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SyncVals · Trajectory

secrets-rotation-kms

claude-code claude-opus-4-7 ✗ failed GOOD_FAILURE ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_FAILUREHonest miss, the agent ran correctly but couldn't solve it. Expected for a hard task; the task is sound.
SubtypeIncomplete Exploration
EvidenceTest output shows 7/8 tests passing including test_rotate_secret_advances_awscurrent (rotation works), but test_kms_key_policy_grants_lambda_role fails with: 'KMS key policy on alias/app-rotation-key has no Allow statement granting [kms:Decrypt, kms:GenerateDataKey] to principal arn:aws:iam::000000000000:role/secrets-rotator-role'. Agent trajectory shows the agent correctly: (1) fixed handler.py finish_secret to promote AWSPENDING to AWSCURRENT, (2) added Lambda invoke permission for secretsmanager.amazonaws.com, (3) added KMS actions to IAM role policy. Agent did NOT update the KMS key policy itself to grant the role permissions.
Root causeThe agent addressed the role's KMS permissions but overlooked that a customer-managed KMS CMK also requires an explicit allow statement in the key policy itself (not just the role policy). While the task description mentions 'the CMK key policy granting the role' needs fixing, the main instruction.md doesn't explicitly state this, requiring the agent to infer it from AWS security patterns or discover it through exploration.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
13 tool calls · 3 tool types · 21 steps
# Make AWS Secrets Manager rotation actually rotate You are working against a LocalStack AWS endpoint at `http://localstack:4566`. The container already has `aws` (AWS CLI v2), `python3`, `boto3`, `jq`, `zip`, and `curl` installed. `AWS_ENDPOINT_URL`, `AWS_ACCESS_KEY_ID=test`, `AWS_SECRET_ACCESS_KEY=test`, and `AWS_DEFAULT_REGION=us-east-1` are already exported. The environment has been pre-seeded by `/app/setup.sh` with a **partially-deployed, broken-by-design** Secrets Manager rotation setup. You must diagnose what's wrong and make rotation actually advance the secret to a new value. ## Starter resources Every resource below already exists , do not rename or recreate unless you know what you're doing: - **Secret**: `app/db/password`, encrypted with a customer-managed CMK - **KMS CMK**: alias `alias/app-rotation-key` (symmetric ENCRYPT_DECRYPT) - **Rotation Lambda**: function `secrets-rotator`, runtime `python3.11`, source on disk at `/app/handler.py` - **IAM role**: `secrets-rotator-role` (inline policy `SecretsRotatorPolicy`) with the Lambda's execution permissions - **Rotation config** is already attached to the secret (pointing at the rotation Lambda), but invoking it fails , the layers needed to actually carry out the rotation are broken. ## Required outcome After your fix, running ```bash aws secretsmanager rotate-secret --secret-id app/db/password ``` must: 1. **Succeed without error.** 2. **Advance `AWSCURRENT`** to a fresh version ID , the version that holds the `AWSCURRENT` label after rotation must be different from the version that held it before, and the string value returned by `get-secret-value` must change. 3. **Label the prior version as `AWSPREVIOUS`.** The verifier inspects both the end-to-end behaviour and the shape of the underlying IAM / KMS / Lambda configuration. Least privilege matters , the grader reads policy documents directly. The rotation Lambda source lives at `/app/handler.py`; redeploy with `aws lambda update-function-code --zip-file fileb://...`. LocalStack spawns Lambda containers on the shared compose network, so `http://localstack:4566` is reachable from inside the function.

List /app directory

shell
ls -la /app/
output
total 28
drwxr-xr-x 1 root root 4096 Apr 22 19:10 .
drwxr-xr-x 1 root root 4096 Apr 22 19:21 ..
-rw-r--r-- 1 root root 4137 Apr 22 19:10 handler.py
-rwxr-xr-x 1 root root 6097 Apr 22 19:10 setup.sh
drwxr-xr-x 2 root root 4096 Apr 22 19:10 starter

[stdout]
total 28
drwxr-xr-x 1 root root 4096 Apr 22 19:10 .
drwxr-xr-x 1 root root 4096 Apr 22 19:21 ..
-rw-r--r-- 1 root root 4137 Apr 22 19:10 handler.py
-rwxr-xr-x 1 root root 6097 Apr 22 19:10 setup.sh
drwxr-xr-x 2 root root 4096 Apr 22 19:10 starter

