/*
* $Id$
*
* Copyright (c) 1999 Andrew G. Morgan <morgan@linux.kernel.org>
*
* This header file provides the prototypes for the PAM client API
*/
#ifndef PAM_CLIENT_H
#define PAM_CLIENT_H
#ifdef __cplusplus
extern "C" {
#endif /* def __cplusplus */
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
/* opaque agent handling structure */
typedef struct pamc_handle_s *pamc_handle_t;
/* binary prompt structure pointer */
typedef struct { u_int32_t length; u_int8_t control; } *pamc_bp_t;
/*
* functions provided by libpamc
*/
/*
* Initialize the agent abstraction library
*/
pamc_handle_t pamc_start(void);
/*
* Terminate the authentication process
*/
int pamc_end(pamc_handle_t *pch);
/*
* force the loading of a specified agent
*/
int pamc_load(pamc_handle_t pch, const char *agent_id);
/*
* Single conversation interface for binary prompts
*/
int pamc_converse(pamc_handle_t pch, pamc_bp_t *prompt_p);
/*
* disable an agent
*/
int pamc_disable(pamc_handle_t pch, const char *agent_id);
/*
* obtain a list of available agents
*/
char **pamc_list_agents(pamc_handle_t pch);
/*
* PAM_BP_ MACROS for creating, destroying and manipulating binary prompts
*/
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#ifndef PAM_BP_ASSERT
# ifdef NDEBUG
# define PAM_BP_ASSERT(x) do {} while (0)
# else
# define PAM_BP_ASSERT(x) do { printf(__FILE__ "(%d): %s\n", \
__LINE__, x) ; exit(1); } while (0)
# endif /* NDEBUG */
#endif /* PAM_BP_ASSERT */
#ifndef PAM_BP_CALLOC
# define PAM_BP_CALLOC calloc
#endif /* PAM_BP_CALLOC */
#ifndef PAM_BP_FREE
# define PAM_BP_FREE free
#endif /* PAM_BP_FREE */
#define __PAM_BP_WOCTET(x,y) (*((y) + (u_int8_t *)(x)))
#define __PAM_BP_ROCTET(x,y) (*((y) + (const u_int8_t *)(x)))
#define PAM_BP_MIN_SIZE (sizeof(u_int32_t) + sizeof(u_int8_t))
#define PAM_BP_MAX_LENGTH 0x20000 /* an advisory limit */
#define PAM_BP_WCONTROL(x) (__PAM_BP_WOCTET(x,4))
#define PAM_BP_RCONTROL(x) (__PAM_BP_ROCTET(x,4))
#define PAM_BP_SIZE(x) ((__PAM_BP_ROCTET(x,0)<<24)+ \
(__PAM_BP_ROCTET(x,1)<<16)+ \
(__PAM_BP_ROCTET(x,2)<< 8)+ \
(__PAM_BP_ROCTET(x,3) ))
#define PAM_BP_LENGTH(x) (PAM_BP_SIZE(x) - PAM_BP_MIN_SIZE)
#define PAM_BP_WDATA(x) (PAM_BP_MIN_SIZE + (u_int8_t *) (x))
#define PAM_BP_RDATA(x) (PAM_BP_MIN_SIZE + (const u_int8_t *) (x))
/* Note, this macro always '\0' terminates renewed packets */
#define PAM_BP_RENEW(old_p, cntrl, data_length) \
do { \
if (old_p) { \
if (*(old_p)) { \
u_int32_t __size; \
__size = PAM_BP_SIZE(*(old_p)); \
memset(*(old_p), 0, __size); \
PAM_BP_FREE(*(old_p)); \
} \
if (cntrl) { \
u_int32_t __size; \
\
__size = PAM_BP_MIN_SIZE + data_length; \
if ((*(old_p) = PAM_BP_CALLOC(1, 1+__size))) { \
__PAM_BP_WOCTET(*(old_p), 3) = __size & 0xFF; \
__PAM_BP_WOCTET(*(old_p), 2) = (__size>>=8) & 0xFF; \
__PAM_BP_WOCTET(*(old_p), 1) = (__size>>=8) & 0xFF; \
__PAM_BP_WOCTET(*(old_p), 0) = (__size>>=8) & 0xFF; \
(*(old_p))->control = cntrl; \
} else { \
PAM_BP_ASSERT("out of memory for binary prompt"); \
} \
} else { \
*old_p = NULL; \
} \
} else { \
PAM_BP_ASSERT("programming error, invalid binary prompt pointer"); \
} \
} while (0)
#define PAM_BP_FILL(prmpt, offset, length, data) \
do { \
size_t bp_length; \
u_int8_t *prompt = (u_int8_t *) (prmpt); \
bp_length = PAM_BP_LENGTH(prompt); \
if (bp_length < ((length)+(offset))) { \
PAM_BP_ASSERT("attempt to write over end of prompt"); \
} \
memcpy((offset) + PAM_BP_WDATA(prompt), (data), (length)); \
} while (0)
#define PAM_BP_EXTRACT(prmpt, offset, length, data) \
do { \
size_t __bp_length; \
const u_int8_t *__prompt = (const u_int8_t *) (prmpt); \
__bp_length = PAM_BP_LENGTH(__prompt); \
if (((offset) < 0) || (__bp_length < ((length)+(offset))) \
|| ((length) < 0)) { \
PAM_BP_ASSERT("invalid extraction from prompt"); \
} \
memcpy((data), (offset) + PAM_BP_RDATA(__prompt), (length)); \
} while (0)
/* Control types */
#define PAM_BPC_FALSE 0
#define PAM_BPC_TRUE 1
#define PAM_BPC_OK 0x01 /* continuation packet */
#define PAM_BPC_SELECT 0x02 /* initialization packet */
#define PAM_BPC_DONE 0x03 /* termination packet */
#define PAM_BPC_FAIL 0x04 /* unable to execute */
/* The following control characters are only legal for echanges
between an agent and a client (it is the responsibility of the
client to enforce this rule in the face of a rogue server): */
#define PAM_BPC_GETENV 0x41 /* obtain client env.var */
#define PAM_BPC_PUTENV 0x42 /* set client env.var */
#define PAM_BPC_TEXT 0x43 /* display message */
#define PAM_BPC_ERROR 0x44 /* display error message */
#define PAM_BPC_PROMPT 0x45 /* echo'd text prompt */
#define PAM_BPC_PASS 0x46 /* non-echo'd text prompt*/
/* quick check for prompts that are legal for the client (by
implication the server too) to send to libpamc */
#define PAM_BPC_FOR_CLIENT(/* pamc_bp_t */ prompt) \
(((prompt)->control <= PAM_BPC_FAIL && (prompt)->control >= PAM_BPC_OK) \
? PAM_BPC_TRUE:PAM_BPC_FALSE)
#ifdef __cplusplus
}
#endif /* def __cplusplus */
#endif /* PAM_CLIENT_H */