Crate embassy_crypto_driver 

embassy-crypto-driver

embassy-crypto provides universal optimized implementations of cryptographic functions, targeted for embedded systems. This crate defines the driver interface for these functions.

Hardware-agnostic crypto driver unitraits for the Embassy ecosystem.

This crate defines a set of unitrait! traits that abstract over hardware-accelerated (or software) cryptographic operations. Each trait declares an opaque context type and a set of functions with stable C linkage symbols, allowing exactly one driver implementation to be selected at link time.

Supported Operations

Digests

• Md5, Sha1, Sha224, Sha256, Sha384, Sha512, Sha512_224, Sha512_256

HMAC

• HmacSha1, HmacSha224, HmacSha256, HmacSha384, HmacSha512, HmacSha512_224, HmacSha512_256

Block Ciphers

• Aes128Ecb, Aes256Ecb — ECB mode
• Aes128Cbc, Aes256Cbc — CBC mode

AEAD

• Aes128Gcm, Aes256Gcm — GCM mode
• Aes128Ccm, Aes256Ccm — CCM mode

Elliptic Curve (P256)

• P256Ecdh — key generation, public-key derivation, and shared-secret computation for TLS and Bluetooth LE Secure Connections
• P256Ecdsa — sign and verify pre-hashed digests for TLS certificate authentication

Elliptic Curve (P384)

• P384Ecdh — key generation, public-key derivation, and shared-secret computation for TLS
• P384Ecdsa — sign and verify pre-hashed digests for TLS certificate authentication

X25519 (Curve25519)

• X25519 — key generation, public-key derivation, and X25519 shared-secret computation for TLS 1.3 ECDHE

High-level EC operations

• P256Ec — combined P-256 ECDH + ECDSA unitrait serving embassy-crypto’s asymmetric module
• P384Ec — combined P-384 ECDH + ECDSA unitrait serving embassy-crypto’s asymmetric::p384 module

Driver Registration

A HAL crate registers itself by invoking the generated *_impl! macro for each supported algorithm. Only one crate in the dependency tree may register a driver for any given algorithm; otherwise linking will fail.

Macros

aes128cbc_impl

aes128ccm_impl

aes128cmac_impl

aes128ctr_impl

aes128ecb_impl

aes128gcm_impl

aes256cbc_impl

aes256ccm_impl

aes256cmac_impl

aes256ctr_impl

aes256ecb_impl

aes256gcm_impl

hmac_sha1_impl

hmac_sha224_impl

hmac_sha256_impl

hmac_sha384_impl

hmac_sha512_224_impl

hmac_sha512_256_impl

hmac_sha512_impl

md5_impl

p256_ec_impl

p256_lincomb_impl

p256_scalar_invert_impl

p256_scalar_mul_impl

p384_ec_impl

p384_lincomb_impl

p384_scalar_invert_impl

p384_scalar_mul_impl

sha1_impl

sha224_impl

sha256_impl

sha384_impl

sha512_224_impl

sha512_256_impl

sha512_impl

x25519_impl

Structs

Aes128CbcImpl

The global Aes128Cbc implementation.

Aes128CbcImplDecryptContext

Opaque storage for the decryptor’s key schedule and chaining state.

Aes128CbcImplEncryptContext

Opaque storage for the encryptor’s key schedule and chaining state.

Aes128CcmImpl

The global Aes128Ccm implementation.

Aes128CcmImplContext

Opaque storage for the implementation’s key schedule.

Aes128CmacImpl

The global Aes128Cmac implementation.

Aes128CmacImplContext

Opaque storage for the implementation’s CMAC state.

Aes128CtrImpl

The global Aes128Ctr implementation.

Aes128CtrImplContext

Opaque storage for key schedule, counter state, and partial-block buffer.

Aes128EcbImpl

The global Aes128Ecb implementation.

Aes128EcbImplContext

Opaque storage for the implementation’s key schedule.

Aes128GcmImpl

The global Aes128Gcm implementation.

Aes128GcmImplContext

Opaque storage for the implementation’s key schedule.

Aes256CbcImpl

The global Aes256Cbc implementation.

Aes256CbcImplDecryptContext

Opaque storage for the decryptor’s key schedule and chaining state.

Aes256CbcImplEncryptContext

Opaque storage for the encryptor’s key schedule and chaining state.

Aes256CcmImpl

The global Aes256Ccm implementation.

Aes256CcmImplContext

Opaque storage for the implementation’s key schedule.

Aes256CmacImpl

The global Aes256Cmac implementation.

Aes256CmacImplContext

Opaque storage for the implementation’s CMAC state.

Aes256CtrImpl

The global Aes256Ctr implementation.

Aes256CtrImplContext

Aes256EcbImpl

The global Aes256Ecb implementation.

Aes256EcbImplContext

Opaque storage for the implementation’s key schedule.

Aes256GcmImpl

The global Aes256Gcm implementation.

Aes256GcmImplContext

Opaque storage for the implementation’s key schedule.

HmacSha1Impl

The global HmacSha1 implementation.

HmacSha1ImplContext

Opaque storage for the implementation’s hash state.

HmacSha224Impl

The global HmacSha224 implementation.

HmacSha224ImplContext

Opaque storage for the implementation’s hash state.

HmacSha256Impl

The global HmacSha256 implementation.

