1RC4_SET_KEY(3) OpenSSL RC4_SET_KEY(3)
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6 RC4_set_key, RC4 - RC4 encryption
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9 #include <openssl/rc4.h>
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11 void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data);
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13 void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata,
14 unsigned char *outdata);
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17 This library implements the Alleged RC4 cipher, which is described for
18 example in Applied Cryptography. It is believed to be compatible with
19 RC4[TM], a proprietary cipher of RSA Security Inc.
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21 RC4 is a stream cipher with variable key length. Typically, 128 bit
22 (16 byte) keys are used for strong encryption, but shorter insecure key
23 sizes have been widely used due to export restrictions.
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25 RC4 consists of a key setup phase and the actual encryption or
26 decryption phase.
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28 RC4_set_key() sets up the RC4_KEY key using the len bytes long key at
29 data.
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31 RC4() encrypts or decrypts the len bytes of data at indata using key
32 and places the result at outdata. Repeated RC4() calls with the same
33 key yield a continuous key stream.
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35 Since RC4 is a stream cipher (the input is XORed with a pseudo-random
36 key stream to produce the output), decryption uses the same function
37 calls as encryption.
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40 RC4_set_key() and RC4() do not return values.
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43 Applications should use the higher level functions EVP_EncryptInit(3)
44 etc. instead of calling these functions directly.
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46 It is difficult to securely use stream ciphers. For example, do not
47 perform multiple encryptions using the same key stream.
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50 EVP_EncryptInit(3)
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53 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
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55 Licensed under the OpenSSL license (the "License"). You may not use
56 this file except in compliance with the License. You can obtain a copy
57 in the file LICENSE in the source distribution or at
58 <https://www.openssl.org/source/license.html>.
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621.1.1q 2023-07-20 RC4_SET_KEY(3)