/app/setup.sh

contents
1	#!/bin/bash
2	# Seeds LocalStack with the broken-by-design state the agent inherits:
3	#   - customer-managed KMS CMK (alias alias/app-rotation-key)
4	#   - Secrets Manager secret encrypted with that CMK
5	#   - IAM role for the rotation Lambda (with deliberately incomplete policy)
6	#   - Rotation Lambda (with a subtle bug in finishSecret)
7	#   - Rotation configured on the secret, pointing at the Lambda
8	#
9	# The task expects these resources to already exist when the agent starts
10	# working. The agent must find the bugs and make `rotate-secret` actually
11	# advance AWSCURRENT end-to-end.
12	
13	set -euo pipefail
14	
15	REGION="${AWS_DEFAULT_REGION:-us-east-1}"
16	ACCOUNT_ID="000000000000"
17	SECRET_NAME="app/db/password"
18	ROLE_NAME="secrets-rotator-role"
19	FUNCTION="secrets-rotator"
20	KEY_ALIAS="alias/app-rotation-key"
21	
22	log() { echo "[setup] $*" >&2; }
23	
24	log "waiting for localstack health..."
25	for _ in $(seq 1 60); do
26	  if curl -sf http://localstack:4566/_localstack/health | grep -q '"secretsmanager": "available"'; then
27	    break
28	  fi
29	  sleep 2
30	done
31	
32	# 1. CMK with a minimal key policy (root admin only , no grant for the
33	#    rotation Lambda role yet).
34	log "creating KMS CMK"
35	KEY_POLICY=$(cat <<JSON
36	{
37	  "Version": "2012-10-17",
38	  "Id": "app-rotation-key-policy",
39	  "Statement": [
40	    {
41	      "Sid": "EnableRootAdmin",
42	      "Effect": "Allow",
43	      "Principal": { "AWS": "arn:aws:iam::${ACCOUNT_ID}:root" },
44	      "Action": "kms:*",
45	      "Resource": "*"
46	    }
47	  ]
48	}
49	JSON
50	)
51	KEY_ID=$(aws kms create-key \
52	  --description "Customer CMK for app/db/password" \
53	  --key-usage ENCRYPT_DECRYPT \
54	  --policy "$KEY_POLICY" \
55	  --query 'KeyMetadata.KeyId' --output text)
56	aws kms create-alias --alias-name "$KEY_ALIAS" --target-key-id "$KEY_ID" >/dev/null
57	KEY_ARN="arn:aws:kms:${REGION}:${ACCOUNT_ID}:key/${KEY_ID}"
58	log "created CMK $KEY_ID"
59	
60	# 2. Secret, encrypted with the CMK.
61	log "creating secret"
62	aws secretsmanager create-secret \
63	  --name "$SECRET_NAME" \
64	  --kms-key-id "$KEY_ARN" \
65	  --secret-string '{"password": "initial-placeholder-value"}' \
66	  --description "App DB password, rotated by Lambda" >/dev/null
67	
68	SECRET_ARN=$(aws secretsmanager describe-secret --secret-id "$SECRET_NAME" \
69	  --query 'ARN' --output text)
70	log "created secret $SECRET_ARN"
71	
72	# 3. IAM role for the rotation Lambda. Deliberately incomplete , has
73	#    secretsmanager:* but no KMS actions. The broken state the agent
74	#    inherits.
75	log "creating rotation Lambda role"
76	TRUST=$(cat <<'JSON'
77	{
78	  "Version": "2012-10-17",
79	  "Statement": [
80	    {"Effect": "Allow", "Principal": {"Service": "lambda.amazonaws.com"}, "Action": "sts:AssumeRole"}
81	  ]
82	}
83	JSON
84	)
85	aws iam create-role \
86	  --role-name "$ROLE_NAME" \
87	  --assume-role-policy-document "$TRUST" >/dev/null
88	
89	aws iam attach-role-policy \
90	  --role-name "$ROLE_NAME" \
91	  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
92	
93	INLINE=$(cat <<JSON
94	{
95	  "Version": "2012-10-17",
96	  "Statement": [
97	    {
98	      "Effect": "Allow",
99	      "Action": [
100	        "secretsmanager:DescribeSecret",
101	        "secretsmanager:GetSecretValue",
102	        "secretsmanager:PutSecretValue",
