ui(3)                       OpenSSL                       ui(3)





NAME
       UI_new, UI_new_method, UI_free, UI_add_input_string,
       UI_dup_input_string, UI_add_verify_string, UI_dup_ver-
       ify_string, UI_add_input_boolean, UI_dup_input_boolean,
       UI_add_info_string, UI_dup_info_string,
       UI_add_error_string, UI_dup_error_string, UI_con-
       struct_prompt UI_add_user_data, UI_get0_user_data,
       UI_get0_result, UI_process, UI_ctrl,
       UI_set_default_method, UI_get_default_method,
       UI_get_method, UI_set_method, UI_OpenSSL,
       ERR_load_UI_strings - New User Interface

SYNOPSIS
        #include <openssl/ui.h>

        typedef struct ui_st UI;
        typedef struct ui_method_st UI_METHOD;

        UI *UI_new(void);
        UI *UI_new_method(const UI_METHOD *method);
        void UI_free(UI *ui);

        int UI_add_input_string(UI *ui, const char *prompt, int flags,
               char *result_buf, int minsize, int maxsize);
        int UI_dup_input_string(UI *ui, const char *prompt, int flags,
               char *result_buf, int minsize, int maxsize);
        int UI_add_verify_string(UI *ui, const char *prompt, int flags,
               char *result_buf, int minsize, int maxsize, const char *test_buf);
        int UI_dup_verify_string(UI *ui, const char *prompt, int flags,
               char *result_buf, int minsize, int maxsize, const char *test_buf);
        int UI_add_input_boolean(UI *ui, const char *prompt, const char *action_desc,
               const char *ok_chars, const char *cancel_chars,
               int flags, char *result_buf);
        int UI_dup_input_boolean(UI *ui, const char *prompt, const char *action_desc,
               const char *ok_chars, const char *cancel_chars,
               int flags, char *result_buf);
        int UI_add_info_string(UI *ui, const char *text);
        int UI_dup_info_string(UI *ui, const char *text);
        int UI_add_error_string(UI *ui, const char *text);
        int UI_dup_error_string(UI *ui, const char *text);

        /* These are the possible flags.  They can be or'ed together. */
        #define UI_INPUT_FLAG_ECHO             0x01
        #define UI_INPUT_FLAG_DEFAULT_PWD      0x02

        char *UI_construct_prompt(UI *ui_method,
               const char *object_desc, const char *object_name);

        void *UI_add_user_data(UI *ui, void *user_data);
        void *UI_get0_user_data(UI *ui);

        const char *UI_get0_result(UI *ui, int i);

        int UI_process(UI *ui);

        int UI_ctrl(UI *ui, int cmd, long i, void *p, void (*f)());
        #define UI_CTRL_PRINT_ERRORS           1
        #define UI_CTRL_IS_REDOABLE            2

        void UI_set_default_method(const UI_METHOD *meth);
        const UI_METHOD *UI_get_default_method(void);
        const UI_METHOD *UI_get_method(UI *ui);
        const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);

        UI_METHOD *UI_OpenSSL(void);

DESCRIPTION
       UI stands for User Interface, and is general purpose set
       of routines to prompt the user for text-based informa-
       tion.  Through user-written methods (see ui_create(3)),
       prompting can be done in any way imaginable, be it plain
       text prompting, through dialog boxes or from a cell
       phone.

       All the functions work through a context of the type UI.
       This context contains all the information needed to
       prompt correctly as well as a reference to a UI_METHOD,
       which is an ordered vector of functions that carry out
       the actual prompting.

       The first thing to do is to create a UI with UI_new() or
       UI_new_method(), then add information to it with the
       UI_add or UI_dup functions.  Also, user-defined random
       data can be passed down to the underlying method through
       calls to UI_add_user_data.  The default UI method
       doesn't care about these data, but other methods might.
       Finally, use UI_process() to actually perform the
       prompting and UI_get0_result() to find the result to the
       prompt.

       A UI can contain more than one prompt, which are per-
       formed in the given sequence.  Each prompt gets an index
       number which is returned by the UI_add and UI_dup func-
       tions, and has to be used to get the corresponding
       result with UI_get0_result().

