.\" $OpenBSD: UI_new.3,v 1.8 2018/03/22 21:08:22 schwarze Exp $ .\" full merge up to: OpenSSL 78b19e90 Jan 11 00:12:01 2017 +0100 .\" selective merge up to: OpenSSL 61f805c1 Jan 16 01:01:46 2018 +0800 .\" .\" This file was written by Richard Levitte . .\" Copyright (c) 2001, 2016, 2017 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: March 22 2018 $ .Dt UI_NEW 3 .Os .Sh NAME .Nm UI_new , .Nm UI_new_method , .Nm UI_free , .Nm UI_add_input_string , .Nm UI_dup_input_string , .Nm UI_add_verify_string , .Nm UI_dup_verify_string , .Nm UI_add_input_boolean , .Nm UI_dup_input_boolean , .Nm UI_add_info_string , .Nm UI_dup_info_string , .Nm UI_add_error_string , .Nm UI_dup_error_string , .Nm UI_construct_prompt , .Nm UI_add_user_data , .Nm UI_get0_user_data , .Nm UI_get0_result , .Nm UI_process , .Nm UI_ctrl , .Nm UI_set_default_method , .Nm UI_get_default_method , .Nm UI_get_method , .Nm UI_set_method , .Nm UI_OpenSSL .Nd New User Interface .Sh SYNOPSIS .In openssl/ui.h .Ft UI * .Fn UI_new void .Ft UI * .Fo UI_new_method .Fa "const UI_METHOD *method" .Fc .Ft void .Fo UI_free .Fa "UI *ui" .Fc .Ft int .Fo UI_add_input_string .Fa "UI *ui" .Fa "const char *prompt" .Fa "int flags" .Fa "char *result_buf" .Fa "int minsize" .Fa "int maxsize" .Fc .Ft int .Fo UI_dup_input_string .Fa "UI *ui" .Fa "const char *prompt" .Fa "int flags" .Fa "char *result_buf" .Fa "int minsize" .Fa "int maxsize" .Fc .Ft int .Fo UI_add_verify_string .Fa "UI *ui" .Fa "const char *prompt" .Fa "int flags" .Fa "char *result_buf" .Fa "int minsize" .Fa "int maxsize" .Fa "const char *test_buf" .Fc .Ft int .Fo UI_dup_verify_string .Fa "UI *ui" .Fa "const char *prompt" .Fa "int flags" .Fa "char *result_buf" .Fa "int minsize" .Fa "int maxsize" .Fa "const char *test_buf" .Fc .Ft int .Fo UI_add_input_boolean .Fa "UI *ui" .Fa "const char *prompt" .Fa "const char *action_desc" .Fa "const char *ok_chars" .Fa "const char *cancel_chars" .Fa "int flags" .Fa "char *result_buf" .Fc .Ft int .Fo UI_dup_input_boolean .Fa "UI *ui" .Fa "const char *prompt" .Fa "const char *action_desc" .Fa "const char *ok_chars" .Fa "const char *cancel_chars" .Fa "int flags" .Fa "char *result_buf" .Fc .Ft int .Fo UI_add_info_string .Fa "UI *ui" .Fa "const char *text" .Fc .Ft int .Fo UI_dup_info_string .Fa "UI *ui" .Fa "const char *text" .Fc .Ft int .Fo UI_add_error_string .Fa "UI *ui" .Fa "const char *text" .Fc .Ft int .Fo UI_dup_error_string .Fa "UI *ui" .Fa "const char *text" .Fc .Fd /* These are the possible flags. They can be OR'ed together. */ .Fd #define UI_INPUT_FLAG_ECHO 0x01 .Fd #define UI_INPUT_FLAG_DEFAULT_PWD 0x02 .Ft char * .Fo UI_construct_prompt .Fa "UI *ui_method" .Fa "const char *object_desc" .Fa "const char *object_name" .Fc .Ft void * .Fo UI_add_user_data .Fa "UI *ui" .Fa "void *user_data" .Fc .Ft void * .Fo UI_get0_user_data .Fa "UI *ui" .Fc .Ft const char * .Fo UI_get0_result .Fa "UI *ui" .Fa "int i" .Fc .Ft int .Fo UI_process .Fa "UI *ui" .Fc .Ft int .Fo UI_ctrl .Fa "UI *ui" .Fa "int cmd" .Fa "long i" .Fa "void *p" .Fa "void (*f)()" .Fc .Fd #define UI_CTRL_PRINT_ERRORS 1 .Fd #define UI_CTRL_IS_REDOABLE 2 .Ft void .Fo UI_set_default_method .Fa "const UI_METHOD *meth" .Fc .Ft const UI_METHOD * .Fo UI_get_default_method .Fa void .Fc .Ft const UI_METHOD * .Fo UI_get_method .Fa "UI *ui" .Fc .Ft const UI_METHOD * .Fo UI_set_method .Fa "UI *ui" .Fa "const UI_METHOD *meth" .Fc .Ft UI_METHOD * .Fo UI_OpenSSL .Fa void .Fc .Sh DESCRIPTION UI stands for User Interface, and is a general purpose set of routines to prompt the user for text-based information. Through user-written methods (see .Xr UI_create_method 3 ) , prompting can be done in any way imaginable, be it plain text prompting, through dialog boxes or from a cell phone. .Pp All the functions work through a context of the type .Vt UI . This context contains all the information needed to prompt correctly as well as a reference to a .Vt UI_METHOD , which is an ordered vector of functions that carry out the actual prompting. .Pp The first thing to do is to create a .Vt UI with .Fn UI_new or .Fn UI_new_method , then add information to it with the .Fn UI_add_* or .Fn UI_dup_* functions. Also, user-defined random data can be passed down to the underlying method through calls to .Fn UI_add_user_data . The default UI method doesn't care about these data, but other methods might. Finally, use .Fn UI_process to actually perform the prompting and .Fn UI_get0_result to find the result to the prompt. .Pp A .Vt 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 .Fn UI_add_* and .Fn UI_dup_* functions, and has to be used to get the corresponding result with .Fn UI_get0_result . .Pp The functions are as follows: .Pp .Fn UI_new creates a new .Vt UI using the default UI method. When done with this UI, it