Add DatabaseLookup and test it

2025-06-07 10:01:41 -04:00 · 2025-02-26 21:21:09 +01:00
parent 17a789bed7
commit 89e51820f1
3 changed files with 720 additions and 14 deletions
--- a/doc/tests/header.mk
+++ b/doc/tests/header.mk
@ -1,5 +1,5 @@

-test-i2np-header-all: test-i2np-type test-i2np-message test-i2np-expiration test-i2np-ntcp-components test-i2np-data test-i2np-regression test-i2np-build-request-record test-i2np-build-response-record
+test-i2np-header-all: test-i2np-type test-i2np-message test-i2np-expiration test-i2np-ntcp-components test-i2np-data test-i2np-regression test-i2np-build-request-record test-i2np-build-response-record test-i2np-database-lookup

 test-i2np-type:
 	$(GO) test -v ./lib/i2np -run TestReadI2NPTypeWith
@ -37,6 +37,31 @@ test-i2np-build-response-record:
 	$(GO) test -v ./lib/i2np -run TestReadBuildResponseRecordTooLittleData
 	$(GO) test -v ./lib/i2np -run TestReadBuildResponseRecordValidData

+test-i2np-database-lookup:
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupKeyTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupKeyValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupFromTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupFromValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupFlagsTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupFlagsValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTunnelIDTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTunnelIDNotIncluded
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTunnelIDValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupSizeTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupSizeValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupExcludedPeersTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupExcludedPeersZeroSize
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupExcludedPeersValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyKeyTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyKeyValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupTagsTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupTagsValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTagsTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTagsZeroTags
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupReplyTagsValidData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupTooLittleData
+	$(GO) test -v ./lib/i2np -run TestReadDatabaseLookupValidData
+
 .PHONY: test-i2np-header-all \
        test-i2np-type \
        test-i2np-message \
@ -45,4 +70,5 @@ test-i2np-build-response-record:
        test-i2np-data \
        test-i2np-regression \
        test-i2np-build-request-record \
-        test-i2np-build-response-record
+        test-i2np-build-response-record \
+        test-i2np-database-lookup
--- a/lib/i2np/database_lookup.go
+++ b/lib/i2np/database_lookup.go
@ -1,6 +1,10 @@
 package i2np

 import (
+	"errors"
+
+	"github.com/sirupsen/logrus"
+
 	common "github.com/go-i2p/go-i2p/lib/common/data"
 	"github.com/go-i2p/go-i2p/lib/common/session_key"
 	"github.com/go-i2p/go-i2p/lib/common/session_tag"
@ -8,8 +12,8 @@ import (

 /*
 I2P I2NP DatabaseLookup
-https://geti2p.net/spec/i2np
-Accurate for version 0.9.28
+https://geti2p.net/spec/i2np#databaselookup
+Accurate for version 0.9.65

 +----+----+----+----+----+----+----+----+
 | SHA256 hash as the key to look up     |
@ -21,7 +25,7 @@ Accurate for version 0.9.28
 |                                       |
 +----+----+----+----+----+----+----+----+
 | SHA256 hash of the routerInfo         |
-+ who is asking, or the gateway to      +
+ who is asking or the gateway to       +
 | send the reply to                     |
 +                                       +
 |                                       |
@ -30,7 +34,7 @@ Accurate for version 0.9.28
 +----+----+----+----+----+----+----+----+
 |flag| reply_tunnelId    | size    |    |
 +----+----+----+----+----+----+----+    +
-| SHA256 of $key1 to exclude            |
+| SHA256 of key1 to exclude             |
 +                                       +
 |                                       |
 +                                       +
@ -38,7 +42,7 @@ Accurate for version 0.9.28
 +                                  +----+
 |                                  |    |
 +----+----+----+----+----+----+----+    +
-| SHA256 of $key2 to exclude            |
+| SHA256 of key2 to exclude             |
 +                                       +
 ~                                       ~
 +                                  +----+
@ -95,12 +99,20 @@ flags ::
                    with version 0.9.16 or higher.
             01  => LS lookup, return LeaseSet or
                    DatabaseSearchReplyMessage
+                    As of release 0.9.38, may also return a
+                    LeaseSet2, MetaLeaseSet, or EncryptedLeaseSet.
             10  => RI lookup, return RouterInfo or
                    DatabaseSearchReplyMessage
             11  => exploration lookup, return DatabaseSearchReplyMessage
                    containing non-floodfill routers only (replaces an
                    excludedPeer of all zeroes)
-     bits 7-4:
+     bit 4: ECIESFlag
+             before release 0.9.46 ignored
+             as of release 0.9.46:
+             0  => send unencrypted or ElGamal reply
+             1  => send ChaCha/Poly encrypted reply using enclosed key
+                   (whether tag is enclosed depends on bit 1)
+     bits 7-5:
             through release 0.9.5, must be set to 0
             as of release 0.9.6, ignored, set to 0 for compatibility with
             future uses and with older routers
@ -108,7 +120,7 @@ flags ::
 reply_tunnelId ::
               4 byte TunnelID
               only included if deliveryFlag == 1
-               tunnelId of the tunnel to send the reply to
+               tunnelId of the tunnel to send the reply to, nonzero

