Merge pull request #109 from golang-fips/tlsprf

Add `label` parameter to TLS1PRF

Author: qmuntal

tls1prf.go

@@ -16,7 +16,7 @@ func SupportsTLS1PRF() bool {
 		(vMajor >= 1 && vMinor >= 1 && vPatch >= 1)
 }
 
-func TLS1PRF(secret, seed []byte, keyLen int, h func() hash.Hash) ([]byte, error) {
+func TLS1PRF(secret, label, seed []byte, keyLen int, h func() hash.Hash) ([]byte, error) {
 	ch := h()
 	md := hashToMD(ch)
 	if md == nil {
@@ -43,6 +43,10 @@ func TLS1PRF(secret, seed []byte, keyLen int, h func() hash.Hash) ([]byte, error
 			base(secret), C.int(len(secret))) != 1 {
 			return nil, newOpenSSLError("EVP_PKEY_CTX_set1_tls1_prf_secret")
 		}
+		if C.go_openssl_EVP_PKEY_CTX_add1_tls1_prf_seed(ctx,
+			base(label), C.int(len(label))) != 1 {
+			return nil, newOpenSSLError("EVP_PKEY_CTX_add1_tls1_prf_seed")
+		}
 		if C.go_openssl_EVP_PKEY_CTX_add1_tls1_prf_seed(ctx,
 			base(seed), C.int(len(seed))) != 1 {
 			return nil, newOpenSSLError("EVP_PKEY_CTX_add1_tls1_prf_seed")
@@ -60,6 +64,12 @@ func TLS1PRF(secret, seed []byte, keyLen int, h func() hash.Hash) ([]byte, error
 			C.int(len(secret)), unsafe.Pointer(base(secret))) != 1 {
 			return nil, newOpenSSLError("EVP_PKEY_CTX_set1_tls1_prf_secret")
 		}
+		if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, -1,
+			C.GO1_EVP_PKEY_OP_DERIVE,
+			C.GO_EVP_PKEY_CTRL_TLS_SEED,
+			C.int(len(label)), unsafe.Pointer(base(label))) != 1 {
+			return nil, newOpenSSLError("EVP_PKEY_CTX_add1_tls1_prf_seed")
+		}
 		if C.go_openssl_EVP_PKEY_CTX_ctrl(ctx, -1,
 			C.GO1_EVP_PKEY_OP_DERIVE,
 			C.GO_EVP_PKEY_CTRL_TLS_SEED,

tls1prf_test.go

@@ -13,6 +13,7 @@ import (
 type tls1prfTest struct {
 	hash   func() hash.Hash
 	secret []byte
+	label  []byte
 	seed   []byte
 	out    []byte
 }
@@ -27,7 +28,8 @@ var tls1prfTests = []tls1prfTest{
 		},
 		[]byte{
 			0x74, 0x65, 0x73, 0x74, 0x20, 0x6c, 0x61, 0x62,
-			0x65, 0x6c,
+			0x65, 0x6c},
+		[]byte{
 			0xa0, 0xba, 0x9f, 0x93, 0x6c, 0xda, 0x31, 0x18,
 			0x27, 0xa6, 0xf7, 0x96, 0xff, 0xd5, 0x19, 0x8c,
 		},
@@ -55,7 +57,8 @@ var tls1prfTests = []tls1prfTest{
 		},
 		[]byte{
 			0x74, 0x65, 0x73, 0x74, 0x20, 0x6c, 0x61, 0x62,
-			0x65, 0x6c,
+			0x65, 0x6c},
+		[]byte{
 			0xcd, 0x66, 0x5c, 0xf6, 0xa8, 0x44, 0x7d, 0xd6,
 			0xff, 0x8b, 0x27, 0x55, 0x5e, 0xdb, 0x74, 0x65,
 		},
@@ -90,6 +93,8 @@ var tls1prfTests = []tls1prfTest{
 		[]byte{
 			0x74, 0x65, 0x73, 0x74, 0x20, 0x6c, 0x61, 0x62,
 			0x65, 0x6c,
+		},
+		[]byte{
 			0xd4, 0x64, 0x0e, 0x12, 0xe4, 0xbc, 0xdb, 0xfb,
 			0x43, 0x7f, 0x03, 0xe6, 0xae, 0x41, 0x8e, 0xe5,
 		},
@@ -128,7 +133,7 @@ func TestTLS1PRF(t *testing.T) {
 		t.Skip("TLS 1.2 PRF is not supported")
 	}
 	for i, tt := range tls1prfTests {
-		out, err := openssl.TLS1PRF(tt.secret, tt.seed, len(tt.out), tt.hash)
+		out, err := openssl.TLS1PRF(tt.secret, tt.label, tt.seed, len(tt.out), tt.hash)
 		if err != nil {
 			t.Errorf("test %d: error deriving TLS 1.2 PRF: %v.", i, err)
 		}