nasl_krb5.c File Reference

#include "nasl_krb5.h"
#include "../misc/openvas-krb5.h"
#include "nasl_debug.h"
#include "nasl_func.h"
#include "nasl_global_ctxt.h"
#include "nasl_lex_ctxt.h"
#include "nasl_tree.h"
#include "nasl_var.h"
#include <gvm/base/networking.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

Include dependency graph for nasl_krb5.c:

Go to the source code of this file.

Macros
#define	NASL_PRINT_KRB_ERROR(lexic, credential, result)
#define	SET_SLICE_FROM_LEX_OR_ENV(lexic, slice, name, env_name)
#define	PERROR_SET_SLICE_FROM_LEX_OR_ENV(lexic, slice, name, env_name)

Functions
static OKrb5Credential	build_krb5_credential (lex_ctxt *lexic)
tree_cell *	nasl_okrb5_find_kdc (lex_ctxt *lexic)
	Returns the defined KDC of a given Realm.
tree_cell *	nasl_okrb5_add_realm (lex_ctxt *lexic)
	Adds the given KDC to the given Realm.
tree_cell *	nasl_okrb5_is_success (lex_ctxt *lexic)
	Returns 1 if the krb5 function was successful 0 otherwise.
tree_cell *	nasl_okrb5_is_failure (lex_ctxt *lexic)
	Returns 0 if the krb5 function was successful and 1 if it failed.
tree_cell *	nasl_okrb5_gss_init (lex_ctxt *lexic)
tree_cell *	nasl_okrb5_gss_prepare_context (lex_ctxt *lexic)
tree_cell *	nasl_okrb5_gss_update_context (lex_ctxt *lexic)
void	nasl_okrb5_clean (void)
tree_cell *	nasl_okrb5_gss_update_context_needs_more (lex_ctxt *lexic)
static tree_cell *	okrb5_slice_to_tree_cell (struct OKrb5Slice *slice)
tree_cell *	nasl_okrb5_gss_update_context_out (lex_ctxt *lexic)
tree_cell *	nasl_okrb5_gss_session_key_context (lex_ctxt *lexic)
tree_cell *	nasl_okrb5_error_code_to_string (lex_ctxt *lexic)

Variables
static OKrb5ErrorCode	last_okrb5_result
static struct OKrb5GSSContext *	cached_gss_context = NULL
static struct OKrb5Slice *	to_application = NULL
static bool	gss_update_context_more = false
static char *	generated_config_path = NULL

Macro Definition Documentation

NASL_PRINT_KRB_ERROR

#define NASL_PRINT_KRB_ERROR	(		lexic,
			credential,
			result )

Value:

do                                                                      \
  {                                                                     \
    char *error_str = okrb5_error_code_to_string (result);              \
    nasl_perror (                                                       \
      lexic, "%s[config_path: '%s' realm: '%s' user: '%s'] => %s (%d)", \
      __func__, credential.config_path.data, credential.realm.data,     \
      credential.user.user.data, error_str, result);                    \
    free (error_str);                                                   \
  }                                                                     \
while (0)

Definition at line 21 of file nasl_krb5.c.

#define NASL_PRINT_KRB_ERROR(lexic, credential, result)                   \
  do                                                                      \
    {                                                                     \
      char *error_str = okrb5_error_code_to_string (result);              \
      nasl_perror (                                                       \
        lexic, "%s[config_path: '%s' realm: '%s' user: '%s'] => %s (%d)", \
        __func__, credential.config_path.data, credential.realm.data,     \
        credential.user.user.data, error_str, result);                    \
      free (error_str);                                                   \
    }                                                                     \
  while (0)

Referenced by build_krb5_credential(), nasl_okrb5_add_realm(), and nasl_okrb5_find_kdc().

