From 4da1f86d94fe1236701fd2dd07be5a170cde7312 Mon Sep 17 00:00:00 2001 From: Roland Shoemaker Date: Thu, 18 Jan 2024 12:51:13 -0800 Subject: [PATCH] [release-branch.go1.22] crypto/x509: make sure pub key is non-nil before interface conversion alreadyInChain assumes all keys fit a interface which contains the Equal method (which they do), but this ignores that certificates may have a nil key when PublicKeyAlgorithm is UnknownPublicKeyAlgorithm. In this case alreadyInChain panics. Check that the key is non-nil as part of considerCandidate (we are never going to build a chain containing UnknownPublicKeyAlgorithm anyway). For #65390 Fixes #65831 Fixes CVE-2024-24783 Change-Id: Ibdccc0a487e3368b6812be35daad2512220243f3 Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2137282 Reviewed-by: Damien Neil Run-TryBot: Roland Shoemaker Reviewed-by: Tatiana Bradley Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2174343 Reviewed-by: Carlos Amedee Reviewed-by: Roland Shoemaker Reviewed-on: https://go-review.googlesource.com/c/go/+/569235 LUCI-TryBot-Result: Go LUCI Auto-Submit: Michael Knyszek Reviewed-by: Carlos Amedee --- src/crypto/x509/verify.go | 2 +- src/crypto/x509/verify_test.go | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/src/crypto/x509/verify.go b/src/crypto/x509/verify.go index 9d3c3246d3098d..6efbff28bf7b6e 100644 --- a/src/crypto/x509/verify.go +++ b/src/crypto/x509/verify.go @@ -899,7 +899,7 @@ func (c *Certificate) buildChains(currentChain []*Certificate, sigChecks *int, o ) considerCandidate := func(certType int, candidate potentialParent) { - if alreadyInChain(candidate.cert, currentChain) { + if candidate.cert.PublicKey == nil || alreadyInChain(candidate.cert, currentChain) { return } diff --git a/src/crypto/x509/verify_test.go b/src/crypto/x509/verify_test.go index 861d2b389064ba..8a7a5f6e2c6d45 100644 --- a/src/crypto/x509/verify_test.go +++ b/src/crypto/x509/verify_test.go @@ -2792,3 +2792,22 @@ func TestVerifyEKURootAsLeaf(t *testing.T) { } } + +func TestVerifyNilPubKey(t *testing.T) { + c := &Certificate{ + RawIssuer: []byte{1, 2, 3}, + AuthorityKeyId: []byte{1, 2, 3}, + } + opts := &VerifyOptions{} + opts.Roots = NewCertPool() + r := &Certificate{ + RawSubject: []byte{1, 2, 3}, + SubjectKeyId: []byte{1, 2, 3}, + } + opts.Roots.AddCert(r) + + _, err := c.buildChains([]*Certificate{r}, nil, opts) + if _, ok := err.(UnknownAuthorityError); !ok { + t.Fatalf("buildChains returned unexpected error, got: %v, want %v", err, UnknownAuthorityError{}) + } +}