--- /dev/null
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+ "crypto/ecdsa"
++ "crypto/internal/boring"
+ "crypto/internal/boring/fipstls"
+ "crypto/rsa"
+ "crypto/x509"
+)
+
++// boringEnabled is an alias of boring.Enabled to avoid a new import in common.go.
++const boringEnabled = boring.Enabled
++
+// needFIPS returns fipstls.Required(); it avoids a new import in common.go.
+func needFIPS() bool {
+ return fipstls.Required()
+}
+
+// fipsMinVersion replaces c.minVersion in FIPS-only mode.
+func fipsMinVersion(c *Config) uint16 {
+ // FIPS requires TLS 1.2.
+ return VersionTLS12
+}
+
+// fipsMaxVersion replaces c.maxVersion in FIPS-only mode.
+func fipsMaxVersion(c *Config) uint16 {
+ // FIPS requires TLS 1.2.
+ return VersionTLS12
+}
+
+// default defaultFIPSCurvePreferences is the FIPS-allowed curves,
+// in preference order (most preferable first).
+var defaultFIPSCurvePreferences = []CurveID{CurveP256, CurveP384, CurveP521}
+
+// fipsCurvePreferences replaces c.curvePreferences in FIPS-only mode.
+func fipsCurvePreferences(c *Config) []CurveID {
+ if c == nil || len(c.CurvePreferences) == 0 {
+ return defaultFIPSCurvePreferences
+ }
+ var list []CurveID
+ for _, id := range c.CurvePreferences {
+ for _, allowed := range defaultFIPSCurvePreferences {
+ if id == allowed {
+ list = append(list, id)
+ break
+ }
+ }
+ }
+ return list
+}
+
+// default FIPSCipherSuites is the FIPS-allowed cipher suites,
+// in preference order (most preferable first).
+var defaultFIPSCipherSuites = []uint16{
+ TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+ TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+ TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+ TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+ TLS_RSA_WITH_AES_128_GCM_SHA256,
+ TLS_RSA_WITH_AES_256_GCM_SHA384,
+}
+
+// fipsCipherSuites replaces c.cipherSuites in FIPS-only mode.
+func fipsCipherSuites(c *Config) []uint16 {
+ if c == nil || c.CipherSuites == nil {
+ return defaultFIPSCipherSuites
+ }
+ var list []uint16
+ for _, id := range c.CipherSuites {
+ for _, allowed := range defaultFIPSCipherSuites {
+ if id == allowed {
+ list = append(list, id)
+ break
+ }
+ }
+ }
+ return list
+}
+
+// isBoringCertificate reports whether a certificate may be used
+// when constructing a verified chain.
+// It is called for each leaf, intermediate, and root certificate.
+func isBoringCertificate(c *x509.Certificate) bool {
+ if !needFIPS() {
+ // Everything is OK if we haven't forced FIPS-only mode.
+ return true
+ }
+
+ // Otherwise the key must be RSA 2048, RSA 3072, or ECDSA P-256.
+ switch k := c.PublicKey.(type) {
+ default:
+ return false
+ case *rsa.PublicKey:
+ if size := k.N.BitLen(); size != 2048 && size != 3072 {
+ return false
+ }
+ case *ecdsa.PublicKey:
+ if name := k.Curve.Params().Name; name != "P-256" && name != "P-384" {
+ return false
+ }
+ }
+
+ return true
+}
+
+// fipsSupportedSignatureAlgorithms currently are a subset of
+// defaultSupportedSignatureAlgorithms without Ed25519 and SHA-1.
+var fipsSupportedSignatureAlgorithms = []SignatureScheme{
+ PSSWithSHA256,
+ PSSWithSHA384,
+ PSSWithSHA512,
+ PKCS1WithSHA256,
+ ECDSAWithP256AndSHA256,
+ PKCS1WithSHA384,
+ ECDSAWithP384AndSHA384,
+ PKCS1WithSHA512,
+ ECDSAWithP521AndSHA512,
+}
+
+// supportedSignatureAlgorithms returns the supported signature algorithms.
+func supportedSignatureAlgorithms() []SignatureScheme {
+ if !needFIPS() {
+ return defaultSupportedSignatureAlgorithms
+ }
+ return fipsSupportedSignatureAlgorithms
+}
+
+var testingOnlyForceClientHelloSignatureAlgorithms []SignatureScheme