In x509.h rev. 1.34 2018/02/22 16:50:30, jsing@ provided

In x509.h rev. 1.34 2018/02/22 16:50:30, jsing@ provided
X509_REQ_get_signature_nid(3), in rev. 1.36 2018/02/22 16:58:45
X509_CRL_get_signature_nid(3), and in rev. 1.40 2018/02/22 17:09:28
X509_get0_tbs_sigalg(3).  Merge the documentation from OpenSSL.