Strings and Similar Data

Since the GSS-API handles all data in internal formats, strings must be converted to a GSS-API format before being passed to GSS-API functions. The GSS-API handles strings with the gss_buffer_desc structure; gss_buffer_t is a pointer to such a structure.

typedef struct gss_buffer_desc_struct {
     size_t     length;
     void       *value;
}  gss_buffer_desc *gss_buffer_t;

Therefore, strings must be put into a gss_buffer_desc structure before being passed to functions that use them. Consider a generic GSS-API function that takes a message and processes it in some way (for example, applies protection to it before it is transmitted), as follows:

Example 1–1 Using Strings

char *message_string;
gss_buffer_desc input_msg_buffer;

input_msg_buffer.value = message_string;
input_msg_buffer.length = strlen(input_msg_buffer.value) + 1;

gss_generic_function(arg1, &input_msg_buffer, arg2...);

gss_release_buffer(input_msg_buffer);

Note that input_msg_buffer must be deallocated with gss_release_buffer() when you are finished with it.

The gss_buffer_desc object is not just for character strings; for example, tokens are manipulated as gss_buffer_desc objects. (See GSS-API Tokens.)