diff --git a/internal/crypto/hkdf.go b/internal/crypto/hkdf.go index c43624bc1..4c6af2890 100644 --- a/internal/crypto/hkdf.go +++ b/internal/crypto/hkdf.go @@ -3,6 +3,7 @@ package crypto import ( "crypto" "crypto/hmac" + "encoding/binary" ) // copied from https://github.com/cloudflare/tls-tris/blob/master/hkdf.go @@ -17,3 +18,39 @@ func hkdfExtract(hash crypto.Hash, secret, salt []byte) []byte { extractor.Write(secret) return extractor.Sum(nil) } + +// copied from https://github.com/cloudflare/tls-tris/blob/master/hkdf.go +func hkdfExpand(hash crypto.Hash, prk, info []byte, l int) []byte { + var ( + expander = hmac.New(hash.New, prk) + res = make([]byte, l) + counter = byte(1) + prev []byte + ) + + if l > 255*expander.Size() { + panic("hkdf: requested too much output") + } + + p := res + for len(p) > 0 { + expander.Reset() + expander.Write(prev) + expander.Write(info) + expander.Write([]byte{counter}) + prev = expander.Sum(prev[:0]) + counter++ + n := copy(p, prev) + p = p[n:] + } + + return res +} + +func qhkdfExpand(secret []byte, label string, length int) []byte { + qlabel := make([]byte, 2+1+5+len(label)) + binary.BigEndian.PutUint16(qlabel[0:2], uint16(length)) + qlabel[2] = uint8(5 + len(label)) + copy(qlabel[3:], []byte("QUIC "+label)) + return hkdfExpand(crypto.SHA256, secret, qlabel, length) +} diff --git a/internal/crypto/hkdf_test.go b/internal/crypto/hkdf_test.go index 2bbd7f9ed..59340c135 100644 --- a/internal/crypto/hkdf_test.go +++ b/internal/crypto/hkdf_test.go @@ -3,16 +3,66 @@ package crypto import ( "bytes" "crypto" + "fmt" . "github.com/onsi/ginkgo" . "github.com/onsi/gomega" ) var _ = Describe("HKDF", func() { - // test case A.1 from https://tools.ietf.org/html/rfc5869 - It("extracts", func() { - salt := []byte{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc} - secret := bytes.Repeat([]byte{0x0b}, 22) - Expect(hkdfExtract(crypto.SHA256, secret, salt)).To(Equal([]byte{0x7, 0x77, 0x9, 0x36, 0x2c, 0x2e, 0x32, 0xdf, 0xd, 0xdc, 0x3f, 0xd, 0xc4, 0x7b, 0xba, 0x63, 0x90, 0xb6, 0xc7, 0x3b, 0xb5, 0xf, 0x9c, 0x31, 0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2, 0xb3, 0xe5})) - }) + type testcase struct { + name string + hash crypto.Hash + salt, secret, info, extracted, expanded []byte + } + // test cases taken from https://tools.ietf.org/html/rfc5869#appendix-A + testcases := []testcase{ + { + name: "RFC5869 A.1", + hash: crypto.SHA256, + salt: []byte{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc}, + secret: bytes.Repeat([]byte{0x0b}, 22), + info: []byte{0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9}, + extracted: []byte{0x7, 0x77, 0x9, 0x36, 0x2c, 0x2e, 0x32, 0xdf, 0xd, 0xdc, 0x3f, 0xd, 0xc4, 0x7b, 0xba, 0x63, 0x90, 0xb6, 0xc7, 0x3b, 0xb5, 0xf, 0x9c, 0x31, 0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2, 0xb3, 0xe5}, + expanded: []byte{0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a, 0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a, 0x2d, 0x2d, 0xa, 0x90, 0xcf, 0x1a, 0x5a, 0x4c, 0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf, 0x34, 0x0, 0x72, 0x8, 0xd5, 0xb8, 0x87, 0x18, 0x58, 0x65}, + }, + { + name: "RFC5869 A.2", + hash: crypto.SHA256, + salt: []byte{0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf}, + secret: []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f}, + info: []byte{0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff}, + extracted: []byte{0x6, 0xa6, 0xb8, 0x8c, 0x58, 0x53, 0x36, 0x1a, 0x6, 0x10, 0x4c, 0x9c, 