103	        "secretsmanager:UpdateSecretVersionStage"
104	      ],
105	      "Resource": "${SECRET_ARN}"
106	    },
107	    {
108	      "Effect": "Allow",
109	      "Action": "secretsmanager:GetRandomPassword",
110	      "Resource": "*"
111	    }
112	  ]
113	}
114	JSON
115	)
116	aws iam put-role-policy \
117	  --role-name "$ROLE_NAME" \
118	  --policy-name SecretsRotatorPolicy \
119	  --policy-document "$INLINE"
120	
121	ROLE_ARN=$(aws iam get-role --role-name "$ROLE_NAME" --query 'Role.Arn' --output text)
122	log "created role $ROLE_ARN"
123	
124	# 4. Package + deploy the rotation Lambda (with its buggy handler).
125	log "packaging rotation Lambda"
126	WORKDIR="$(mktemp -d)"
127	cp /app/handler.py "${WORKDIR}/handler.py"
128	(cd "$WORKDIR" && zip -q handler.zip handler.py)
129	
130	aws lambda create-function \
131	  --function-name "$FUNCTION" \
132	  --runtime python3.11 \
133	  --role "$ROLE_ARN" \
134	  --handler handler.lambda_handler \
135	  --timeout 30 \
136	  --memory-size 256 \
137	  --environment "Variables={SECRETS_MANAGER_ENDPOINT=http://localstack:4566}" \
138	  --zip-file "fileb://${WORKDIR}/handler.zip" >/dev/null
139	
140	for _ in $(seq 1 30); do
141	  STATE=$(aws lambda get-function --function-name "$FUNCTION" \
142	    --query 'Configuration.State' --output text 2>/dev/null || echo "Pending")
143	  [ "$STATE" = "Active" ] && break
144	  sleep 1
145	done
146	log "Lambda $FUNCTION active"
147	
148	# NOTE: deliberately NOT calling `aws lambda add-permission` with
149	# principal secretsmanager.amazonaws.com. The agent must add that.
150	
151	# 5. Attach rotation config on the secret. Secrets Manager refuses to
152	#    attach unless the rotation Lambda already grants it InvokeFunction,
153	#    so we temporarily add that permission, attach rotation, then remove
154	#    the permission so the agent still has to re-add it as part of their
155	#    fix. Net result: RotationEnabled=true but rotation fails at runtime
156	#    because of the other broken layers (KMS grants, handler bug, Lambda
157	#    resource policy).
158	log "attaching rotation config (temp Lambda permission)"
159	FUNCTION_ARN="arn:aws:lambda:${REGION}:${ACCOUNT_ID}:function:${FUNCTION}"
160	aws lambda add-permission \
161	  --function-name "$FUNCTION" \
162	  --statement-id TempRotationSetup \
163	  --action lambda:InvokeFunction \
164	  --principal secretsmanager.amazonaws.com \
165	  --source-arn "$SECRET_ARN" >/dev/null 2>&1 || true
166	
167	if aws secretsmanager rotate-secret \
168	     --secret-id "$SECRET_NAME" \
169	     --rotation-lambda-arn "$FUNCTION_ARN" \
170	     --rotation-rules AutomaticallyAfterDays=30 \
171	     --no-rotate-immediately >/dev/null 2>&1; then
172	  log "rotation attached (no immediate trigger)"
173	elif aws secretsmanager rotate-secret \
174	       --secret-id "$SECRET_NAME" \
175	       --rotation-lambda-arn "$FUNCTION_ARN" \
176	       --rotation-rules AutomaticallyAfterDays=30 >/dev/null 2>&1; then
177	  log "rotation attached (first run may have fired)"
178	else
179	  log "rotate-secret failed even with temp permission , check LocalStack compat"
180	fi
181	
182	# Strip the temp permission so the agent still has to add it.
183	aws lambda remove-permission \
184	  --function-name "$FUNCTION" \
185	  --statement-id TempRotationSetup >/dev/null 2>&1 || true
186	
187	log "done"
188

