fix error sharing image and failing to upload, fix upload in webkit/safari, and test it

src/libs/util.ts

@@ -26,6 +26,7 @@ import { createPeerDid } from "@/libs/crypto/vc/didPeer";
 
 export const PRIVACY_MESSAGE =
   "The data you send will be visible to the world -- except: your IDs and the IDs of anyone you tag will stay private, only visible to them and others you explicitly allow.";
+export const SHARED_PHOTO_BASE64_KEY = "shared-photo-base64";
 
 /* eslint-disable prettier/prettier */
 export const UNIT_SHORT: Record<string, string> = {
@@ -116,6 +117,38 @@ export const isGiveRecordTheUserCanConfirm = (
   );
 };
 
+export async function blobToBase64(blob: Blob): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onloadend = () => resolve(reader.result as string); // potential problem if it returns an ArrayBuffer?
+    reader.onerror = reject;
+    reader.readAsDataURL(blob);
+  });
+}
+
+export function base64ToBlob(base64DataUrl: string, sliceSize = 512) {
+  // Extract the content type and the Base64 data
+  const [metadata, base64] = base64DataUrl.split(",");
+  const contentTypeMatch = metadata.match(/data:(.*?);base64/);
+  const contentType = contentTypeMatch ? contentTypeMatch[1] : "";
+
+  const byteCharacters = atob(base64);
+  const byteArrays = [];
+
+  for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {
+    const slice = byteCharacters.slice(offset, offset + sliceSize);
+
+    const byteNumbers = new Array(slice.length);
+    for (let i = 0; i < slice.length; i++) {
+      byteNumbers[i] = slice.charCodeAt(i);
+    }
+
+    const byteArray = new Uint8Array(byteNumbers);
+    byteArrays.push(byteArray);
+  }
+  return new Blob(byteArrays, { type: contentType });
+}
+
 /**
  * @returns the DID of the person who offered, or undefined if hidden
  * @param veriClaim is expected to have fields: claim and issuer