contrib/libpam/libpamc/include/security/pam_client.h

   1 /*
   2  * $Id: pam_client.h,v 1.4 2001/01/20 22:29:47 agmorgan Exp $
   3  *
   4  * Copyright (c) 1999 Andrew G. Morgan <morgan@linux.kernel.org>
   5  *
   6  * This header file provides the prototypes for the PAM client API
   7  */
   8
   9 #ifndef PAM_CLIENT_H
  10 #define PAM_CLIENT_H
  11
  12 #include <unistd.h>
  13 #include <string.h>
  14 #include <stdio.h>
  15
  16 /* opaque agent handling structure */
  17
  18 typedef struct pamc_handle_s *pamc_handle_t;
  19
  20 /* binary prompt structure pointer */
  21 #ifndef __u32
  22 # define __u32  unsigned int
  23 #endif
  24 #ifndef __u8
  25 # define __u8  unsigned char
  26 #endif
  27 typedef struct { __u32 length; __u8 control; } *pamc_bp_t;
  28
  29 /*
  30  * functions provided by libpamc
  31  */
  32
  33 /*
  34  * Initialize the agent abstraction library
  35  */
  36
  37 pamc_handle_t pamc_start(void);
  38
  39 /*
  40  * Terminate the authentication process
  41  */
  42
  43 int pamc_end(pamc_handle_t *pch);
  44
  45 /*
  46  * force the loading of a specified agent
  47  */
  48
  49 int pamc_load(pamc_handle_t pch, const char *agent_id);
  50
  51 /*
  52  * Single conversation interface for binary prompts
  53  */
  54
  55 int pamc_converse(pamc_handle_t pch, pamc_bp_t *prompt_p);
  56
  57 /*
  58  * disable an agent
  59  */
  60
  61 int pamc_disable(pamc_handle_t pch, const char *agent_id);
  62
  63 /*
  64  * obtain a list of available agents
  65  */
  66
  67 char **pamc_list_agents(pamc_handle_t pch);
  68
  69 /*
  70  * PAM_BP_ MACROS for creating, destroying and manipulating binary prompts
  71  */
  72
  73 #include <stdlib.h>
  74 #include <stdio.h>
  75 #include <unistd.h>
  76
  77 #ifndef PAM_BP_ASSERT
  78 # define PAM_BP_ASSERT(x)   do { printf(__FILE__ "(%d): %s\n", \
  79                                         __LINE__, x) ; exit(1); } while (0)
  80 #endif /* PAM_BP_ASSERT */
  81
  82 #ifndef PAM_BP_CALLOC
  83 # define PAM_BP_CALLOC      calloc
  84 #endif /* PAM_BP_CALLOC */
  85
  86 #ifndef PAM_BP_FREE
  87 # define PAM_BP_FREE        free
  88 #endif /* PAM_BP_FREE */
  89
  90 #define __PAM_BP_WOCTET(x,y)  (*((y) + (__u8 *)(x)))
  91 #define __PAM_BP_ROCTET(x,y)  (*((y) + (const __u8 *)(x)))
  92
  93 #define PAM_BP_MIN_SIZE       (sizeof(__u32) + sizeof(__u8))
  94 #define PAM_BP_MAX_LENGTH     0x20000                   /* an advisory limit */
  95 #define PAM_BP_WCONTROL(x)    (__PAM_BP_WOCTET(x,4))
  96 #define PAM_BP_RCONTROL(x)    (__PAM_BP_ROCTET(x,4))
  97 #define PAM_BP_SIZE(x)        ((__PAM_BP_ROCTET(x,0)<<24)+      \
  98                                (__PAM_BP_ROCTET(x,1)<<16)+      \
  99                                (__PAM_BP_ROCTET(x,2)<< 8)+      \
 100                                (__PAM_BP_ROCTET(x,3)    ))
 101 #define PAM_BP_LENGTH(x)      (PAM_BP_SIZE(x) - PAM_BP_MIN_SIZE)
 102 #define PAM_BP_WDATA(x)       (PAM_BP_MIN_SIZE + (__u8 *) (x))
 103 #define PAM_BP_RDATA(x)       (PAM_BP_MIN_SIZE + (const __u8 *) (x))
 104
 105 /* Note, this macro always '\0' terminates renewed packets */
 106
 107 #define PAM_BP_RENEW(old_p, cntrl, data_length)                            \
 108 do {                                                                       \
 109     if (old_p) {                                                           \
 110         if (*(old_p)) {                                                    \
 111             __u32 __size;                                                  \
 112             __size = PAM_BP_SIZE(*(old_p));                                \
 113             memset(*(old_p), 0, __size);                                   \
 114             PAM_BP_FREE(*(old_p));                                         \
 115         }                                                                  \
 116         if (cntrl) {                                                       \
 117             __u32 __size;                                                  \
 118                                                                            \
 119             __size = PAM_BP_MIN_SIZE + data_length;                        \
