Skip to main content
Version: 0.1.24

AES (shared)

Shared AES types and generic entry points.

For mode-specific APIs and guidance, use the pages for each mode: AES - ECB, AES CBC, AES CTR, AES CFB, AES OFB, AES GCM, AES CCM, AES XTS.

Streaming API​

AES now supports incremental processing with a context object for scenarios where plaintext/ciphertext arrives in chunks.

  • Use noxtls_aes_init() once with key/IV/mode/direction.
  • Call noxtls_aes_update() any number of times as data arrives.
  • Call noxtls_aes_final() once at the end to flush any buffered data.

Supported streaming modes:

  • NOXTLS_AES_ECB, NOXTLS_AES_CBC, NOXTLS_AES_CTR, NOXTLS_AES_CFB, NOXTLS_AES_OFB

Notes:

  • NOXTLS_AES_CTR, NOXTLS_AES_CFB, and NOXTLS_AES_OFB behave as stream modes: noxtls_aes_final() emits no extra bytes.
  • NOXTLS_AES_ECB and NOXTLS_AES_CBC buffer partial blocks; on encrypt, noxtls_aes_final() emits one final block if needed.
  • NOXTLS_AES_GCM and NOXTLS_AES_XTS are currently one-shot APIs in this library (use their dedicated functions).

Types​

noxtls_aes_context_t​

Opaque context for incremental AES encryption/decryption. Used by noxtls_aes_init, noxtls_aes_update, noxtls_aes_final. Allocate and pass to noxtls_aes_init; do not access fields directly.

noxtls_aes_type_t​

AES key size: NOXTLS_AES_128_BIT, NOXTLS_AES_192_BIT, or NOXTLS_AES_256_BIT. Determines key length (16, 24, or 32 bytes).

noxtls_aes_mode_t​

AES mode of operation: NOXTLS_AES_ECB, NOXTLS_AES_CBC, NOXTLS_AES_CTR, NOXTLS_AES_CFB, or NOXTLS_AES_OFB for streaming; NOXTLS_AES_GCM and NOXTLS_AES_XTS are one-shot only.

noxtls_aes_operation_t​

Direction: NOXTLS_AES_OP_ENCRYPT or NOXTLS_AES_OP_DECRYPT.

API​

noxtls_aes_init​

noxtls_return_t noxtls_aes_init(noxtls_aes_context_t *ctx,
             const uint8_t *key,
             const uint8_t *iv,
             noxtls_aes_type_t type,
             noxtls_aes_mode_t mode,
             noxtls_aes_operation_t op);

Initialize AES streaming context.

Parameters:

  • ctx — noxtls_aes_context_t to initialize
  • key — AES key (size depends on type)
  • iv — IV/nonce (required for CTR/CFB/OFB, optional for CBC, unused for ECB)
  • type — noxtls_aes_type_t: key size (NOXTLS_AES_128_BIT, NOXTLS_AES_192_BIT, NOXTLS_AES_256_BIT)
  • mode — noxtls_aes_mode_t: NOXTLS_AES_ECB, NOXTLS_AES_CBC, NOXTLS_AES_CTR, NOXTLS_AES_CFB, or NOXTLS_AES_OFB
  • op — noxtls_aes_operation_t: NOXTLS_AES_OP_ENCRYPT or NOXTLS_AES_OP_DECRYPT

Returns: noxtls_return_t: NOXTLS_RETURN_SUCCESS on success; NOXTLS_RETURN_NULL if ctx or key is NULL; NOXTLS_RETURN_INVALID_KEY_SIZE, NOXTLS_RETURN_INVALID_PARAM, NOXTLS_RETURN_NOT_SUPPORTED, or NOXTLS_RETURN_INVALID_MODE on error.

noxtls_aes_update​

noxtls_return_t noxtls_aes_update(noxtls_aes_context_t *ctx,
               const uint8_t *input,
               uint32_t input_len,
               uint8_t *output,
               uint32_t *output_len);

Process the next chunk.

Parameters:

Returns: noxtls_return_t: NOXTLS_RETURN_SUCCESS on success.

noxtls_aes_final​

noxtls_return_t noxtls_aes_final(noxtls_aes_context_t *ctx,
              uint8_t *output,
              uint32_t *output_len);

Finalize streaming operation and flush buffered data.

Parameters:

Returns: noxtls_return_t: NOXTLS_RETURN_SUCCESS on success; NOXTLS_RETURN_NULL, NOXTLS_RETURN_NOT_INITIALIZED, NOXTLS_RETURN_INVALID_BLOCK_SIZE, or NOXTLS_RETURN_INVALID_MODE on error.