 size ::
     2 byte Integer
@ -124,18 +136,53 @@ excludedPeers ::
              to list non-floodfill routers only.

 reply_key ::
-     32 byte SessionKey
-     only included if encryptionFlag == 1, only as of release 0.9.7
+     32 byte key
+     see below

 tags ::
     1 byte Integer
     valid range: 1-32 (typically 1)
     the number of reply tags that follow
-     only included if encryptionFlag == 1, only as of release 0.9.7
+     see below
+
+reply_tags ::
+     one or more 8 or 32 byte session tags (typically one)
+     see below
+
+
+ElG to ElG
+
+reply_key ::
+     32 byte SessionKey big-endian
+     only included if encryptionFlag == 1 AND ECIESFlag == 0, only as of release 0.9.7
+
+tags ::
+     1 byte Integer
+     valid range: 1-32 (typically 1)
+     the number of reply tags that follow
+     only included if encryptionFlag == 1 AND ECIESFlag == 0, only as of release 0.9.7

 reply_tags ::
     one or more 32 byte SessionTags (typically one)
-     only included if encryptionFlag == 1, only as of release 0.9.7
+     only included if encryptionFlag == 1 AND ECIESFlag == 0, only as of release 0.9.7
+
+
+ECIES to ElG
+
+reply_key ::
+     32 byte ECIES SessionKey big-endian
+     only included if encryptionFlag == 0 AND ECIESFlag == 1, only as of release 0.9.46
+
+tags ::
+     1 byte Integer
+     required value: 1
+     the number of reply tags that follow
+     only included if encryptionFlag == 0 AND ECIESFlag == 1, only as of release 0.9.46
+
+reply_tags ::
+     an 8 byte ECIES SessionTag
+     only included if encryptionFlag == 0 AND ECIESFlag == 1, only as of release 0.9.46
+
 */

