EVP_rc4(3ssl)

EVP_rc43ssl

Evp rc4 stream cipher

Usage

 #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);

Overview

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WARNING: this function is obsolete.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.

Releases

6 releases since Debian 9 (Stretch); the text changed 5 times.

  1. 9
  2. 10
  3. 11
  4. 12
  5. 13
  6. Arch

From openssl 3.6.5-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.