Linux程序PKI实现方案（公钥加密+AES加密私钥）是否符合安全标准？

Hey Daniel, let's break down your PKI implementation plan against current security community standards:

Your core approach (using public keys for encryption, encrypting private keys with AES) aligns with industry best practices, but storing an unencrypted private key for testing is a critical security violation that does NOT meet standard requirements.

What's Done Right #

• Public key encryption for data: This is a foundational, secure use of PKI. Public keys are designed to be openly shared, and using them to encrypt data that only the corresponding private key can decrypt is fully compliant with security norms.
• AES encryption for private key storage: Private keys are highly sensitive assets, so encrypting them at rest with AES (preferably an authenticated mode like AES-256-GCM) is the industry standard way to mitigate risks if the disk is compromised or accessed by unauthorized parties.

What's a Major Red Flag #

• Storing unencrypted private keys for testing: This is never acceptable, even in test environments. An unencrypted private key exposed on disk can be easily exfiltrated by attackers—allowing them to decrypt all data encrypted with the matching public key, or impersonate your identity for signing operations. The security community’s universal rule is: private keys should never exist in plaintext on any persistent storage medium at any point in their lifecycle.

Better Alternatives for Testing #

Instead of keeping a plaintext private key, use one of these secure testing workflows:

• Generate ephemeral key pairs in memory: Create temporary key pairs directly in your program’s memory during testing, and wipe them from memory immediately after tests finish—never write them to disk.
• Use encrypted private keys for testing: Load the encrypted private key in your test environment, decrypt it dynamically (via a passphrase input or secure key management service), and clear the decrypted private key from memory as soon as tests are done.
• Use dedicated test key pairs: Generate a separate set of keys exclusively for testing. Even if these keys are compromised, they won’t affect production data—but you still must store the test private key in encrypted form, not plaintext.

Extra Security Best Practices for Linux #

• Lock down file permissions: On Linux, set encrypted private key files to chmod 600 (only the owner can read/write) and public key files to chmod 644 (read-only for everyone else) to limit unauthorized access.
• Use strong passphrases: The passphrase used to encrypt your private key should be a long, complex passphrase (16+ characters, mixed case, numbers, symbols)—not a simple password.
• Choose authenticated AES modes: Prefer AES-GCM over unauthenticated modes like AES-CBC—GCM provides both encryption and integrity verification, preventing tampering and padding oracle attacks.

内容的提问来源于stack exchange，提问作者Daniel F