mirror of
https://github.com/go-i2p/go-i2p.git
synced 2025-07-07 06:58:09 -04:00
More function deletions
This commit is contained in:
eyedeekay
@ -1,73 +1,16 @@
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package ntcp
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import (
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"crypto/rand"
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"io"
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"math/big"
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mrand "math/rand"
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"net"
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"time"
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"github.com/go-i2p/go-i2p/lib/common/data"
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"github.com/go-i2p/go-i2p/lib/crypto/curve25519"
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"github.com/go-i2p/go-i2p/lib/transport/ntcp/handshake"
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"github.com/go-i2p/go-i2p/lib/transport/ntcp/messages"
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"github.com/samber/oops"
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)
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func (s *NTCP2Session) CreateSessionRequest() (*messages.SessionRequest, error) {
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// Get our ephemeral key pair
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ephemeralKey := make([]byte, 32)
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if _, err := rand.Read(ephemeralKey); err != nil {
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return nil, err
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}
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// Add random padding (implementation specific)
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randomInt, err := rand.Int(rand.Reader, big.NewInt(16))
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if err != nil {
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return nil, err
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}
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padding := make([]byte, randomInt.Int64()) // Up to 16 bytes of padding
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if err != nil {
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return nil, err
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}
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netId, err := data.NewIntegerFromInt(2, 1)
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if err != nil {
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return nil, err
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}
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version, err := data.NewIntegerFromInt(2, 1)
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if err != nil {
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return nil, err
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}
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paddingLen, _, err := data.NewInteger([]byte{byte(len(padding))}, 1)
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if err != nil {
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return nil, err
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}
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//message3Part2Len, err := data.NewInteger()
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//if err != nil {
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// return nil, err
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//}
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timestamp, err := data.DateFromTime(s.GetCurrentTime())
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if err != nil {
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return nil, err
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}
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requestOptions := &messages.RequestOptions{
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NetworkID: netId,
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ProtocolVersion: version,
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PaddingLength: paddingLen,
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// Message3Part2Length: ,
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Timestamp: timestamp,
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}
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return &messages.SessionRequest{
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XContent: [32]byte(ephemeralKey),
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Options: *requestOptions,
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Padding: padding,
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}, nil
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}
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// DecryptOptionsBlock decrypts the options block from a SessionRequest message
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func (c *NTCP2Session) DecryptOptionsBlock(encryptedOptions []byte, obfuscatedX []byte, deobfuscatedX []byte) ([]byte, error) {
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return c.PerformAEADOperation(
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@ -79,6 +22,30 @@ func (c *NTCP2Session) DecryptOptionsBlock(encryptedOptions []byte, obfuscatedX
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)
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}
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// addDelayForSecurity adds a small random delay to resist probing
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func (c *NTCP2Session) addDelayForSecurity() {
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// Sleep between 50-250ms to make timing attacks harder
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// delay := time.Duration(50+mrand.Intn(200)) * time.Millisecond
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delay := time.Duration(0)
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time.Sleep(delay)
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}
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// validateTimestamp checks if the timestamp is within acceptable range
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func (c *NTCP2Session) validateTimestamp(timestamp data.Date) error {
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timestampTime := timestamp.Time()
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now := c.GetCurrentTime()
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diff := now.Sub(timestampTime)
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// Allow ±60 seconds clock skew
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if diff < -60*time.Second || diff > 60*time.Second {
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log.Warnf("NTCP2: Rejecting SessionRequest - clock skew too large: %v", diff)
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return oops.Errorf("clock skew too large: %v", diff)
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}
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return nil
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}
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// readEphemeralKey reads the ephemeral key (X) from the connection
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func (c *NTCP2Session) readEphemeralKey(conn net.Conn) ([]byte, error) {
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ephemeralKey := make([]byte, 32)
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@ -113,113 +80,6 @@ func (c *NTCP2Session) processEphemeralKey(obfuscatedX []byte, hs *handshake.Han
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return deobfuscatedX, nil
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}
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// readOptionsBlock reads the encrypted options block from the connection
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func (c *NTCP2Session) readOptionsBlock(conn net.Conn) ([]byte, error) {
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// Options block with auth tag is 16 bytes minimum
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optionsBlock := make([]byte, 16)
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if _, err := io.ReadFull(conn, optionsBlock); err != nil {
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if err == io.ErrUnexpectedEOF {
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return nil, oops.Errorf("incomplete options block: connection closed prematurely")
