1ui(3)                               OpenSSL                              ui(3)
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NAME

6       UI_new, UI_new_method, UI_free, UI_add_input_string,
7       UI_dup_input_string, UI_add_verify_string, UI_dup_verify_string,
8       UI_add_input_boolean, UI_dup_input_boolean, UI_add_info_string,
9       UI_dup_info_string, UI_add_error_string, UI_dup_error_string, UI_con‐
10       struct_prompt, UI_add_user_data, UI_get0_user_data, UI_get0_result,
11       UI_process, UI_ctrl, UI_set_default_method, UI_get_default_method,
12       UI_get_method, UI_set_method, UI_OpenSSL, ERR_load_UI_strings - New
13       User Interface
14

SYNOPSIS

16        #include <openssl/ui.h>
17
18        typedef struct ui_st UI;
19        typedef struct ui_method_st UI_METHOD;
20
21        UI *UI_new(void);
22        UI *UI_new_method(const UI_METHOD *method);
23        void UI_free(UI *ui);
24
25        int UI_add_input_string(UI *ui, const char *prompt, int flags,
26               char *result_buf, int minsize, int maxsize);
27        int UI_dup_input_string(UI *ui, const char *prompt, int flags,
28               char *result_buf, int minsize, int maxsize);
29        int UI_add_verify_string(UI *ui, const char *prompt, int flags,
30               char *result_buf, int minsize, int maxsize, const char *test_buf);
31        int UI_dup_verify_string(UI *ui, const char *prompt, int flags,
32               char *result_buf, int minsize, int maxsize, const char *test_buf);
33        int UI_add_input_boolean(UI *ui, const char *prompt, const char *action_desc,
34               const char *ok_chars, const char *cancel_chars,
35               int flags, char *result_buf);
36        int UI_dup_input_boolean(UI *ui, const char *prompt, const char *action_desc,
37               const char *ok_chars, const char *cancel_chars,
38               int flags, char *result_buf);
39        int UI_add_info_string(UI *ui, const char *text);
40        int UI_dup_info_string(UI *ui, const char *text);
41        int UI_add_error_string(UI *ui, const char *text);
42        int UI_dup_error_string(UI *ui, const char *text);
43
44        /* These are the possible flags.  They can be or'ed together. */
45        #define UI_INPUT_FLAG_ECHO             0x01
46        #define UI_INPUT_FLAG_DEFAULT_PWD      0x02
47
48        char *UI_construct_prompt(UI *ui_method,
49               const char *object_desc, const char *object_name);
50
51        void *UI_add_user_data(UI *ui, void *user_data);
52        void *UI_get0_user_data(UI *ui);
53
54        const char *UI_get0_result(UI *ui, int i);
55
56        int UI_process(UI *ui);
57
58        int UI_ctrl(UI *ui, int cmd, long i, void *p, void (*f)());
59        #define UI_CTRL_PRINT_ERRORS           1
60        #define UI_CTRL_IS_REDOABLE            2
61
62        void UI_set_default_method(const UI_METHOD *meth);
63        const UI_METHOD *UI_get_default_method(void);
64        const UI_METHOD *UI_get_method(UI *ui);
65        const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);
66
67        UI_METHOD *UI_OpenSSL(void);
68

