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3dbf824380
There was recently an instance where a user was confused by the deprecation warnings in the docs. They believed the warning applied to the immediately preceding function declarations, when it fact it applied to the following function declarations. https://mta.openssl.org/pipermail/openssl-users/2021-December/014665.html We clarify the wording to make it clear that the warning applies to the following functions. Reviewed-by: Paul Dale <pauli@openssl.org> Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/17180)
79 lines
2.3 KiB
Plaintext
79 lines
2.3 KiB
Plaintext
=pod
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=head1 NAME
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RC4_set_key, RC4 - RC4 encryption
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=head1 SYNOPSIS
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#include <openssl/rc4.h>
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The following functions have been deprecated since OpenSSL 3.0, and can be
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hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
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see L<openssl_user_macros(7)>:
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void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data);
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void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata,
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unsigned char *outdata);
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=head1 DESCRIPTION
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All of the functions described on this page are deprecated. Applications should
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instead use L<EVP_EncryptInit_ex(3)>, L<EVP_EncryptUpdate(3)> and
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L<EVP_EncryptFinal_ex(3)> or the equivalently named decrypt functions.
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This library implements the Alleged RC4 cipher, which is described for
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example in I<Applied Cryptography>. It is believed to be compatible
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with RC4[TM], a proprietary cipher of RSA Security Inc.
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RC4 is a stream cipher with variable key length. Typically, 128 bit
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(16 byte) keys are used for strong encryption, but shorter insecure
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key sizes have been widely used due to export restrictions.
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RC4 consists of a key setup phase and the actual encryption or
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decryption phase.
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RC4_set_key() sets up the B<RC4_KEY> B<key> using the B<len> bytes long
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key at B<data>.
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RC4() encrypts or decrypts the B<len> bytes of data at B<indata> using
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B<key> and places the result at B<outdata>. Repeated RC4() calls with
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the same B<key> yield a continuous key stream.
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Since RC4 is a stream cipher (the input is XORed with a pseudo-random
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key stream to produce the output), decryption uses the same function
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calls as encryption.
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=head1 RETURN VALUES
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RC4_set_key() and RC4() do not return values.
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=head1 NOTE
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Applications should use the higher level functions
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L<EVP_EncryptInit(3)> etc. instead of calling these
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functions directly.
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It is difficult to securely use stream ciphers. For example, do not perform
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multiple encryptions using the same key stream.
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=head1 SEE ALSO
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L<EVP_EncryptInit(3)>
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=head1 HISTORY
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All of these functions were deprecated in OpenSSL 3.0.
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=head1 COPYRIGHT
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Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
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Licensed under the Apache License 2.0 (the "License"). You may not use
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this file except in compliance with the License. You can obtain a copy
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in the file LICENSE in the source distribution or at
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L<https://www.openssl.org/source/license.html>.
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=cut
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