struct pam_message {
int msg_style;
char *msg;
};
struct pam_response {
char *resp;
int resp_retcode;
};
struct pam_conv {
int (*conv)(int, const struct pam_message **,
struct pam_response **, void *);
void *appdata_ptr;
};
)
at the start of the transaction.
It is also possible to set or change the conversation function at any
point during a PAM transaction by changing the value of the
PAM_CONV
item.
The conversation function's first argument specifies the number of
messages (up to
PAM_NUM_MSG
)
to process.
The second argument is a pointer to an array of pointers to
structures containing the actual messages.
Each message can have one of four types, specified by the msg_style member of
PAM_PROMPT_ECHO_OFF
PAM_PROMPT_ECHO_ON
PAM_ERROR_MSG
PAM_TEXT_INFO
In each case, the prompt or message to display is pointed to by the
msg
member of
It can be up to
PAM_MAX_MSG_SIZE
characters long, including the terminating NUL.
On success, the conversation function should allocate and fill a
contiguous array of
one for each message that was passed in.
A pointer to the user's response to each message (or
NULL
in the case of informational or error messages) should be stored in
the
resp
member of the corresponding
Each response can be up to
PAM_MAX_RESP_SIZE
characters long, including the terminating NUL.
The resp_retcode member of is unused and should be set to zero.
The conversation function should store a pointer to this array in the location pointed to by its third argument. It is the caller's responsibility to release both this array and the responses themselves, using free(3). It is the conversation function's responsibility to ensure that it is legal to do so.
The appdata_ptr member of is passed unmodified to the conversation function as its fourth and final argument.
On failure, the conversation function should release any resources it has allocated, and return one of the predefined PAM error codes.
PAM_BUF_ERR
]
PAM_CONV_ERR
]
PAM_SUCCESS
]
PAM_SYSTEM_ERR
]