[Security] Insecure Random Number Generation for Secrets and Keys

[osmontero]

The installer currently uses math/rand for generating security-sensitive data, which is a significant security risk.

Identified Problems:

• Insecure Randomness: In utils/secret.go, math/rand is used to generate passwords and internal keys. math/rand is a deterministic pseudo-random number generator and is not suitable for cryptographic or security purposes.
• Predictability: Secrets generated this way can potentially be predicted if the seed is known or guessed.

Affected Code:

• installer/utils/secret.go: GenerateSecret function.
• installer/config/config.go: Usage of utils.GenerateSecret for default passwords and internal keys.

Recommended Actions:

• Replace math/rand with crypto/rand for all secret and key generation.
• Ensure proper error handling when reading from crypto/rand.