 120             if ((*(old_p) = PAM_BP_CALLOC(1, 1+__size))) {                 \
 121                 __PAM_BP_WOCTET(*(old_p), 3) =  __size      & 0xFF;        \
 122                 __PAM_BP_WOCTET(*(old_p), 2) = (__size>>=8) & 0xFF;        \
 123                 __PAM_BP_WOCTET(*(old_p), 1) = (__size>>=8) & 0xFF;        \
 124                 __PAM_BP_WOCTET(*(old_p), 0) = (__size>>=8) & 0xFF;        \
 125                 (*(old_p))->control = cntrl;                               \
 126             } else {                                                       \
 127                 PAM_BP_ASSERT("out of memory for binary prompt");          \
 128             }                                                              \
 129         } else {                                                           \
 130             *old_p = NULL;                                                 \
 131         }                                                                  \
 132     } else {                                                               \
 133         PAM_BP_ASSERT("programming error, invalid binary prompt pointer"); \
 134     }                                                                      \
 135 } while (0)
 136
 137 #define PAM_BP_FILL(prmpt, offset, length, data)                           \
 138 do {                                                                       \
 139     int bp_length;                                                         \
 140     __u8 *prompt = (__u8 *) (prmpt);                                       \
 141     bp_length = PAM_BP_LENGTH(prompt);                                     \
 142     if (bp_length < ((length)+(offset))) {                                 \
 143         PAM_BP_ASSERT("attempt to write over end of prompt");              \
 144     }                                                                      \
 145     memcpy((offset) + PAM_BP_WDATA(prompt), (data), (length));             \
 146 } while (0)
 147
 148 #define PAM_BP_EXTRACT(prmpt, offset, length, data)                        \
 149 do {                                                                       \
 150     int __bp_length;                                                       \
 151     const __u8 *__prompt = (const __u8 *) (prmpt);                         \
 152     __bp_length = PAM_BP_LENGTH(__prompt);                                 \
 153     if (((offset) < 0) || (__bp_length < ((length)+(offset)))              \
 154         || ((length) < 0)) {                                               \
 155         PAM_BP_ASSERT("invalid extraction from prompt");                   \
 156     }                                                                      \
 157     memcpy((data), (offset) + PAM_BP_RDATA(__prompt), (length));           \
 158 } while (0)
 159
 160
 161 /* Control types */
 162
 163 #define PAM_BPC_FALSE   0
 164 #define PAM_BPC_TRUE    1
 165
 166 #define PAM_BPC_OK      0x01   /* continuation packet   */
 167 #define PAM_BPC_SELECT  0x02   /* initialization packet */
 168 #define PAM_BPC_DONE    0x03   /* termination packet    */
 169 #define PAM_BPC_FAIL    0x04   /* unable to execute     */
 170
 171 /* The following control characters are only legal for echanges
 172    between an agent and a client (it is the responsibility of the
 173    client to enforce this rule in the face of a rogue server): */
 174
 175 #define PAM_BPC_GETENV  0x41   /* obtain client env.var */
 176 #define PAM_BPC_PUTENV  0x42   /* set client env.var    */
 177 #define PAM_BPC_TEXT    0x43   /* display message       */
 178 #define PAM_BPC_ERROR   0x44   /* display error message */
 179 #define PAM_BPC_PROMPT  0x45   /* echo'd text prompt    */
 180 #define PAM_BPC_PASS    0x46   /* non-echo'd text prompt*/
 181
 182 /* quick check for prompts that are legal for the client (by
 183    implication the server too) to send to libpamc */
 184
 185 #define PAM_BPC_FOR_CLIENT(/* pamc_bp_t */ prompt)                            \
 186     (((prompt)->control <= PAM_BPC_FAIL && (prompt)->control >= PAM_BPC_OK)   \
 187      ? PAM_BPC_TRUE:PAM_BPC_FALSE)
 188
 189
 190 #endif /* PAM_CLIENT_H */