CRL-Monitor monitors CRLs
sequenceDiagram
participant churn as Certificate Churner<br />Lambda
participant ca as Let's Encrypt<br />Certification Authority
participant ddb as Pending Certificates<br />DynamoDB
participant s3 as CRL Storage<br />S3 Bucket
participant checker as CRL Checker<br />Lambda
loop timer
activate churn
churn->>ca: Issue certificate
churn->>ca: Revoke certificate
churn->>ddb: Store certificate metadata
ddb->>churn: Get previous revoked serials
Note over churn: Alert if any<br />expected serials missed<br />inclusion deadline
deactivate churn
end
loop New CRL
ca->>s3: Publish CRL Shard
activate checker
s3->>checker: S3 Event
checker->>s3: Read current CRL
checker->>s3: Read previous CRL
Note over checker: Alert if CRL<br />fails linting
loop random selection of serials
checker->>ca: Get Certificate
end
Note over checker: Alert if CRL had<br />serials leave early
checker->>ddb: Get revoked serials
checker->>ddb: Delete seen serials
deactivate checker
end