1UI_NEW(3ossl)                       OpenSSL                      UI_NEW(3ossl)
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NAME

6       UI, 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,
10       UI_construct_prompt, UI_add_user_data, UI_dup_user_data,
11       UI_get0_user_data, UI_get0_result, UI_get_result_length, UI_process,
12       UI_ctrl, UI_set_default_method, UI_get_default_method, UI_get_method,
13       UI_set_method, UI_OpenSSL, UI_null - user interface
14

SYNOPSIS

16        #include <openssl/ui.h>
17
18        typedef struct ui_st UI;
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,
30                                 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,
33                                 const char *test_buf);
34        int UI_add_input_boolean(UI *ui, const char *prompt, const char *action_desc,
35                                 const char *ok_chars, const char *cancel_chars,
36                                 int flags, char *result_buf);
37        int UI_dup_input_boolean(UI *ui, const char *prompt, const char *action_desc,
38                                 const char *ok_chars, const char *cancel_chars,
39                                 int flags, char *result_buf);
40        int UI_add_info_string(UI *ui, const char *text);
41        int UI_dup_info_string(UI *ui, const char *text);
42        int UI_add_error_string(UI *ui, const char *text);
43        int UI_dup_error_string(UI *ui, const char *text);
44
45        char *UI_construct_prompt(UI *ui_method,
46                                  const char *phrase_desc, const char *object_name);
47
48        void *UI_add_user_data(UI *ui, void *user_data);
49        int UI_dup_user_data(UI *ui, void *user_data);
50        void *UI_get0_user_data(UI *ui);
51
52        const char *UI_get0_result(UI *ui, int i);
53        int UI_get_result_length(UI *ui, int i);
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55        int UI_process(UI *ui);
56
57        int UI_ctrl(UI *ui, int cmd, long i, void *p, void (*f)());
58
59        void UI_set_default_method(const UI_METHOD *meth);
60        const UI_METHOD *UI_get_default_method(void);
61        const UI_METHOD *UI_get_method(UI *ui);
62        const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);
63
64        UI_METHOD *UI_OpenSSL(void);
65        const UI_METHOD *UI_null(void);
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DESCRIPTION