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}
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return nil, oops.Errorf("failed to read options block: %w", err)
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}
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return optionsBlock, nil
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}
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// processOptionsBlock decrypts and processes the options block
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func (c *NTCP2Session) processOptionsBlock(
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encryptedOptions []byte,
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obfuscatedX []byte,
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deobfuscatedX []byte,
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hs *handshake.HandshakeState,
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) (*messages.RequestOptions, error) {
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// Decrypt options block
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decryptedOptions, err := c.DecryptOptionsBlock(encryptedOptions, obfuscatedX, deobfuscatedX)
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if err != nil {
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c.addDelayForSecurity()
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return nil, oops.Errorf("failed to decrypt options block: %w", err)
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}
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// Minimum size for valid options
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if len(decryptedOptions) < 9 {
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return nil, oops.Errorf("options block too small: %d bytes", len(decryptedOptions))
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}
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// Parse network ID
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networkID, _, err := data.NewInteger([]byte{decryptedOptions[0]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse network ID: %w", err)
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}
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if networkID.Int() != 2 {
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return nil, oops.Errorf("invalid network ID: %d", networkID.Int())
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}
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// Parse protocol version
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protocolVersion, _, err := data.NewInteger([]byte{decryptedOptions[1]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse protocol version: %w", err)
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}
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if protocolVersion.Int() != 2 {
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return nil, oops.Errorf("unsupported protocol version: %d", protocolVersion.Int())
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}
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// Parse padding length
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paddingLength, _, err := data.NewInteger([]byte{decryptedOptions[2]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse padding length: %w", err)
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}
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// Parse message 3 part 2 length (2 bytes)
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msg3p2Len, _, err := data.NewInteger(decryptedOptions[3:5], 2)
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if err != nil {
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return nil, oops.Errorf("failed to parse message 3 part 2 length: %w", err)
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}
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// Parse timestamp (4 bytes)
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timestamp, _, err := data.NewDate(decryptedOptions[5:9])
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if err != nil {
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return nil, oops.Errorf("failed to parse timestamp: %w", err)
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}
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// Validate timestamp
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if err := c.validateTimestamp(*timestamp); err != nil {
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return nil, err
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}
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// Update handshake state
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timestampVal := timestamp.Time()
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hs.Timestamp = uint32(timestampVal.Unix())
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// Construct the RequestOptions object
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requestOptions := &messages.RequestOptions{
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NetworkID: networkID,
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ProtocolVersion: protocolVersion,
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PaddingLength: paddingLength,
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Message3Part2Length: msg3p2Len,
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Timestamp: timestamp,
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}
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return requestOptions, nil
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}
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// validateTimestamp checks if the timestamp is within acceptable range
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func (c *NTCP2Session) validateTimestamp(timestamp data.Date) error {
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timestampTime := timestamp.Time()
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now := c.GetCurrentTime()
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diff := now.Sub(timestampTime)
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// Allow ±60 seconds clock skew
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if diff < -60*time.Second || diff > 60*time.Second {
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log.Warnf("NTCP2: Rejecting SessionRequest - clock skew too large: %v", diff)
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return oops.Errorf("clock skew too large: %v", diff)
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}
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return nil
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}
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// readAndValidatePadding reads the padding from the connection
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func (c *NTCP2Session) readAndValidatePadding(conn net.Conn, paddingLen int) error {
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// Check reasonable padding size to prevent DoS
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@ -239,10 +99,3 @@ func (c *NTCP2Session) readAndValidatePadding(conn net.Conn, paddingLen int) err
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// No need to validate padding content - it's random data
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return nil
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}
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// addDelayForSecurity adds a small random delay to resist probing
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func (c *NTCP2Session) addDelayForSecurity() {
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// Sleep between 50-250ms to make timing attacks harder
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delay := time.Duration(50+mrand.Intn(200)) * time.Millisecond
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time.Sleep(delay)
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}
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@ -2,6 +2,7 @@ package ntcp
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import (
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"crypto/rand"
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"io"
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"math/big"
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"net"
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@ -64,7 +65,42 @@ func (s *SessionRequestProcessor) MessageType() messages.MessageType {
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// ProcessMessage implements handshake.HandshakeMessageProcessor.
