libssh2_session_supported_algs - get list of supported algorithms
Contents
Availability
Added in 1.4.0
Description
session - An instance of initialized LIBSSH2_SESSION (the function will use its pointer to the memory
allocation function). method_type - Method type. See libssh2_session_method_pref(3). algs - Address of a
pointer that will point to an array of returned algorithms
Get a list of supported algorithms for the given method_type. The method_type parameter is equivalent to
method_type in libssh2_session_method_pref(3). If successful, the function will allocate the appropriate
amount of memory. When not needed anymore, it must be deallocated by calling libssh2_free(3). When this
function is unsuccessful, this must not be done.
In order to get a list of all supported compression algorithms, libssh2_session_flag(session,
LIBSSH2_FLAG_COMPRESS, 1) must be called before calling this function, otherwise only "none" will be
returned.
If successful, the function will allocate and fill the array with supported algorithms (the same names as
defined in RFC 4253). The array is not NULL terminated.
Errors
LIBSSH2_ERROR_BAD_USE - Invalid address of algs.
LIBSSH2_ERROR_METHOD_NOT_SUPPORTED - Unknown method type.
LIBSSH2_ERROR_INVAL - Internal error (normally should not occur).
LIBSSH2_ERROR_ALLOC - Allocation of memory failed.
Example
#include "libssh2.h"
const char **algorithms;
int rc, i;
LIBSSH2_SESSION *session;
/* initialize session */
session = libssh2_session_init();
rc = libssh2_session_supported_algs(session,
LIBSSH2_METHOD_CRYPT_CS,
&algorithms);
if(rc > 0) {
/* the call succeeded, do sth. with the list of algorithms
(e.g. list them)... */
printf("Supported symmetric algorithms:\n");
for(i = 0; i < rc; i++)
printf("\t%s\n", algorithms[i]);
/* ... and free the allocated memory when not needed anymore */
libssh2_free(session, algorithms);
}
else {
/* call failed, error handling */
}
Name
libssh2_session_supported_algs - get list of supported algorithms
Return Value
On success, a number of returned algorithms (i.e a positive number will be returned). In case of a
failure, an error code (a negative number, see below) is returned. 0 should never be returned.
See Also
libssh2_session_methods(3),libssh2_session_method_pref(3)libssh2_free(3) libssh2 23 Oct 2011 libssh2_session_supported_algs(3)
Synopsis
#include <libssh2.h>
int
libssh2_session_supported_algs(LIBSSH2_SESSION* session,
int method_type,
const char*** algs);
