Switch NIST PDFs from nvlpubs to csrc which is HTTPS (#3929)
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index e27490d..aa63278 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -521,7 +521,7 @@
.. _`NESSIE IDEA vectors`: https://www.cosic.esat.kuleuven.be/nessie/testvectors/bc/idea/Idea-128-64.verified.test-vectors
.. _`NESSIE`: https://en.wikipedia.org/wiki/NESSIE
.. _`Ed25519 website`: https://ed25519.cr.yp.to/software.html
-.. _`NIST SP-800-38B`: http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38b.pdf
+.. _`NIST SP-800-38B`: https://csrc.nist.gov/publications/detail/sp/800-38b/archive/2005-05-01
.. _`NIST PKI Testing`: https://csrc.nist.gov/Projects/PKI-Testing
.. _`testx509.pem`: https://github.com/openssl/openssl/blob/master/test/testx509.pem
.. _`DigiCert Global Root G3`: http://cacerts.digicert.com/DigiCertGlobalRootG3.crt