From 2883e0964c869f2657cb6e0cb517fbd96f4d9a92 Mon Sep 17 00:00:00 2001
From: "Tobias S. Josefowitz" <tobij@tobij.de>
Date: Mon, 24 Feb 2020 00:05:51 +0100
Subject: [PATCH] SSL: Do not accept MD2, MD5 and SHA1 signatures any longer
Web browsers and others have distrusted SHA1 a long while ago, MD2 and
MD5 are at this point simply dangerous to support. However, we now
support configuration of supported signature algorithms via
@[SSL.Context] in case any use case simply needs to support older
signature algorithms.
---
lib/modules/SSL.pmod/Connection.pike | 4 +++-
lib/modules/SSL.pmod/Context.pike | 16 ++++++++++++++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/lib/modules/SSL.pmod/Connection.pike b/lib/modules/SSL.pmod/Connection.pike
index 68e11dfc66..bdc53ecfd1 100644
--- a/lib/modules/SSL.pmod/Connection.pike
+++ b/lib/modules/SSL.pmod/Connection.pike
@@ -264,7 +264,9 @@ int verify_certificate_chain(array(string) certs)
mapping result =
Standards.X509.verify_certificate_chain(certs,
context->trusted_issuers_cache,
- context->require_trust);
+ context->require_trust,
+ ([ "verifier_algorithms"
+ : context->verifier_algorithms]));
// This data isn't actually used internally.
session->cert_data = result;
diff --git a/lib/modules/SSL.pmod/Context.pike b/lib/modules/SSL.pmod/Context.pike
index 7071d36073..3c916fa998 100644
--- a/lib/modules/SSL.pmod/Context.pike
+++ b/lib/modules/SSL.pmod/Context.pike
@@ -70,6 +70,22 @@ ProtocolVersion max_version = PROTOCOL_TLS_MAX;
//! protocol negotiation.
array(string(8bit)) advertised_protocols;
+//! Mapping of supported verifier algorithms to hash implementation.
+//!
+//! @seealso
+//! @[Standards.X509.get_algorithms()]
+mapping(Standards.ASN1.Types.Identifier:Crypto.Hash) verifier_algorithms
+= filter(Standards.X509.get_algorithms(),
+ lambda(object o) {
+ return !(<
+#if constant(Crypto.MD2)
+ Crypto.MD2,
+#endif
+ Crypto.MD5,
+ Crypto.SHA1
+ >)[o];
+});
+
//! The maximum amount of data that is sent in each SSL packet by
//! @[File]. A value between 1 and @[Constants.PACKET_MAX_SIZE].
int packet_max_size = PACKET_MAX_SIZE;
--
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