Optimizing docker image encryption—tradeoff between performance and protection level
One example method includes inserting a signal layer in an image, the signal layer indicating that a sensitive layer in the image is a candidate for encryption, creating a single layer archive file that includes the sensitive layer, encrypting the single layer archive file to create an encrypted layer, constructing a new image that includes the encrypted layer, inserting, in the new image, a decryptor layer that is operable to decrypt the encrypted layer, and designating the decryptor layer as an entry point of the new image.
1. A method, comprising:
inserting a signal layer in an image which, when instantiated, is executable on an engine that is operable to build and containerize an application, the signal layer indicating that a sensitive layer in the image is a candidate for encryption;
creating a single layer archive file that includes the sensitive layer;
encrypting the single layer archive file to create an encrypted layer;
constructing a new image that includes the encrypted layer;
inserting, in the new image, a decryptor layer that is operable to decrypt the encrypted layer; and
designating the decryptor layer as an entry point of the new image so that the decryptor layer of the new image runs first when the new image is instantiated.
2. The method as recited in claim 1 , wherein the new image further comprises:
a signal layer; and
an unencrypted non-sensitive layer.
3. The method as recited in claim 1 , further comprising restoring one or more non-sensitive layers from the image to the new image.
4. The method as recited in claim 1 , wherein the single layer archive file comprises multiple sensitive layers of the image.
5. The method as recited in claim 1 , further comprising traversing the image to identify the signal layer and the sensitive layer.
6. The method as recited in claim 1 , wherein the new image is configured to call an original entry point after decryption of the encrypted layer has been performed by the decryptor layer.
7. The method as recited in claim 1 , further comprising instantiating the new image by performing operations comprising:
running the decryption layer to decrypt the encrypted layer, open the single layer archive file, and restore the sensitive layer of the image from the single layer archive file to the new image; and
after decryption of the encrypted layer, running one or more layers of the new image.
8. The method as recited in claim 1 , wherein the image comprises a stop encryption layer that defines where, in the image, encryption ends.
9. The method as recited in claim 1 , wherein one or both of the image and the new image is a Docker image.
10. The method as recited in claim 1 , wherein the new image does not require a process external to the new image to perform decryption of the encrypted layer.
11. A non-transitory storage medium having stored therein instructions that are executable by one or more hardware processors to perform operations comprising:
inserting a signal layer in an image which, when instantiated, is executable on an engine that is operable to build and containerize an application, the signal layer indicating that a sensitive layer in the image is a candidate for encryption;
creating a single layer archive file that includes the sensitive layer;
encrypting the single layer archive file to create an encrypted layer;
constructing a new image that includes the encrypted layer;
inserting, in the new image, a decryptor layer that is operable to decrypt the encrypted layer; and
designating the decryptor layer as an entry point of the new image so that the decryptor layer of the new image runs first when the new image is instantiated.
12. The non-transitory storage medium as recited in claim 11 , wherein the new image further comprises:
a signal layer; and
an unencrypted non-sensitive layer.
13. The non-transitory storage medium as recited in claim 11 , wherein the operations further comprise restoring one or more non-sensitive layers from the image to the new image.
14. The non-transitory storage medium as recited in claim 11 , wherein the single layer archive file comprises multiple sensitive layers of the image.
15. The non-transitory storage medium as recited in claim 11 , wherein the operations further comprise traversing the image to identify the signal layer and the sensitive layer.
16. The non-transitory storage medium as recited in claim 11 , wherein the new image is configured to call an original entry point after decryption of the encrypted layer has been performed by the decryptor layer.
17. The non-transitory storage medium as recited in claim 11 , wherein the operations further comprise instantiating the new image by performing additional operations comprising:
running the decryption layer to decrypt the encrypted layer, open the single layer archive file, and restore the sensitive layer of the image from the single layer archive file to the new image; and
after decryption of the encrypted layer, running one or more layers of the new image.
18. The non-transitory storage medium as recited in claim 11 , wherein the image comprises a stop encryption layer that defines where, in the image, encryption ends.
19. The non-transitory storage medium as recited in claim 11 , wherein one or both of the image and the new image is a Docker image.
20. The non-transitory storage medium as recited in claim 11 , wherein the new image does not require a process external to the new image to perform decryption of the encrypted layer.