I am storing data in file in aws s3 and already enabled SSE. but i am curious to know is there a way to encrypt the data so when someone download the file so they cant see the content?? I am just new to AWS and it would be great if somw one give the input
Use the AWS Key Management Service (AWS KMS) to encrypt the data prior to uploading it to an Amazon S3 bucket. Then the data will remain encrypted until it's decrypted using the key. YOu can find an example here (for Java SDK)
https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/javav2/example_code/s3/src/main/java/com/example/s3/KMSEncryptionExample.java
already enabled SSE.
SSE encrypts the content on S3, but an authenticated client cloud access the content in plain, the encryption is done under the hood and the client is unable to access the ciphertext (encrypted form)
You can use the default s3 key or a custom KMS key (CMS) , where the client need explicit access to decrypt the content.
download the file so they cant see the content??
Then the content needs to be encrypted before the upload. AWS provides some support for the client-side encryption but the client is free to implement its own encryption strategy and the key management.
To solve trouble with managing the keys on the client side, it's often more practical to stick with SSE and allow access to S3 or the used CMS (key) only to identities that must access the content.
Related
My understanding is that by generating your own key and use that to encrypt stuff, it prevents a cloud provider from being able to read your data at rest. But before a cloud provider can use this customer managed key to encrypt/decrypt, it has to first have access to the key's plaintext. What stops a cloud provider from actually storing that plaintext and still has access to my data at rest?
Different cloud provider might have different approach to this, so I'm using AWS S3 as a reference here, which requires you to send the key in the request. https://docs.aws.amazon.com/AmazonS3/latest/userguide/ServerSideEncryptionCustomerKeys.html
In the SSE-C scenario you refer to, the user provides AWS the plaintext data and plaintext key (over https) and then AWS performs the encryption and discards the key. The benefit to the user is that the user does not have to perform cryptographic operations.
If there is a concern about AWS having access to plaintext data or keys, the user can encrypt the data on the client computer and then send the data to AWS already encrypted. This is the client-side encryption scenario.
My needs - Read/Write Encrypted Data
I have a software application that can build webpages and emails and I need to encrypt content stored in the database (PII plus user generated content by financial/healthcare institutions).
I would like to use AWS KMS/AWS Secrets Manager to manage the hash so the hash is secured and keys that gate the hash are automatically rotated and managed by AWS. I'll use this hash to encrypt/decrypt data. Two way encryption is required.
My Question
It seems there are two options, and I'm not sure which is preferred and which is the proper way to use AWS for this:
Option 1 - Encrypt DB Access (Not preferred)
I could store all PII and encrypted data in a separate RDS DB, and simply gate API access with encryption provided by AWS Secrets Manger and KMS. This kinda stinks because the encrypted data relates to tables in the main DB. So hosting this data elsewhere is cumbersome to maintain.
Option 2 - Encrypt the data on a field level (!Preferred!)
I would prefer to store encrypted data in the DB directly. For instance a table may have 7 columns unencrypted, but the content column contains encrypted data. I then need to figure out a way to encrypt/decrypt this securely. I would need some sort hash that encrypts/decrypts the data. Storing in directly in PHP seems like a bad idea so could I use AWS KMS / Secrets Manager to do this?
Plan A -
I store a hash in Secrets Manager (Encrypted with KMS), so when the application wants to encrypt/decrypt content, it uses the required IAM user to get the hash from AWS Secrets Manager, encrypts/decrypts the content and then removes the hash from memory.
Plan B* -
I use KMS directly (No secrets manager) and pass encrypted/decrypted content to KMS directly and it encrypts/decrypts on the fly, never needing to expose or send the key it's using to perform these actions.
Thanks again for taking the time
Is it possible to get files from encrypted S3 buckets using boto 2? I am working with a project that uses S3 in several places and has to read/write to an encrypted S3 bucket. I would like to make as small a change as possible, for the time being, to support encryption.
Encryption actually works at the object level, rather than the bucket.