PERROR_SET_SLICE_FROM_LEX_OR_ENV

#define PERROR_SET_SLICE_FROM_LEX_OR_ENV	(		lexic,
			slice,
			name,
			env_name )

Value:

do                                                                   \
  {                                                                  \
    SET_SLICE_FROM_LEX_OR_ENV (lexic, slice, name, env_name);        \
    if (slice.len == 0)                                              \
      {                                                              \
        nasl_perror (lexic, "Expected %s or env variable %s", name,  \
                     env_name);                                      \
      }                                                              \
  }                                                                  \
while (0)

Definition at line 73 of file nasl_krb5.c.

#define PERROR_SET_SLICE_FROM_LEX_OR_ENV(lexic, slice, name, env_name) \
  do                                                                   \
    {                                                                  \
      SET_SLICE_FROM_LEX_OR_ENV (lexic, slice, name, env_name);        \
      if (slice.len == 0)                                              \
        {                                                              \
          nasl_perror (lexic, "Expected %s or env variable %s", name,  \
                       env_name);                                      \
        }                                                              \
    }                                                                  \
  while (0)

Referenced by build_krb5_credential().

SET_SLICE_FROM_LEX_OR_ENV

#define SET_SLICE_FROM_LEX_OR_ENV	(		lexic,
			slice,
			name,
			env_name )

Value:

do                                                                       \
  {                                                                      \
    okrb5_set_slice_from_str (slice, get_str_var_by_name (lexic, name)); \
    if (slice.len == 0)                                                  \
      {                                                                  \
        okrb5_set_slice_from_str (slice, getenv (env_name));             \
      }                                                                  \
    else                                                                 \
      {                                                                  \
        setenv (env_name, get_str_var_by_name (lexic, name), 1);         \
      }                                                                  \
  }                                                                      \
while (0)

Definition at line 58 of file nasl_krb5.c.

#define SET_SLICE_FROM_LEX_OR_ENV(lexic, slice, name, env_name)            \
  do                                                                       \
    {                                                                      \
      okrb5_set_slice_from_str (slice, get_str_var_by_name (lexic, name)); \
      if (slice.len == 0)                                                  \
        {                                                                  \
          okrb5_set_slice_from_str (slice, getenv (env_name));             \
        }                                                                  \
      else                                                                 \
        {                                                                  \
          setenv (env_name, get_str_var_by_name (lexic, name), 1);         \
        }                                                                  \
    }                                                                      \
  while (0)

Referenced by build_krb5_credential().

Function Documentation

build_krb5_credential()

OKrb5Credential build_krb5_credential ( lex_ctxt * lexic )

static

Definition at line 86 of file nasl_krb5.c.

{
  OKrb5Credential credential = {0};
  OKrb5ErrorCode code;
 
  char *kdc = NULL;
 
  SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.config_path, "config_path",
                             "KRB5_CONFIG");
  if (credential.config_path.len == 0)
    {
      char *ip_str = addr6_as_str (lexic->script_infos->ip);
      for (int i = 0; ip_str[i] != '\0'; i++)
        {
          if (ip_str[i] == '.' || ip_str[i] == ':')
            {
              ip_str[i] = '_';
            }
        }
      char default_config_path[256];
      snprintf (default_config_path, sizeof (default_config_path),
                "/tmp/krb5_%s.conf", ip_str);
      setenv ("KRB5_CONFIG", default_config_path, 1);
      okrb5_set_slice_from_str (credential.config_path, default_config_path);
    }
 
  // Store path for cleanup
  if (generated_config_path != NULL)
    free (generated_config_path);
  generated_config_path =
    strndup (credential.config_path.data, credential.config_path.len);
 
