1EVP_MD-SHAKE(7ossl)                 OpenSSL                EVP_MD-SHAKE(7ossl)
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NAME

6       EVP_MD-SHAKE, EVP_MD-KECCAK-KMAC - The SHAKE / KECCAK family EVP_MD
7       implementations
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DESCRIPTION

10       Support for computing SHAKE or KECCAK-KMAC digests through the EVP_MD
11       API.
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13       KECCAK-KMAC is a special digest that's used by the KMAC EVP_MAC
14       implementation (see EVP_MAC-KMAC(7)).
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16   Identities
17       This implementation is available in the FIPS provider as well as the
18       default provider, and includes the following varieties:
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20       KECCAK-KMAC-128
21           Known names are "KECCAK-KMAC-128" and "KECCAK-KMAC128" This is used
22           by EVP_MAC-KMAC128(7)
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24       KECCAK-KMAC-256
25           Known names are "KECCAK-KMAC-256" and "KECCAK-KMAC256" This is used
26           by EVP_MAC-KMAC256(7)
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28       SHAKE-128
29           Known names are "SHAKE-128" and "SHAKE128"
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31       SHAKE-256
32           Known names are "SHAKE-256" and "SHAKE256"
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34   Gettable Parameters
35       This implementation supports the common gettable parameters described
36       in EVP_MD-common(7).
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38   Settable Context Parameters
39       These implementations support the following OSSL_PARAM(3) entries,
40       settable for an EVP_MD_CTX with EVP_MD_CTX_set_params(3):
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42       "xoflen" (OSSL_DIGEST_PARAM_XOFLEN) <unsigned integer>
43           Sets the digest length for extendable output functions.  The length
44           of the "xoflen" parameter should not exceed that of a size_t.
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46           For backwards compatibility reasons the default xoflen length for
47           SHAKE-128 is 16 (bytes) which results in a security strength of
48           only 64 bits. To ensure the maximum security strength of 128 bits,
49           the xoflen should be set to at least 32.
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51           For backwards compatibility reasons the default xoflen length for
52           SHAKE-256 is 32 (bytes) which results in a security strength of
53           only 128 bits. To ensure the maximum security strength of 256 bits,
54           the xoflen should be set to at least 64.
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SEE ALSO

57       EVP_MD_CTX_set_params(3), provider-digest(7), OSSL_PROVIDER-default(7)
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60       Copyright 2020-2022 The OpenSSL Project Authors. All Rights Reserved.
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62       Licensed under the Apache License 2.0 (the "License").  You may not use
63       this file except in compliance with the License.  You can obtain a copy
64       in the file LICENSE in the source distribution or at
65       <https://www.openssl.org/source/license.html>.
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693.0.9                             2023-07-27               EVP_MD-SHAKE(7ossl)
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