 type DatabaseLookup struct {
@ -146,6 +193,209 @@ type DatabaseLookup struct {
 	Size          int
 	ExcludedPeers []common.Hash
 	ReplyKey      session_key.SessionKey
-	tags          int
+	Tags          int
 	ReplyTags     []session_tag.SessionTag
 }
+
+var ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA = errors.New("not enough i2np database lookup data")
+
+func ReadDatabaseLookup(data []byte) (DatabaseLookup, error) {
+	log.Debug("Reading DatabaseLookup")
+	databaseLookup := DatabaseLookup{}
+
+	length, key, err := readDatabaseLookupKey(data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read Key")
+		return databaseLookup, err
+	}
+	databaseLookup.Key = key
+
+	length, from, err := readDatabaseLookupFrom(length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read From")
+		return databaseLookup, err
+	}
+	databaseLookup.From = from
+
+	length, flags, err := readDatabaseLookupFlags(length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read Flags")
+		return databaseLookup, err
+	}
+	databaseLookup.Flags = flags
+
+	length, replyTunnelID, err := readDatabaseLookupReplyTunnelID(flags, length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read ReplyTunnelID")
+		return databaseLookup, err
+	}
+	databaseLookup.ReplyTunnelID = replyTunnelID
+
+	length, size, err := readDatabaseLookupSize(length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read Size")
+		return databaseLookup, err
+	}
+	databaseLookup.Size = size
+
+	length, excludedPeers, err := readDatabaseLookupExcludedPeers(length, data, size)
+	if err != nil {
+		log.WithError(err).Error("Failed to read ExcludedPeers")
+		return databaseLookup, err
+	}
+	databaseLookup.ExcludedPeers = excludedPeers
+
+	length, reply_key, err := readDatabaseLookupReplyKey(length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read ReplyKey")
+		return databaseLookup, err
+	}
+	databaseLookup.ReplyKey = reply_key
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+	if err != nil {
+		log.WithError(err).Error("Failed to read Tags")
+		return databaseLookup, err
+	}
+	databaseLookup.Tags = tags
+
+	length, reply_tags, err := readDatabaseLookupReplyTags(length, data, tags)
+	if err != nil {
+		log.WithError(err).Error("Failed to read ReplyTags")
+		return databaseLookup, err
+	}
+	databaseLookup.ReplyTags = reply_tags
+
+	log.Debug("DatabaseLookup read successfully")
+	return databaseLookup, nil
+}
+
+func readDatabaseLookupKey(data []byte) (int, common.Hash, error) {
+	if len(data) < 32 {
+		return 0, common.Hash{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+
+	key := common.Hash(data[:32])
+	log.WithFields(logrus.Fields{
+		"at":    "i2np.readDatabaseLookupKey",
+		"key":   key,
+	}).Debug("parsed_database_lookup_key")
+	return 32, key, nil
+}
+
+func readDatabaseLookupFrom(length int, data []byte) (int, common.Hash, error) {
+	if len(data) < length + 32 {
+		return length, common.Hash{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+
+	from := common.Hash(data[length:length + 32])
+	log.WithFields(logrus.Fields{
+		"at":    "i2np.database_lookup.readDatabaseLookupFrom",
+		"from":   from,
+	}).Debug("parsed_database_lookup_from")
+	return length + 32, from, nil
+}
+
+func readDatabaseLookupFlags(length int, data []byte) (int, byte, error) {
+	if len(data) < length + 1 {
+		return length, byte(0), ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+	flags := data[length]
+
+	log.WithFields(logrus.Fields{
+		"at":    "i2np.database_lookup.readDatabaseLookupFlags",
+		"flags":   flags,
+	}).Debug("parsed_database_lookup_flags")
+	return length + 1, flags, nil
+}
+
+func readDatabaseLookupReplyTunnelID(flags byte, length int, data []byte) (int, [4]byte, error) {
+	if flags & 1 != 1 {
+		return length, [4]byte{}, nil
+	}
+	if len(data) < length + 4 {
+		return length, [4]byte{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+
+	replyTunnelID := [4]byte(data[length:length + 4])
+	log.WithFields(logrus.Fields{
+		"at":          "i2np.database_lookup.readDatabaseLookupReplyTunnelID",
+		"reply_tunnel_id":   replyTunnelID,
+	}).Debug("parsed_database_lookup_reply_tunnel_id")
+	return length + 4, replyTunnelID, nil
+}
+
+func readDatabaseLookupSize(length int, data []byte) (int, int, error) {
+	if len(data) < length + 2 {
+		return length, 0, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+
+	size := common.Integer(data[length:length + 2]).Int()
+	log.WithFields(logrus.Fields{
+		"at":      "i2np.database_lookup.readDatabaseLookupSize",
+		"size":    size,
+	}).Debug("parsed_database_lookup_size")