  PERROR_SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.realm, "realm",
                                    "KRB5_REALM");
  PERROR_SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.kdc, "kdc", "KRB5_KDC");
  PERROR_SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.user.user, "user",
                                    "KRB5_USER");
  PERROR_SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.user.password, "password",
                                    "KRB5_PASSWORD");
  PERROR_SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.target.host_name, "host",
                                    "KRB5_TARGET_HOST");
  // SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.target.service, "service",
  // "KRB5_TARGET_SERVICE");
 
  if ((code = o_krb5_find_kdc (&credential, &kdc)))
    {
      if (code != O_KRB5_REALM_NOT_FOUND && code != O_KRB5_CONF_NOT_FOUND)
        {
          NASL_PRINT_KRB_ERROR (lexic, credential, code);
        }
      else
        {
          if ((code = o_krb5_add_realm (&credential, credential.kdc.data)))
            {
              NASL_PRINT_KRB_ERROR (lexic, credential, code);
            }
        }
    }
  else
    {
      free (kdc);
    }
  if (credential.target.service.len == 0)
    {
      okrb5_set_slice_from_str (credential.target.service, "cifs");
    }
  SET_SLICE_FROM_LEX_OR_ENV (lexic, credential.kdc, "kdc", "KRB5_KDC");
 
  memset (&credential.target.domain, 0, sizeof (struct OKrb5Slice));
 
  return credential;
}

References code, OKrb5Credential::config_path, OKrb5Slice::data, OKrb5Target::domain, free(), generated_config_path, OKrb5Target::host_name, script_infos::ip, OKrb5Credential::kdc, OKrb5Slice::len, NASL_PRINT_KRB_ERROR, o_krb5_add_realm(), O_KRB5_CONF_NOT_FOUND, o_krb5_find_kdc(), O_KRB5_REALM_NOT_FOUND, okrb5_set_slice_from_str, OKrb5User::password, PERROR_SET_SLICE_FROM_LEX_OR_ENV, OKrb5Credential::realm, struct_lex_ctxt::script_infos, OKrb5Target::service, SET_SLICE_FROM_LEX_OR_ENV, OKrb5Credential::target, OKrb5Credential::user, and OKrb5User::user.

Referenced by nasl_okrb5_add_realm(), nasl_okrb5_find_kdc(), and nasl_okrb5_gss_prepare_context().

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nasl_okrb5_add_realm()

tree_cell * nasl_okrb5_add_realm

(

lex_ctxt *

lexic

)

Adds the given KDC to the given Realm.

This function returns 0 on success. To retrieve a human readable error message, the function okrb5_result can be used.

The nasl function has three optional parameter:

• realm: The realm for which the KDC should be returned. If the realm is not defined, then the env parameter KRB5_REALM is used.
• kdc: The realm for which the KDC should be returned. If the realm is not defined, then the env parameter KRB5_KDC is used.
• config_path: The path to the krb5.conf file. If the path is not defined, then the env parameter KRB5_CONFIG is used.

This function should only be used for debug purposes.

Parameters

[in]

lexic

NASL lexer.

Returns

lex cell containing a number indicating success or failure.

Definition at line 200 of file nasl_krb5.c.

{
  tree_cell *retc;
  OKrb5Credential credential;
  char *kdc = get_str_var_by_name (lexic, "kdc");
  if (kdc == NULL)
    {
      kdc = getenv ("KRB5_KDC");
      if (kdc == NULL)
        {
          last_okrb5_result = O_KRB5_EXPECTED_NOT_NULL;
          NASL_PRINT_KRB_ERROR (lexic, credential, last_okrb5_result);
          goto exit;
        }
    }
 
  credential = build_krb5_credential (lexic);
 
  if ((last_okrb5_result = o_krb5_add_realm (&credential, kdc)))
    {
      NASL_PRINT_KRB_ERROR (lexic, credential, last_okrb5_result);
    }
 
exit:
  retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = last_okrb5_result;
  return retc;
}

References alloc_typed_cell(), build_krb5_credential(), CONST_INT, get_str_var_by_name(), TC::i_val, last_okrb5_result, NASL_PRINT_KRB_ERROR, o_krb5_add_realm(), O_KRB5_EXPECTED_NOT_NULL, and TC::x.

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nasl_okrb5_clean()

void nasl_okrb5_clean

(

void

)

Definition at line 340 of file nasl_krb5.c.

