Gentoo's Bugzilla –
Attachment 387438 Details for
Bug 526920dev-lang/php-5.5.18 with dev-libs/openssl-1.0.2_pre20141024[-md4] - ext/openssl/.libs/openssl.o: In function `php_openssl_get_evp_md_from_algo': openssl.c:(.text+0x53ff): undefined reference to `EVP_md4'