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,
10       UI_construct_prompt, UI_add_user_data, UI_get0_user_data,
11       UI_get0_result, UI_process, UI_ctrl, UI_set_default_method,
12       UI_get_default_method, UI_get_method, UI_set_method, UI_OpenSSL,
13       ERR_load_UI_strings - New 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
72       methods (see ui_create(3)), prompting can be done in any way
73       imaginable, be it plain text prompting, through dialog boxes or from a
74       cell phone.
75
76       All the functions work through a context of the type UI.  This context
77       contains all the information needed to prompt correctly as well as a
78       reference to a UI_METHOD, which is an ordered vector of functions that
79       carry out the actual prompting.
80
81       The first thing to do is to create a UI with UI_new() or
82       UI_new_method(), then add information to it with the UI_add or UI_dup
83       functions.  Also, user-defined random data can be passed down to the
84       underlying method through calls to UI_add_user_data.  The default UI
85       method doesn't care about these data, but other methods might.
86       Finally, use UI_process() to actually perform the prompting and
87       UI_get0_result() to find the result to the prompt.
88
89       A UI can contain more than one prompt, which are performed in the given
90       sequence.  Each prompt gets an index number which is returned by the
91       UI_add and UI_dup functions, and has to be used to get the
92       corresponding result with UI_get0_result().
93
94       The functions are as follows:
95
96       UI_new() creates a new UI using the default UI method.  When done with
97       this UI, it should be freed using UI_free().
98
99       UI_new_method() creates a new UI using the given UI method.  When done
100       with this UI, it should be freed using UI_free().
101
102       UI_OpenSSL() returns the built-in UI method (note: not the default one,
103       since the default can be changed.  See further on).  This method is the
104       most machine/OS dependent part of OpenSSL and normally generates the
105       most problems when porting.
106
107       UI_free() removes a UI from memory, along with all other pieces of
108       memory that's connected to it, like duplicated input strings, results
109       and others.
110
111       UI_add_input_string() and UI_add_verify_string() add a prompt to the
112       UI, as well as flags and a result buffer and the desired minimum and
113       maximum sizes of the result.  The given information is used to prompt
114       for information, for example a password, and to verify a password (i.e.
115       having the user enter it twice and check that the same string was
116       entered twice).  UI_add_verify_string() takes and extra argument that
117       should be a pointer to the result buffer of the input string that it's
118       supposed to verify, or verification will fail.
119
120       UI_add_input_boolean() adds a prompt to the UI that's supposed to be
121       answered in a boolean way, with a single character for yes and a
122       different character for no.  A set of characters that can be used to
123       cancel the prompt is given as well.  The prompt itself is really
124       divided in two, one part being the descriptive text (given through the
125       prompt argument) and one describing the possible answers (given through
126       the action_desc argument).
127
128       UI_add_info_string() and UI_add_error_string() add strings that are
129       shown at the same time as the prompt for extra information or to show
130       an error string.  The difference between the two is only conceptual.
131       With the builtin method, there's no technical difference between them.
132       Other methods may make a difference between them, however.
133
134       The flags currently supported are UI_INPUT_FLAG_ECHO, which is relevant
135       for UI_add_input_string() and will have the users response be echoed
136       (when prompting for a password, this flag should obviously not be used,
137       and UI_INPUT_FLAG_DEFAULT_PWD, which means that a default password of
138       some sort will be used (completely depending on the application and the
139       UI method).
140
141       UI_dup_input_string(), UI_dup_verify_string(), UI_dup_input_boolean(),
142       UI_dup_info_string() and UI_dup_error_string() are basically the same
143       as their UI_add counterparts, except that they make their own copies of
144       all strings.
145
146       UI_construct_prompt() is a helper function that can be used to create a
147       prompt from two pieces of information: an description and a name.  The
148       default constructor (if there is none provided by the method used)
149       creates a string "Enter description for name:".  With the description
150       "pass phrase" and the file name "foo.key", that becomes "Enter pass
151       phrase for foo.key:".  Other methods may create whatever string and may
152       include encodings that will be processed by the other method functions.
153
154       UI_add_user_data() adds a piece of memory for the method to use at any
155       time.  The builtin UI method doesn't care about this info.  Note that
156       several calls to this function doesn't add data, it replaces the
157       previous blob with the one given as argument.
158
159       UI_get0_user_data() retrieves the data that has last been given to the
160       UI with UI_add_user_data().
161
162       UI_get0_result() returns a pointer to the result buffer associated with
163       the information indexed by i.
164
165       UI_process() goes through the information given so far, does all the
166       printing and prompting and returns.
167
168       UI_ctrl() adds extra control for the application author.  For now, it
169       understands two commands: UI_CTRL_PRINT_ERRORS, which makes
170       UI_process() print the OpenSSL error stack as part of processing the
171       UI, and UI_CTRL_IS_REDOABLE, which returns a flag saying if the used UI
172       can be used again or not.
173
174       UI_set_default_method() changes the default UI method to the one given.
175
176       UI_get_default_method() returns a pointer to the current default UI
177       method.
178
179       UI_get_method() returns the UI method associated with a given UI.
180
181       UI_set_method() changes the UI method associated with a given UI.
182

SEE ALSO

184       ui_create(3), ui_compat(3)
185

HISTORY

187       The UI section was first introduced in OpenSSL 0.9.7.
188

AUTHOR

190       Richard Levitte (richard@levitte.org) for the OpenSSL project
191       (http://www.openssl.org).
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1951.0.0e                            2003-09-30                             ui(3)
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