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_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 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 textbased
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 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 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 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 dependent 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 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 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 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 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)
0.9.7l 2003-09-30 ui(3)
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