1 .\" Copyright 2000 Nicolás Lichtmaier <nick@debian.org>
2 .\" Created 2000-07-22 00:52-0300
4 .\" %%%LICENSE_START(GPLv2+_DOC_FULL)
5 .\" This is free documentation; you can redistribute it and/or
6 .\" modify it under the terms of the GNU General Public License as
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25 .\" Modified 2002-07-23 19:21:35 CEST 2002 Walter Harms
26 .\" <walter.harms@informatik.uni-oldenburg.de>
28 .\" Modified 2003-04-04, aeb
30 .TH ENCRYPT 3 2015-08-08 "" "Linux Programmer's Manual"
32 encrypt, setkey, encrypt_r, setkey_r \- encrypt 64-bit messages
34 .BR "#define _XOPEN_SOURCE" " /* See feature_test_macros(7) */"
36 .B #include <unistd.h>
38 .BI "void encrypt(char " block "[64], int " edflag );
40 .BR "#define _XOPEN_SOURCE" " /* See feature_test_macros(7) */"
42 .B #include <stdlib.h>
44 .BI "void setkey(const char *" key );
46 .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
48 .B "#include <crypt.h>"
50 .BI "void setkey_r(const char *" key ", struct crypt_data *" data );
52 .BI "void encrypt_r(char *" block ", int " edflag \
53 ", struct crypt_data *" data );
55 Each of these requires linking with \fI\-lcrypt\fP.
57 These functions encrypt and decrypt 64-bit messages.
60 function sets the key used by
64 argument used here is an array of 64 bytes, each of which has
65 numerical value 1 or 0.
66 The bytes key[n] where n=8*i-1 are ignored,
67 so that the effective key length is 56 bits.
71 function modifies the passed buffer, encoding if
73 is 0, and decoding if 1 is being passed.
78 is a bit vector representation of the actual value that is encoded.
79 The result is returned in that same vector.
81 These two functions are not reentrant, that is, the key data is
82 kept in static storage.
87 are the reentrant versions.
88 They use the following
89 structure to hold the key data:
94 char keysched[16 * 8];
100 char current_salt[2];
101 long int current_saltbits;
111 .I data\->initialized
114 These functions do not return any value.
118 to zero before calling the above functions.
119 On success, it is unchanged.
122 The function is not provided.
123 (For example because of former USA export restrictions.)
125 For an explanation of the terms used in this section, see
131 Interface Attribute Value
135 T} Thread safety MT-Unsafe race:crypt
139 T} Thread safety MT-Safe
144 POSIX.1-2001, POSIX.1-2008, SUS, SVr4.
152 In glibc 2.2, these functions use the DES algorithm.
155 #define _XOPEN_SOURCE
165 char orig[9] = "eggplant";
170 for (i = 0; i < 64; i++) {
174 for (i = 0; i < 8; i++) {
175 for (j = 0; j < 8; j++) {
176 buf[i * 8 + j] = orig[i] >> j & 1;
180 printf("Before encrypting: %s\\n", orig);
183 for (i = 0; i < 8; i++) {
184 for (j = 0, txt[i] = \(aq\\0\(aq; j < 8; j++) {
185 txt[i] |= buf[i * 8 + j] << j;
187 txt[8] = \(aq\\0\(aq;
189 printf("After encrypting: %s\\n", txt);
192 for (i = 0; i < 8; i++) {
193 for (j = 0, txt[i] = \(aq\\0\(aq; j < 8; j++) {
194 txt[i] |= buf[i * 8 + j] << j;
196 txt[8] = \(aq\\0\(aq;
198 printf("After decrypting: %s\\n", txt);