1=pod 2 3=head1 NAME 4 5UI, 6UI_new, UI_new_method, UI_free, UI_add_input_string, UI_dup_input_string, 7UI_add_verify_string, UI_dup_verify_string, UI_add_input_boolean, 8UI_dup_input_boolean, UI_add_info_string, UI_dup_info_string, 9UI_add_error_string, UI_dup_error_string, UI_construct_prompt, 10UI_add_user_data, UI_dup_user_data, UI_get0_user_data, UI_get0_result, 11UI_get_result_length, 12UI_process, UI_ctrl, UI_set_default_method, UI_get_default_method, 13UI_get_method, UI_set_method, UI_OpenSSL, UI_null - user interface 14 15=head1 SYNOPSIS 16 17 #include <openssl/ui.h> 18 19 typedef struct ui_st UI; 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, 31 const char *test_buf); 32 int UI_dup_verify_string(UI *ui, const char *prompt, int flags, 33 char *result_buf, int minsize, int maxsize, 34 const char *test_buf); 35 int UI_add_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_dup_input_boolean(UI *ui, const char *prompt, const char *action_desc, 39 const char *ok_chars, const char *cancel_chars, 40 int flags, char *result_buf); 41 int UI_add_info_string(UI *ui, const char *text); 42 int UI_dup_info_string(UI *ui, const char *text); 43 int UI_add_error_string(UI *ui, const char *text); 44 int UI_dup_error_string(UI *ui, const char *text); 45 46 char *UI_construct_prompt(UI *ui_method, 47 const char *phrase_desc, const char *object_name); 48 49 void *UI_add_user_data(UI *ui, void *user_data); 50 int UI_dup_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 int UI_get_result_length(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 60 void UI_set_default_method(const UI_METHOD *meth); 61 const UI_METHOD *UI_get_default_method(void); 62 const UI_METHOD *UI_get_method(UI *ui); 63 const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth); 64 65 UI_METHOD *UI_OpenSSL(void); 66 const UI_METHOD *UI_null(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_method(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() or UI_dup_user_data(). The default 85UI method doesn't care about these data, but other methods might. Finally, 86use UI_process() to actually perform the prompting and UI_get0_result() 87and UI_get_result_length() to find the result to the prompt and its length. 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() and UI_get_result_length(). 93 94UI_process() can be called more than once on the same UI, thereby allowing 95a UI to have a long lifetime, but can just as well have a short lifetime. 96 97The functions are as follows: 98 99UI_new() creates a new UI using the default UI method. When done with 100this UI, it should be freed using UI_free(). 101 102UI_new_method() creates a new UI using the given UI method. When done with 103this UI, it should be freed using UI_free(). 104 105UI_OpenSSL() returns the built-in UI method (note: not necessarily the 106default one, since the default can be changed. See further on). This 107method is the most machine/OS dependent part of OpenSSL and normally 108generates the most problems when porting. 109 110UI_null() returns a UI method that does nothing. Its use is to avoid 111getting internal defaults for passed UI_METHOD pointers. 112 113UI_free() removes a UI from memory, along with all other pieces of memory 114that's connected to it, like duplicated input strings, results and others. 115If B<ui> is NULL nothing is done. 116 117UI_add_input_string() and UI_add_verify_string() add a prompt to the UI, 118as well as flags and a result buffer and the desired minimum and maximum 119sizes of the result, not counting the final NUL character. The given 120information is used to prompt for information, for example a password, 121and to verify a password (i.e. having the user enter it twice and check 122that the same string was entered twice). UI_add_verify_string() takes 123and extra argument that should be a pointer to the result buffer of the 124input string that it's supposed to verify, or verification will fail. 125 126UI_add_input_boolean() adds a prompt to the UI that's supposed to be answered 127in a boolean way, with a single character for yes and a different character 128for no. A set of characters that can be used to cancel the prompt is given 129as well. The prompt itself is divided in two, one part being the 130descriptive text (given through the I<prompt> argument) and one describing 131the possible answers (given through the I<action_desc> argument). 132 133UI_add_info_string() and UI_add_error_string() add strings that are shown at 134the same time as the prompt for extra information or to show an error string. 135The difference between the two is only conceptual. With the built-in method, 136there's no technical difference between them. Other methods may make a 137difference between them, however. 138 139The flags currently supported are B<UI_INPUT_FLAG_ECHO>, which is relevant for 140UI_add_input_string() and will have the users response be echoed (when 141prompting for a password, this flag should obviously not be used, and 142B<UI_INPUT_FLAG_DEFAULT_PWD>, which means that a default password of some 143sort will be used (completely depending on the application and the UI 144method). 