ci(NODE-5668): remove custom dep tests against master and fix prose test 14

.evergreen/config.yml

@@ -3069,23 +3069,6 @@ tasks:
       - func: bootstrap mongo-orchestration
       - func: bootstrap kms servers
       - func: run custom csfle tests
-  - name: run-custom-csfle-tests-5.0-master
-    tags:
-      - run-custom-dependency-tests
-    commands:
-      - command: expansions.update
-        type: setup
-        params:
-          updates:
-            - {key: NODE_LTS_VERSION, value: '14'}
-            - {key: NPM_VERSION, value: '9'}
-            - {key: VERSION, value: '5.0'}
-            - {key: TOPOLOGY, value: replica_set}
-            - {key: CSFLE_GIT_REF, value: master}
-      - func: install dependencies
-      - func: bootstrap mongo-orchestration
-      - func: bootstrap kms servers
-      - func: run custom csfle tests
   - name: run-custom-csfle-tests-rapid-pinned-commit
     tags:
       - run-custom-dependency-tests
@@ -3103,23 +3086,6 @@ tasks:
       - func: bootstrap mongo-orchestration
       - func: bootstrap kms servers
       - func: run custom csfle tests
-  - name: run-custom-csfle-tests-rapid-master
-    tags:
-      - run-custom-dependency-tests
-    commands:
-      - command: expansions.update
-        type: setup
-        params:
-          updates:
-            - {key: NODE_LTS_VERSION, value: '14'}
-            - {key: NPM_VERSION, value: '9'}
-            - {key: VERSION, value: rapid}
-            - {key: TOPOLOGY, value: replica_set}
-            - {key: CSFLE_GIT_REF, value: master}
-      - func: install dependencies
-      - func: bootstrap mongo-orchestration
-      - func: bootstrap kms servers
-      - func: run custom csfle tests
   - name: run-custom-csfle-tests-latest-pinned-commit
     tags:
       - run-custom-dependency-tests
@@ -3137,23 +3103,6 @@ tasks:
       - func: bootstrap mongo-orchestration
       - func: bootstrap kms servers
       - func: run custom csfle tests
-  - name: run-custom-csfle-tests-latest-master
-    tags:
-      - run-custom-dependency-tests
-    commands:
-      - command: expansions.update
-        type: setup
-        params:
-          updates:
-            - {key: NODE_LTS_VERSION, value: '14'}
-            - {key: NPM_VERSION, value: '9'}
-            - {key: VERSION, value: latest}
-            - {key: TOPOLOGY, value: replica_set}
-            - {key: CSFLE_GIT_REF, value: master}
-      - func: install dependencies
-      - func: bootstrap mongo-orchestration
-      - func: bootstrap kms servers
-      - func: run custom csfle tests
   - name: test-latest-server-noauth
     tags:
       - latest
@@ -4483,11 +4432,8 @@ buildvariants:
     run_on: rhel80-large
     tasks:
       - run-custom-csfle-tests-5.0-pinned-commit
-      - run-custom-csfle-tests-5.0-master
       - run-custom-csfle-tests-rapid-pinned-commit
-      - run-custom-csfle-tests-rapid-master
       - run-custom-csfle-tests-latest-pinned-commit
-      - run-custom-csfle-tests-latest-master
   - name: rhel8-test-serverless
     display_name: Serverless Test
     run_on: rhel80-large

.evergreen/generate_evergreen_tasks.js

@@ -611,28 +611,24 @@ BUILD_VARIANTS.push({
 
 const oneOffFuncAsTasks = [];
 
-const FLE_PINNED_COMMIT = 'c56c70340093070b1ef5c8a28190187eea21a6e9';
-
 for (const version of ['5.0', 'rapid', 'latest']) {
-  for (const ref of [FLE_PINNED_COMMIT, 'master']) {
-    oneOffFuncAsTasks.push({
-      name: `run-custom-csfle-tests-${version}-${ref === 'master' ? ref : 'pinned-commit'}`,
-      tags: ['run-custom-dependency-tests'],
-      commands: [
-        updateExpansions({
-          NODE_LTS_VERSION: LOWEST_LTS,
-          NPM_VERSION: 9,
-          VERSION: version,
-          TOPOLOGY: 'replica_set',
-          CSFLE_GIT_REF: ref
-        }),
-        { func: 'install dependencies' },
-        { func: 'bootstrap mongo-orchestration' },
-        { func: 'bootstrap kms servers' },
-        { func: 'run custom csfle tests' }
-      ]
-    });
-  }
+  oneOffFuncAsTasks.push({
+    name: `run-custom-csfle-tests-${version}-pinned-commit`,
+    tags: ['run-custom-dependency-tests'],
+    commands: [
+      updateExpansions({
+        NODE_LTS_VERSION: LOWEST_LTS,
+        NPM_VERSION: 9,
+        VERSION: version,
+        TOPOLOGY: 'replica_set',
+        CSFLE_GIT_REF: 'c56c70340093070b1ef5c8a28190187eea21a6e9'
+      }),
+      { func: 'install dependencies' },
+      { func: 'bootstrap mongo-orchestration' },
+      { func: 'bootstrap kms servers' },
+      { func: 'run custom csfle tests' }
+    ]
+  });
 }
 
 const coverageTask = {

test/integration/client-side-encryption/client_side_encryption.prose.14.decryption_events.test.ts

@@ -74,10 +74,12 @@ describe('14. Decryption Events', metadata, function () {
       keyId: keyId,
       algorithm: 'AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic'
     });
-    // Copy ``ciphertext`` into a variable named ``malformedCiphertext``.
-    // Change the last byte to 0. This will produce an invalid HMAC tag.
+    // Copy ``ciphertext`` into a variable named ``malformedCiphertext``. Change the
+    // last byte to a different value. This will produce an invalid HMAC tag.
     const buffer = Buffer.from(cipherText.buffer);
-    buffer.writeInt8(0, buffer.length - 1);
+    const lastByte = buffer.readUInt8(buffer.length - 1);
+    const replacementByte = lastByte === 0 ? 1 : 0;
+    buffer.writeUInt8(replacementByte, buffer.length - 1);
     malformedCiphertext = new Binary(buffer, 6);
     // Create a MongoClient named ``encryptedClient`` with these ``AutoEncryptionOpts``:
     //   AutoEncryptionOpts {