security: CWE-326: Replace DES with AES256 for SSH legacy PEM encryption — VC-53763

[torresashjiancyber]

Summary

Replaces weak single-DES (56-bit) encryption with AES-256 for SSH RSA private keys when using --format legacy-pem in vcert sshenroll.

Finding

CWE-326 / CWE-327: encodePrivKeyToPEM() in pkg/util/sshKeyGenerator.go was hard-coded to use PEMCipherDES (single 56-bit DES) when encrypting SSH RSA private keys with the legacy-pem format. This cipher is cryptographically weak and susceptible to exhaustive key search regardless of passphrase strength.

The vulnerable line at pkg/util/sshKeyGenerator.go:44 used:

X509EncryptPEMBlock(rand.Reader, RsaPrivKeyType, privDER, []byte(keyPassword), PEMCipherDES)

Remediation

Changed the cipher parameter from PEMCipherDES to PEMCipherAES256 to align with the encryption used in all other legacy-PEM code paths in the codebase (e.g., pkg/util/utils.go:77,82).

Changed file:

• pkg/util/sshKeyGenerator.go: Line 44 - replaced PEMCipherDES with PEMCipherAES256

Verification

This is a minimal, single-token change that upgrades the encryption cipher from 56-bit DES to 256-bit AES for password-protected SSH private keys in legacy PEM format, matching the existing security standard used elsewhere in the codebase.

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Auto-generated by Project Logos Pattern-C remediation (VC-53763)