145 146UI_dup_input_string(), UI_dup_verify_string(), UI_dup_input_boolean(), 147UI_dup_info_string() and UI_dup_error_string() are basically the same 148as their UI_add counterparts, except that they make their own copies 149of all strings. 150 151UI_construct_prompt() is a helper function that can be used to create 152a prompt from two pieces of information: a phrase description I<phrase_desc> 153and an object name I<object_name>, where the latter may be NULL. 154The default constructor (if there is none provided by the method used) 155creates a string "Enter I<phrase_desc> for I<object_name>:" 156where the " for I<object_name>" part is left out if I<object_name> is NULL. 157With the description "pass phrase" and the filename "foo.key", that becomes 158"Enter pass phrase for foo.key:". Other methods may create whatever 159string and may include encodings that will be processed by the other 160method functions. 161 162UI_add_user_data() adds a user data pointer for the method to use at any 163time. The built-in UI method doesn't care about this info. Note that several 164calls to this function doesn't add data, it replaces the previous blob 165with the one given as argument. 166 167UI_dup_user_data() duplicates the user data and works as an alternative 168to UI_add_user_data() when the user data needs to be preserved for a longer 169duration, perhaps even the lifetime of the application. The UI object takes 170ownership of this duplicate and will free it whenever it gets replaced or 171the UI is destroyed. UI_dup_user_data() returns 0 on success, or -1 on memory 172allocation failure or if the method doesn't have a duplicator function. 173 174UI_get0_user_data() retrieves the data that has last been given to the 175UI with UI_add_user_data() or UI_dup_user_data. 176 177UI_get0_result() returns a pointer to the result buffer associated with 178the information indexed by I<i>. 179 180UI_get_result_length() returns the length of the result buffer associated with 181the information indexed by I<i>. 182 183UI_process() goes through the information given so far, does all the printing 184and prompting and returns the final status, which is -2 on out-of-band events 185(Interrupt, Cancel, ...), -1 on error and 0 on success. 186 187UI_ctrl() adds extra control for the application author. For now, it 188understands two commands: B<UI_CTRL_PRINT_ERRORS>, which makes UI_process() 189print the OpenSSL error stack as part of processing the UI, and 190B<UI_CTRL_IS_REDOABLE>, which returns a flag saying if the used UI can 191be used again or not. 192 193UI_set_default_method() changes the default UI method to the one given. 194This function is not thread-safe and should not be called at the same time 195as other OpenSSL functions. 196 197UI_get_default_method() returns a pointer to the current default UI method. 198 199UI_get_method() returns the UI method associated with a given UI. 200 201UI_set_method() changes the UI method associated with a given UI. 202 203=head1 NOTES 204 205The resulting strings that the built in method UI_OpenSSL() generate 206are assumed to be encoded according to the current locale or (for 207Windows) code page. 208For applications having different demands, these strings need to be 209converted appropriately by the caller. 210For Windows, if the B<OPENSSL_WIN32_UTF8> environment variable is set, 211the built-in method UI_OpenSSL() will produce UTF-8 encoded strings 212instead. 213 214=head1 RETURN VALUES 215 216UI_new() and UI_new_method() return a valid B<UI> structure or NULL if an error 217occurred. 218 219UI_add_input_string(), UI_dup_input_string(), UI_add_verify_string(), 220UI_dup_verify_string(), UI_add_input_boolean(), UI_dup_input_boolean(), 221UI_add_info_string(), UI_dup_info_string(), UI_add_error_string() 222and UI_dup_error_string() return a positive number on success or a value which 223is less than or equal to 0 otherwise. 224 225UI_construct_prompt() returns a string or NULL if an error occurred. 226 227UI_dup_user_data() returns 0 on success or -1 on error. 228 229UI_get0_result() returns a string or NULL on error. 230 231UI_get_result_length() returns a positive integer or 0 on success; otherwise it 232returns -1 on error. 233 234UI_process() returns 0 on success or a negative value on error. 235 236UI_ctrl() returns a mask on success or -1 on error. 237 238UI_get_default_method(), UI_get_method(), UI_OpenSSL(), UI_null() and 239UI_set_method() return either a valid B<UI_METHOD> structure or NULL 240respectively. 241 242=head1 HISTORY 243 244The UI_dup_user_data() function was added in OpenSSL 1.1.1. 245 246=head1 COPYRIGHT 247 248Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved. 249 250Licensed under the Apache License 2.0 (the "License"). You may not use 251this file except in compliance with the License. You can obtain a copy 252in the file LICENSE in the source distribution or at 253L<https://www.openssl.org/source/license.html>. 254 255=cut 256