       The functions are as follows:

       UI_new() creates a new UI using the default UI method.
       When done with this UI, it should be freed using
       UI_free().

       UI_new_method() creates a new UI using the given UI
       method.  When done with this UI, it should be freed
       using UI_free().

       UI_OpenSSL() returns the built-in UI method (note: not
       the default one, since the default can be changed.  See
       further on).  This method is the most machine/OS depen-
       dent part of OpenSSL and normally generates the most
       problems when porting.

       UI_free() removes a UI from memory, along with all other
       pieces of memory that's connected to it, like duplicated
       input strings, results and others.

       UI_add_input_string() and UI_add_verify_string() add a
       prompt to the UI, as well as flags and a result buffer
       and the desired minimum and maximum sizes of the result.
       The given information is used to prompt for information,
       for example a password, and to verify a password (i.e.
       having the user enter it twice and check that the same
       string was entered twice).  UI_add_verify_string() takes
       and extra argument that should be a pointer to the
       result buffer of the input string that it's supposed to
       verify, or verification will fail.

       UI_add_input_boolean() adds a prompt to the UI that's
       supposed to be answered in a boolean way, with a single
       character for yes and a different character for no.  A
       set of characters that can be used to cancel the prompt
       is given as well.  The prompt itself is really divided
       in two, one part being the descriptive text (given
       through the prompt argument) and one describing the
       possible answers (given through the action_desc argu-
       ment).

       UI_add_info_string() and UI_add_error_string() add
       strings that are shown at the same time as the prompt
       for extra information or to show an error string.  The
       difference between the two is only conceptual.  With the
       builtin method, there's no technical difference between
       them.  Other methods may make a difference between them,
       however.

       The flags currently supported are UI_INPUT_FLAG_ECHO,
       which is relevant for UI_add_input_string() and will
       have the users response be echoed (when prompting for a
       password, this flag should obviously not be used, and
       UI_INPUT_FLAG_DEFAULT_PWD, which means that a default
       password of some sort will be used (completely depending
       on the application and the UI method).

       UI_dup_input_string(), UI_dup_verify_string(),
       UI_dup_input_boolean(), UI_dup_info_string() and
       UI_dup_error_string() are basically the same as their
       UI_add counterparts, except that they make their own
       copies of all strings.

       UI_construct_prompt() is a helper function that can be
       used to create a prompt from two pieces of information:
       an description and a name.  The default constructor (if
       there is none provided by the method used) creates a
       string "Enter description for name:".  With the descrip-
       tion "pass phrase" and the file name "foo.key", that
       becomes "Enter pass phrase for foo.key:".  Other methods
       may create whatever string and may include encodings
       that will be processed by the other method functions.

       UI_add_user_data() adds a piece of memory for the method
       to use at any time.  The builtin UI method doesn't care
       about this info.  Note that several calls to this func-
       tion doesn't add data, it replaces the previous blob
       with the one given as argument.

       UI_get0_user_data() retrieves the data that has last
       been given to the UI with UI_add_user_data().

       UI_get0_result() returns a pointer to the result buffer
       associated with the information indexed by i.

       UI_process() goes through the information given so far,
       does all the printing and prompting and returns.

       UI_ctrl() adds extra control for the application author.
       For now, it understands two commands:
       UI_CTRL_PRINT_ERRORS, which makes UI_process() print the
       OpenSSL error stack as part of processing the UI, and
       UI_CTRL_IS_REDOABLE, which returns a flag saying if the
       used UI can be used again or not.

       UI_set_default_method() changes the default UI method to
       the one given.

       UI_get_default_method() returns a pointer to the current
       default UI method.

       UI_get_method() returns the UI method associated with a
       given UI.

       UI_set_method() changes the UI method associated with a
       given UI.

SEE ALSO
       ui_create(3), ui_compat(3)

HISTORY
       The UI section was first introduced in OpenSSL 0.9.7.

AUTHOR
       Richard Levitte (richard@levitte.org) for the OpenSSL
       project (http://www.openssl.org).



0.9.7c                     2001-10-25                     ui(3)
