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Diffstat (limited to 'doc/man/pam_conv.3')
| -rw-r--r-- | doc/man/pam_conv.3 | 262 |
1 files changed, 228 insertions, 34 deletions
diff --git a/doc/man/pam_conv.3 b/doc/man/pam_conv.3 index 626d47af..bf7ef3bf 100644 --- a/doc/man/pam_conv.3 +++ b/doc/man/pam_conv.3 @@ -1,26 +1,187 @@ .\" Title: pam_conv -.\" Author: -.\" Generator: DocBook XSL Stylesheets v1.73.1 <http://docbook.sf.net/> -.\" Date: 04/16/2008 +.\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] +.\" Generator: DocBook XSL Stylesheets v1.74.0 <http://docbook.sf.net/> +.\" Date: 03/02/2009 .\" Manual: Linux-PAM Manual .\" Source: Linux-PAM Manual +.\" Language: English .\" -.TH "PAM_CONV" "3" "04/16/2008" "Linux-PAM Manual" "Linux-PAM Manual" +.TH "PAM_CONV" "3" "03/02/2009" "Linux-PAM Manual" "Linux-PAM Manual" +.\" ----------------------------------------------------------------- +.\" * (re)Define some macros +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" toupper - uppercase a string (locale-aware) +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de toupper +.tr aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ +\\$* +.tr aabbccddeeffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SH-xref - format a cross-reference to an SH section +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de SH-xref +.ie n \{\ +.\} +.toupper \\$* +.el \{\ +\\$* +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SH - level-one heading that works better for non-TTY output +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de1 SH +.\" put an extra blank line of space above the head in non-TTY output +.if t \{\ +.sp 1 +.\} +.sp \\n[PD]u +.nr an-level 1 +.set-an-margin +.nr an-prevailing-indent \\n[IN] +.fi +.in \\n[an-margin]u +.ti 0 +.HTML-TAG ".NH \\n[an-level]" +.it 1 an-trap +.nr an-no-space-flag 1 +.nr an-break-flag 1 +\." make the size of the head bigger +.ps +3 +.ft B +.ne (2v + 1u) +.ie n \{\ +.\" if n (TTY output), use uppercase +.toupper \\$* +.\} +.el \{\ +.nr an-break-flag 0 +.\" if not n (not TTY), use normal case (not uppercase) +\\$1 +.in \\n[an-margin]u +.ti 0 +.\" if not n (not TTY), put a border/line under subheading +.sp -.6 +\l'\n(.lu' +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SS - level-two heading that works better for non-TTY output +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de1 SS +.sp \\n[PD]u +.nr an-level 1 +.set-an-margin +.nr an-prevailing-indent \\n[IN] +.fi +.in \\n[IN]u +.ti \\n[SN]u +.it 1 an-trap +.nr an-no-space-flag 1 +.nr an-break-flag 1 +.ps \\n[PS-SS]u +\." make the size of the head bigger +.ps +2 +.ft B +.ne (2v + 1u) +.if \\n[.$] \&\\$* +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" BB/BE - put background/screen (filled box) around block of text +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de BB +.if t \{\ +.sp -.5 +.br +.in +2n +.ll -2n +.gcolor red +.di BX +.\} +.. +.de EB +.if t \{\ +.if "\\$2"adjust-for-leading-newline" \{\ +.sp -1 +.\} +.br +.di +.in +.ll +.gcolor +.nr BW \\n(.lu-\\n(.i +.nr BH \\n(dn+.5v +.ne \\n(BHu+.5v +.ie "\\$2"adjust-for-leading-newline" \{\ +\M[\\$1]\h'1n'\v'+.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[] +.\} +.el \{\ +\M[\\$1]\h'1n'\v'-.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[] +.\} +.in 0 +.sp -.5v +.nf +.BX +.in +.sp .5v +.fi +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" BM/EM - put colored marker in margin next to block of text +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de BM +.if t \{\ +.br +.ll -2n +.gcolor red +.di BX +.\} +.. +.de EM +.if t \{\ +.br +.di +.ll +.gcolor +.nr BH \\n(dn +.ne \\n(BHu +\M[\\$1]\D'P -.75n 0 0 \\n(BHu -(\\n[.i]u - \\n(INu - .75n) 0 0 -\\n(BHu'\M[] +.in 0 +.nf +.BX +.in +.fi +.\} +.. +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l -.SH "NAME" -pam_conv - PAM conversation function -.SH "SYNOPSIS" +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "Name" +pam_conv \- PAM conversation function +.SH "Synopsis" .sp .ft B +.fam C +.ps -1 .nf -#include <security/pam_appl\.h> +#include <security/pam_appl\&.h> .fi +.fam +.ps +1 .ft .sp -.RS 4 +.fam C +.ps -1 .nf struct pam_message { int msg_style; @@ -39,39 +200,40 @@ struct pam_conv { }; .fi -.RE +.fam +.ps +1 .SH "DESCRIPTION" .PP -The PAM library uses an application\-defined callback to allow a direct communication between a loaded module and the application\. This callback is specified by the +The PAM library uses an application\-defined callback to allow a direct communication between a loaded module and the application\&. This callback is specified by the \fIstruct pam_conv\fR passed to \fBpam_start\fR(3) -at the start of the transaction\. +at the start of the transaction\&. .PP When a module calls the referenced conv() function, the argument \fIappdata_ptr\fR -is set to the second element of this structure\. +is set to the second element of this structure\&. .PP -The other arguments of a call to conv() concern the information exchanged by module and application\. That is to say, +The other arguments of a call to conv() concern the information exchanged by module and application\&. That is to say, \fInum_msg\fR holds the length of the array of pointers, -\fImsg\fR\. After a successful return, the pointer +\fImsg\fR\&. After a successful return, the pointer \fIresp\fR -points to an array of pam_response structures, holding the application supplied text\. The +points to an array of pam_response structures, holding the application supplied text\&. The \fIresp_retcode\fR -member of this struct is unused and should be set to zero\. It is the caller\'s responsibility to release both, this array and the responses