mbedtls_gcm_starts() function

The GCM context. This must be initialized.

The operation to perform: #MBEDTLS_GCM_ENCRYPT or #MBEDTLS_GCM_DECRYPT.

The initialization vector. This must be a readable buffer of at least \p iv_len Bytes.

The length of the IV.

The buffer holding the additional data, or \c NULL if \p add_len is \c 0.

The length of the additional data. If \c 0, \p add may be \c NULL.

This function finishes the GCM operation and generates the authentication tag. It wraps up the GCM stream, and generates the tag. The tag can have a maximum length of 16 Bytes.

This function associates a GCM context with a cipher algorithm and a key.

This function performs GCM encryption or decryption of a buffer. \warning When this function performs a decryption, it outputs the authentication tag and does not verify that the data is authentic. You should use this function to perform encryption only. For decryption, use mbedtls_gcm_auth_decrypt() instead.

This function feeds an input buffer into an ongoing GCM encryption or decryption operation. ` The function expects input to be a multiple of 16 Bytes. Only the last call before calling mbedtls_gcm_finish() can be less than 16 Bytes.

This function initializes the specified GCM context, to make references valid, and prepares the context for mbedtls_gcm_setkey() or mbedtls_gcm_free(). The function does not bind the GCM context to a particular cipher, nor set the key. For this purpose, use mbedtls_gcm_setkey().

This function performs a GCM authenticated decryption of a buffer.

This function clears a GCM context and the underlying cipher sub-context.