68       UI stands for User Interface, and is general purpose set of routines to
69       prompt the user for text-based information.  Through user-written
70       methods (see UI_create_method(3)), prompting can be done in any way
71       imaginable, be it plain text prompting, through dialog boxes or from a
72       cell phone.
73
74       All the functions work through a context of the type UI.  This context
75       contains all the information needed to prompt correctly as well as a
76       reference to a UI_METHOD, which is an ordered vector of functions that
77       carry out the actual prompting.
78
79       The first thing to do is to create a UI with UI_new() or
80       UI_new_method(), then add information to it with the UI_add or UI_dup
81       functions.  Also, user-defined random data can be passed down to the
82       underlying method through calls to UI_add_user_data() or
83       UI_dup_user_data().  The default UI method doesn't care about these
84       data, but other methods might.  Finally, use UI_process() to actually
85       perform the prompting and UI_get0_result() and UI_get_result_length()
86       to find the result to the prompt and its length.
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
91       corresponding result with UI_get0_result() and UI_get_result_length().
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93       UI_process() can be called more than once on the same UI, thereby
94       allowing a UI to have a long lifetime, but can just as well have a
95       short lifetime.
96
97       The functions are as follows:
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99       UI_new() creates a new UI using the default UI method.  When done with
100       this UI, it should be freed using UI_free().
101
102       UI_new_method() creates a new UI using the given UI method.  When done
103       with this UI, it should be freed using UI_free().
104
105       UI_OpenSSL() returns the built-in UI method (note: not necessarily the
106       default one, since the default can be changed.  See further on).  This
107       method is the most machine/OS dependent part of OpenSSL and normally
108       generates the most problems when porting.
109
110       UI_null() returns a UI method that does nothing.  Its use is to avoid
111       getting internal defaults for passed UI_METHOD pointers.
112
113       UI_free() removes a UI from memory, along with all other pieces of
114       memory that's connected to it, like duplicated input strings, results
115       and others.  If ui is NULL nothing is done.
116
117       UI_add_input_string() and UI_add_verify_string() add a prompt to the
118       UI, as well as flags and a result buffer and the desired minimum and
119       maximum sizes of the result, not counting the final NUL character.  The
120       given information is used to prompt for information, for example a
121       password, and to verify a password (i.e. having the user enter it twice
122       and check that the same string was entered twice).
123       UI_add_verify_string() takes and extra argument that should be a
124       pointer to the result buffer of the input string that it's supposed to
125       verify, or verification will fail.
126
127       UI_add_input_boolean() adds a prompt to the UI that's supposed to be
128       answered in a boolean way, with a single character for yes and a
129       different character for no.  A set of characters that can be used to
130       cancel the prompt is given as well.  The prompt itself is divided in
131       two, one part being the descriptive text (given through the prompt
132       argument) and one describing the possible answers (given through the
133       action_desc argument).
134
135       UI_add_info_string() and UI_add_error_string() add strings that are
136       shown at the same time as the prompt for extra information or to show
137       an error string.  The difference between the two is only conceptual.
138       With the built-in method, there's no technical difference between them.
139       Other methods may make a difference between them, however.
140
141       The flags currently supported are UI_INPUT_FLAG_ECHO, which is relevant
142       for UI_add_input_string() and will have the users response be echoed
143       (when prompting for a password, this flag should obviously not be used,
144       and UI_INPUT_FLAG_DEFAULT_PWD, which means that a default password of
145       some sort will be used (completely depending on the application and the
146       UI method).
147
148       UI_dup_input_string(), UI_dup_verify_string(), UI_dup_input_boolean(),
149       UI_dup_info_string() and UI_dup_error_string() are basically the same
150       as their UI_add counterparts, except that they make their own copies of
151       all strings.
152
153       UI_construct_prompt() is a helper function that can be used to create a
154       prompt from two pieces of information: a phrase description phrase_desc
155       and an object name object_name, where the latter may be NULL.  The
156       default constructor (if there is none provided by the method used)
157       creates a string "Enter phrase_desc for object_name:" where the " for
158       object_name" part is left out if object_name is NULL.  With the
159       description "pass phrase" and the filename "foo.key", that becomes
160       "Enter pass phrase for foo.key:".  Other methods may create whatever
161       string and may include encodings that will be processed by the other
162       method functions.
163
164       UI_add_user_data() adds a user data pointer for the method to use at
165       any time.  The built-in UI method doesn't care about this info.  Note
166       that several calls to this function doesn't add data, it replaces the
167       previous blob with the one given as argument.
168
169       UI_dup_user_data() duplicates the user data and works as an alternative
170       to UI_add_user_data() when the user data needs to be preserved for a
171       longer duration, perhaps even the lifetime of the application.  The UI
172       object takes ownership of this duplicate and will free it whenever it
173       gets replaced or the UI is destroyed.  UI_dup_user_data() returns 0 on
174       success, or -1 on memory allocation failure or if the method doesn't
175       have a duplicator function.
176
177       UI_get0_user_data() retrieves the data that has last been given to the
178       UI with UI_add_user_data() or UI_dup_user_data.
179
180       UI_get0_result() returns a pointer to the result buffer associated with
181       the information indexed by i.
182
183       UI_get_result_length() returns the length of the result buffer
184       associated with the information indexed by i.
185
186       UI_process() goes through the information given so far, does all the
187       printing and prompting and returns the final status, which is -2 on
188       out-of-band events (Interrupt, Cancel, ...), -1 on error and 0 on
189       success.
190
191       UI_ctrl() adds extra control for the application author.  For now, it
192       understands two commands: UI_CTRL_PRINT_ERRORS, which makes
193       UI_process() print the OpenSSL error stack as part of processing the
194       UI, and UI_CTRL_IS_REDOABLE, which returns a flag saying if the used UI
195       can be used again or not.
196
197       UI_set_default_method() changes the default UI method to the one given.
198       This function is not thread-safe and should not be called at the same
199       time as other OpenSSL functions.
200
201       UI_get_default_method() returns a pointer to the current default UI
202       method.
203
204       UI_get_method() returns the UI method associated with a given UI.
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206       UI_set_method() changes the UI method associated with a given UI.
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NOTES

209       The resulting strings that the built in method UI_OpenSSL() generate
210       are assumed to be encoded according to the current locale or (for
211       Windows) code page.  For applications having different demands, these
212       strings need to be converted appropriately by the caller.  For Windows,
213       if the OPENSSL_WIN32_UTF8 environment variable is set, the built-in
214       method UI_OpenSSL() will produce UTF-8 encoded strings instead.
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RETURN VALUES

217       UI_new() and UI_new_method() return a valid UI structure or NULL if an
218       error occurred.
219
220       UI_add_input_string(), UI_dup_input_string(), UI_add_verify_string(),
221       UI_dup_verify_string(), UI_add_input_boolean(), UI_dup_input_boolean(),
222       UI_add_info_string(), UI_dup_info_string(), UI_add_error_string() and
223       UI_dup_error_string() return a positive number on success or a value
224       which is less than or equal to 0 otherwise.
225
226       UI_construct_prompt() returns a string or NULL if an error occurred.
227
228       UI_dup_user_data() returns 0 on success or -1 on error.
229
230       UI_get0_result() returns a string or NULL on error.
231
232       UI_get_result_length() returns a positive integer or 0 on success;
233       otherwise it returns -1 on error.
234
235       UI_process() returns 0 on success or a negative value on error.
236
237       UI_ctrl() returns a mask on success or -1 on error.
238
239       UI_get_default_method(), UI_get_method(), UI_OpenSSL(), UI_null() and
240       UI_set_method() return either a valid UI_METHOD structure or NULL
241       respectively.
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HISTORY

244       The UI_dup_user_data() function was added in OpenSSL 1.1.1.
245
247       Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
248
249       Licensed under the Apache License 2.0 (the "License").  You may not use
250       this file except in compliance with the License.  You can obtain a copy
251       in the file LICENSE in the source distribution or at
252       <https://www.openssl.org/source/license.html>.
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2563.0.5                             2022-07-05                     UI_NEW(3ossl)
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