Module lib_gistit::encrypt

The encryption module

Hashing

Md5 digestion algorithm was used to implement the Gistit payload hashing procedure since we just need a fast hash algorithm to uniquely identify our Gistits and here security is not an concern. Also, 128bits is fine and doesn’t look too long of a hex-string when copying and sharing.

Secrets

Scrypt algorithm was used to hash the provided secret. The params values choosen N = 2^2, R = 8, and P = 1 as discussed here.

Encryption

The encryption/decryption process relies on AesGcm algorithm with 256-bit key and 96-bit nounce. See aes_gcm for more info.

Structs

HashedSecret

The hashed secret

Secret

The data structure to hold the provided secret

Functions

decrypt_aes256_u12nonce

Decrypts encrypted_data given the magic and a Md5 hash of the provided secret. Expects the same nounce (magic) and secret as given in the encryption process.

digest_md5

Digests a single byte array into Md5 and outputs the resulting string

digest_md5_multi

Digests a slice of byte arrays into Md5 and outputs the resulting string

encrypt_aes256_u12nonce

Encrypts raw_data with a randomly generated nounce and a Md5 hash of the provided secret