NAME

       EVP_MD-BLAKE2 - The BLAKE2 EVP_MD implementation

DESCRIPTION

       Support for computing BLAKE2 digests through the EVP_MD API.

   Identities
       This implementation is only available with the default provider, and includes the
       following varieties:

       BLAKE2S-256
           Known names are "BLAKE2S-256" and "BLAKE2s256".

       BLAKE2B-512
           Known names are "BLAKE2B-512" and "BLAKE2b512".

   Settable Parameters
       "BLAKE2B-512" supports the following EVP_MD_CTX_set_params() key described in
       "PARAMETERS" in EVP_DigestInit(3).

       "xoflen" (OSSL_DIGEST_PARAM_XOFLEN) <unsigned integer>

   Gettable Parameters
       This implementation supports the common gettable parameters described in EVP_MD-common(7).

   Settable Context Parameters
       The implementation supports the following OSSL_PARAM(3) entries which are settable for an
       EVP_MD_CTX with EVP_DigestInit_ex2(3) or EVP_MD_CTX_set_params(3):

       "size" (OSSL_DIGEST_PARAM_SIZE) <unsigned integer>
           Sets a different digest length for the EVP_DigestFinal(3) output.  The value of the
           "size" parameter must not exceed the default digest length of the respective BLAKE2
           algorithm variants, 64 for BLAKE2B-512 and 32 for BLAKE2S-256. The parameter must be
           set with the EVP_DigestInit_ex2(3) call to have an immediate effect. When set with
           EVP_MD_CTX_set_params(3) it will have an effect only if the EVP_MD_CTX context is
           reinitialized.

SEE ALSO

       provider-digest(7), OSSL_PROVIDER-default(7)

HISTORY

       This functionality was added in OpenSSL 3.0.

       The variable size support was added in OpenSSL 3.2 for BLAKE2B-512 and in OpenSSL 3.3 for
       BLAKE2S-256.

COPYRIGHT

       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>.