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 CFLAG when compiling PHP, and enable-md2 when compiling OpenSSL 1.0.0+.