From: Gabor Tanz <gabor.tanz@swisscom.com>
Date: Fri, 18 Nov 2022 07:59:03 +0000 (+0000)
Subject: crypto/tls: add CertificateVerificationError to tls handshake
X-Git-Tag: go1.20rc1~160
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f64c2a2ce5dc859315047184e310879dcf747d53;p=gostls13.git

crypto/tls: add CertificateVerificationError to tls handshake

Fixes #48152

Change-Id: I503f088edeb5574fd5eb5905bff7c3c23b2bc8fc
GitHub-Last-Rev: 2b0e982f3f6bca33062b0bbd64ed1804801e2c13
GitHub-Pull-Request: golang/go#56686
Reviewed-on: https://go-review.googlesource.com/c/go/+/449336
Run-TryBot: Roland Shoemaker <roland@golang.org>
Auto-Submit: Roland Shoemaker <roland@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Julie Qiu <julieqiu@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
---

diff --git a/api/next/48152.txt b/api/next/48152.txt
new file mode 100644
index 0000000000..9ff5f995cf
--- /dev/null
+++ b/api/next/48152.txt
@@ -0,0 +1,5 @@
+pkg crypto/tls, type CertificateVerificationError struct #48152
+pkg crypto/tls, type CertificateVerificationError struct, UnverifiedCertificates []*x509.Certificate #48152
+pkg crypto/tls, type CertificateVerificationError struct, Err error #48152
+pkg crypto/tls, method (*CertificateVerificationError) Error() string #48152
+pkg crypto/tls, method (*CertificateVerificationError) Unwrap() error #48152
diff --git a/src/crypto/tls/common.go b/src/crypto/tls/common.go
index 62324de513..007f0f47b2 100644
--- a/src/crypto/tls/common.go
+++ b/src/crypto/tls/common.go
@@ -1493,3 +1493,18 @@ func isSupportedSignatureAlgorithm(sigAlg SignatureScheme, supportedSignatureAlg
 	}
 	return false
 }
+
+// CertificateVerificationError is returned when certificate verification fails during the handshake.
+type CertificateVerificationError struct {
+	// UnverifiedCertificates and its contents should not be modified.
+	UnverifiedCertificates []*x509.Certificate
+	Err                    error
+}
+
+func (e *CertificateVerificationError) Error() string {
+	return fmt.Sprintf("tls: failed to verify certificate: %s", e.Err)
+}
+
+func (e *CertificateVerificationError) Unwrap() error {
+	return e.Err
+}
diff --git a/src/crypto/tls/handshake_client.go b/src/crypto/tls/handshake_client.go
index 2e3b693199..7cf906c91d 100644
--- a/src/crypto/tls/handshake_client.go
+++ b/src/crypto/tls/handshake_client.go
@@ -876,7 +876,7 @@ func (c *Conn) verifyServerCertificate(certificates [][]byte) error {
 		c.verifiedChains, err = certs[0].Verify(opts)
 		if err != nil {
 			c.sendAlert(alertBadCertificate)
-			return err
+			return &CertificateVerificationError{UnverifiedCertificates: certs, Err: err}
 		}
 	}
 
diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go
index fc0a7ac13d..682cfc2061 100644
--- a/src/crypto/tls/handshake_server.go
+++ b/src/crypto/tls/handshake_server.go
@@ -831,7 +831,7 @@ func (c *Conn) processCertsFromClient(certificate Certificate) error {
 		chains, err := certs[0].Verify(opts)
 		if err != nil {
 			c.sendAlert(alertBadCertificate)
-			return errors.New("tls: failed to verify client certificate: " + err.Error())
+			return &CertificateVerificationError{UnverifiedCertificates: certs, Err: err}
 		}
 
 		c.verifiedChains = chains
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index b637e40cb4..c0cabccab8 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -4818,7 +4818,7 @@ func testTransportEventTraceTLSVerify(t *testing.T, mode testMode) {
 
 	wantOnce("TLSHandshakeStart")
 	wantOnce("TLSHandshakeDone")
-	wantOnce("err = x509: certificate is valid for example.com")
+	wantOnce("err = tls: failed to verify certificate: x509: certificate is valid for example.com")
 
 	if t.Failed() {
 		t.Errorf("Output:\n%s", got)