/app/handler.py

contents
1	# Rotation Lambda for AWS Secrets Manager, "single-user" pattern
2	# (no external database, value is self-contained).
3	#
4	# Secrets Manager calls this function 4 times in sequence per rotation,
5	# passing a Step field: createSecret, setSecret, testSecret, finishSecret.
6	# Each step must return cleanly for the rotation to advance.
7	#
8	# Reference:
9	#   https://docs.aws.amazon.com/secretsmanager/latest/userguide/rotate-secrets_lambda-functions.html
10	
11	import json
12	import logging
13	import os
14	
15	import boto3
16	
17	logger = logging.getLogger()
18	logger.setLevel(logging.INFO)
19	
20	ENDPOINT = os.environ.get("SECRETS_MANAGER_ENDPOINT") or os.environ.get(
21	    "AWS_ENDPOINT_URL"
22	)
23	
24	
25	def _client():
26	    return boto3.client("secretsmanager", endpoint_url=ENDPOINT) if ENDPOINT else boto3.client("secretsmanager")
27	
28	
29	def lambda_handler(event, context):
30	    arn = event["SecretId"]
31	    token = event["ClientRequestToken"]
32	    step = event["Step"]
33	
34	    client = _client()
35	
36	    desc = client.describe_secret(SecretId=arn)
37	    if not desc.get("RotationEnabled"):
38	        logger.error("Secret %s is not enabled for rotation", arn)
39	        raise ValueError(f"Secret {arn} is not enabled for rotation")
40	
41	    versions = desc.get("VersionIdsToStages", {})
42	    if token not in versions:
43	        logger.error("Secret version %s has no stage for rotation of %s", token, arn)
44	        raise ValueError(f"Secret version {token} has no stage for rotation of secret {arn}")
45	    if "AWSCURRENT" in versions[token]:
46	        logger.info("Secret version %s already AWSCURRENT for %s", token, arn)
47	        return
48	    if "AWSPENDING" not in versions[token]:
49	        logger.error("Secret version %s not staged as AWSPENDING for %s", token, arn)
50	        raise ValueError(f"Secret version {token} not set as AWSPENDING for rotation of secret {arn}")
51	
52	    if step == "createSecret":
53	        create_secret(client, arn, token)
54	    elif step == "setSecret":
55	        set_secret(client, arn, token)
56	    elif step == "testSecret":
57	        test_secret(client, arn, token)
58	    elif step == "finishSecret":
59	        finish_secret(client, arn, token)
60	    else:
61	        raise ValueError(f"Invalid step parameter: {step}")
62	
63	
64	def create_secret(client, arn, token):
65	    # Generate a new candidate value and stash it as AWSPENDING.
66	    client.get_secret_value(SecretId=arn, VersionStage="AWSCURRENT")
67	
68	    try:
69	        client.get_secret_value(SecretId=arn, VersionId=token, VersionStage="AWSPENDING")
70	        logger.info("createSecret: pending version %s already exists", token)
71	    except client.exceptions.ResourceNotFoundException:
72	        password = client.get_random_password(PasswordLength=32, ExcludePunctuation=True)
73	        client.put_secret_value(
74	            SecretId=arn,
75	            ClientRequestToken=token,
76	            SecretString=json.dumps({"password": password["RandomPassword"]}),
77	            VersionStages=["AWSPENDING"],
78	        )
79	        logger.info("createSecret: stored new AWSPENDING version %s", token)
80	
81	
82	def set_secret(client, arn, token):
83	    # No external system to update for a self-contained secret; validate
84	    # that both AWSCURRENT and AWSPENDING are readable and move on.
85	    client.get_secret_value(SecretId=arn, VersionStage="AWSCURRENT")
86	    client.get_secret_value(SecretId=arn, VersionId=token, VersionStage="AWSPENDING")
87	    logger.info("setSecret: both stages readable")
88	
89	
90	def test_secret(client, arn, token):
91	    # Sanity-check the pending value parses as JSON with a non-empty
92	    # password field. Real handlers would attempt a login here.
93	    pending = client.get_secret_value(SecretId=arn, VersionId=token, VersionStage="AWSPENDING")
94	    parsed = json.loads(pending["SecretString"])
95	    if not parsed.get("password"):
96	        raise ValueError("testSecret: pending value has no password")
97	    logger.info("testSecret: pending value validated")
98	
99	
100	def finish_secret(client, arn, token):
101	    # TODO: promote the AWSPENDING version to AWSCURRENT here.
102	    # Without this, rotation will appear to succeed from Secrets
103	    # Manager's orchestrator but AWSCURRENT never advances and
104	    # consumers keep reading the old password.
105	    logger.info("finishSecret: (no-op)")
106
I've identified the broken layers from handler.py and setup.sh. Let me verify the current state.

Describe secret

shell
aws secretsmanager describe-secret --secret-id app/db/password 2>&1 | head -40
output
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "Description": "App DB password, rotated by Lambda",
    "KmsKeyId": "arn:aws:kms:us-east-1:000000000000:key/78235e23-91ea-4053-93f8-1e2193243b1d",
    "RotationEnabled": true,
    "RotationLambdaARN": "arn:aws:lambda:us-east-1:000000000000:function:secrets-rotator",
    "RotationRules": {
        "AutomaticallyAfterDays": 30
    },
    "LastRotatedDate": "2026-04-22T19:21:20+00:00",
    "LastChangedDate": "2026-04-22T19:21:16.312000+00:00",
    "LastAccessedDate": "2026-04-22T00:00:00+00:00",
    "NextRotationDate": "2026-05-22T19:21:14+00:00",
    "VersionIdsToStages": {
        "fee6ddce-afbd-47d7-998e-365b118047f9": [
            "AWSCURRENT"
        ],
        "03762056-8c88-454f-b66e-5d31b070f5f3": [
            "AWSPENDING"
        ]
    },
    "CreatedDate": "2026-04-22T19:21:06.573974+00:00"
}

[stdout]
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "Description": "App DB password, rotated by Lambda",
    "KmsKeyId": "arn:aws:kms:us-east-1:000000000000:key/78235e23-91ea-4053-93f8-1e2193243b1d",
    "RotationEnabled": true,
    "RotationLambdaARN": "arn:aws:lambda:us-east-1:000000000000:function:secrets-rotator",
    "RotationRules": {
        "AutomaticallyAfterDays": 30
    },
    "LastRotatedDate": "2026-04-22T19:21:20+00:00",
    "LastChangedDate": "2026-04-22T19:21:16.312000+00:00",
    "LastAccessedDate": "2026-04-22T00:00:00+00:00",
    "NextRotationDate": "2026-05-22T19:21:14+00:00",
    "VersionIdsToStages": {
        "fee6ddce-afbd-47d7-998e-365b118047f9": [
            "AWSCURRENT"
        ],
        "03762056-8c88-454f-b66e-5d31b070f5f3": [
            "AWSPENDING"
        ]
    },
    "CreatedDate": "2026-04-22T19:21:06.573974+00:00"
}

