From 43a123c1ae6613b3efeed291fa552ecd909d3acf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:23:18 +0200 Subject: Adding upstream version 1.20.14. Signed-off-by: Daniel Baumann --- src/crypto/tls/ticket.go | 185 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 src/crypto/tls/ticket.go (limited to 'src/crypto/tls/ticket.go') diff --git a/src/crypto/tls/ticket.go b/src/crypto/tls/ticket.go new file mode 100644 index 0000000..b82ccd1 --- /dev/null +++ b/src/crypto/tls/ticket.go @@ -0,0 +1,185 @@ +// Copyright 2012 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 ( + "bytes" + "crypto/aes" + "crypto/cipher" + "crypto/hmac" + "crypto/sha256" + "crypto/subtle" + "errors" + "io" + + "golang.org/x/crypto/cryptobyte" +) + +// sessionState contains the information that is serialized into a session +// ticket in order to later resume a connection. +type sessionState struct { + vers uint16 + cipherSuite uint16 + createdAt uint64 + masterSecret []byte // opaque master_secret<1..2^16-1>; + // struct { opaque certificate<1..2^24-1> } Certificate; + certificates [][]byte // Certificate certificate_list<0..2^24-1>; + + // usedOldKey is true if the ticket from which this session came from + // was encrypted with an older key and thus should be refreshed. + usedOldKey bool +} + +func (m *sessionState) marshal() ([]byte, error) { + var b cryptobyte.Builder + b.AddUint16(m.vers) + b.AddUint16(m.cipherSuite) + addUint64(&b, m.createdAt) + b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { + b.AddBytes(m.masterSecret) + }) + b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { + for _, cert := range m.certificates { + b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { + b.AddBytes(cert) + }) + } + }) + return b.Bytes() +} + +func (m *sessionState) unmarshal(data []byte) bool { + *m = sessionState{usedOldKey: m.usedOldKey} + s := cryptobyte.String(data) + if ok := s.ReadUint16(&m.vers) && + s.ReadUint16(&m.cipherSuite) && + readUint64(&s, &m.createdAt) && + readUint16LengthPrefixed(&s, &m.masterSecret) && + len(m.masterSecret) != 0; !ok { + return false + } + var certList cryptobyte.String + if !s.ReadUint24LengthPrefixed(&certList) { + return false + } + for !certList.Empty() { + var cert []byte + if !readUint24LengthPrefixed(&certList, &cert) { + return false + } + m.certificates = append(m.certificates, cert) + } + return s.Empty() +} + +// sessionStateTLS13 is the content of a TLS 1.3 session ticket. Its first +// version (revision = 0) doesn't carry any of the information needed for 0-RTT +// validation and the nonce is always empty. +type sessionStateTLS13 struct { + // uint8 version = 0x0304; + // uint8 revision = 0; + cipherSuite uint16 + createdAt uint64 + resumptionSecret []byte // opaque resumption_master_secret<1..2^8-1>; + certificate Certificate // CertificateEntry certificate_list<0..2^24-1>; +} + +func (m *sessionStateTLS13) marshal() ([]byte, error) { + var b cryptobyte.Builder + b.AddUint16(VersionTLS13) + b.AddUint8(0) // revision + b.AddUint16(m.cipherSuite) + addUint64(&b, m.createdAt) + b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { + b.AddBytes(m.resumptionSecret) + }) + marshalCertificate(&b, m.certificate) + return b.Bytes() +} + +func (m *sessionStateTLS13) unmarshal(data []byte) bool { + *m = sessionStateTLS13{} + s := cryptobyte.String(data) + var version uint16 + var revision uint8 + return s.ReadUint16(&version) && + version == VersionTLS13 && + s.ReadUint8(&revision) && + revision == 0 && + s.ReadUint16(&m.cipherSuite) && + readUint64(&s, &m.createdAt) && + readUint8LengthPrefixed(&s, &m.resumptionSecret) && + len(m.resumptionSecret) != 0 && + unmarshalCertificate(&s, &m.certificate) && + s.Empty() +} + +func (c *Conn) encryptTicket(state []byte) ([]byte, error) { + if len(c.ticketKeys) == 0 { + return nil, errors.New("tls: internal error: session ticket keys unavailable") + } + + encrypted := make([]byte, ticketKeyNameLen+aes.BlockSize+len(state)+sha256.Size) + keyName := encrypted[:ticketKeyNameLen] + iv := encrypted[ticketKeyNameLen : ticketKeyNameLen+aes.BlockSize] + macBytes := encrypted[len(encrypted)-sha256.Size:] + + if _, err := io.ReadFull(c.config.rand(), iv); err != nil { + return nil, err + } + key := c.ticketKeys[0] + copy(keyName, key.keyName[:]) + block, err := aes.NewCipher(key.aesKey[:]) + if err != nil { + return nil, errors.New("tls: failed to create cipher while encrypting ticket: " + err.Error()) + } + cipher.NewCTR(block, iv).XORKeyStream(encrypted[ticketKeyNameLen+aes.BlockSize:], state) + + mac := hmac.New(sha256.New, key.hmacKey[:]) + mac.Write(encrypted[:len(encrypted)-sha256.Size]) + mac.Sum(macBytes[:0]) + + return encrypted, nil +} + +func (c *Conn) decryptTicket(encrypted []byte) (plaintext []byte, usedOldKey bool) { + if len(encrypted) < ticketKeyNameLen+aes.BlockSize+sha256.Size { + return nil, false + } + + keyName := encrypted[:ticketKeyNameLen] + iv := encrypted[ticketKeyNameLen : ticketKeyNameLen+aes.BlockSize] + macBytes := encrypted[len(encrypted)-sha256.Size:] + ciphertext := encrypted[ticketKeyNameLen+aes.BlockSize : len(encrypted)-sha256.Size] + + keyIndex := -1 + for i, candidateKey := range c.ticketKeys { + if bytes.Equal(keyName, candidateKey.keyName[:]) { + keyIndex = i + break + } + } + if keyIndex == -1 { + return nil, false + } + key := &c.ticketKeys[keyIndex] + + mac := hmac.New(sha256.New, key.hmacKey[:]) + mac.Write(encrypted[:len(encrypted)-sha256.Size]) + expected := mac.Sum(nil) + + if subtle.ConstantTimeCompare(macBytes, expected) != 1 { + return nil, false + } + + block, err := aes.NewCipher(key.aesKey[:]) + if err != nil { + return nil, false + } + plaintext = make([]byte, len(ciphertext)) + cipher.NewCTR(block, iv).XORKeyStream(plaintext, ciphertext) + + return plaintext, keyIndex > 0 +} -- cgit v1.2.3