Certificate Authority Service in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

Understanding Certificate Authority Service (CAS) Issuance Behavior

You create a private CA in Google Cloud Certificate Authority Service (CAS) and issue a certificate. What happens if the CA is disabled after issuing the certificate?

A All existing certificates are immediately revoked and become invalid.

B Existing certificates remain valid until their expiration, but no new certificates can be issued.

C The CA automatically renews all existing certificates despite being disabled.

D The CA continues issuing new certificates but marks them as untrusted.

💡 Hint

Think about what disabling a CA means for new and existing certificates.

Disabling a CA stops new certificate issuance but does not affect already issued certificates, which remain valid until they expire or are revoked.

❓ Architecture

intermediate

Designing a Secure CA Hierarchy in Google CAS

You want to design a secure certificate authority hierarchy using Google CAS. Which architecture provides the best security and operational flexibility?

A Create a root CA offline and one or more subordinate CAs online to issue certificates.

B Create a single root CA and use it directly to issue all certificates.

C Create multiple root CAs and issue certificates from all of them directly.

D Use only subordinate CAs without a root CA.

💡 Hint

Consider the role of root and subordinate CAs in security and management.

Using an offline root CA with online subordinate CAs limits exposure of the root key and allows flexible certificate issuance and revocation.

❓ security

advanced

Handling Certificate Revocation in Google CAS

You have issued certificates using Google CAS. Which method does CAS support to notify clients that a certificate is revoked?

A Automatically deleting revoked certificates from client devices.

B Using Online Certificate Status Protocol (OCSP) responses served by CAS.

C Publishing Certificate Revocation Lists (CRLs) that clients check periodically.

D Sending email notifications to clients about revoked certificates.

💡 Hint

Think about standard protocols for certificate revocation notification.

Google CAS publishes CRLs that clients can download and check to verify if a certificate is revoked. OCSP is not currently supported.

❓ Configuration

advanced

Configuring a Private CA with Specific Key Algorithm in Google CAS

You want to create a private CA in Google CAS that uses the ECDSA P-384 key algorithm. Which configuration snippet correctly specifies this?

GCP

private_ca_config = {
  "key_spec": {
    "algorithm": "EC_P384"
  },
  "tier": "ENTERPRISE"
}

A { "key_spec": { "algorithm": "EC_P256_SHA256" }, "tier": "ENTERPRISE" }

B { "key_spec": { "algorithm": "RSA_2048" }, "tier": "ENTERPRISE" }

C { "key_spec": { "algorithm": "EC_P521_SHA512" }, "tier": "ENTERPRISE" }

D { "key_spec": { "algorithm": "EC_P384" }, "tier": "ENTERPRISE" }

💡 Hint

Look for the exact algorithm name for ECDSA P-384 in Google CAS.

The correct algorithm name for ECDSA P-384 is "EC_P384". Other options specify different algorithms.

✅ Best Practice

expert

Best Practice for Protecting Root CA Private Key in Google CAS

What is the best practice to protect the root CA private key in Google Certificate Authority Service?

A Keep the root CA private key offline and only use it to sign subordinate CAs.

B Store the root CA private key in a Google Cloud Storage bucket with restricted access.

C Use the root CA private key directly to issue all end-entity certificates.

D Share the root CA private key with all team members for backup.

💡 Hint

Think about minimizing exposure of the most sensitive key.

Keeping the root CA private key offline reduces risk of compromise. It should only be used to sign subordinate CAs, which handle certificate issuance.

Practice

1. What is the main purpose of the Certificate Authority Service in Google Cloud?

easy

A. To store large amounts of data securely

B. To create and manage digital certificates for secure communication

C. To monitor network traffic in real-time

D. To provide virtual machines for computing tasks

Solution

1. Step 1: Understand the role of Certificate Authority Service

   This service is designed to create and manage digital certificates that prove identity and secure communication.

2. Step 2: Compare with other options

   Options A, C, and D describe other cloud services unrelated to certificate management.

3. Final Answer:

   To create and manage digital certificates for secure communication -> Option B

4. Quick Check:

   Certificate Authority Service = Manage digital certificates [OK]

Hint: Remember: Certificate Authority = issues certificates [OK]

Common Mistakes:

• Confusing certificate management with data storage
• Thinking it monitors network traffic
• Assuming it provides computing resources

2. Which of the following is the correct way to create a self-signed certificate authority using gcloud CLI?

easy

A. gcloud privateca certificates create my-cert --issuer=my-root --location=us-central1

B. gcloud privateca subordinate create my-sub --subject="CN=My Sub CA" --location=us-central1

C. gcloud privateca roots create my-root --subject="CN=My Root CA" --pool=my-pool --location=us-central1

D. gcloud privateca revoke my-cert --location=us-central1

Solution

1. Step 1: Identify command for self-signed root CA creation

   The command gcloud privateca roots create is used to create a self-signed root certificate authority.

