summaryrefslogtreecommitdiff
path: root/doc/man/pam_start.3
blob: 17c9aee416868eb88812201f4ffdacbba0ee6a97 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
.\"     Title: pam_start
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.74.0 <http://docbook.sf.net/>
.\"      Date: 04/01/2010
.\"    Manual: Linux-PAM Manual
.\"    Source: Linux-PAM Manual
.\"  Language: English
.\"
.TH "PAM_START" "3" "04/01/2010" "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
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "Name"
pam_start \- initialization of PAM transaction
.SH "Synopsis"
.sp
.ft B
.fam C
.ps -1
.nf
#include <security/pam_appl\&.h>
.fi
.fam
.ps +1
.ft
.fam C
.HP \w'int\ pam_start('u
.BI "int pam_start(const\ char\ *" "service_name" ", const\ char\ *" "user" ", const\ struct\ pam_conv\ *" "pam_conversation" ", pam_handle_t\ **" "pamh" ");"
.fam
.SH "DESCRIPTION"
.PP
The
\fBpam_start\fR
function creates the PAM context and initiates the PAM transaction\&. It is the first of the PAM functions that needs to be called by an application\&. The transaction state is contained entirely within the structure identified by this handle, so it is possible to have multiple transactions in parallel\&. But it is not possible to use the same handle for different transactions, a new one is needed for every new context\&.
.PP
The
\fIservice_name\fR
argument specifies the name of the service to apply and will be stored as PAM_SERVICE item in the new context\&. The policy for the service will be read from the file
\FC/etc/pam\&.d/service_name\F[]
or, if that file does not exist, from
\FC/etc/pam\&.conf\F[]\&.
.PP
The
\fIuser\fR
argument can specify the name of the target user and will be stored as PAM_USER item\&. If the argument is NULL, the module has to ask for this item if necessary\&.
.PP
The
\fIpam_conversation\fR
argument points to a
\fIstruct pam_conv\fR
describing the conversation function to use\&. An application must provide this for direct communication between a loaded module and the application\&.
.PP
Following a successful return (PAM_SUCCESS) the contents of
\fIpamh\fR
is a handle that contains the PAM context for successive calls to the PAM functions\&. In an error case is the content of
\fIpamh\fR
undefined\&.
.PP
The
\fIpam_handle_t\fR
is a blind structure and the application should not attempt to probe it directly for information\&. Instead the PAM library provides the functions
\fBpam_set_item\fR(3)
and
\fBpam_get_item\fR(3)\&. The PAM handle cannot be used for mulitiple authentications at the same time as long as
\fBpam_end\fR
was not called on it before\&.
.SH "RETURN VALUES"
.PP
PAM_ABORT
.RS 4
General failure\&.
.RE
.PP
PAM_BUF_ERR
.RS 4
Memory buffer error\&.
.RE
.PP
PAM_SUCCESS
.RS 4
Transaction was successful created\&.
.RE
.PP
PAM_SYSTEM_ERR
.RS 4
System error, for example a NULL pointer was submitted instead of a pointer to data\&.
.RE
.SH "SEE ALSO"
.PP

\fBpam_get_data\fR(3),
\fBpam_set_data\fR(3),
\fBpam_end\fR(3),
\fBpam_strerror\fR(3)