6f3aae256d
Reviewed-by: Tim Hudson <tjh@openssl.org> (Merged from https://github.com/openssl/openssl/pull/8780)
65 lines
1.5 KiB
Text
65 lines
1.5 KiB
Text
=pod
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=head1 NAME
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EVP_chacha20,
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EVP_chacha20_poly1305
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- EVP ChaCha20 stream cipher
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=head1 SYNOPSIS
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#include <openssl/evp.h>
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const EVP_CIPHER *EVP_chacha20(void)
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const EVP_CIPHER *EVP_chacha20_poly1305(void)
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=head1 DESCRIPTION
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The ChaCha20 stream cipher for EVP.
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=over 4
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=item EVP_chacha20()
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The ChaCha20 stream cipher. The key length is 256 bits, the IV is 128 bits long.
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The first 32 bits consists of a counter in little-endian order followed by a 96
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bit nonce. For example a nonce of:
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000000000000000000000002
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With an initial counter of 42 (2a in hex) would be expressed as:
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2a000000000000000000000000000002
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=item EVP_chacha20_poly1305()
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Authenticated encryption with ChaCha20-Poly1305. Like EVP_chacha20(), the key
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is 256 bits and the IV is 96 bits. This supports additional authenticated data
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(AAD) and produces a 128-bit authentication tag. See the
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L<EVP_EncryptInit(3)/AEAD Interface> section for more information.
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=back
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=head1 RETURN VALUES
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These functions return an B<EVP_CIPHER> structure that contains the
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implementation of the symmetric cipher. See L<EVP_CIPHER_meth_new(3)> for
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details of the B<EVP_CIPHER> structure.
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=head1 SEE ALSO
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L<evp(7)>,
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L<EVP_EncryptInit(3)>,
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L<EVP_CIPHER_meth_new(3)>
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=head1 COPYRIGHT
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Copyright 2017 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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