Check lambda resource policy

shell
aws lambda get-policy --function-name secrets-rotator 2>&1
output
Exit code 254

aws: [ERROR]: An error occurred (ResourceNotFoundException) when calling the GetPolicy operation: The resource you requested does not exist.

Additional error details:
Type: User

[error] tool reported failure

Check KMS key policy

shell
aws kms describe-key --key-id alias/app-rotation-key --query 'KeyMetadata.KeyId' --output text && aws kms get-key-policy --key-id alias/app-rotation-key --policy-name default
output
78235e23-91ea-4053-93f8-1e2193243b1d
{
    "Policy": "{\n  \"Version\": \"2012-10-17\",\n  \"Id\": \"app-rotation-key-policy\",\n  \"Statement\": [\n    {\n      \"Sid\": \"EnableRootAdmin\",\n      \"Effect\": \"Allow\",\n      \"Principal\": { \"AWS\": \"arn:aws:iam::000000000000:root\" },\n      \"Action\": \"kms:*\",\n      \"Resource\": \"*\"\n    }\n  ]\n}"
}

[stdout]
78235e23-91ea-4053-93f8-1e2193243b1d
{
    "Policy": "{\n  \"Version\": \"2012-10-17\",\n  \"Id\": \"app-rotation-key-policy\",\n  \"Statement\": [\n    {\n      \"Sid\": \"EnableRootAdmin\",\n      \"Effect\": \"Allow\",\n      \"Principal\": { \"AWS\": \"arn:aws:iam::000000000000:root\" },\n      \"Action\": \"kms:*\",\n      \"Resource\": \"*\"\n    }\n  ]\n}"
}
Now I understand the broken state. Four layers need fixing: 1. `handler.py` `finish_secret` is a no-op , won't promote AWSPENDING → AWSCURRENT 2. Lambda has no `secretsmanager.amazonaws.com` invoke permission 3. IAM role has no KMS permissions (needed since secret uses a CMK) 4. Key policy is root-only (but delegates via IAM so fixing #3 suffices) Let me fix the handler first.

/app/handler.py

− removed
def finish_secret(client, arn, token):
    # TODO: promote the AWSPENDING version to AWSCURRENT here.
    # Without this, rotation will appear to succeed from Secrets
    # Manager's orchestrator but AWSCURRENT never advances and
    # consumers keep reading the old password.
    logger.info("finishSecret: (no-op)")
+ added
def finish_secret(client, arn, token):
    desc = client.describe_secret(SecretId=arn)
    current_version = None
    for version_id, stages in desc["VersionIdsToStages"].items():
        if "AWSCURRENT" in stages:
            if version_id == token:
                logger.info("finishSecret: %s already AWSCURRENT", token)
                return
            current_version = version_id
            break

    client.update_secret_version_stage(
        SecretId=arn,
        VersionStage="AWSCURRENT",
        MoveToVersionId=token,
        RemoveFromVersionId=current_version,
    )
    logger.info("finishSecret: moved AWSCURRENT to %s", token)
Now repackage and redeploy, add the Lambda invoke permission, and extend the IAM policy with KMS access scoped to the key.

Repackage and update Lambda code

shell
WORKDIR=$(mktemp -d) && cp /app/handler.py "$WORKDIR/handler.py" && (cd "$WORKDIR" && zip -q handler.zip handler.py) && aws lambda update-function-code --function-name secrets-rotator --zip-file "fileb://$WORKDIR/handler.zip" --query 'LastUpdateStatus' --output text
output
InProgress

[stdout]
InProgress

Wait for lambda update

shell
for _ in $(seq 1 30); do STATE=$(aws lambda get-function --function-name secrets-rotator --query 'Configuration.LastUpdateStatus' --output text); [ "$STATE" = "Successful" ] && echo "ready" && break; sleep 1; done
output
ready

[stdout]
ready

Allow Secrets Manager to invoke Lambda

shell
SECRET_ARN=$(aws secretsmanager describe-secret --secret-id app/db/password --query 'ARN' --output text) && aws lambda add-permission --function-name secrets-rotator --statement-id AllowSecretsManagerInvoke --action lambda:InvokeFunction --principal secretsmanager.amazonaws.com --source-arn "$SECRET_ARN"
output
{
    "Statement": "{\"Sid\": \"AllowSecretsManagerInvoke\", \"Effect\": \"Allow\", \"Action\": \"lambda:InvokeFunction\", \"Resource\": \"arn:aws:lambda:us-east-1:000000000000:function:secrets-rotator\", \"Principal\": {\"Service\": \"secretsmanager.amazonaws.com\"}, \"Condition\": {\"ArnLike\": {\"AWS:SourceArn\": \"arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT\"}}}"
}

