Module aes 

Advanced Encryption Standard (AES) hardware accelerator.

This module drives the on-chip AES block. The hardware revisions below are supported, selected automatically from the target chip:

• aes_v1 (STM32L0, L1, L4, F423) — blocking driver, plus an interrupt-driven async API where the engine has its own interrupt (L4). This revision only does ECB, CBC and CTR with 128-bit keys.
• aes_v2 (STM32G0, G4, L5, U0, WL) — blocking driver, plus an interrupt-driven async API where the engine has its own interrupt (L5, WL). Elsewhere the engine shares its interrupt line with another peripheral (e.g. RNG) or has no dedicated line at all, so only the blocking API is offered.
• aes_f7 (STM32F72x, F73x) — same register map as aes_v2 minus the NPBLB field, so a final partial payload block cannot be masked out of the authentication: GCM (both directions) and CCM decryption return Error::ConfigError when the payload is not a multiple of 16 bytes.
• aes_v3a (STM32U5) and aes_v3b (STM32H5, WBA) — blocking driver plus an interrupt/DMA-backed async API. The two revisions have the same register map.

All revisions expose the same cipher types and the same start / aad_blocking / payload_blocking / finish_blocking blocking flow, so blocking code is portable across them.

Supported cipher modes

Mode	Padding	Auth	Use case
ECB	Required	No	Keys only (not recommended for data)
CBC	Required	No	File/disk encryption
CTR	No	No	Streaming data, random access
GCM	No	Yes	Recommended — modern applications
GMAC	No	Yes	Authentication without encryption
CCM	No	Yes	Resource‑constrained devices

GCM, GMAC and CCM are not available on aes_v1.

Key sizes

• 128-bit (16 bytes) and 256-bit (32 bytes); only 128-bit on aes_v1.
• 192-bit keys are not supported by this hardware.

IV / nonce requirements

• CBC: random, unique per message.
• CTR: must never repeat with the same key.
• GCM/GMAC: 96-bit (12 bytes), unique per message. IV reuse is catastrophic.

Structs

Aes

AES driver.

AesCbc

AES-CBC Cipher Mode

AesCcm

AES-CCM Cipher Mode (Counter with CBC-MAC)

AesCtr

AES-CTR Cipher Mode

AesEcb

AES-ECB Cipher Mode

AesGcm

AES-GCM Cipher Mode

AesGmac

AES-GMAC Cipher Mode (Galois Message Authentication Code)

Context

Stores the state of the AES peripheral for a cipher operation.

InterruptHandler

AES interrupt handler.

Enums

Direction

AES cipher direction

Error

AES error

KeySize

AES key size

Traits

Cipher

This trait encapsulates all cipher-specific behavior.

CipherAuthenticated

This trait enables restriction of a header phase to authenticated ciphers only.

CipherSized

This trait enables restriction of ciphers to specific key sizes.

DmaIn

DmaIn DMA request trait

DmaOut

DmaOut DMA request trait

IVSized

This trait enables restriction of initialization vectors to sizes compatible with a cipher mode.

Instance

AES instance trait.