should be freed using .Fn UI_free . .Pp .Fn UI_new_method creates a new .Vt UI using the given UI method. When done with this UI, it should be freed using .Fn UI_free . .Pp .Fn UI_OpenSSL returns the built-in UI method (note: not necessarily 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. .Pp .Fn UI_free removes .Fa ui from memory, along with all other pieces of memory that are connected to it, like duplicated input strings, results and others. If .Fa ui is a .Dv NULL pointer, no action occurs. .Pp .Fn UI_add_input_string and .Fn UI_add_verify_string add a prompt to .Fa 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). .Fn UI_add_verify_string takes an 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. .Pp .Fn UI_add_input_boolean adds a prompt to .Fa 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 .Fa prompt argument) and one describing the possible answers (given through the .Fa action_desc argument). .Pp .Fn UI_add_info_string and .Fn 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. .Pp The flags currently supported are .Dv UI_INPUT_FLAG_ECHO , which is relevant for .Fn 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 .Dv 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). .Pp .Fn UI_dup_input_string , .Fn UI_dup_verify_string , .Fn UI_dup_input_boolean , .Fn UI_dup_info_string , and .Fn UI_dup_error_string are basically the same as their .Fn UI_add_* counterparts, except that they make their own copies of all strings. .Pp .Fn UI_construct_prompt is a helper function that can be used to create a prompt from two pieces of information: a description and a name. The default constructor (if there is none provided by the method used) creates a string "Enter .Em description for .Em name Ns :". 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. .Pp .Fn UI_add_user_data adds a user data pointer 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 - the previous blob is replaced with the one given as argument. .Pp .Fn UI_get0_user_data retrieves the data that has last been given to the .Fa ui with .Fn UI_add_user_data . .Pp .Fn UI_get0_result returns a pointer to the result buffer associated with the information indexed by .Fa i . .Pp .Fn UI_process goes through the information given so far, does all the printing and prompting and returns the final status, which is -2 on out-of-band events (Interrupt, Cancel, ...), -1 on error, or 0 on success. .Pp .Fn UI_ctrl adds extra control for the application author. For now, it understands two commands: .Dv UI_CTRL_PRINT_ERRORS , which makes .Fn UI_process print the OpenSSL error stack as part of processing the .Fa ui , and .Dv UI_CTRL_IS_REDOABLE , which returns a flag saying if the used .Fa ui can be used again or not. .Pp .Fn UI_set_default_method changes the default UI method to the one given. This function is not thread-safe and should not be called at the same time as other OpenSSL functions. .Pp .Fn UI_get_default_method returns a pointer to the current default UI method. .Pp .Fn UI_get_method returns the UI method associated with a given .Fa ui . .Pp .Fn UI_set_method changes the UI method associated with a given .Fa ui . .Sh RETURN VALUES .Fn UI_new and .Fn UI_new_method return a valid .Vt UI structure or .Dv NULL if an error occurred. .Pp .Fn UI_add_input_string , .Fn UI_dup_input_string , .Fn UI_add_verify_string , .Fn UI_dup_verify_string , .Fn UI_add_input_boolean , .Fn UI_dup_input_boolean , .Fn UI_add_info_string , .Fn UI_dup_info_string , .Fn UI_add_error_string , and .Fn UI_dup_error_string return a positive number on success or a number less than or equal to zero otherwise. .Pp .Fn UI_construct_prompt and .Fn UI_get0_result return a string or .Dv NULL if an error occurred. .Pp .Fn UI_add_user_data and .Fn UI_get0_user_data return a pointer to the user data that was contained in .Fa ui before the call. In particular, .Dv NULL is a valid return value. .Pp .Fn UI_process returns 0 on success or a negative value on error. .Pp .Fn UI_ctrl returns a mask on success or \-1 on error. .Pp .Fn UI_get_default_method and .Fn UI_OpenSSL always return a pointer to a valid .Vt UI_METHOD structure. .Pp .Fn UI_get_method and .Fn UI_set_method return a pointer to the .Vt UI_METHOD structure that is installed in .Fa ui after the call. The OpenSSL documentation says that they can fail and return .Dv NULL , but currently, this can only happen when and after .Fn UI_set_method is called with an explicit .Dv NULL argument. .Sh SEE ALSO .Xr des_read_pw 3 , .Xr UI_create_method 3 , .Xr UI_get_string_type 3 , .Xr UI_UTIL_read_pw 3 .Sh HISTORY These functions first appeared in OpenSSL 0.9.7 and have been available since .Ox 3.2 . .Sh AUTHORS .An Richard Levitte Aq Mt richard@levitte.org for the OpenSSL project.