[stdout]
{
    "Statement": "{\"Sid\": \"AllowSecretsManagerInvoke\", \"Effect\": \"Allow\", \"Action\": \"lambda:InvokeFunction\", \"Resource\": \"arn:aws:lambda:us-east-1:000000000000:function:secrets-rotator\", \"Principal\": {\"Service\": \"secretsmanager.amazonaws.com\"}, \"Condition\": {\"ArnLike\": {\"AWS:SourceArn\": \"arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT\"}}}"
}
Now the IAM policy , I'll extend `SecretsRotatorPolicy` with least-privilege KMS access scoped to the CMK, restricted to the Secrets Manager service via `kms:ViaService`.

Update Lambda role with KMS permissions

shell
SECRET_ARN=$(aws secretsmanager describe-secret --secret-id app/db/password --query 'ARN' --output text)
KEY_ARN=$(aws kms describe-key --key-id alias/app-rotation-key --query 'KeyMetadata.Arn' --output text)
echo "secret=$SECRET_ARN"
echo "key=$KEY_ARN"
cat > /tmp/policy.json <<JSON
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "secretsmanager:DescribeSecret",
        "secretsmanager:GetSecretValue",
        "secretsmanager:PutSecretValue",
        "secretsmanager:UpdateSecretVersionStage"
      ],
      "Resource": "${SECRET_ARN}"
    },
    {
      "Effect": "Allow",
      "Action": "secretsmanager:GetRandomPassword",
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "kms:Decrypt",
        "kms:GenerateDataKey"
      ],
      "Resource": "${KEY_ARN}",
      "Condition": {
        "StringEquals": {
          "kms:ViaService": "secretsmanager.us-east-1.amazonaws.com"
        }
      }
    }
  ]
}
JSON
aws iam put-role-policy --role-name secrets-rotator-role --policy-name SecretsRotatorPolicy --policy-document file:///tmp/policy.json
output
secret=arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT
key=arn:aws:kms:us-east-1:000000000000:key/78235e23-91ea-4053-93f8-1e2193243b1d

[stdout]
secret=arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT
key=arn:aws:kms:us-east-1:000000000000:key/78235e23-91ea-4053-93f8-1e2193243b1d
Now test the rotation end-to-end.

Rotate and verify

shell
echo "=== BEFORE ===" 
aws secretsmanager describe-secret --secret-id app/db/password --query 'VersionIdsToStages'
BEFORE=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'SecretString' --output text)
BEFORE_VID=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'VersionId' --output text)
echo "before value: $BEFORE"
echo "before vid:   $BEFORE_VID"

echo
echo "=== ROTATE ==="
aws secretsmanager rotate-secret --secret-id app/db/password

echo
echo "waiting for rotation to complete..."
for i in $(seq 1 20); do
  sleep 2
  STAGES=$(aws secretsmanager describe-secret --secret-id app/db/password --query 'VersionIdsToStages' --output json)
  if ! echo "$STAGES" | grep -q AWSPENDING; then
    echo "rotation settled after ${i} polls"
    break
  fi
done

echo
echo "=== AFTER ==="
aws secretsmanager describe-secret --secret-id app/db/password --query 'VersionIdsToStages'
AFTER=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'SecretString' --output text)
AFTER_VID=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'VersionId' --output text)
echo "after value: $AFTER"
echo "after vid:   $AFTER_VID"

echo
[ "$BEFORE_VID" != "$AFTER_VID" ] && echo "VERSION ID ADVANCED ✓" || echo "VERSION ID DID NOT ADVANCE ✗"
[ "$BEFORE" != "$AFTER" ] && echo "VALUE CHANGED ✓" || echo "VALUE DID NOT CHANGE ✗"
output
=== BEFORE ===
{
    "fee6ddce-afbd-47d7-998e-365b118047f9": [
        "AWSCURRENT"
    ],
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPENDING"
    ]
}
before value: {"password": "initial-placeholder-value"}
before vid:   fee6ddce-afbd-47d7-998e-365b118047f9

=== ROTATE ===
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "VersionId": "03762056-8c88-454f-b66e-5d31b070f5f3"
}

waiting for rotation to complete...

