Correct plaintext size limitation

Cosmian · Sep 20, 2022 · afaee4c · afaee4c
1 parent c702042
commit afaee4c
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/src/symmetric_crypto/aes_256_gcm_pure/mod.rs b/src/symmetric_crypto/aes_256_gcm_pure/mod.rs
@@ -24,8 +24,9 @@ const NONCE_LENGTH: usize = 12;
 /// Use a 128-bit MAC tag
 const MAC_LENGTH: usize = 16;
 
-/// A 96-bit nonce restricts the plaintext size to 4096 bytes
-const MAX_PLAINTEXT_LENGTH: usize = 4096;
+/// Plaintext size restriction from the NIST
+/// https://csrc.nist.gov/publications/detail/sp/800-38d/final
+const MAX_PLAINTEXT_LENGTH: usize = (2_usize.pow(39) - 256) / 8;
 
 /// Structure implementing `SymmetricCrypto` and the `DEM` interfaces based on
 /// AES 256 GCM.

diff --git a/src/symmetric_crypto/mod.rs b/src/symmetric_crypto/mod.rs
@@ -54,7 +54,7 @@ pub trait Dem<const KEY_LENGTH: usize>: Debug + PartialEq {
     ///
     /// - `rng`         : secure random number generator
     /// - `secret_key`  : secret symmetric key
-    /// - `plaintext`     : plaintext message
+    /// - `plaintext`   : plaintext message
     /// - `aad`         : optional data to use in the authentication method,
     /// must use the same for decryption
     fn encrypt<R: RngCore + CryptoRng>(