SSL directive configuration in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the ssl_certificate directive in nginx?

The ssl_certificate directive specifies the path to the SSL certificate file used to encrypt data between the server and clients.

beginner

Which directive in nginx is used to specify the private key for SSL?

The ssl_certificate_key directive points to the private key file that matches the SSL certificate for secure communication.

intermediate

What does the ssl_protocols directive control in nginx?

It controls which SSL/TLS protocol versions nginx will accept, such as TLSv1.2 and TLSv1.3, helping improve security by disabling older protocols.

intermediate

Why is the ssl_ciphers directive important in nginx SSL configuration?

It defines the list of encryption algorithms (ciphers) nginx will use for SSL connections, allowing control over security strength and compatibility.

intermediate

What is the effect of enabling ssl_session_cache in nginx?

Enabling ssl_session_cache allows nginx to store SSL session parameters, speeding up repeated connections by reusing previous SSL handshakes.

Which directive specifies the SSL certificate file in nginx?

A ssl_key_file

B ssl_certificate

C ssl_private_key

D ssl_cert_path

The ssl_certificate directive points to the SSL certificate file used by nginx.

To enable only TLSv1.2 and TLSv1.3 protocols in nginx, which directive should you configure?

A ssl_protocols

B ssl_ciphers

C ssl_session_cache

D ssl_verify_client

The ssl_protocols directive controls which TLS versions nginx accepts.

What does the ssl_certificate_key directive specify?

A Path to the SSL certificate

B SSL session timeout value

C List of allowed SSL ciphers

D Path to the private key matching the certificate

The ssl_certificate_key directive points to the private key file for SSL.

Why configure ssl_ciphers in nginx?

A To control encryption algorithms used

B To set SSL protocol versions

C To enable SSL session caching

D To specify SSL certificate location

The ssl_ciphers directive defines which encryption algorithms nginx uses.

What benefit does ssl_session_cache provide?

A Defines allowed SSL protocols

B Specifies SSL certificate file

C Improves SSL handshake speed by reusing sessions

D Sets private key path

Caching SSL sessions speeds up repeated connections by avoiding full handshakes.

Explain the key SSL directives needed to configure HTTPS in nginx and their roles.

Think about certificate files, encryption protocols, and performance.

Describe how you would improve SSL security in nginx using directive settings.

Focus on protocols, ciphers, and caching.

Practice

1. Which nginx directive is used to specify the SSL certificate file for HTTPS?

easy

A. ssl_key_certificate

B. ssl_key

C. ssl_cert_file

D. ssl_certificate

Solution

1. Step 1: Understand SSL certificate directive

   The directive to specify the SSL certificate file in nginx is ssl_certificate.

2. Step 2: Compare options with correct syntax

   Options B, C, and D are incorrect because they are not valid nginx directives for SSL certificate files.

3. Final Answer:

   ssl_certificate -> Option D

4. Quick Check:

   ssl_certificate = ssl_certificate [OK]

Hint: Remember: certificate file uses ssl_certificate directive [OK]

Common Mistakes:

• Confusing ssl_certificate_key with ssl_certificate
• Using incorrect directive names like ssl_key
• Mixing certificate and key directives

2. Which of the following is the correct syntax to enable SSL in an nginx server block?

easy

A. ssl on;

B. enable ssl;

C. ssl_enable on;

D. ssl active;

Solution

1. Step 1: Recall SSL enabling syntax in nginx

   In older nginx versions, SSL was enabled with ssl on; inside the server block.

2. Step 2: Validate options

   Options A, B, and D are not valid nginx directives or syntax for enabling SSL.

3. Final Answer:

   ssl on; -> Option A

4. Quick Check:

   ssl on; = ssl on; [OK]

Hint: Use 'ssl on;' to enable SSL in nginx server block [OK]

Common Mistakes:

• Using non-existent directives like enable ssl
• Confusing directive names
• Omitting the semicolon

3. Given this nginx SSL configuration snippet, what TLS versions are allowed?

ssl_protocols TLSv1.2 TLSv1.3;

medium

A. TLS 1.0, 1.1, 1.2, and 1.3 are allowed

B. Only TLS 1.2 and TLS 1.3 are allowed

C. Only TLS 1.3 is allowed

D. No TLS versions are allowed

Solution

1. Step 1: Read ssl_protocols directive

   The directive ssl_protocols TLSv1.2 TLSv1.3; explicitly allows only TLS version 1.2 and 1.3.

2. Step 2: Understand allowed TLS versions

   Older versions like TLS 1.0 and 1.1 are not included, so they are disallowed.

3. Final Answer:

   Only TLS 1.2 and TLS 1.3 are allowed -> Option B

4. Quick Check:

   ssl_protocols = TLSv1.2 and TLSv1.3 [OK]

Hint: ssl_protocols lists allowed TLS versions explicitly [OK]

Common Mistakes:

• Assuming all TLS versions are allowed by default
• Confusing ssl_protocols with ssl_ciphers
• Ignoring missing older TLS versions

4. Identify the error in this nginx SSL configuration snippet:

ssl_certificate /etc/nginx/certs/server.crt
ssl_certificate_key /etc/nginx/certs/server.key;

medium

A. Missing semicolon after ssl_certificate directive

B. Wrong file path for ssl_certificate_key

C. ssl_certificate_key directive is misspelled

D. ssl_certificate directive should not have a file path

Solution

1. Step 1: Check syntax for each directive

   Each nginx directive must end with a semicolon. The first line lacks a semicolon.

2. Step 2: Verify other parts

   The file paths and directive names are correct, only the missing semicolon causes a syntax error.

3. Final Answer:

   Missing semicolon after ssl_certificate directive -> Option A

4. Quick Check:

   Every directive ends with ; [OK]

Hint: Always end nginx directives with a semicolon [OK]

Common Mistakes:

• Forgetting semicolons at line ends
• Assuming file paths are incorrect without checking
• Misspelling directive names

5. You want to configure nginx to use a strong cipher suite and only TLS 1.3. Which configuration snippet achieves this securely?

hard

A. ssl_protocols TLSv1.2;
ssl_ciphers 'TLS_AES_128_GCM_SHA256';

B. ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers 'HIGH:!aNULL:!MD5';

C. ssl_protocols TLSv1.3;
ssl_ciphers 'TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256';

D. ssl_protocols TLSv1.3;
ssl_ciphers 'ALL';

Solution

1. Step 1: Select TLS version

   Only TLS 1.3 is allowed by ssl_protocols TLSv1.3;, matching the requirement.

2. Step 2: Choose strong cipher suites

   ssl_ciphers 'TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256'; uses strong TLS 1.3 ciphers explicitly. Other options either allow older TLS versions, use insecure cipher lists, or use generic 'ALL' which is insecure.

3. Final Answer:

   ssl_protocols TLSv1.3; ssl_ciphers 'TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256'; -> Option C

4. Quick Check:

   Only TLS 1.3 + strong ciphers = ssl_protocols TLSv1.3; ssl_ciphers 'TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256'; [OK]

Hint: Use ssl_protocols TLSv1.3 and specify strong TLS 1.3 ciphers [OK]

Common Mistakes:

• Allowing older TLS versions accidentally
• Using 'ALL' cipher which is insecure
• Mismatch between TLS version and cipher suite