ui(3)                        OpenSSL                        ui(3)


     UI_new, UI_new_method, UI_free, UI_add_input_string,
     UI_dup_input_string, UI_add_verify_string,
     UI_dup_verify_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_construct_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


      #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);

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ui(3)                        OpenSSL                        ui(3)

      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);


     UI stands for User Interface, and is general purpose set of
     routines to prompt the user for text-based information.
     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

     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 performed
     in the given sequence.  Each prompt gets an index number
     which is returned by the UI_add and UI_dup functions, and
     has to be used to get the corresponding result with

     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().

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ui(3)                        OpenSSL                        ui(3)

     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 dependent part of
     OpenSSL and normally generates the most problems when

     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, not
     counting the final NUL character.  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 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 argument).

     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

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ui(3)                        OpenSSL                        ui(3)

     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 description "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 function 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

     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.


     ui_create(3), ui_compat(3)


     The UI section was first introduced in OpenSSL 0.9.7.


     Richard Levitte ( for the OpenSSL

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ui(3)                        OpenSSL                        ui(3)

     project (

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