ENCRYPT(3)                 POSIX Programmer's Manual                ENCRYPT(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       encrypt -- encoding function (CCRRYYPPTT)

SSYYNNOOPPSSIISS
       #include <unistd.h>

       void encrypt(char _b_l_o_c_k[64], int _e_d_f_l_a_g);

DDEESSCCRRIIPPTTIIOONN
       The _e_n_c_r_y_p_t() function shall provide access to an implementation-
       defined encoding algorithm. The key generated by _s_e_t_k_e_y() is used to
       encrypt the string _b_l_o_c_k with _e_n_c_r_y_p_t().

       The _b_l_o_c_k argument to _e_n_c_r_y_p_t() shall be an array of length 64 bytes
       containing only the bytes with values of 0 and 1. The array is modified
       in place to a similar array using the key set by _s_e_t_k_e_y().  If _e_d_f_l_a_g
       is 0, the argument is encoded. If _e_d_f_l_a_g is 1, the argument may be
       decoded (see the APPLICATION USAGE section); if the argument is not
       decoded, _e_r_r_n_o shall be set to [[EENNOOSSYYSS]].

       The _e_n_c_r_y_p_t() function shall not change the setting of _e_r_r_n_o if
       successful. An application wishing to check for error situations should
       set _e_r_r_n_o to 0 before calling _e_n_c_r_y_p_t().  If _e_r_r_n_o is non-zero on
       return, an error has occurred.

       The _e_n_c_r_y_p_t() function need not be thread-safe.

RREETTUURRNN VVAALLUUEE
       The _e_n_c_r_y_p_t() function shall not return a value.

EERRRROORRSS
       The _e_n_c_r_y_p_t() function shall fail if:

       EENNOOSSYYSS The functionality is not supported on this implementation.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       Historical implementations of the _e_n_c_r_y_p_t() function used a rather
       primitive encoding algorithm.

       In some environments, decoding might not be implemented. This is
       related to some Government restrictions on encryption and decryption
       routines. Historical practice has been to ship a different version of
       the encryption library without the decryption feature in the routines
       supplied. Thus the exported version of _e_n_c_r_y_p_t() does encoding but not
       decoding.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       A future version of the standard may mark this interface as obsolete or
       remove it altogether.

SSEEEE AALLSSOO
       _c_r_y_p_t(), _s_e_t_k_e_y()

       The Base Definitions volume of POSIX.1-2017, <<uunniissttdd..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                           ENCRYPT(3)
