gnutls_buffer_append_data - Linux


gnutls_buffer_append_data appends data to the end of a gnutls_buffer instance. It is primarily used to create or modify application data such as certificates, credentials, or messages in the context of secure network communications using the GnuTLS library.


int gnutls_buffer_append_data(gnutls_buffer_t *buffer, const void *data, size_t length)


  • buffer: Pointer to the gnutls_buffer instance where data will be appended.
  • data: Pointer to the data that will be appended.
  • length: Length of the data to be appended.


Simple Append:

char *message = "Hello World";
gnutls_buffer_t buffer;
gnutls_buffer_append_data(&buffer, message, strlen(message));

Concatenating Multiple Strings:

gnutls_buffer_t buffer;
gnutls_buffer_append_data(&buffer, "Hello ", 6);
gnutls_buffer_append_data(&buffer, "World", 5);

Common Issues

  • Buffer Overflow: Make sure that the length of the data to be appended does not exceed the available space in the gnutls_buffer.
  • Memory Leaks: Remember to free the memory allocated by gnutls_buffer using gnutls_buffer_destroy() to avoid leaks.


gnutls_buffer_append_data is often used in conjunction with other GnuTLS functions for secure data handling and network communication.

  • TLS Handshake: Appending certificates and credentials to a buffer for transmission during TLS handshake.
  • Message Exchange: Appending application data to a buffer for encrypted transmission.

Related Commands

  • gnutls_buffer_init() – Initializes a gnutls_buffer instance.
  • gnutls_buffer_destroy() – Destroys a gnutls_buffer instance and frees its allocated memory.
  • gnutls_buffer_size() – Returns the size of data stored in a gnutls_buffer.
  • gnutls_buffer_data() – Returns a pointer to the data stored in a gnutls_buffer.