DESCRIPTION

70       UI stands for User Interface, and is general purpose set of routines to
71       prompt the user for text-based information.  Through user-written meth‐
72       ods (see ui_create(3)), prompting can be done in any way imaginable, be
73       it plain text prompting, through dialog boxes or from a cell phone.
74
75       All the functions work through a context of the type UI.  This context
76       contains all the information needed to prompt correctly as well as a
77       reference to a UI_METHOD, which is an ordered vector of functions that
78       carry out the actual prompting.
79
80       The first thing to do is to create a UI with UI_new() or
81       UI_new_method(), then add information to it with the UI_add or UI_dup
82       functions.  Also, user-defined random data can be passed down to the
83       underlying method through calls to UI_add_user_data.  The default UI
84       method doesn't care about these data, but other methods might.
85       Finally, use UI_process() to actually perform the prompting and
86       UI_get0_result() to find the result to the prompt.
87
88       A UI can contain more than one prompt, which are performed in the given
89       sequence.  Each prompt gets an index number which is returned by the
90       UI_add and UI_dup functions, and has to be used to get the correspond‐
91       ing result with UI_get0_result().
92
93       The functions are as follows:
94
95       UI_new() creates a new UI using the default UI method.  When done with
96       this UI, it should be freed using UI_free().
97
98       UI_new_method() creates a new UI using the given UI method.  When done
99       with this UI, it should be freed using UI_free().
100
101       UI_OpenSSL() returns the built-in UI method (note: not the default one,
102       since the default can be changed.  See further on).  This method is the
103       most machine/OS dependent part of OpenSSL and normally generates the
104       most problems when porting.
105
106       UI_free() removes a UI from memory, along with all other pieces of mem‐
107       ory that's connected to it, like duplicated input strings, results and
108       others.
109
110       UI_add_input_string() and UI_add_verify_string() add a prompt to the
111       UI, as well as flags and a result buffer and the desired minimum and
112       maximum sizes of the result.  The given information is used to prompt
113       for information, for example a password, and to verify a password (i.e.
114       having the user enter it twice and check that the same string was
115       entered twice).  UI_add_verify_string() takes and extra argument that
116       should be a pointer to the result buffer of the input string that it's
117       supposed to verify, or verification will fail.
118
119       UI_add_input_boolean() adds a prompt to the UI that's supposed to be
120       answered in a boolean way, with a single character for yes and a dif‐
121       ferent character for no.  A set of characters that can be used to can‐
122       cel the prompt is given as well.  The prompt itself is really divided
123       in two, one part being the descriptive text (given through the prompt
124       argument) and one describing the possible answers (given through the
125       action_desc argument).
126
127       UI_add_info_string() and UI_add_error_string() add strings that are
128       shown at the same time as the prompt for extra information or to show
129       an error string.  The difference between the two is only conceptual.
130       With the builtin method, there's no technical difference between them.
131       Other methods may make a difference between them, however.
132
133       The flags currently supported are UI_INPUT_FLAG_ECHO, which is relevant
134       for UI_add_input_string() and will have the users response be echoed
135       (when prompting for a password, this flag should obviously not be used,
136       and UI_INPUT_FLAG_DEFAULT_PWD, which means that a default password of
137       some sort will be used (completely depending on the application and the
138       UI method).
139
140       UI_dup_input_string(), UI_dup_verify_string(), UI_dup_input_boolean(),
141       UI_dup_info_string() and UI_dup_error_string() are basically the same
142       as their UI_add counterparts, except that they make their own copies of
143       all strings.
144
145       UI_construct_prompt() is a helper function that can be used to create a
146       prompt from two pieces of information: an description and a name.  The
147       default constructor (if there is none provided by the method used) cre‐
148       ates a string "Enter description for name:".  With the description
149       "pass phrase" and the file name "foo.key", that becomes "Enter pass
150       phrase for foo.key:".  Other methods may create whatever string and may
151       include encodings that will be processed by the other method functions.
152
153       UI_add_user_data() adds a piece of memory for the method to use at any
154       time.  The builtin UI method doesn't care about this info.  Note that
155       several calls to this function doesn't add data, it replaces the previ‐
156       ous blob with the one given as argument.
157
158       UI_get0_user_data() retrieves the data that has last been given to the
159       UI with UI_add_user_data().
160
161       UI_get0_result() returns a pointer to the result buffer associated with
162       the information indexed by i.
163
164       UI_process() goes through the information given so far, does all the
165       printing and prompting and returns.
166
167       UI_ctrl() adds extra control for the application author.  For now, it
168       understands two commands: UI_CTRL_PRINT_ERRORS, which makes
169       UI_process() print the OpenSSL error stack as part of processing the
170       UI, and UI_CTRL_IS_REDOABLE, which returns a flag saying if the used UI
171       can be used again or not.
172
173       UI_set_default_method() changes the default UI method to the one given.
174
175       UI_get_default_method() returns a pointer to the current default UI
176       method.
177
178       UI_get_method() returns the UI method associated with a given UI.
179
180       UI_set_method() changes the UI method associated with a given UI.
181

SEE ALSO

183       ui_create(3), ui_compat(3)
184

HISTORY

186       The UI section was first introduced in OpenSSL 0.9.7.
187

AUTHOR

189       Richard Levitte (richard@levitte.org) for the OpenSSL project
190       (http://www.openssl.org).
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1940.9.8b                            2003-09-30                             ui(3)
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