There are several ways to use encryption. If it is Protecting Data Using Server-Side Encryption with Amazon S3-Managed Encryption Keys (SSE-S3), then as long as your app has permission to access the object then it will be automatically decrypted. (The app won't even notice that it was encrypted!)
If it is Protecting Data Using Server-Side Encryption with AWS KMS–Managed Keys (SSE-KMS), the app will also need adequate permissions to use the key in KMS. The object will be automatically decrypted, but it needs permissions to use the key.
If the app is Protecting Data Using Server-Side Encryption with Customer-Provided Encryption Keys (SSE-C), then the app must provide the encryption key when it tries to access the object.
And finally, if it is Protecting Data Using Client-Side Encryption, then the app is totally responsible for encryption/decryption.
It is most likely that your data is using Server-Side Encryption with Amazon S3-Managed Encryption Keys (SSE-S3). If so, then your app doesn't have to do anything — it will all be handled automagically by Amazon S3.
Say for example I leave an AWS S3 bucket open to the public.
My goal is that if someone downloads a file from that bucket then what they get is an encrypted file.
I thought SSE-S3 would do this but it does not - it appears that any file downloaded is not encrypted.
So how can I reach my goal of ensuring that files served from S3 are encrypted?
What you are looking for is Protecting Data Using Client-Side Encryption. If you want S3 to serve encrypted files, then you have to save them as encrypted object. You manage encryption/decryption. SSE will store the data after encrypting it and will decrypt it automatically when it is downloaded.
From: Protecting Data Using Encryption
Use Server-Side Encryption – You request Amazon S3 to encrypt your object before saving it on disks in its data centers and decrypt it when you download the objects.
Use Client-Side Encryption – You can encrypt data client-side and upload the encrypted data to Amazon S3. In this case, you manage the encryption process, the encryption keys, and related tools.
I'm trying to use server side encryption having AWS KMS setup to upload objects to S3.
The documentation says that the uploaded objects should be encrypted;
Server-side encryption is about data encryption at rest—that is,
Amazon S3 encrypts your data at the object level as it writes it to
disks in its data centers and decrypts it for you when you access it.
I've setup KMS master key and trying to use CLI to upload an object in the following way
aws s3api put-object --bucket test --key keys/test.txt --server-side-encryption aws:kms --ssekms-key-id <my_master_Key_id> --body test.txt
The upload succeeds and I see the following response
{
"SSEKMSKeyId": "arn:aws:kms:eu-central-1:<id>:key/<my_master_key>",
"ETag": "\"a4f4fdf078bdd5df758bf81b2d9bc94d\"",
"ServerSideEncryption": "aws:kms"
}
Also when checking the file in S3 I see in details that it has been encrypted server side with a proper master key.
The problem is that when I download the file with a user not having a permission to use the KMS master key, I can open and read the file without a problem, when it should be encrypted.
Note: I also have PutObject policy denying all uploads without server-side encryption, which works fine.
I wonder if I misunderstand the server side encryption, or do I do something wrong? Any help is appreciated.
Unfortunately, I think you misunderstood server-side encryption in S3. Like you pointed yourself, from S3 server-side encryption (SSE) docs:
Server-side encryption is about protecting data at rest.
When S3 receives your object, it calls KMS to create a data key, encrypts your data with that data key (not the master key), and stores the encrypted data key along with the encrypted data.
When you try to download the encrypted files, S3 sees it has been encrypted, asks KMS to decrypt the data key (using the master key), and then uses the decrypted data key to decrypt the data before returning to you. My understanding from the docs and from the way SSE and KMS work is that there is no assumption on the user needing to have access to the master key for that to work -- it suffices that S3 has access to it.
The use case you described is more similar to S3 client-side encryption:
Client-side encryption refers to encrypting data before sending it to
Amazon S3.
In this scenario, the S3 client (instead of S3 on the backend) will ask for a KMS data key (derived from the master key), encrypt data client-side and upload it. It will not be possible to decrypt it on the server, and when clients download the (encrypted) files, decryption needs to happen client-side (the S3 client deals with that for you, though).