feat(fips): restrict supported tls curve types in fips mode (#294)

* feat(fips): restrict supported tls curve types in fips mode

match NIST SP 800-52r2 approved list

* Update types_test.go

* Update tls_test.go

* Update server_config_test.go

Author: kruskall

transport/tlscommon/config.go

@@ -103,6 +103,11 @@ func (c *Config) Validate() error {
 			return err
 		}
 	}
+	for _, ct := range c.CurveTypes {
+		if err := ct.Validate(); err != nil {
+			return err
+		}
+	}
 	return c.Certificate.Validate()
 }
 

transport/tlscommon/server_config_test.go

@@ -113,7 +113,7 @@ func Test_ServerConfig_Repack(t *testing.T) {
     certificate: /path/to/cert.cry
     key: /path/to/key/crt
     curve_types:
-      - P-521
+      - P-384
     client_authentication: optional
     ca_sha256:
       - example`,
@@ -131,7 +131,7 @@ func Test_ServerConfig_Repack(t *testing.T) {
     certificate: /path/to/cert.cry
     key: /path/to/key/crt
     curve_types:
-      - P-521
+      - P-384
     ca_sha256:
       - example`,
 		auth: &required,
@@ -146,7 +146,7 @@ func Test_ServerConfig_Repack(t *testing.T) {
     certificate: /path/to/cert.cry
     key: /path/to/key/crt
     curve_types:
-      - P-521
+      - P-384
     ca_sha256:
       - example`,
 		auth: nil,
@@ -190,7 +190,7 @@ func Test_ServerConfig_RepackJSON(t *testing.T) {
     "certificate_authorities": ["/path/to/ca.crt"],
     "certificate": "/path/to/cert.crt",
     "key": "/path/to/key.crt",
-    "curve_types": "P-521",
+    "curve_types": "P-384",
     "renegotiation": "freely",
     "ca_sha256": ["example"],
     "ca_trusted_fingerprint": "fingerprint",
@@ -207,7 +207,7 @@ func Test_ServerConfig_RepackJSON(t *testing.T) {
     "certificate_authorities": ["/path/to/ca.crt"],
     "certificate": "/path/to/cert.crt",
     "key": "/path/to/key.crt",
-    "curve_types": "P-521",
+    "curve_types": "P-384",
     "renegotiation": "freely",
     "ca_sha256": ["example"],
     "ca_trusted_fingerprint": "fingerprint"
@@ -222,7 +222,7 @@ func Test_ServerConfig_RepackJSON(t *testing.T) {
     "cipher_suites": ["RSA-AES-256-CBC-SHA"],
     "certificate": "/path/to/cert.crt",
     "key": "/path/to/key.crt",
-    "curve_types": "P-521",
+    "curve_types": "P-384",
     "renegotiation": "freely",
     "ca_sha256": ["example"]
     }`,

transport/tlscommon/tls_test.go

@@ -78,7 +78,7 @@ func TestValuesSet(t *testing.T) {
       - ECDHE-ECDSA-AES-256-GCM-SHA384
     supported_protocols: [TLSv1.3]
     curve_types:
-      - P-521
+      - P-384
     renegotiation: freely
   `)
 

transport/tlscommon/types.go

@@ -96,6 +96,7 @@ func init() {
 	}
 }
 
+var supportedCurveTypes = make(map[tlsCurveType]string, len(tlsCurveTypes))
 var tlsCurveTypes = map[string]tlsCurveType{
 	"P-256":  tlsCurveType(tls.CurveP256),
 	"P-384":  tlsCurveType(tls.CurveP384),
@@ -292,6 +293,13 @@ func (ct *tlsCurveType) Unpack(i interface{}) error {
 	return nil
 }
 
+func (ct *tlsCurveType) Validate() error {
+	if _, ok := supportedCurveTypes[*ct]; !ok {
+		return fmt.Errorf("unsupported curve type: %s", tls.CurveID(*ct).String())
+	}
+	return nil
+}
+
 type TLSRenegotiationSupport tls.RenegotiationSupport
 
 func (r TLSRenegotiationSupport) String() string {

transport/tlscommon/types_fips.go

@@ -37,4 +37,11 @@ func init() {
 			supportedCipherSuites[i] = cipherName
 		}
 	}
+	// only allow P256, P384.
+	for name, curveType := range tlsCurveTypes {
+		switch tls.CurveID(curveType) {
+		case tls.CurveP256, tls.CurveP384:
+			supportedCurveTypes[curveType] = name
+		}
+	}
 }

transport/tlscommon/types_fips_test.go

@@ -53,3 +53,19 @@ func TestLoadUnsupportedCiphers(t *testing.T) {
 	assert.ErrorContains(t, err, "unsupported tls cipher suite: TLS_RSA_WITH_AES_256_CBC_SHA")
 	assert.Nil(t, cfg)
 }
+
+func TestLoadUnsupportedCurveTypes(t *testing.T) {
+	cfg, err := load(`
+    enabled: true
+    certificate: mycert.pem
+    key: mycert.key
+    verification_mode: ""
+    supported_protocols: [TLSv1.2, TLSv1.3]
+    curve_types:
+      - X25519
+    renegotiation: freely
+  `)
+
+	assert.ErrorContains(t, err, "unsupported curve type: X25519")
+	assert.Nil(t, cfg)
+}

transport/tlscommon/types_nofips.go

@@ -24,4 +24,7 @@ func init() {
 	for cipherName, i := range tlsCipherSuites {
 		supportedCipherSuites[i] = cipherName
 	}
+	for name, curveType := range tlsCurveTypes {
+		supportedCurveTypes[curveType] = name
+	}
 }

transport/tlscommon/types_test.go

@@ -78,7 +78,7 @@ func TestLoadWithEmptyVerificationMode(t *testing.T) {
     verification_mode:
     supported_protocols: [TLSv1.2, TLSv1.3]
     curve_types:
-      - P-521
+      - P-384
     renegotiation: freely
   `)
 
@@ -98,7 +98,7 @@ func TestRepackConfig(t *testing.T) {
     certificate: /path/to/cert.crt
     key: /path/to/key.crt
     curve_types:
-      - P-521
+      - P-384
     renegotiation: freely
     ca_sha256:
       - example
@@ -125,7 +125,7 @@ func TestRepackConfigFromJSON(t *testing.T) {
     "certificate_authorities": ["/path/to/ca.crt"],
     "certificate": "/path/to/cert.crt",
     "key": "/path/to/key.crt",
-    "curve_types": "P-521",
+    "curve_types": "P-384",
     "renegotiation": "freely",
     "ca_sha256": ["example"],
     "ca_trusted_fingerprint": "fingerprint"