{
  if (to_application != NULL)
    {
      free (to_application->data);
      free (to_application);
      to_application = NULL;
    }
  if (cached_gss_context != NULL)
    {
      okrb5_gss_free_context (cached_gss_context);
      cached_gss_context = NULL;
    }
  if (generated_config_path != NULL)
    {
      unlink (generated_config_path);
      free (generated_config_path);
      generated_config_path = NULL;
    }
}

References cached_gss_context, free(), generated_config_path, okrb5_gss_free_context(), and to_application.

Referenced by exec_nasl_script().

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nasl_okrb5_error_code_to_string()

tree_cell * nasl_okrb5_error_code_to_string

(

lex_ctxt *

lexic

)

Definition at line 414 of file nasl_krb5.c.

{
  (void) lexic;
  tree_cell *retc = alloc_typed_cell (CONST_STR);
  retc->x.str_val = okrb5_error_code_to_string (last_okrb5_result);
  retc->size = strlen (retc->x.str_val);
  return retc;
}

References alloc_typed_cell(), CONST_STR, last_okrb5_result, okrb5_error_code_to_string(), TC::size, TC::str_val, and TC::x.

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nasl_okrb5_find_kdc()

tree_cell * nasl_okrb5_find_kdc

(

lex_ctxt *

lexic

)

Returns the defined KDC of a given Realm.

This function returns the KDC of a given Realm. The Realm is defined in the krb5.conf file. If there is no KDC for the given Realm, the function returns NULL within the tree_cell to the script.

The nasl function has two optional parameter:

• realm: The realm for which the KDC should be returned. If the realm is not defined, then the env parameter KRB5_REALM is used.
• config_path: The path to the krb5.conf file. If the path is not defined, then the env parameter KRB5_CONFIG is used.

This function should only be used for debug purposes.

Parameters

[in]

lexic

NASL lexer.

Returns

lex cell containing the KDC as a string.

Definition at line 179 of file nasl_krb5.c.

{
  tree_cell *retc;
  char *kdc = NULL;
  OKrb5Credential credential;
 
  credential = build_krb5_credential (lexic);
 
  if ((last_okrb5_result = o_krb5_find_kdc (&credential, &kdc)))
    {
      NASL_PRINT_KRB_ERROR (lexic, credential, last_okrb5_result);
      return FAKE_CELL;
    }
 
  retc = alloc_typed_cell (CONST_DATA);
  retc->x.str_val = kdc;
  retc->size = strlen (kdc);
  return retc;
}

References alloc_typed_cell(), build_krb5_credential(), CONST_DATA, FAKE_CELL, last_okrb5_result, NASL_PRINT_KRB_ERROR, o_krb5_find_kdc(), TC::size, TC::str_val, and TC::x.

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nasl_okrb5_gss_init()

tree_cell * nasl_okrb5_gss_init

(

lex_ctxt *

lexic

)

Definition at line 272 of file nasl_krb5.c.

{
  (void) lexic;
  cached_gss_context = okrb5_gss_init_context ();
  if (cached_gss_context == NULL)
    {
      last_okrb5_result = O_KRB5_EXPECTED_NOT_NULL;
    }
  else
    {
      last_okrb5_result = O_KRB5_SUCCESS;
    };
  tree_cell *retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = last_okrb5_result;
  return retc;
}

References alloc_typed_cell(), cached_gss_context, CONST_INT, TC::i_val, last_okrb5_result, O_KRB5_EXPECTED_NOT_NULL, O_KRB5_SUCCESS, okrb5_gss_init_context(), and TC::x.

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nasl_okrb5_gss_prepare_context()

tree_cell * nasl_okrb5_gss_prepare_context

(

lex_ctxt *

lexic

)

Definition at line 289 of file nasl_krb5.c.

