ui.pod revision 279265 
1=pod
2
3=head1 NAME
4
5UI_new, UI_new_method, UI_free, UI_add_input_string, UI_dup_input_string,
6UI_add_verify_string, UI_dup_verify_string, UI_add_input_boolean,
7UI_dup_input_boolean, UI_add_info_string, UI_dup_info_string,
8UI_add_error_string, UI_dup_error_string, UI_construct_prompt,
9UI_add_user_data, UI_get0_user_data, UI_get0_result, UI_process,
10UI_ctrl, UI_set_default_method, UI_get_default_method, UI_get_method,
11UI_set_method, UI_OpenSSL, ERR_load_UI_strings - New User Interface
12
13=head1 SYNOPSIS
14
15 #include <openssl/ui.h>
16
17 typedef struct ui_st UI;
18 typedef struct ui_method_st UI_METHOD;
19
20 UI *UI_new(void);
21 UI *UI_new_method(const UI_METHOD *method);
22 void UI_free(UI *ui);
23
24 int UI_add_input_string(UI *ui, const char *prompt, int flags,
25	char *result_buf, int minsize, int maxsize);
26 int UI_dup_input_string(UI *ui, const char *prompt, int flags,
27	char *result_buf, int minsize, int maxsize);
28 int UI_add_verify_string(UI *ui, const char *prompt, int flags,
29	char *result_buf, int minsize, int maxsize, const char *test_buf);
30 int UI_dup_verify_string(UI *ui, const char *prompt, int flags,
31	char *result_buf, int minsize, int maxsize, const char *test_buf);
32 int UI_add_input_boolean(UI *ui, const char *prompt, const char *action_desc,
33	const char *ok_chars, const char *cancel_chars,
34	int flags, char *result_buf);
35 int UI_dup_input_boolean(UI *ui, const char *prompt, const char *action_desc,
36	const char *ok_chars, const char *cancel_chars,
37	int flags, char *result_buf);
38 int UI_add_info_string(UI *ui, const char *text);
39 int UI_dup_info_string(UI *ui, const char *text);
40 int UI_add_error_string(UI *ui, const char *text);
41 int UI_dup_error_string(UI *ui, const char *text);
42
43 /* These are the possible flags.  They can be or'ed together. */
44 #define UI_INPUT_FLAG_ECHO		0x01
45 #define UI_INPUT_FLAG_DEFAULT_PWD	0x02
46
47 char *UI_construct_prompt(UI *ui_method,
48	const char *object_desc, const char *object_name);
49
50 void *UI_add_user_data(UI *ui, void *user_data);
51 void *UI_get0_user_data(UI *ui);
52
53 const char *UI_get0_result(UI *ui, int i);
54
55 int UI_process(UI *ui);
56
57 int UI_ctrl(UI *ui, int cmd, long i, void *p, void (*f)());
58 #define UI_CTRL_PRINT_ERRORS		1
59 #define UI_CTRL_IS_REDOABLE		2
60
61 void UI_set_default_method(const UI_METHOD *meth);
62 const UI_METHOD *UI_get_default_method(void);
63 const UI_METHOD *UI_get_method(UI *ui);
64 const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);
65
66 UI_METHOD *UI_OpenSSL(void);
67
68=head1 DESCRIPTION
69
70UI stands for User Interface, and is general purpose set of routines to
71prompt the user for text-based information.  Through user-written methods
72(see L<ui_create(3)|ui_create(3)>), prompting can be done in any way
73imaginable, be it plain text prompting, through dialog boxes or from a
74cell phone.
75
76All the functions work through a context of the type UI.  This context
77contains all the information needed to prompt correctly as well as a
78reference to a UI_METHOD, which is an ordered vector of functions that
79carry out the actual prompting.
80
81The first thing to do is to create a UI with UI_new() or UI_new_method(),
82then add information to it with the UI_add or UI_dup functions.  Also,
83user-defined random data can be passed down to the underlying method
84through calls to UI_add_user_data.  The default UI method doesn't care
85about these data, but other methods might.  Finally, use UI_process()
86to actually perform the prompting and UI_get0_result() to find the result
87to the prompt.
88
89A UI can contain more than one prompt, which are performed in the given
90sequence.  Each prompt gets an index number which is returned by the
91UI_add and UI_dup functions, and has to be used to get the corresponding
92result with UI_get0_result().