themselves, using -\fBfree\fR(3)\. Note, +member of this struct is unused and should be set to zero\&. It is the caller\'s responsibility to release both, this array and the responses themselves, using +\fBfree\fR(3)\&. Note, \fI*resp\fR is a \fIstruct pam_response\fR -array and not an array of pointers\. +array and not an array of pointers\&. .PP The number of responses is always equal to the \fInum_msg\fR -conversation function argument\. This does require that the response array is -\fBfree\fR(3)\'d after every call to the conversation function\. The index of the responses corresponds directly to the prompt index in the pam_message array\. +conversation function argument\&. This does require that the response array is +\fBfree\fR(3)\'d after every call to the conversation function\&. The index of the responses corresponds directly to the prompt index in the pam_message array\&. .PP -On failure, the conversation function should release any resources it has allocated, and return one of the predefined PAM error codes\. +On failure, the conversation function should release any resources it has allocated, and return one of the predefined PAM error codes\&. .PP Each message can have one of four types, specified by the \fImsg_style\fR @@ -80,60 +242,92 @@ member of .PP PAM_PROMPT_ECHO_OFF .RS 4 -Obtain a string without echoing any text\. +Obtain a string without echoing any text\&. .RE .PP PAM_PROMPT_ECHO_ON .RS 4 -Obtain a string whilst echoing text\. +Obtain a string whilst echoing text\&. .RE .PP PAM_ERROR_MSG .RS 4 -Display an error message\. +Display an error message\&. .RE .PP PAM_TEXT_INFO .RS 4 -Display some text\. +Display some text\&. .RE .PP -The point of having an array of messages is that it becomes possible to pass a number of things to the application in a single call from the module\. It can also be convenient for the application that related things come at once: a windows based application can then present a single form with many messages/prompts on at once\. +The point of having an array of messages is that it becomes possible to pass a number of things to the application in a single call from the module\&. It can also be convenient for the application that related things come at once: a windows based application can then present a single form with many messages/prompts on at once\&. .PP -In passing, it is worth noting that there is a descrepency between the way Linux\-PAM handles the const struct pam_message **msg conversation function argument from the way that Solaris\' PAM (and derivitives, known to include HP/UX, are there others?) does\. Linux\-PAM interprets the msg argument as entirely equivalent to the following prototype const struct pam_message *msg[] (which, in spirit, is consistent with the commonly used prototypes for argv argument to the familiar main() function: char **argv; and char *argv[])\. Said another way Linux\-PAM interprets the msg argument as a pointer to an array of num_msg read only \'struct pam_message\' pointers\. Solaris\' PAM implementation interprets this argument as a pointer to a pointer to an array of num_msg pam_message structures\. Fortunately, perhaps, for most module/application developers when num_msg has a value of one these two definitions are entirely equivalent\. Unfortunately, casually raising this number to two has led to unanticipated compatibility problems\. +In passing, it is worth noting that there is a descrepency between the way Linux\-PAM handles the const struct pam_message **msg conversation function argument from the way that Solaris\' PAM (and derivitives, known to include HP/UX, are there others?) does\&. Linux\-PAM interprets the msg argument as entirely equivalent to the following prototype const struct pam_message *msg[] (which, in spirit, is consistent with the commonly used prototypes for argv argument to the familiar main() function: char **argv; and char *argv[])\&. Said another way Linux\-PAM interprets the msg argument as a pointer to an array of num_msg read only \'struct pam_message\' pointers\&. Solaris\' PAM implementation interprets this argument as a pointer to a pointer to an array of num_msg pam_message structures\&. Fortunately, perhaps, for most module/application developers when num_msg has a value of one these two definitions are entirely equivalent\&. Unfortunately, casually raising this number to two has led to unanticipated compatibility problems\&. .PP For what its worth the two known module writer work\-arounds for trying to maintain source level compatibility with both PAM implementations are: .sp .RS 4 -\h'-04'\(bu\h'+03'never call the conversation function with num_msg greater than one\. +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +never call the conversation function with num_msg greater than one\&. .RE .sp .RS 4 -\h'-04'\(bu\h'+03'set up msg as doubly referenced so both types of conversation function can find the messages\. That is, make +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +set up msg as doubly referenced so both types of conversation function can find the messages\&. That is, make .sp +.if n \{\ .RS 4 +.\} +.fam C +.ps -1 .nf +.if t \{\ +.sp -1 +.\} +.BB lightgray adjust-for-leading-newline +.sp -1 + msg[n] = & (( *msg )[n]) +.EB lightgray adjust-for-leading-newline +.if t \{\ +.sp 1 +.\} .fi +.fam +.ps +1 +.if n \{\ .RE +.\} .RE .SH "RETURN VALUES" .PP PAM_BUF_ERR .RS 4 -Memory buffer error\. +Memory buffer error\&. .RE .PP PAM_CONV_ERR .RS 4 -Conversation failure\. The application should not set -\fI*resp\fR\. +Conversation failure\&. The application should not set +\fI*resp\fR\&. .RE .PP PAM_SUCCESS .RS 4 -Success\. +Success\&. .RE .SH "SEE ALSO" .PP |