{
  (void) lexic;
 
  OKrb5Credential credential;
  credential = build_krb5_credential (lexic);
  OKrb5ErrorCode result = O_KRB5_SUCCESS;
  if (cached_gss_context == NULL)
    {
      cached_gss_context = okrb5_gss_init_context ();
    }
  result = o_krb5_gss_prepare_context (&credential, cached_gss_context);
  tree_cell *retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = result;
  last_okrb5_result = result;
  return retc;
}

References alloc_typed_cell(), build_krb5_credential(), cached_gss_context, CONST_INT, TC::i_val, last_okrb5_result, o_krb5_gss_prepare_context(), O_KRB5_SUCCESS, okrb5_gss_init_context(), and TC::x.

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nasl_okrb5_gss_session_key_context()

tree_cell * nasl_okrb5_gss_session_key_context

(

lex_ctxt *

lexic

)

Definition at line 395 of file nasl_krb5.c.

{
  (void) lexic;
  struct OKrb5Slice *session_key = NULL;
  if (cached_gss_context == NULL)
    {
      last_okrb5_result = O_KRB5_EXPECTED_NOT_NULL;
      return FAKE_CELL;
    }
  if ((last_okrb5_result =
         o_krb5_gss_session_key_context (cached_gss_context, &session_key))
      != O_KRB5_SUCCESS)
    {
      return FAKE_CELL;
    }
  return okrb5_slice_to_tree_cell (session_key);
}

References cached_gss_context, FAKE_CELL, last_okrb5_result, O_KRB5_EXPECTED_NOT_NULL, o_krb5_gss_session_key_context(), O_KRB5_SUCCESS, and okrb5_slice_to_tree_cell().

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nasl_okrb5_gss_update_context()

tree_cell * nasl_okrb5_gss_update_context

(

lex_ctxt *

lexic

)

Definition at line 308 of file nasl_krb5.c.

{
  OKrb5ErrorCode result = O_KRB5_SUCCESS;
  tree_cell *retc;
  struct OKrb5Slice from_application;
 
  if (to_application != NULL)
    {
      free (to_application->data);
      free (to_application);
      to_application = NULL;
    }
 
  from_application.data = (void *) get_str_var_by_num (lexic, 0);
  from_application.len = get_var_size_by_num (lexic, 0);
 
  if (cached_gss_context == NULL)
    {
      last_okrb5_result = O_KRB5_EXPECTED_NOT_NULL;
      goto result;
    }
  result =
    o_krb5_gss_update_context (cached_gss_context, &from_application,
                               &to_application, &gss_update_context_more);
result:
  retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = result;
  last_okrb5_result = result;
  return retc;
}

References alloc_typed_cell(), cached_gss_context, CONST_INT, OKrb5Slice::data, free(), get_str_var_by_num(), get_var_size_by_num(), gss_update_context_more, TC::i_val, last_okrb5_result, OKrb5Slice::len, O_KRB5_EXPECTED_NOT_NULL, o_krb5_gss_update_context(), O_KRB5_SUCCESS, to_application, and TC::x.

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nasl_okrb5_gss_update_context_needs_more()

tree_cell * nasl_okrb5_gss_update_context_needs_more

(

lex_ctxt *

lexic

)

Definition at line 362 of file nasl_krb5.c.

{
  (void) lexic;
  tree_cell *retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = gss_update_context_more;
  return retc;
}

References alloc_typed_cell(), CONST_INT, gss_update_context_more, TC::i_val, and TC::x.

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nasl_okrb5_gss_update_context_out()

tree_cell * nasl_okrb5_gss_update_context_out

(

lex_ctxt *

lexic

)

Definition at line 380 of file nasl_krb5.c.

{
  (void) lexic;
  if (to_application == NULL)
    {
      return FAKE_CELL;
    }
  tree_cell *out = okrb5_slice_to_tree_cell (to_application);
  // we need to prevent accidental free it as it is freed when the tree_cell is
  // cleaned up
  to_application = NULL;
  return out;
}

References FAKE_CELL, okrb5_slice_to_tree_cell(), and to_application.

