Gitweb:
https://git.exim.org/exim.git/commitdiff/e34d3c68f457d4ca8238a604aff4bfe8727ebe0d
Commit: e34d3c68f457d4ca8238a604aff4bfe8727ebe0d
Parent: a92592c77ed477aff76b59881f68cbc4b2a13112
Author: Jeremy Harris <jgh146exb@???>
AuthorDate: Sat Jan 14 13:14:15 2023 +0000
Committer: Jeremy Harris <jgh146exb@???>
CommitDate: Sat Jan 14 13:14:15 2023 +0000
Docs: expand OCSP description
---
doc/doc-docbook/spec.xfpt | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 49ec9fd4e..6545d091b 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -30000,10 +30000,13 @@ file from every certificate authority they know of.
.next
The way with most moving parts at query time is Online Certificate
Status Protocol (OCSP), where the client verifies the certificate
-against an OCSP server run by the CA. This lets the CA track all
-usage of the certs. It requires running software with access to the
-private key of the CA, to sign the responses to the OCSP queries. OCSP
-is based on HTTP and can be proxied accordingly.
+against an OCSP server run by the CA.
+OCSP is based on HTTP and can be proxied accordingly.
+It requires the CA running software with access to the
+private key of the CA, to sign the responses to the OCSP queries.
+Because every client TLS transaction with a server results in an OCSP
+access to the CA, it results in a heavy load on the CA.
+It also lets the CA track all usage of the certs, which is a privacy problem.
The only widespread OCSP server implementation (known to this writer)
comes as part of OpenSSL and aborts on an invalid request, such as
@@ -30013,7 +30016,8 @@ re-entering the passphrase each time some random client does this.
.next
The third way is OCSP Stapling; in this, the server using a certificate
issued by the CA periodically requests an OCSP proof of validity from
-the OCSP server, then serves it up inline as part of the TLS
+the OCSP server (probably using the original OCSP above),
+then serves it up inline as part of the TLS
negotiation. This approach adds no extra round trips, does not let the
CA track users, scales well with number of certs issued by the CA and is
resilient to temporary OCSP server failures, as long as the server
