Add documentation on parameter preconditions to ChaChaPoly modules
diff --git a/include/mbedtls/chachapoly.h b/include/mbedtls/chachapoly.h
index 7de6f4e..80d20e5 100644
--- a/include/mbedtls/chachapoly.h
+++ b/include/mbedtls/chachapoly.h
@@ -115,27 +115,29 @@
* all previous outputs of \c mbedtls_chachapoly_update(),
* otherwise you can now safely use the plaintext.
*
- * \param ctx The ChachaPoly context to initialize.
+ * \param ctx The ChachaPoly context to initialize. Must not be \c NULL.
*/
void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx );
/**
- * \brief This function releases and clears the specified ChaCha20-Poly1305 context.
+ * \brief This function releases and clears the specified
+ * ChaCha20-Poly1305 context.
*
- * \param ctx The ChachaPoly context to clear.
+ * \param ctx The ChachaPoly context to clear. May be \c NULL, in which
+ * case this function is a no-op.
*/
void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx );
/**
- * \brief This function sets the ChaCha20-Poly1305 symmetric encryption key.
+ * \brief This function sets the ChaCha20-Poly1305
+ * symmetric encryption key.
*
* \param ctx The ChaCha20-Poly1305 context to which the key should be
- * bound.
+ * bound. Must be initialized.
* \param key The 256-bit (32 bytes) key.
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if \p ctx or \p key are NULL.
+ * \return A negative error code on failure.
*/
int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
const unsigned char key[32] );
@@ -155,14 +157,13 @@
* \warning Decryption with the piecewise API is discouraged, see the
* warning on \c mbedtls_chachapoly_init().
*
- * \param ctx The ChaCha20-Poly1305 context.
+ * \param ctx The ChaCha20-Poly1305 context. Must be initialized.
* \param nonce The nonce/IV to use for the message. Must be 12 bytes.
* \param mode The operation to perform: #MBEDTLS_CHACHAPOLY_ENCRYPT or
* #MBEDTLS_CHACHAPOLY_DECRYPT (discouraged, see warning).
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if \p ctx or \p mac are NULL.
+ * \return A negative error code on failure.
*/
int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx,
const unsigned char nonce[12],
@@ -227,20 +228,19 @@
* \warning Decryption with the piecewise API is discouraged, see the
* warning on \c mbedtls_chachapoly_init().
*
- * \param ctx The ChaCha20-Poly1305 context to use.
+ * \param ctx The ChaCha20-Poly1305 context to use. Must be initialized.
* \param len The length (in bytes) of the data to encrypt or decrypt.
* \param input The buffer containing the data to encrypt or decrypt.
- * This pointer can be NULL if len == 0.
- * \param output The buffer to where the encrypted or decrypted data is written.
- * Must be able to hold \p len bytes.
- * This pointer can be NULL if len == 0.
+ * This pointer can be \c NULL if `len == 0`.
+ * \param output The buffer to where the encrypted or decrypted data is
+ * written. Must be able to hold \p len bytes.
+ * This pointer can be \c NULL if `len == 0`.
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if \p ctx, \p input, or \p output are NULL.
* \return #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
* if the operation has not been started or has been
* finished.
+ * \return Another negative error code on other kinds of failure.
*/
int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx,
size_t len,
@@ -251,18 +251,17 @@
* \brief This function finished the ChaCha20-Poly1305 operation and
* generates the MAC (authentication tag).
*
- * \param ctx The ChaCha20-Poly1305 context to use.
+ * \param ctx The ChaCha20-Poly1305 context to use. Must be initialized.
* \param mac The buffer to where the 128-bit (16 bytes) MAC is written.
*
* \warning Decryption with the piecewise API is discouraged, see the
* warning on \c mbedtls_chachapoly_init().
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if \p ctx or \p mac are NULL.
* \return #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
* if the operation has not been started or has been
* finished.
+ * \return Another negative error code on other kinds of failure.
*/
int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
unsigned char mac[16] );
@@ -280,20 +279,20 @@
* and key.
*
* \param ctx The ChaCha20-Poly1305 context to use (holds the key).
+ * Must be initialized.
* \param length The length (in bytes) of the data to encrypt or decrypt.
* \param nonce The 96-bit (12 bytes) nonce/IV to use.
* \param aad The buffer containing the additional authenticated data (AAD).
- * This pointer can be NULL if aad_len == 0.
+ * This pointer can be \c NULL if `aad_len == 0`.
* \param aad_len The length (in bytes) of the AAD data to process.
* \param input The buffer containing the data to encrypt or decrypt.
- * This pointer can be NULL if ilen == 0.
+ * This pointer can be \c NULL if `ilen == 0`.
* \param output The buffer to where the encrypted or decrypted data is written.
- * This pointer can be NULL if ilen == 0.
+ * This pointer can be \c NULL if `ilen == 0`.
* \param tag The buffer to where the computed 128-bit (16 bytes) MAC is written.
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if one or more of the required parameters are NULL.
+ * \return A negative error code on failure.
*/
int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx,
size_t length,
@@ -324,10 +323,9 @@
* This pointer can be NULL if ilen == 0.
*
* \return \c 0 on success.
- * \return #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- * if one or more of the required parameters are NULL.
* \return #MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED
* if the data was not authentic.
+ * \return Another negative error code on other kinds of failure.
*/
int mbedtls_chachapoly_auth_decrypt( mbedtls_chachapoly_context *ctx,
size_t length,