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).

"size" (OSSL_DIGEST_PARAM_SIZE) <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.

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

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>.