+	return length + 2, size, nil
+}
+
+func readDatabaseLookupExcludedPeers(length int, data []byte, size int) (int, []common.Hash, error) {
+	if len(data) < length + size * 32 {
+		return length, []common.Hash{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+	var excludedPeers []common.Hash
+	for i := 0; i < size; i++ {
+		offset := length + i * 32
+		peer := common.Hash(data[offset:offset + 32])
+		excludedPeers = append(excludedPeers, peer)
+	}
+
+	log.WithFields(logrus.Fields{
+		"at":             "i2np.database_lookup.readDatabaseLookupExcludedPeers",
+		"excluded_peers": excludedPeers,
+	}).Debug("parsed_database_lookup_excluded_peers")
+	return length + size * 32, excludedPeers, nil
+}
+
+func readDatabaseLookupReplyKey(length int, data []byte) (int, session_key.SessionKey, error) {
+	if len(data) < length + 32 {
+		return length, session_key.SessionKey{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+	replyKey := session_key.SessionKey(data[length:length + 32])
+
+	log.WithFields(logrus.Fields{
+		"at":          "i2np.database_lookup.readDatabaseLookupReplyKey",
+		"reply_key": replyKey,
+	}).Debug("parsed_database_lookup_reply_key")
+	return length + 32, replyKey, nil
+}
+
+func readDatabaseLookupTags(length int, data []byte) (int, int, error) {
+	if len(data) < length + 1 {
+		return length, 0, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+	tags := int(data[length])
+
+	log.WithFields(logrus.Fields{
+		"at":     "i2np.database_lookup.readDatabaseLookupTags",
+		"tags":   tags,
+	}).Debug("parsed_database_lookup_tags")
+	return length + 1, tags, nil
+}
+
+func readDatabaseLookupReplyTags(length int, data []byte, tags int) (int, []session_tag.SessionTag, error) {
+	if len(data) < length + tags * 32 {
+		return length, []session_tag.SessionTag{}, ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA
+	}
+	var reply_tags []session_tag.SessionTag
+	for i := 0; i < tags; i++ {
+		offset := length + i * 32
+		tag := session_tag.SessionTag(data[offset:offset + 32])
+		reply_tags = append(reply_tags, tag)
+	}
+
+	log.WithFields(logrus.Fields{
+		"at":     "i2np.database_lookup.readDatabaseLookupReplyTags",
+		"reply_tags":   reply_tags,
+	}).Debug("parsed_database_lookup_reply_tags")
+	return length + tags * 32, reply_tags, nil
+}
--- a/lib/i2np/database_lookup_test.go
+++ b/lib/i2np/database_lookup_test.go
@ -0,0 +1,430 @@
+package i2np
+
+import (
+	"testing"
+
+	common "github.com/go-i2p/go-i2p/lib/common/data"
+	"github.com/go-i2p/go-i2p/lib/common/session_key"
+	"github.com/go-i2p/go-i2p/lib/common/session_tag"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReadDatabaseLookupKeyTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length, key, err := readDatabaseLookupKey([]byte{0x01})
+	assert.Equal(0, length)
+	assert.Equal(common.Hash{}, key)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupKeyValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	data := make([]byte, 32)
+	for i := range 31 {
+		data[i] = 0x31
+	}
+	length, key, err := readDatabaseLookupKey(data)
+	expected := common.Hash(data)
+
+	assert.Equal(32, length)
+	assert.Equal(expected, key)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupFromTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 32
+	prev := make([]byte, length)
+	data := append(prev, 0x01)
+
+	length, key, err := readDatabaseLookupFrom(length, data)
+	assert.Equal(32, length)
+	assert.Equal(common.Hash{}, key)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupFromValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 32
+	prev := make([]byte, length)
+	expectedFrom := make([]byte, 32)
+	expectedFrom[23] = 0x21
+	expectedFrom[29] = 0x37
+	data := append(prev, expectedFrom...)
+	length, from, err := readDatabaseLookupFrom(length, data)
+	expected := common.Hash(expectedFrom)
+
+	assert.Equal(64, length)
+	assert.Equal(from, expected)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupFlagsTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 64
+	prev := make([]byte, length)
+	data := prev
+
+	length, flags, err := readDatabaseLookupFlags(length, data)
+	assert.Equal(64, length)
+	assert.Equal(byte(0), flags)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupFlagsValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 64
+	prev := make([]byte, length)
+	expected := byte(0x1)
+	data := append(prev, expected)
+	length, flags, err := readDatabaseLookupFlags(length, data)
+
+	assert.Equal(65, length)
+	assert.Equal(flags, expected)
+	assert.Equal(nil, err)
+}
+func TestReadDatabaseLookupReplyTunnelIDTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 64