=== AFTER ===
{
    "fee6ddce-afbd-47d7-998e-365b118047f9": [
        "AWSPREVIOUS"
    ],
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPENDING",
        "AWSCURRENT"
    ]
}
after value: {"password": "A2QHNAWhbsIsFp4pSJLc7mXhWJ4uPdF7"}
after vid:   03762056-8c88-454f-b66e-5d31b070f5f3

VERSION ID ADVANCED ✓
VALUE CHANGED ✓

[stdout]
=== BEFORE ===
{
    "fee6ddce-afbd-47d7-998e-365b118047f9": [
        "AWSCURRENT"
    ],
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPENDING"
    ]
}
before value: {"password": "initial-placeholder-value"}
before vid:   fee6ddce-afbd-47d7-998e-365b118047f9

=== ROTATE ===
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "VersionId": "03762056-8c88-454f-b66e-5d31b070f5f3"
}

waiting for rotation to complete...

=== AFTER ===
{
    "fee6ddce-afbd-47d7-998e-365b118047f9": [
        "AWSPREVIOUS"
    ],
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPENDING",
        "AWSCURRENT"
    ]
}
after value: {"password": "A2QHNAWhbsIsFp4pSJLc7mXhWJ4uPdF7"}
after vid:   03762056-8c88-454f-b66e-5d31b070f5f3

VERSION ID ADVANCED ✓
VALUE CHANGED ✓
Rotation works. Let me do one more full cycle to verify the fix works from a clean state (not just consuming the pre-seeded AWSPENDING).

Second rotation

shell
BEFORE_VID=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'VersionId' --output text)
BEFORE=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'SecretString' --output text)
echo "before vid: $BEFORE_VID"
echo "before val: $BEFORE"

aws secretsmanager rotate-secret --secret-id app/db/password

for i in $(seq 1 20); do sleep 2; STAGES=$(aws secretsmanager describe-secret --secret-id app/db/password --query 'VersionIdsToStages' --output json); if ! echo "$STAGES" | grep -q AWSPENDING; then echo "settled after $i polls"; break; fi; done

echo
echo "=== AFTER ==="
aws secretsmanager describe-secret --secret-id app/db/password --query 'VersionIdsToStages'
AFTER_VID=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'VersionId' --output text)
AFTER=$(aws secretsmanager get-secret-value --secret-id app/db/password --version-stage AWSCURRENT --query 'SecretString' --output text)
echo "after vid: $AFTER_VID"
echo "after val: $AFTER"
[ "$BEFORE_VID" != "$AFTER_VID" ] && echo "VID ADVANCED ✓" || echo "VID DID NOT ADVANCE ✗"
[ "$BEFORE" != "$AFTER" ] && echo "VALUE CHANGED ✓" || echo "VALUE DID NOT CHANGE ✗"
output
before vid: 03762056-8c88-454f-b66e-5d31b070f5f3
before val: {"password": "A2QHNAWhbsIsFp4pSJLc7mXhWJ4uPdF7"}
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "VersionId": "6fec7174-015f-4a33-9cd1-3c8ba7ccf88e"
}

=== AFTER ===
{
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPREVIOUS"
    ],
    "6fec7174-015f-4a33-9cd1-3c8ba7ccf88e": [
        "AWSPENDING",
        "AWSCURRENT"
    ]
}
after vid: 6fec7174-015f-4a33-9cd1-3c8ba7ccf88e
after val: {"password": "YHV5wclcpXdaay16RqUsmIx2URjI6nI5"}
VID ADVANCED ✓
VALUE CHANGED ✓

[stdout]
before vid: 03762056-8c88-454f-b66e-5d31b070f5f3
before val: {"password": "A2QHNAWhbsIsFp4pSJLc7mXhWJ4uPdF7"}
{
    "ARN": "arn:aws:secretsmanager:us-east-1:000000000000:secret:app/db/password-RZRdqT",
    "Name": "app/db/password",
    "VersionId": "6fec7174-015f-4a33-9cd1-3c8ba7ccf88e"
}

