无法理解在哪里存储私钥

Question

I am having an issue determining how to store API keys or other private information correctly. I have a helper library for a large set of inner-facing company applications that calls an external API for emailing and must have access to the API key. I store this key in a shared configuration file used by these applications. If I wanted to further secure the key by encrypting it or moving it to a service like Azure Key Vault, I then am stuck with the dilemma of having simply complicated the problem because I now have the private key for that encryption or the key to access Azure Key Vault that I now need to secure. Because this type of issue is so common I am assuming I am missing something here. Each time I try to further encrypt or otherwise secure a key I am simply adding another layer of the same problem. I still end up with a private key sitting somewhere in plain text. Is it the case that having a plain text key in an otherwise secure environment is just not an issue after all?

I would like to point out that I cannot use Environment Variables or some of the other tools I have seen to secure keys on the machine as these applications can be run on any number of terminal servers or local machines throughout the company. Most are click-once Dot Net applications written in .Net 4.5 and can run anywhere in our environment, some by any user in our domain.

Answer 1

I don't use azure but I assume Azure Key Vault is very similar to AWS Secrets Manager which is exactly the thing I would use (I wrote about one use case for storing Amplitude API keys on my blog ).

Why is this better than simply having the key lying around in a file?

• Simplified key distribution: you don't need to download the key on all the machines
• Improved security: you simply load the key at runtime, no need to have the key lying on the disk forever

Note there's not much point in double-encrypting the key as you mentioned. That's just increasing complexity without improving the security of the solution much. Also, in case of AWS, you would specify a very granular IAM policy/permissions for accessing the specific secret and attach the policy to the IAM role assigned to the instances needing to work with the key.