http2: remove TLSConfig.CipherSuites order check
The order of CipherSuites is ignored as of Go 1.17, and the effective
order will always put good ciphers first, as tested by TestCipherSuites
in crypto/tls.
Updates golang/go#45430
Change-Id: I54424f68bffe805f504b57eb025601c08c6357f6
Reviewed-on: https://go-review.googlesource.com/c/net/+/314611
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
diff --git a/http2/server.go b/http2/server.go
index e125bbd..5ad3a2d 100644
--- a/http2/server.go
+++ b/http2/server.go
@@ -231,13 +231,12 @@
if s.TLSConfig == nil {
s.TLSConfig = new(tls.Config)
- } else if s.TLSConfig.CipherSuites != nil {
- // If they already provided a CipherSuite list, return
- // an error if it has a bad order or is missing
- // ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
+ } else if s.TLSConfig.CipherSuites != nil && s.TLSConfig.MinVersion < tls.VersionTLS13 {
+ // If they already provided a TLS 1.0–1.2 CipherSuite list, return an
+ // error if it is missing ECDHE_RSA_WITH_AES_128_GCM_SHA256 or
+ // ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
haveRequired := false
- sawBad := false
- for i, cs := range s.TLSConfig.CipherSuites {
+ for _, cs := range s.TLSConfig.CipherSuites {
switch cs {
case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
// Alternative MTI cipher to not discourage ECDSA-only servers.
@@ -245,14 +244,9 @@
tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
haveRequired = true
}
- if isBadCipher(cs) {
- sawBad = true
- } else if sawBad {
- return fmt.Errorf("http2: TLSConfig.CipherSuites index %d contains an HTTP/2-approved cipher suite (%#04x), but it comes after unapproved cipher suites. With this configuration, clients that don't support previous, approved cipher suites may be given an unapproved one and reject the connection.", i, cs)
- }
}
if !haveRequired {
- return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).")
+ return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)")
}
}
diff --git a/http2/server_test.go b/http2/server_test.go
index 10a7f7e..a543b2b 100644
--- a/http2/server_test.go
+++ b/http2/server_test.go
@@ -3386,6 +3386,17 @@
name: "empty server",
},
{
+ name: "empty CipherSuites",
+ tlsConfig: &tls.Config{},
+ },
+ {
+ name: "bad CipherSuites but MinVersion TLS 1.3",
+ tlsConfig: &tls.Config{
+ MinVersion: tls.VersionTLS13,
+ CipherSuites: []uint16{tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384},
+ },
+ },
+ {
name: "just the required cipher suite",
tlsConfig: &tls.Config{
CipherSuites: []uint16{tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
@@ -3409,7 +3420,6 @@
tlsConfig: &tls.Config{
CipherSuites: []uint16{tls.TLS_RSA_WITH_RC4_128_SHA, tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
},
- wantErr: "contains an HTTP/2-approved cipher suite (0xc02f), but it comes after",
},
{
name: "bad after required",
