xref: /openssl/doc/man3/EVP_rc4.pod (revision b6eb95fa)
1=pod
2
3=head1 NAME
4
5EVP_rc4,
6EVP_rc4_40,
7EVP_rc4_hmac_md5
8- EVP RC4 stream cipher
9
10=head1 SYNOPSIS
11
12 #include <openssl/evp.h>
13
14 const EVP_CIPHER *EVP_rc4(void);
15 const EVP_CIPHER *EVP_rc4_40(void);
16 const EVP_CIPHER *EVP_rc4_hmac_md5(void);
17
18=head1 DESCRIPTION
19
20The RC4 stream cipher for EVP.
21
22=over 4
23
24=item EVP_rc4()
25
26RC4 stream cipher. This is a variable key length cipher with a default key
27length of 128 bits.
28
29=item EVP_rc4_40()
30
31RC4 stream cipher with 40 bit key length.
32
33WARNING: this function is obsolete. Its usage should be replaced with the
34EVP_rc4() and the EVP_CIPHER_CTX_set_key_length() functions.
35
36=item EVP_rc4_hmac_md5()
37
38Authenticated encryption with the RC4 stream cipher with MD5 as HMAC.
39
40WARNING: this is not intended for usage outside of TLS and requires calling of
41some undocumented ctrl functions. These ciphers do not conform to the EVP AEAD
42interface.
43
44=back
45
46=head1 NOTES
47
48Developers should be aware of the negative performance implications of
49calling these functions multiple times and should consider using
50L<EVP_CIPHER_fetch(3)> with L<EVP_CIPHER-RC4(7)> instead.
51See L<crypto(7)/Performance> for further information.
52
53=head1 RETURN VALUES
54
55These functions return an B<EVP_CIPHER> structure that contains the
56implementation of the symmetric cipher. See L<EVP_CIPHER_meth_new(3)> for
57details of the B<EVP_CIPHER> structure.
58
59=head1 SEE ALSO
60
61L<evp(7)>,
62L<EVP_EncryptInit(3)>,
63L<EVP_CIPHER_meth_new(3)>
64
65=head1 COPYRIGHT
66
67Copyright 2017-2023 The OpenSSL Project Authors. All Rights Reserved.
68
69Licensed under the Apache License 2.0 (the "License").  You may not use
70this file except in compliance with the License.  You can obtain a copy
71in the file LICENSE in the source distribution or at
72L<https://www.openssl.org/source/license.html>.
73
74=cut
75