgZoXgT4nUE91ViXQ0pBmJGKF6GePOC+w2xTocUAzEjFPcm3sZgdtNKrH0gxUDMCMZvxDoXzDWJtxqkGIgZwXicWO+CeT6xWvWCFAMxIxgnEm9xsNr5mlifQJKBmBGMJYl3K1hbEO8aSDIQM4JR52tiTbQMGPU+It56kGQgZgTndOJ9JEDxecT7XntIMhAzgjO7ZuI9rwGK9tJKvLMhzUDMCNZNxHxXP2izi0u0Em+cWSHNQMwI1hyaiDneXVbTHqad0zF+IO4FkGggZgTveOKP9qLbXOo813vYl8T/XW9INBAzgtfBf0ntdoBUAzEjmPP5m9TqVkg2EDOCu6ZmUps3dYFkAzEj2NtoIbV4z4yQbiBmBH9jY0j1R5gJEg7EjFBBHx+Taj+kAVIOxIxQSReXGU+q2ewYdZB0IGaEyhZzj4mkam/oD4kHYkaosI8PSJW+tb06SD0QM0JFnZyjhVRnuJ3UQ/qBmBEqWcQIUpU/3GAVKEUgZoQKttNEKh/nZWdaVXsoSSBmBP8kraToAdd51Pt+MoZM86v3PetOZ9hBfx2hRIGYEewzSeFZ6mBqnZ4mBShlIGYE9xBSeAOUPRAzgtlfCyn6UTcoeyBmBPNZUngalD4QM4LXjxRvDKUPxIzgnUCKl4XSB2JG8J4kxftB6QMxI3jfkeIfzQ9lD8SM4I0hxm/2UQ/lDsSM4I0i1p/usLul9IDyBmJG8D4jfpPvfekDwxS95RlPutMljrGlxdRD2oGYEbyHSU1a/Ncl1tcR0g3EjODtT2r2l1stC6kGYkbwehhDavi69SHNQMwI5mmkpk+YF1IMxIxgdvIBqWmj7SDBQMwIbl+NpLZnQHqBmBHsdTST2l4GyQViRvDXMprU9hhILRAzQgWLGkZqOsFqkFggZoRKOtrPd6SWX+oMaQViRqhgUcd7QTOp6dGQViBmBLeXw71Pav6LLpBUIGYEb1aXaSIp7AlJBWJGcDo50RiSxtOQVCBmBKOv90gqE/SClAIxIxRvbSxJZyNIqZ35mF2hcC8TSUJnQwm30krMH93jOJtYTX/zaXNhS5m0lq0c7GxDfWoi8R+B8vXRRKx/3GpVdVBBd1sYrImY70PpOhhJrEHmgIpncivxfofSHUCcJttBVU4g1hgoW72fiNFkFajSY8RC2XYkzh5QrRWJhbI9SIxXoGp1GokxHkpWbxwxNoPqDSPGL1CyZYgxXheo3hvEeBdKthMxPoYqfkaMB6BkJxHjVaheMIEYZ0HJziXGO1C9vYizBZTscmKM1R6q1cnnxJioN5TsLOKsCdW6ljhvQtmOIc7jUKVTiXUElG0HYu0O1ejhJmI1mxHKNoBYzTaFiuvs4mfi3Qql6+RfYk10tk5QUXube4OY4y0I5XuUmF/bUxdwO1jRxb4n9uVQwn2J/ZdbbWNWKGpnXhs42SMaSQXfC1DCHhpJJT97we0uca5jHeJYk45znmsN9JJP/UsqnGAtKOWFJJ2ToZwz+J2kcqs6KOkuJJGB2kNZ69xFkrhaeyhvF2+S2v/jICh1T6+TWn9qAJS8m8dITce7WAOUvs6xWkjtnrEYZGFpw0mNXrMB5KKdPXxNqj/OIMtDTjra0eukqhM9azcBsrOg03xMqvSLIXYzM2RqAfu600cmkIr+9oKL7GQRyFyDFe3hDHd4xcd+NZ601ehbIzzuNqfbyxrmhKx219Ns5jN5bj1N6g6pkZB5EldknisHZJ4DL8g8L9TIPBXPyDwlGSdknRMZQYOs0xCTKEjIOImCmMwKGWdDTCHnimxzJSemMkO2WRDTskWm2RHT0eUTWeaTLjE9Q/6QYX4YEm3RYYvssqVDFDDjgqxyYU4UM2JDQjZJbBgRFgVLzsgiZ5YUhE1GSc0Le+48kC0e3NnzQk1JRrQNAA=="
+	icon, err := parseImageDataURL(iconURL)
+	if err != nil {
+		t.Fatalf(`We should be able to parse valid data URL: %v`, err)
+	}
+
+	if icon.MimeType != "image/webp" {
+		t.Fatal(`Invalid mime type parsed`)
+	}
+
+	if icon.Hash == "" {
+		t.Fatal(`Image hash should be computed`)
+	}
+}
+
+func TestParseInvalidImageDataURLWithBadMimeType(t *testing.T) {
+	_, err := parseImageDataURL("data:text/plain;base64,blob")
+	if err == nil {
+		t.Fatal(`We should detect invalid mime type`)
+	}
+}
+
+func TestParseInvalidImageDataURLWithUnsupportedEncoding(t *testing.T) {
+	_, err := parseImageDataURL("data:image/png;base32,blob")
+	if err == nil {
+		t.Fatal(`We should detect unsupported encoding`)
+	}
+}
+
+func TestParseInvalidImageDataURLWithInvalidEncodedData(t *testing.T) {
+	_, err := parseImageDataURL("data:image/png;base64,")
+	if err == nil {
+		t.Fatal(`We should detect invalid encoded data`)
+	}
+}
+
+func TestParseInvalidImageDataURL(t *testing.T) {
+	_, err := parseImageDataURL("data:image/jpeg")
+	if err == nil {
+		t.Fatal(`We should detect malformed image data URL`)
+	}
+}