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func (s *SessionRequestProcessor) ProcessMessage(message messages.Message, hs *handshake.HandshakeState) error {
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panic("unimplemented")
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req, ok := message.(*messages.SessionRequest)
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if !ok {
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return oops.Errorf("expected SessionRequest message, got %T", message)
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}
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// Validate timestamp using existing method
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if err := s.validateTimestamp(*req.Options.Timestamp); err != nil {
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return err
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}
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// Store padding length for message 3 if provided
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if req.Options.PaddingLength != nil {
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paddingLen := req.Options.PaddingLength.Int()
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hs.RemotePaddingLen = paddingLen
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}
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// Store message 3 part 2 length if provided
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if req.Options.Message3Part2Length != nil {
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hs.Message3Length = req.Options.Message3Part2Length.Int()
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}
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log.Debugf("NTCP2: Session request processed successfully")
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return nil
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}
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// readOptionsBlock reads the encrypted options block from the connection
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func (c *SessionRequestProcessor) readOptionsBlock(conn net.Conn) ([]byte, error) {
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// Options block with auth tag is 16 bytes minimum
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optionsBlock := make([]byte, 16)
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if _, err := io.ReadFull(conn, optionsBlock); err != nil {
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if err == io.ErrUnexpectedEOF {
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return nil, oops.Errorf("incomplete options block: connection closed prematurely")
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}
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return nil, oops.Errorf("failed to read options block: %w", err)
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}
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return optionsBlock, nil
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}
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// ReadMessage reads a SessionRequest message from the connection
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@ -76,19 +112,19 @@ func (p *SessionRequestProcessor) ReadMessage(conn net.Conn, hs *handshake.Hands
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}
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// 2. Process ephemeral key
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deobfuscatedX, err := p.NTCP2Session.processEphemeralKey(obfuscatedX, hs)
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deobfuscatedX, err := p.processEphemeralKey(obfuscatedX, hs)
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if err != nil {
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return nil, err
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}
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// 3. Read options block
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encryptedOptions, err := p.NTCP2Session.readOptionsBlock(conn)
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encryptedOptions, err := p.readOptionsBlock(conn)
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if err != nil {
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return nil, err
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}
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// 4. Process options block
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options, err := p.NTCP2Session.processOptionsBlock(encryptedOptions, obfuscatedX, deobfuscatedX, hs)
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options, err := p.processOptionsBlock(encryptedOptions, obfuscatedX, deobfuscatedX, hs)
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if err != nil {
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return nil, err
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}
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@ -186,4 +222,82 @@ func (p *SessionRequestProcessor) ObfuscateKey(message messages.Message, hs *han
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return p.NTCP2Session.ObfuscateEphemeral(req.XContent[:])
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}
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// processOptionsBlock decrypts and processes the options block from the session request
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func (p *SessionRequestProcessor) processOptionsBlock(
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encryptedOptions []byte,
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obfuscatedX []byte,
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deobfuscatedX []byte,
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hs *handshake.HandshakeState,
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) (*messages.RequestOptions, error) {
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// Decrypt options block
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decryptedOptions, err := p.NTCP2Session.DecryptOptionsBlock(encryptedOptions, obfuscatedX, deobfuscatedX)
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if err != nil {
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p.addDelayForSecurity()
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return nil, oops.Errorf("failed to decrypt options block: %w", err)
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}
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// Minimum size for valid options
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if len(decryptedOptions) < 9 {
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return nil, oops.Errorf("options block too small: %d bytes", len(decryptedOptions))
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}
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// Parse network ID
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networkID, _, err := data.NewInteger([]byte{decryptedOptions[0]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse network ID: %w", err)
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}
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if networkID.Int() != 2 {
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return nil, oops.Errorf("invalid network ID: %d", networkID.Int())
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}
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// Parse protocol version
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protocolVersion, _, err := data.NewInteger([]byte{decryptedOptions[1]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse protocol version: %w", err)
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}
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if protocolVersion.Int() != 2 {
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return nil, oops.Errorf("unsupported protocol version: %d", protocolVersion.Int())
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}
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// Parse padding length
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paddingLength, _, err := data.NewInteger([]byte{decryptedOptions[2]}, 1)
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if err != nil {
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return nil, oops.Errorf("failed to parse padding length: %w", err)
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}
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// Parse message 3 part 2 length (2 bytes)
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msg3p2Len, _, err := data.NewInteger(decryptedOptions[3:5], 2)
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if err != nil {
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return nil, oops.Errorf("failed to parse message 3 part 2 length: %w", err)
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}
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// Parse timestamp (4 bytes)
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timestamp, _, err := data.NewDate(decryptedOptions[5:9])
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if err != nil {
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return nil, oops.Errorf("failed to parse timestamp: %w", err)
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}
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// Validate timestamp
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if err := p.validateTimestamp(*timestamp); err != nil {
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return nil, err
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}
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// Update handshake state
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timestampVal := timestamp.Time()
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hs.Timestamp = uint32(timestampVal.Unix())
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// Construct the RequestOptions object
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requestOptions := &messages.RequestOptions{
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NetworkID: networkID,
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ProtocolVersion: protocolVersion,
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PaddingLength: paddingLength,
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Message3Part2Length: msg3p2Len,
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Timestamp: timestamp,
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}
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return requestOptions, nil
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}
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var _ handshake.HandshakeMessageProcessor = (*SessionRequestProcessor)(nil)
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