EVP_MD-SHAKE, EVP_MD-KECCAK-KMAC - The SHAKE / KECCAK family EVP_MD
implementations
Support for computing SHAKE or KECCAK-KMAC digests through the EVP_MD
API.
KECCAK-KMAC is a special digest that's used by the KMAC EVP_MAC
implementation (see EVP_MAC-KMAC(7)).
This implementation is available in the FIPS provider as well as the default
provider, and includes the following varieties:
- KECCAK-KMAC-128
- Known names are "KECCAK-KMAC-128" and "KECCAK-KMAC128"
This is used by EVP_MAC-KMAC128(7)
- KECCAK-KMAC-256
- Known names are "KECCAK-KMAC-256" and "KECCAK-KMAC256"
This is used by EVP_MAC-KMAC256(7)
- SHAKE-128
- Known names are "SHAKE-128" and "SHAKE128"
- SHAKE-256
- Known names are "SHAKE-256" and "SHAKE256"
This implementation supports the common gettable parameters described in
EVP_MD-common(7).
These implementations support the following OSSL_PARAM(3) entries,
settable for an EVP_MD_CTX with EVP_MD_CTX_set_params(3):
- "xoflen" (OSSL_DIGEST_PARAM_XOFLEN) <unsigned
integer>
- Sets the digest length for extendable output functions. The length of the
"xoflen" parameter should not exceed that of a size_t.
For backwards compatibility reasons the default xoflen length
for SHAKE-128 is 16 (bytes) which results in a security strength of only
64 bits. To ensure the maximum security strength of 128 bits, the xoflen
should be set to at least 32.
For backwards compatibility reasons the default xoflen length
for SHAKE-256 is 32 (bytes) which results in a security strength of only
128 bits. To ensure the maximum security strength of 256 bits, the
xoflen should be set to at least 64.
EVP_MD_CTX_set_params(3), provider-digest(7),
OSSL_PROVIDER-default(7)
Copyright 2020-2022 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License").
You may not use this file except in compliance with the License. You can
obtain a copy in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.