=== AFTER ===
{
    "03762056-8c88-454f-b66e-5d31b070f5f3": [
        "AWSPREVIOUS"
    ],
    "6fec7174-015f-4a33-9cd1-3c8ba7ccf88e": [
        "AWSPENDING",
        "AWSCURRENT"
    ]
}
after vid: 6fec7174-015f-4a33-9cd1-3c8ba7ccf88e
after val: {"password": "YHV5wclcpXdaay16RqUsmIx2URjI6nI5"}
VID ADVANCED ✓
VALUE CHANGED ✓
Rotation now works end-to-end on consecutive runs. ## Summary of fixes 1. **`/app/handler.py` `finish_secret`** , was a no-op. Now looks up the current AWSCURRENT version and calls `update_secret_version_stage` with `MoveToVersionId=token` + `RemoveFromVersionId=<old>`, which promotes AWSPENDING→AWSCURRENT and demotes the old version to AWSPREVIOUS. 2. **Lambda resource policy** , added a single `lambda:InvokeFunction` statement (sid `AllowSecretsManagerInvoke`) for principal `secretsmanager.amazonaws.com`, scoped with `SourceArn` to the specific secret. 3. **`SecretsRotatorPolicy` IAM inline policy** , added `kms:Decrypt` + `kms:GenerateDataKey`, scoped to the specific CMK ARN, further gated by `kms:ViaService = secretsmanager.us-east-1.amazonaws.com`. Existing Secrets Manager statements left intact and still scoped to the single secret ARN. The key's existing root-admin policy already delegates to IAM, so no key-policy change was needed. Verified: `rotate-secret` succeeds, AWSCURRENT advances to a new VersionId, the secret string changes, and the prior version is labeled AWSPREVIOUS.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
============================= test session starts ==============================
platform linux -- Python 3.12.3, pytest-8.4.1, pluggy-1.6.0 -- /root/.cache/uv/archive-v0/Tl2gjpemLBs8aWNddCVzk/bin/python
cachedir: .pytest_cache
rootdir: /tests
plugins: json-ctrf-0.3.5
collecting ... collected 8 items

../tests/test_outputs.py::test_aws_cli_binary_is_real PASSED             [ 12%]
../tests/test_outputs.py::test_localstack_reachable PASSED               [ 25%]
../tests/test_outputs.py::test_secret_exists_and_uses_customer_cmk PASSED [ 37%]
../tests/test_outputs.py::test_rotation_lambda_exists PASSED             [ 50%]
../tests/test_outputs.py::test_role_policy_grants_kms_actions PASSED     [ 62%]
../tests/test_outputs.py::test_kms_key_policy_grants_lambda_role FAILED  [ 75%]
../tests/test_outputs.py::test_lambda_permission_allows_secretsmanager_invoke PASSED [ 87%]
../tests/test_outputs.py::test_rotate_secret_advances_awscurrent PASSED  [100%]

=================================== FAILURES ===================================
____________________ test_kms_key_policy_grants_lambda_role ____________________

iam = <botocore.client.IAM object at 0xffff9888c8f0>
kms = <botocore.client.KMS object at 0xffff991df6b0>

    def test_kms_key_policy_grants_lambda_role(iam, kms):
        role_arn = iam.get_role(RoleName=ROLE_NAME)["Role"]["Arn"]
        policy_str = kms.get_key_policy(KeyId=KEY_ALIAS, PolicyName="default")["Policy"]
        policy = json.loads(policy_str)
        match = False
        for st in policy.get("Statement", []):
            if _statement_matches(
                st,
                principal_arn=role_arn,
                required_actions=REQUIRED_KMS_ACTIONS,
            ):
                match = True
                break
>       assert match, (
            f"KMS key policy on {KEY_ALIAS} has no Allow statement granting "
            f"{sorted(REQUIRED_KMS_ACTIONS)} to principal {role_arn}. Key "
            f"policy: {policy_str}"
        )
E       AssertionError: KMS key policy on alias/app-rotation-key has no Allow statement granting ['kms:Decrypt', 'kms:GenerateDataKey'] to principal arn:aws:iam::000000000000:role/secrets-rotator-role. Key policy: {
E           "Version": "2012-10-17",
E           "Id": "app-rotation-key-policy",
E           "Statement": [
E             {
E               "Sid": "EnableRootAdmin",
E               "Effect": "Allow",
E               "Principal": { "AWS": "arn:aws:iam::000000000000:root" },
E               "Action": "kms:*",
E               "Resource": "*"
E             }
E           ]
E         }
E       assert False

/tests/test_outputs.py:256: AssertionError
=============================== warnings summary ===============================
test_outputs.py: 14 warnings
  /root/.cache/uv/archive-v0/Tl2gjpemLBs8aWNddCVzk/lib/python3.12/site-packages/botocore/auth.py:424: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    datetime_now = datetime.datetime.utcnow()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
==================================== PASSES ====================================
=========================== short test summary info ============================
PASSED ../tests/test_outputs.py::test_aws_cli_binary_is_real
PASSED ../tests/test_outputs.py::test_localstack_reachable
PASSED ../tests/test_outputs.py::test_secret_exists_and_uses_customer_cmk
PASSED ../tests/test_outputs.py::test_rotation_lambda_exists
PASSED ../tests/test_outputs.py::test_role_policy_grants_kms_actions
PASSED ../tests/test_outputs.py::test_lambda_permission_allows_secretsmanager_invoke
PASSED ../tests/test_outputs.py::test_rotate_secret_advances_awscurrent
FAILED ../tests/test_outputs.py::test_kms_key_policy_grants_lambda_role - Ass...
=================== 1 failed, 7 passed, 14 warnings in 5.37s ===================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_5119e8938c684759. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_5119e8938c684759 · verifier authoritative; classifier explanatory.