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nasl_okrb5_is_failure()

tree_cell * nasl_okrb5_is_failure

(

lex_ctxt *

lexic

)

Returns 0 if the krb5 function was successful and 1 if it failed.

The nasl function has one optional parameter:

• retval: the return value of the krb5 function. If the value is not defined, the return value of the last krb5 function is used.

Parameters

[in]

lexic

NASL lexer.

Returns

lex cell containing a number indicating success.

Definition at line 263 of file nasl_krb5.c.

{
  OKrb5ErrorCode result = get_int_var_by_num (lexic, 0, last_okrb5_result);
  tree_cell *retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = result != O_KRB5_SUCCESS;
  return retc;
}

References alloc_typed_cell(), CONST_INT, get_int_var_by_num(), TC::i_val, last_okrb5_result, O_KRB5_SUCCESS, and TC::x.

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nasl_okrb5_is_success()

tree_cell * nasl_okrb5_is_success

(

lex_ctxt *

lexic

)

Returns 1 if the krb5 function was successful 0 otherwise.

The nasl function has one optional parameter:

• retval: the return value of the krb5 function. If the value is not defined, the return value of the last krb5 function is used.

Parameters

[in]

lexic

NASL lexer.

Returns

lex cell containing a number indicating success.

Definition at line 242 of file nasl_krb5.c.

{
  OKrb5ErrorCode result = get_int_var_by_num (lexic, 0, last_okrb5_result);
  tree_cell *retc = alloc_typed_cell (CONST_INT);
  retc->x.i_val = result == O_KRB5_SUCCESS;
  return retc;
}

References alloc_typed_cell(), CONST_INT, get_int_var_by_num(), TC::i_val, last_okrb5_result, O_KRB5_SUCCESS, and TC::x.

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okrb5_slice_to_tree_cell()

tree_cell * okrb5_slice_to_tree_cell ( struct OKrb5Slice * slice )

inlinestatic

Definition at line 371 of file nasl_krb5.c.

{
  tree_cell *retc = alloc_typed_cell (CONST_DATA);
  retc->x.str_val = slice->data;
  retc->size = slice->len;
  return retc;
}

References alloc_typed_cell(), CONST_DATA, OKrb5Slice::data, OKrb5Slice::len, TC::size, TC::str_val, and TC::x.

Referenced by nasl_okrb5_gss_session_key_context(), and nasl_okrb5_gss_update_context_out().

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Variable Documentation

cached_gss_context

struct OKrb5GSSContext* cached_gss_context = NULL

static

Definition at line 45 of file nasl_krb5.c.

Referenced by nasl_okrb5_clean(), nasl_okrb5_gss_init(), nasl_okrb5_gss_prepare_context(), nasl_okrb5_gss_session_key_context(), and nasl_okrb5_gss_update_context().

generated_config_path

char* generated_config_path = NULL

static

Definition at line 56 of file nasl_krb5.c.

Referenced by build_krb5_credential(), and nasl_okrb5_clean().

gss_update_context_more

bool gss_update_context_more = false

static

Definition at line 53 of file nasl_krb5.c.

Referenced by nasl_okrb5_gss_update_context(), and nasl_okrb5_gss_update_context_needs_more().

last_okrb5_result

OKrb5ErrorCode last_okrb5_result

static

Definition at line 37 of file nasl_krb5.c.

Referenced by nasl_okrb5_add_realm(), nasl_okrb5_error_code_to_string(), nasl_okrb5_find_kdc(), nasl_okrb5_gss_init(), nasl_okrb5_gss_prepare_context(), nasl_okrb5_gss_session_key_context(), nasl_okrb5_gss_update_context(), nasl_okrb5_is_failure(), and nasl_okrb5_is_success().

to_application

struct OKrb5Slice* to_application = NULL

static

Definition at line 49 of file nasl_krb5.c.

Referenced by nasl_okrb5_clean(), nasl_okrb5_gss_update_context(), and nasl_okrb5_gss_update_context_out().