+	prev := make([]byte, length)
+	flag := byte(0x1)
+	data := append(prev, flag)
+
+	excessData := make([]byte, 2)
+	excessData[1] = 0x32
+	data = append(data, excessData...)
+	length, flags, err := readDatabaseLookupFlags(length, data)
+
+	length, replyTunnelID, err := readDatabaseLookupReplyTunnelID(flags, length, data)
+	assert.Equal(65, length)
+	assert.Equal([4]byte{}, replyTunnelID)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupReplyTunnelIDNotIncluded(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	length, flags, err := readDatabaseLookupFlags(length, data)
+
+	length, tunnelID, err := readDatabaseLookupReplyTunnelID(flags, length, data)
+	assert.Equal(65, length)
+	assert.Equal([4]byte{}, tunnelID)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupReplyTunnelIDValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 64
+	prev := make([]byte, length)
+	flag := byte(0x1)
+	data := append(prev, flag)
+
+	expected := make([]byte, 4)
+	expected[1] = 0x32
+	expected[3] = 0x34
+	data = append(data, expected...)
+	length, flags, err := readDatabaseLookupFlags(length, data)
+
+	length, replyTunnelID, err := readDatabaseLookupReplyTunnelID(flags, length, data)
+	assert.Equal(69, length)
+	assert.Equal([4]byte(expected), replyTunnelID)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupSizeTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	data = append(data, 0x2)
+
+	length, size, err := readDatabaseLookupSize(length, data)
+	assert.Equal(65, length)
+	assert.Equal(0, size)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupSizeValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	expectedSizeData := []byte{0x16,0x9}
+	data = append(data, expectedSizeData...)
+
+	length, size, err := readDatabaseLookupSize(length, data)
+	assert.Equal(67, length)
+	assert.Equal(common.Integer(expectedSizeData).Int(), size)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupExcludedPeersTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	sizeData := []byte{0x0,0x3}
+	data = append(data, sizeData...)
+	data = append(data, 0x23)
+
+	length, size, err := readDatabaseLookupSize(length, data)
+	length, excludedPeers, err := readDatabaseLookupExcludedPeers(length, data, size)
+	assert.Equal([]common.Hash{}, excludedPeers)
+	assert.Equal(67, length)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupExcludedPeersZeroSize(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	sizeData := []byte{0x0,0x0}
+	data = append(data, sizeData...)
+	data = append(data, 0x23)
+
+	length, size, err := readDatabaseLookupSize(length, data)
+
+	var expectedExcludedPeers []common.Hash
+
+	length, excludedPeers, err := readDatabaseLookupExcludedPeers(length, data, size)
+	assert.Equal(expectedExcludedPeers, excludedPeers)
+	assert.Equal(67, length)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupExcludedPeersValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 65
+	data := make([]byte, length)
+	sizeData := []byte{0x0,0x3}
+	data = append(data, sizeData...)
+
+	length, size, err := readDatabaseLookupSize(length, data)
+
+	var expectedExcludedPeers []common.Hash
+	for i := range size {
+		peer := make([]byte, 32)
+		// random data:
+		peer[i + 1] = 0x43
+		peer[i + 23] = 0x89
+		expectedExcludedPeers = append(expectedExcludedPeers, common.Hash(peer))
+		data = append(data, peer...)
+	}
+
+	length, excludedPeers, err := readDatabaseLookupExcludedPeers(length, data, size)
+	assert.Equal(expectedExcludedPeers, excludedPeers)
+	assert.Equal(67 + 32 * size, length)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupReplyKeyTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 67
+	data := make([]byte, length)
+	data = append(data, 0x2)
+
+	length, replyKey, err := readDatabaseLookupReplyKey(length, data)
+	assert.Equal(67, length)
+	assert.Equal(session_key.SessionKey{}, replyKey)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupReplyKeyValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 67
+	data := make([]byte, length)
+	expectedReplyKeyData := make([]byte, 32)
+	expectedReplyKeyData[3] = 0x31
+	expectedReplyKey := session_key.SessionKey(expectedReplyKeyData)
+	data = append(data, expectedReplyKeyData...)
+
+	length, replyKey, err := readDatabaseLookupReplyKey(length, data)
+	assert.Equal(67 + 32, length)
+	assert.Equal(expectedReplyKey, replyKey)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupTagsTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 99
+	data := make([]byte, length)
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+	assert.Equal(99, length)
