NAME

       EVP_rc4, EVP_rc4_40, EVP_rc4_hmac_md5 - EVP RC4 stream cipher

SYNOPSIS

        #include <openssl/evp.h>

        const EVP_CIPHER *EVP_rc4(void);
        const EVP_CIPHER *EVP_rc4_40(void);
        const EVP_CIPHER *EVP_rc4_hmac_md5(void);

DESCRIPTION

       The RC4 stream cipher for EVP.

       EVP_rc4()
           RC4 stream cipher. This is a variable key length cipher with a default key length of 128 bits.

       EVP_rc4_40()
           RC4 stream cipher with 40 bit key length.

           WARNING: this function is obsolete. Its usage should be replaced with the EVP_rc4() and the
           EVP_CIPHER_CTX_set_key_length() functions.

       EVP_rc4_hmac_md5()
           Authenticated encryption with the RC4 stream cipher with MD5 as HMAC.

           WARNING: this is not intended for usage outside of TLS and requires calling of some undocumented ctrl
           functions. These ciphers do not conform to the EVP AEAD interface.

NOTES

       Developers should be aware of the negative performance implications of calling these functions multiple
       times and should consider using EVP_CIPHER_fetch(3) with EVP_CIPHER-RC4(7) instead.  See "Performance" in
       crypto(7) for further information.

RETURN VALUES

       These functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher.
       See EVP_CIPHER_meth_new(3) for details of the EVP_CIPHER structure.

SEE ALSO

       evp(7), EVP_EncryptInit(3), EVP_CIPHER_meth_new(3)

COPYRIGHT

       Copyright 2017-2023 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance
       with the License.  You can obtain a copy in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.