This implements RFC 9155 by removing support for SHA-1 algorithms:
- we don't advertise them in ClientHello and CertificateRequest
(where supportedSignatureAlgorithms is used directly)
- we don't select them in our ServerKeyExchange and CertificateVerify
(where supportedSignatureAlgorithms filters signatureSchemesForCertificate)
- we reject them in the peer's ServerKeyExchange and CertificateVerify
(where we check against the algorithms we advertised in ClientHello
and CertificateRequest)
Fixes#72883
Change-Id: I6a6a4656e2aafd2c38cdd32090d3d8a9a8047818
Reviewed-on: https://go-review.googlesource.com/c/go/+/658216
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
If a ClientHello only supports TLS 1.3, or if a CertificateRequest is
sent after selecting TLS 1.3, we should not advertise TLS 1.2-only
signature_algorithms like PKCS#1 v1.5 or SHA-1.
However, since crypto/x509 still supports PKCS#1 v1.5, and a direct
CertPool match might not care about the signature in the certificate at
all, start sending a separate signature_algorithms_cert extension to
indicate support for PKCS#1 v1.5 and SHA-1 in certificates.
We were already correctly rejecting these algorithms if the peer
selected them in a TLS 1.3 connection.
Updates #72883
Change-Id: I6a6a4656ab60e1b7fb20fdedc32604dc156953ae
Reviewed-on: https://go-review.googlesource.com/c/go/+/658215
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
yuhan6665