+	assert.Equal(0, tags)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupTagsValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 99
+	data := make([]byte, length)
+	expected := 121
+	data = append(data, byte(expected))
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+	assert.Equal(100, length)
+	assert.Equal(expected, tags)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupReplyTagsTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 99
+	data := make([]byte, length)
+	tags := 10
+	data = append(data, byte(tags))
+	data = append(data, 0x34)
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+	length, replyTags, err := readDatabaseLookupReplyTags(length, data, tags)
+	assert.Equal(100, length)
+	assert.Equal([]session_tag.SessionTag{}, replyTags)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupReplyTagsZeroTags(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 99
+	data := make([]byte, length)
+	tags := 0
+	data = append(data, byte(tags))
+	data = append(data, 0x23)
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+
+	var expectedReplyTags []session_tag.SessionTag
+
+	length, replyTags, err := readDatabaseLookupReplyTags(length, data, tags)
+	assert.Equal(expectedReplyTags, replyTags)
+	assert.Equal(100, length)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupReplyTagsValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 99
+	data := make([]byte, length)
+	tags := 10
+	data = append(data, byte(tags))
+
+	length, tags, err := readDatabaseLookupTags(length, data)
+
+	var expectedReplyTags []session_tag.SessionTag
+	for i := range tags {
+		tag := make([]byte, 32)
+		// random data:
+		tag[i + 1] = 0x43
+		tag[i + 5] = 0x89
+		expectedReplyTags = append(expectedReplyTags, session_tag.SessionTag(tag))
+		data = append(data, tag...)
+	}
+
+	length, replyTags, err := readDatabaseLookupReplyTags(length, data, tags)
+	assert.Equal(expectedReplyTags, replyTags)
+	assert.Equal(100 + 32 * tags, length)
+	assert.Equal(nil, err)
+}
+
+func TestReadDatabaseLookupTooLittleData(t *testing.T) {
+	assert := assert.New(t)
+
+	length := 67
+	data := make([]byte, length)
+	expectedReplyKeyData := make([]byte, 32)
+	expectedReplyKeyData[3] = 0x31
+	expectedReplyKey := session_key.SessionKey(expectedReplyKeyData)
+	data = append(data, expectedReplyKeyData...)
+
+	databaseLookup, err := ReadDatabaseLookup(data)
+	assert.Equal(expectedReplyKey, databaseLookup.ReplyKey)
+	assert.Equal(ERR_DATABASE_LOOKUP_NOT_ENOUGH_DATA, err)
+}
+
+func TestReadDatabaseLookupValidData(t *testing.T) {
+	assert := assert.New(t)
+
+	data := make([]byte, 32)
+	for i := range 31 {
+		data[i] = 0x31
+	}
+	expectedKey := common.Hash(data)
+
+	from := make([]byte, 32)
+	from[14] = 0x69
+	from[27] = 0x15
+	data = append(data, from...)
+	expectedFrom := common.Hash(from)
+
+	expectedFlags := byte(0x1)
+	data = append(data, expectedFlags)
+
+	tunnelIDData := make([]byte, 4)
+	tunnelIDData[0] = 0xff
+	tunnelIDData[2] = 0xf2
+	data = append(data, tunnelIDData...)
+	expectedTunnelID := [4]byte(tunnelIDData)
+
+	sizeData := []byte{0x0,0xf}
+	data = append(data, sizeData...)
+	expectedSize := common.Integer(sizeData).Int()
+
+	var expectedExcludedPeers []common.Hash
+	for i := range expectedSize {
+		peer := make([]byte, 32)
+		// random data:
+		peer[i + 5] = 0xdd
+		peer[i + 13] = 0x35
+		expectedExcludedPeers = append(expectedExcludedPeers, common.Hash(peer))
+		data = append(data, peer...)
+	}
+
+	replyKeyData := make([]byte, 32)
+	replyKeyData[6] = 0x11
+	replyKeyData[14] = 0x13
+	data = append(data, replyKeyData...)
+	expectedReplyKey := session_key.SessionKey(replyKeyData)
+
+	expectedTags := 15
+	data = append(data, byte(expectedTags))
+
+	var expectedReplyTags []session_tag.SessionTag
+	for i := range expectedTags {
+		tag := make([]byte, 32)
+		// random data:
+		tag[i + 3] = 0x22
+		tag[i + 13] = 0x11
+		expectedReplyTags = append(expectedReplyTags, session_tag.SessionTag(tag))
+		data = append(data, tag...)
+	}
+	databaseLookup, err := ReadDatabaseLookup(data)
+	assert.Equal(expectedKey, databaseLookup.Key)
+	assert.Equal(expectedFrom, databaseLookup.From)
+	assert.Equal(expectedFlags, databaseLookup.Flags)
+	assert.Equal(expectedTunnelID, databaseLookup.ReplyTunnelID)
+	assert.Equal(expectedSize, databaseLookup.Size)
+	assert.Equal(expectedExcludedPeers, databaseLookup.ExcludedPeers)
+	assert.Equal(expectedReplyKey, databaseLookup.ReplyKey)
+	assert.Equal(expectedTags, databaseLookup.Tags)
+	assert.Equal(expectedReplyTags, databaseLookup.ReplyTags)
+	assert.Equal(err, nil)
+}