0xeb, 0x35, 0xb4, 0x5c, 0xef, 0x76, 0x0, 0x14, 0x90, 0x46, 0x71, 0x1, 0x4a, 0x19, 0x3f, 0x40, 0xc1, 0x5f, 0xc2, 0x44}, + expanded: []byte{0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x3, 0x27, 0xa1, 0xc8, 0xe7, 0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34, 0x4f, 0x1, 0x2e, 0xda, 0x2d, 0x4e, 0xfa, 0xd8, 0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf, 0xa9, 0x7c, 0x59, 0x4, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72, 0x71, 0xcb, 0x41, 0xc6, 0x5e, 0x59, 0xe, 0x9, 0xda, 0x32, 0x75, 0x60, 0xc, 0x2f, 0x9, 0xb8, 0x36, 0x77, 0x93, 0xa9, 0xac, 0xa3, 0xdb, 0x71, 0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec, 0x3e, 0x87, 0xc1, 0x4c, 0x1, 0xd5, 0xc1, 0xf3, 0x43, 0x4f, 0x1d, 0x87}, + }, + { + name: "RFC5869 A.3", + hash: crypto.SHA256, + secret: bytes.Repeat([]byte{0x0b}, 22), + extracted: []byte{0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16, 0x7f, 0x33, 0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf, 0x96, 0x59, 0x67, 0x76, 0xaf, 0xdb, 0x63, 0x77, 0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c, 0xcb, 0x4}, + expanded: []byte{0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f, 0x71, 0x5f, 0x80, 0x2a, 0x6, 0x3c, 0x5a, 0x31, 0xb8, 0xa1, 0x1f, 0x5c, 0x5e, 0xe1, 0x87, 0x9e, 0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d, 0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a, 0x96, 0xc8}, + }, + { + name: "RFC5869 A.4", + hash: crypto.SHA1, + salt: []byte{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc}, + secret: bytes.Repeat([]byte{0x0b}, 11), + info: []byte{0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9}, + extracted: []byte{0x9b, 0x6c, 0x18, 0xc4, 0x32, 0xa7, 0xbf, 0x8f, 0xe, 0x71, 0xc8, 0xeb, 0x88, 0xf4, 0xb3, 0xb, 0xaa, 0x2b, 0xa2, 0x43}, + expanded: []byte{0x8, 0x5a, 0x1, 0xea, 0x1b, 0x10, 0xf3, 0x69, 0x33, 0x6, 0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81, 0xa4, 0xf1, 0x4b, 0x82, 0x2f, 0x5b, 0x9, 0x15, 0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55, 0xfd, 0xa2, 0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x5, 0xf3, 0xf8, 0x96}, + }, + } + + for i := range testcases { + t := testcases[i] + + It(fmt.Sprintf("case %s: extracts", t.name), func() { + Expect(hkdfExtract(t.hash, t.secret, t.salt)).To(Equal(t.extracted)) + }) + + It(fmt.Sprintf("case %s: expands", t.name), func() { + prk := hkdfExtract(t.hash, t.secret, t.salt) + Expect(hkdfExpand(t.hash, prk, t.info, len(t.expanded))).To(Equal(t.expanded)) + }) + } }) diff --git a/internal/crypto/key_derivation.go b/internal/crypto/key_derivation.go index 8aa187ffa..fe71ab966 100644 --- a/internal/crypto/key_derivation.go +++ b/internal/crypto/key_derivation.go @@ -1,9 +1,6 @@ package crypto import ( - "crypto" - "encoding/binary" - "github.com/bifurcation/mint" "github.com/lucas-clemente/quic-go/internal/protocol" ) @@ -19,14 +16,6 @@ type TLSExporter interface { ComputeExporter(label string, context []byte, keyLength int) ([]byte, error) } -func qhkdfExpand(secret []byte, label string, length int) []byte { - qlabel := make([]byte, 2+1+5+len(label)) - binary.BigEndian.PutUint16(qlabel[0:2], uint16(length)) - qlabel[2] = uint8(5 + len(label)) - copy(qlabel[3:], []byte("QUIC "+label)) - return mint.HkdfExpand(crypto.SHA256, secret, qlabel, length) -} - // DeriveAESKeys derives the AES keys and creates a matching AES-GCM AEAD instance func DeriveAESKeys(tls TLSExporter, pers protocol.Perspective) (AEAD, error) { var myLabel, otherLabel string