| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
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| .\" manual under the conditions for verbatim copying, provided that the |
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| .\" permission notice identical to this one. |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 18:54:45 1993 by Rik Faith (faith@cs.unc.edu) |
| .TH MEMFROB 3 2017-03-13 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| memfrob \- frobnicate (encrypt) a memory area |
| .SH SYNOPSIS |
| .nf |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <string.h> |
| .PP |
| .BI "void *memfrob(void *" s ", size_t " n ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR memfrob () |
| function encrypts the first \fIn\fP bytes of the |
| memory area \fIs\fP by exclusive-ORing each character with the number |
| 42. |
| The effect can be reversed by using |
| .BR memfrob () |
| on the |
| encrypted memory area. |
| .PP |
| Note that this function is not a proper encryption routine as the XOR |
| constant is fixed, and is suitable only for hiding strings. |
| .SH RETURN VALUE |
| The |
| .BR memfrob () |
| function returns a pointer to the encrypted memory |
| area. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lb lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR memfrob () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| The |
| .BR memfrob () |
| function is unique to the |
| GNU C Library. |
| .SH SEE ALSO |
| .BR bstring (3), |
| .BR strfry (3) |