2. Step 2: Verify other options

   gcloud privateca subordinate create my-sub --subject="CN=My Sub CA" --location=us-central1 creates a subordinate CA, C creates a certificate, and D revokes a certificate, so they are incorrect for creating a self-signed CA.

3. Final Answer:

   gcloud privateca roots create my-root --subject="CN=My Root CA" --pool=my-pool --location=us-central1 -> Option C

4. Quick Check:

   Self-signed CA uses 'roots create' command [OK]

Hint: Self-signed CA uses 'roots create' command in gcloud [OK]

Common Mistakes:

• Using subordinate create command for root CA
• Confusing certificate creation with CA creation
• Trying to revoke instead of create

3. Given the following code snippet, what will be the output of the command?

gcloud privateca certificates list --location=us-central1 --ca-pool=my-pool

medium

A. Lists all certificates issued by the CA pool named 'my-pool' in us-central1

B. Deletes all certificates in the CA pool 'my-pool'

C. Creates a new certificate in the CA pool 'my-pool'

D. Shows the details of the CA pool 'my-pool' without certificates

Solution

1. Step 1: Understand the command purpose

   The command gcloud privateca certificates list lists certificates issued by a specified CA pool.

2. Step 2: Analyze parameters

   The parameters specify the location and the CA pool name, so the output will be the list of certificates issued by that pool in that location.

3. Final Answer:

   Lists all certificates issued by the CA pool named 'my-pool' in us-central1 -> Option A

4. Quick Check:

   Certificates list command outputs issued certificates [OK]

Hint: List command shows issued certificates, not create or delete [OK]

Common Mistakes:

• Thinking list deletes or creates certificates
• Confusing CA pool details with certificate list
• Ignoring the location parameter

4. You tried to create a subordinate CA with the command:

gcloud privateca subordinate create my-sub --pool=my-pool --issuer=my-root --location=us-central1

But got an error about missing permissions. What is the most likely cause?

medium

A. You do not have the required IAM role to create subordinate CAs

B. The command syntax is incorrect; 'subordinate create' is invalid

C. The location 'us-central1' does not support subordinate CAs

D. The issuer 'my-root' does not exist in the project

Solution

1. Step 1: Understand permission errors

   Permission errors usually mean the user lacks the required IAM role or permission to perform the action.

2. Step 2: Check command validity and other options

   The command syntax is valid, 'us-central1' supports subordinate CAs, and issuer existence errors usually mention not found, not permissions.

3. Final Answer:

   You do not have the required IAM role to create subordinate CAs -> Option A

4. Quick Check:

   Permission error = missing IAM role [OK]

Hint: Permission errors usually mean missing IAM role [OK]

Common Mistakes:

• Assuming syntax error causes permission issues
• Ignoring IAM roles and permissions
• Confusing location support with permission problems

5. You want to set up a secure internal network where your services trust certificates issued by your own CA. Which steps should you follow using Certificate Authority Service to achieve this?

hard

A. Create multiple root CAs and assign each service a different root CA

B. Create only a self-signed root CA and issue certificates directly from it to services

C. Use Google-managed CA and import your certificates manually to services

D. Create a root CA, create a subordinate CA signed by the root, then issue certificates from the subordinate CA to services

Solution

1. Step 1: Understand best practice for internal CA hierarchy

   Best practice is to create a root CA and then a subordinate CA signed by the root to issue certificates, improving security and manageability.

2. Step 2: Evaluate options

   Create only a self-signed root CA and issue certificates directly from it to services is less secure because issuing directly from root CA is discouraged. Use Google-managed CA and import your certificates manually to services uses Google-managed CA, not your own. Create multiple root CAs and assign each service a different root CA creates unnecessary complexity.

3. Final Answer:

   Create a root CA, create a subordinate CA signed by the root, then issue certificates from the subordinate CA to services -> Option D

4. Quick Check:

   Root CA + subordinate CA hierarchy = secure internal trust [OK]

Hint: Use root CA + subordinate CA for secure internal certificates [OK]

Common Mistakes:

• Issuing certificates directly from root CA
• Using Google-managed CA instead of own CA
• Creating multiple root CAs unnecessarily