HmacSha256ImplContext

Opaque storage for the implementation’s hash state.

HmacSha384Impl

The global HmacSha384 implementation.

HmacSha384ImplContext

Opaque storage for the implementation’s hash state.

HmacSha512Impl

The global HmacSha512 implementation.

HmacSha512ImplContext

Opaque storage for the implementation’s hash state.

HmacSha512_224Impl

The global HmacSha512_224 implementation.

HmacSha512_224ImplContext

Opaque storage for the implementation’s hash state.

HmacSha512_256Impl

The global HmacSha512_256 implementation.

HmacSha512_256ImplContext

Opaque storage for the implementation’s hash state.

InOutBuf

A lightweight I/O buffer abstraction without depending on the RustCrypto inout crate.

Md5Impl

The global Md5 implementation.

Md5ImplContext

Opaque storage for the implementation’s hash state.

NotEqualError

Error returned when a pair of input/output slices have unequal lengths.

P256AffinePoint

Canonical P-256 affine point: big-endian (x, y), uncompressed.

P256EcImpl

The global P256Ec implementation.

P256LincombImpl

The global P256Lincomb implementation.

P256Scalar

Canonical P-256 scalar: big-endian, 32 bytes.

P256ScalarInvertImpl

The global P256ScalarInvert implementation.

P256ScalarMulImpl

The global P256ScalarMul implementation.

P256Signature

Raw P-256 ECDSA signature: canonical (r, s), each 32 bytes big-endian.

P384AffinePoint

Canonical P-384 affine point: big-endian (x, y), uncompressed.

P384EcImpl

The global P384Ec implementation.

P384LincombImpl

The global P384Lincomb implementation.

P384Scalar

Canonical P-384 scalar: big-endian, 48 bytes.

P384ScalarInvertImpl

The global P384ScalarInvert implementation.

P384ScalarMulImpl

The global P384ScalarMul implementation.

P384Signature

Sha1Impl

The global Sha1 implementation.

Sha1ImplContext

Opaque storage for the implementation’s hash state.

Sha224Impl

The global Sha224 implementation.

Sha224ImplContext

Opaque storage for the implementation’s hash state.

Sha256Impl

The global Sha256 implementation.

Sha256ImplContext

Opaque storage for the implementation’s hash state.

Sha384Impl

The global Sha384 implementation.

Sha384ImplContext

Opaque storage for the implementation’s hash state.

Sha512Impl

The global Sha512 implementation.

Sha512ImplContext

Opaque storage for the implementation’s hash state.

Sha512_224Impl

The global Sha512_224 implementation.

Sha512_224ImplContext

Opaque storage for the implementation’s hash state.

Sha512_256Impl

The global Sha512_256 implementation.

Sha512_256ImplContext

Opaque storage for the implementation’s hash state.

X25519Impl

The global X25519 implementation.

X25519PrivateKey

An X25519 private key: 32-byte Curve25519 scalar, little-endian.

X25519PublicKey

An X25519 public key: 32-byte Curve25519 u-coordinate, little-endian (RFC 7748).

Enums

CryptoError

Error type for crypto operations.

Traits

Aes128Cbc

AES-128 CBC block cipher trait.

Aes128Ccm

AES-128 CCM AEAD trait.

Aes128Cmac

AES-128 CMAC (Cipher-based Message Authentication Code) trait.

Aes128Ctr

AES-128 CTR stream cipher trait.

Aes128Ecb

AES-128 ECB block cipher trait.

Aes128Gcm

AES-128 GCM AEAD trait.

Aes256Cbc

AES-256 CBC block cipher trait.

Aes256Ccm

AES-256 CCM AEAD trait.

Aes256Cmac

AES-256 CMAC (Cipher-based Message Authentication Code) trait.

Aes256Ctr

AES-256 CTR stream cipher trait.

Aes256Ecb

AES-256 ECB block cipher trait.

Aes256Gcm

AES-256 GCM AEAD trait.

HmacSha1

Sha1 trait

HmacSha224

Sha224 trait

HmacSha256

Sha256 trait

HmacSha384

Sha384 trait

HmacSha512

Sha512 trait

HmacSha512_224

Sha512_224 trait

HmacSha512_256

Sha512_256 trait

Md5

Md5 trait

P256Ec

High-level P-256 operations for TLS 1.3 and BLE Secure Connections.

P256Lincomb

P-256 double-base scalar multiplication accelerator (optional).

P256ScalarInvert

P-256 scalar field inversion accelerator (optional).

P256ScalarMul

P-256 scalar multiplication accelerator.

P384Ec

High-level P-384 operations for TLS 1.3.

P384Lincomb

P-384 double-base scalar multiplication accelerator (optional).

P384ScalarInvert

P-384 scalar field inversion accelerator (optional).

P384ScalarMul

P-384 scalar multiplication accelerator.

Rng

Caller-provided entropy source for crypto operations that need fresh randomness (ECDSA nonces, ephemeral key generation).

Sha1

Sha1 trait

Sha224

Sha224 trait

Sha256

Sha256 trait

Sha384

Sha384 trait

Sha512

Sha512 trait

Sha512_224

Sha512_224 trait

Sha512_256

Sha512_256 trait

X25519

X25519 (Curve25519) ECDH operations for TLS 1.3.