OPENSSL_ALGO_DSS1
(int)
OPENSSL_ALGO_SHA1
(int)
OPENSSL_ALGO_SHA224
(int)
OPENSSL_ALGO_SHA256
(int)
OPENSSL_ALGO_SHA384
(int)
OPENSSL_ALGO_SHA512
(int)
OPENSSL_ALGO_RMD160
(int)
OPENSSL_ALGO_MD5
(int)
OPENSSL_ALGO_MD4
(int)
OPENSSL_ALGO_MD2
(int)
-DHAVE_OPENSSL_MD2_H
и включить enable-md2 при компиляции OpenSSL 1.0.0+.
It should be noted that the default signature algorithm used by openssl_sign() and openssl_verify (OPENSSL_ALGO_SHA1) is no longer supported by default in OpenSSL Version 3 series.
With an up to date OpenSSL library, one has to run
"update-crypto-policies --set LEGACY"
on the server where the library resides in order to allow these functions to work without the optional alternative algorithm argument.