93
94The functions are as follows:
95
96UI_new() creates a new UI using the default UI method.  When done with
97this UI, it should be freed using UI_free().
98
99UI_new_method() creates a new UI using the given UI method.  When done with
100this UI, it should be freed using UI_free().
101
102UI_OpenSSL() returns the built-in UI method (note: not the default one,
103since the default can be changed.  See further on).  This method is the
104most machine/OS dependent part of OpenSSL and normally generates the
105most problems when porting.
106
107UI_free() removes a UI from memory, along with all other pieces of memory
108that's connected to it, like duplicated input strings, results and others.
109
110UI_add_input_string() and UI_add_verify_string() add a prompt to the UI,
111as well as flags and a result buffer and the desired minimum and maximum
112sizes of the result.  The given information is used to prompt for
113information, for example a password, and to verify a password (i.e. having
114the user enter it twice and check that the same string was entered twice).
115UI_add_verify_string() takes and extra argument that should be a pointer
116to the result buffer of the input string that it's supposed to verify, or
117verification will fail.
118
119UI_add_input_boolean() adds a prompt to the UI that's supposed to be answered
120in a boolean way, with a single character for yes and a different character
121for no.  A set of characters that can be used to cancel the prompt is given
122as well.  The prompt itself is divided in two, one part being the
123descriptive text (given through the I<prompt> argument) and one describing
124the possible answers (given through the I<action_desc> argument).
125
126UI_add_info_string() and UI_add_error_string() add strings that are shown at
127the same time as the prompt for extra information or to show an error string.
128The difference between the two is only conceptual.  With the builtin method,
129there's no technical difference between them.  Other methods may make a
130difference between them, however.
131
132The flags currently supported are UI_INPUT_FLAG_ECHO, which is relevant for
133UI_add_input_string() and will have the users response be echoed (when
134prompting for a password, this flag should obviously not be used, and
135UI_INPUT_FLAG_DEFAULT_PWD, which means that a default password of some
136sort will be used (completely depending on the application and the UI
137method).
138
139UI_dup_input_string(), UI_dup_verify_string(), UI_dup_input_boolean(),
140UI_dup_info_string() and UI_dup_error_string() are basically the same
141as their UI_add counterparts, except that they make their own copies
142of all strings.
143
144UI_construct_prompt() is a helper function that can be used to create
145a prompt from two pieces of information: an description and a name.
146The default constructor (if there is none provided by the method used)
147creates a string "Enter I<description> for I<name>:".  With the
148description "pass phrase" and the file name "foo.key", that becomes
149"Enter pass phrase for foo.key:".  Other methods may create whatever
150string and may include encodings that will be processed by the other
151method functions.
152
153UI_add_user_data() adds a piece of memory for the method to use at any
154time.  The builtin UI method doesn't care about this info.  Note that several
155calls to this function doesn't add data, it replaces the previous blob
156with the one given as argument.
157
158UI_get0_user_data() retrieves the data that has last been given to the
159UI with UI_add_user_data().
160
161UI_get0_result() returns a pointer to the result buffer associated with
162the information indexed by I<i>.
163
164UI_process() goes through the information given so far, does all the printing
165and prompting and returns.
166
167UI_ctrl() adds extra control for the application author.  For now, it
168understands two commands: UI_CTRL_PRINT_ERRORS, which makes UI_process()
169print the OpenSSL error stack as part of processing the UI, and
170UI_CTRL_IS_REDOABLE, which returns a flag saying if the used UI can
171be used again or not.
172
173UI_set_default_method() changes the default UI method to the one given.
174
175UI_get_default_method() returns a pointer to the current default UI method.
176
177UI_get_method() returns the UI method associated with a given UI.
178
179UI_set_method() changes the UI method associated with a given UI.
180
181=head1 SEE ALSO
182
183L<ui_create(3)|ui_create(3)>, L<ui_compat(3)|ui_compat(3)>
184
185=head1 HISTORY
186
187The UI section was first introduced in OpenSSL 0.9.7.
188
189=head1 AUTHOR
190
191Richard Levitte (richard@levitte.org) for the OpenSSL project
192(http://www.openssl.org).
193
194=cut
195