Fix broken links in the documentation (#611)

* Fix broken link described in #610

* Fix two other broken links
diff --git a/doc/api/crypto.rst b/doc/api/crypto.rst
index cac9dd9..525553f 100644
--- a/doc/api/crypto.rst
+++ b/doc/api/crypto.rst
@@ -319,7 +319,7 @@
 
 More information and a list of these digest names can be found in the ``EVP_DigestInit(3)`` man page of your OpenSSL installation.
 This page can be found online for the latest version of OpenSSL:
-https://www.openssl.org/docs/manmaster/crypto/EVP_DigestInit.html
+https://www.openssl.org/docs/manmaster/man3/EVP_DigestInit.html
 
 
 Backwards compatible type names