feat(ref-imp): #781 - make jcs long form do size check on delta

decentralized-identity · Sep 23, 2020 · f71108c · f71108c
1 parent 5808eaf
commit f71108c
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diff --git a/lib/core/versions/latest/Delta.ts b/lib/core/versions/latest/Delta.ts
@@ -19,4 +19,18 @@ export default class Delta {
       throw new SidetreeError(ErrorCode.DeltaExceedsMaximumSize, errorMessage);
     }
   }
+
+  /**
+   * Validates size of the delta object
+   * TODO: SIP 2 #781 make observer check that the chunk file is cannonicalized, so we know that no filler characters are used
+   * Once we know there are no filler characters, it is valid to do size check on delta object because we know the object size === size in file
+   */
+  public static validateDeltaSize (delta: object) {
+    const size = Buffer.byteLength(JSON.stringify(delta), 'utf8');
+    if (size > ProtocolParameters.maxDeltaSizeInBytes) {
+      const errorMessage = `${size} bytes of 'delta' exceeded limit of ${ProtocolParameters.maxDeltaSizeInBytes} bytes.`;
+      console.info(errorMessage);
+      throw new SidetreeError(ErrorCode.DeltaExceedsMaximumSize, errorMessage);
+    }
+  }
 }
diff --git a/lib/core/versions/latest/Did.ts b/lib/core/versions/latest/Did.ts
@@ -178,6 +178,7 @@ export default class Did {
     }
 
     Did.validateInitialState(initialStateEncodedJcs, initialStateObject);
+    Delta.validateDeltaSize(initialStateObject.delta);
 
     const createOperationRequest = {
       type: OperationType.Create,

diff --git a/tests/core/Did.spec.ts b/tests/core/Did.spec.ts
@@ -3,6 +3,7 @@ import Did from '../../lib/core/versions/latest/Did';
 import Encoder from '../../lib/core/versions/latest/Encoder';
 import ErrorCode from '../../lib/core/versions/latest/ErrorCode';
 import JasmineSidetreeErrorValidator from '../JasmineSidetreeErrorValidator';
+import JsonCanonicalizer from '../../lib/core/versions/latest/util/JsonCanonicalizer';
 import OperationGenerator from '../generators/OperationGenerator';
 import SidetreeError from '../../lib/common/SidetreeError';
 
@@ -27,6 +28,19 @@ describe('DID', async () => {
         expect(e).toEqual(new SidetreeError(ErrorCode.DidInitialStateJcsIsNotJcs, 'Initial state object and JCS string mismatch.'));
       }
     });
+
+    it('should throw sidetree error if delta exceeds size limit', () => {
+      const largeData = crypto.randomBytes(2000).toString('hex');// Intentionally exceeding max size.
+      const largeDelta = { data: largeData };
+      const testInitialState = Encoder.encode(JsonCanonicalizer.canonicalizeAsBuffer({ suffix_data: 'some data', delta: largeDelta }));
+
+      try {
+        Did['constructCreateOperationFromEncodedJcs'](testInitialState);
+        fail('expect to throw sidetree error but did not');
+      } catch (e) {
+        expect(e.code).toEqual(ErrorCode.DeltaExceedsMaximumSize);
+      }
+    })
   });
 
   describe('create()', async () => {