EVP_MAC-Siphash(7ssl)

EVP_MAC-Siphash7ssl

The siphash evp_mac implementation

Overview

Support for computing Siphash MACs through the EVP_MAC API.

Identity

This implementation is identified with this name and properties, to be used with EVP_MAC_fetch():

"SIPHASH", "provider=default"

Supported parameters

The general description of these parameters can be found in "PARAMETERS" in EVP_MAC(3).

All these parameters can be set with EVP_MAC_CTX_set_params(). Furthermore, the "size" parameter can be retrieved with EVP_MAC_CTX_get_params(), or with EVP_MAC_CTX_get_mac_size(). The length of the "size" parameter should not exceed that of a size_t.

"key" (OSSL_MAC_PARAM_KEY) <octet string>

Sets the MAC key. Setting this parameter is identical to passing a key to EVP_MAC_init(3).

"size" (OSSL_MAC_PARAM_SIZE) <unsigned integer>

Sets the MAC size.

"c-rounds" (OSSL_MAC_PARAM_C_ROUNDS) <unsigned integer>

Specifies the number of rounds per message block. By default this is 2.

"d-rounds" (OSSL_MAC_PARAM_D_ROUNDS) <unsigned integer>

Specifies the number of finalisation rounds. By default this is 4.

Releases

3 releases since Debian 12 (Bookworm); the text changed 2 times.

  1. 12
  2. 13
  3. Arch

From openssl 3.6.5-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.