Access sharing example (#276)

Co-authored-by: upalinski <[email protected]>

examples/node/7-private-bucket-access-sharing/index.ts

@@ -0,0 +1,75 @@
+import { DdcClient, File, TESTNET, AuthToken, UriSigner, AuthTokenOperation } from '@cere-ddc-sdk/ddc-client';
+import path from 'path';
+import { fileURLToPath } from 'url';
+import * as fs from 'fs';
+
+// The Bob's wallet should have enough CERE to pay for the transaction fees
+const bob = 'hybrid label reunion only dawn maze asset draft cousin height flock nation';
+const bobSigner = new UriSigner(bob);
+/**
+ * The Alice wallet doesn't require any tokens because it accesses Bob's bucket so Bob pays for it.
+ * Actually the Alice doesn't need to have a wallet on blockchain, it can be a simple key pair used to sign access tokens.
+ */
+const alice = 'system visit notice before step medal top theme oblige river inner bracket';
+const aliceSigner = new UriSigner(alice);
+
+// The DDC cluster where the bucket will be created (mainnet cluster id is '0x0059f5ada35eee46802d80750d5ca4a490640511')
+const clusterId = '0x825c4b2352850de9986d9d28568db6f0c023a1e3';
+
+// Create a DDC client instance
+const client = await DdcClient.create(bob, TESTNET);
+
+// Create a private bucket
+const bucketId = await client.createBucket(clusterId, { isPublic: false });
+console.log('Private bucket created', bucketId);
+
+// Detect the current directory
+const dir = path.dirname(fileURLToPath(import.meta.url));
+
+const pathToFileToUpload = path.resolve(dir, '../assets/nature.jpg');
+
+// Upload file
+const fileSize = fs.statSync(pathToFileToUpload).size;
+const fileToUpload = new File(fs.createReadStream(pathToFileToUpload), { size: fileSize });
+const uploadedFileUri = await client.store(bucketId, fileToUpload);
+console.log('File stored into bucket', bucketId, 'with CID', uploadedFileUri.cid);
+console.log(
+  "The file can't be accessed by this URL because bucket is private and access token required",
+  `https://cdn.testnet.cere.network/${bucketId}/${uploadedFileUri.cid}`,
+);
+
+// Create an access token that is signed by a Bob and can be shared so that anyone having this token can access a bucket (or specific file)
+const bobToken = new AuthToken({
+  bucketId,
+  pieceCid: uploadedFileUri.cid,
+  operations: [AuthTokenOperation.GET],
+});
+await bobToken.sign(bobSigner);
+console.log(
+  "The file can be accessed by this URL (Bob's token passed in query parameters)",
+  `https://cdn.testnet.cere.network/${bucketId}/${uploadedFileUri.cid}?token=${bobToken.toString()}`,
+);
+
+/**
+ * Create an access token that is signed by a Bob and is granted to Alice so that only Alice can use this token to access a content.
+ * The Bobs token can't be used directly because he has specified an Alice in a token 'subject' so this token should be wrapped into another token that is signed by Alice
+ */
+const bobTokenGrantedToAlice = await client.grantAccess(aliceSigner.address, {
+  bucketId,
+  operations: [AuthTokenOperation.GET],
+  pieceCid: uploadedFileUri.cid,
+});
+// Alice wraps Bob's token (aka token chain) and sign wrapped token by Alice key pair. The token expiration time is 5 minutes.
+const aliceToken = new AuthToken({
+  operations: [AuthTokenOperation.GET],
+  pieceCid: uploadedFileUri.cid,
+  prev: bobTokenGrantedToAlice,
+  expiresIn: 5 * 60 * 1000,
+});
+await aliceToken.sign(aliceSigner);
+console.log(
+  "The file can be accessed by this URL (Alice's token passed in query parameters)",
+  `https://cdn.testnet.cere.network/${bucketId}/${uploadedFileUri.cid}?token=${aliceToken.toString()}`,
+);
+
+await client.disconnect();

examples/node/README.md

@@ -8,6 +8,7 @@ This examples directory contains several common DDC SDK use-cases for NodeJs app
 - [How to stream events](./4-store-read-events/index.ts)
 - [How to use exported account (Cere Wallet)](./5-use-exported-account/index.ts)
 - [How to index files so that they are visible in Developer Console](./6-developer-console-compatibility/index.ts)
+- [How to share access to a content in private bucket](./7-private-bucket-access-sharing/index.ts)
 
 ## Quick start
 
@@ -40,7 +41,7 @@ Run the following commands from the project root
 5. Run an example
 
    ```bash
-   npm run example:1 # can be 1-6
+   npm run example:1 # can be 1-7
    ```
 
 

examples/node/package.json

@@ -9,7 +9,8 @@
     "example:3": "ts-node --esm ./3-upload-website/index.ts",
     "example:4": "ts-node --esm ./4-store-read-events/index.ts",
     "example:5": "ts-node --esm ./5-use-exported-account/index.ts",
-    "example:6": "ts-node --esm ./6-developer-console-compatibility/index.ts"
+    "example:6": "ts-node --esm ./6-developer-console-compatibility/index.ts",
+    "example:7": "ts-node --esm ./7-private-bucket-access-sharing/index.ts"
   },
   "dependencies": {
     "@cere-ddc-sdk/ddc-client": "2.13.0",