psiphon

package
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 Go to latest Published: Nov 27, 2015 License: GPL-3.0 Imports: 44 Imported by: 0

Documentation

Overview

Package psiphon implements the core tunnel functionality of a Psiphon client. The main function is RunForever, which runs a Controller that obtains lists of servers, establishes tunnel connections, and runs local proxies through which tunneled traffic may be sent.

Index

Constants

View Source 
const (
	LEGACY_DATA_STORE_FILENAME                     = "psiphon.db"
	DATA_STORE_FILENAME                            = "psiphon.boltdb"
	CONNECTION_WORKER_POOL_SIZE                    = 10
	TUNNEL_POOL_SIZE                               = 1
	TUNNEL_CONNECT_TIMEOUT                         = 20 * time.Second
	TUNNEL_OPERATE_SHUTDOWN_TIMEOUT                = 1 * time.Second
	TUNNEL_PORT_FORWARD_DIAL_TIMEOUT               = 10 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PAYLOAD_MAX_BYTES        = 256
	TUNNEL_SSH_KEEP_ALIVE_PERIOD_MIN               = 60 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PERIOD_MAX               = 120 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PERIODIC_TIMEOUT         = 30 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PERIODIC_INACTIVE_PERIOD = 10 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PROBE_TIMEOUT            = 5 * time.Second
	TUNNEL_SSH_KEEP_ALIVE_PROBE_INACTIVE_PERIOD    = 10 * time.Second
	ESTABLISH_TUNNEL_TIMEOUT_SECONDS               = 300
	ESTABLISH_TUNNEL_WORK_TIME                     = 60 * time.Second
	ESTABLISH_TUNNEL_PAUSE_PERIOD                  = 5 * time.Second
	ESTABLISH_TUNNEL_SERVER_AFFINITY_GRACE_PERIOD  = 1 * time.Second
	HTTP_PROXY_ORIGIN_SERVER_TIMEOUT               = 15 * time.Second
	HTTP_PROXY_MAX_IDLE_CONNECTIONS_PER_HOST       = 50
	FETCH_REMOTE_SERVER_LIST_TIMEOUT               = 30 * time.Second
	FETCH_REMOTE_SERVER_LIST_RETRY_PERIOD          = 5 * time.Second
	FETCH_REMOTE_SERVER_LIST_STALE_PERIOD          = 6 * time.Hour
	PSIPHON_API_CLIENT_SESSION_ID_LENGTH           = 16
	PSIPHON_API_SERVER_TIMEOUT                     = 20 * time.Second
	PSIPHON_API_SHUTDOWN_SERVER_TIMEOUT            = 1 * time.Second
	PSIPHON_API_STATUS_REQUEST_PERIOD_MIN          = 5 * time.Minute
	PSIPHON_API_STATUS_REQUEST_PERIOD_MAX          = 10 * time.Minute
	PSIPHON_API_STATUS_REQUEST_SHORT_PERIOD_MIN    = 5 * time.Second
	PSIPHON_API_STATUS_REQUEST_SHORT_PERIOD_MAX    = 10 * time.Second
	PSIPHON_API_STATUS_REQUEST_PADDING_MAX_BYTES   = 256
	PSIPHON_API_CONNECTED_REQUEST_PERIOD           = 24 * time.Hour
	PSIPHON_API_CONNECTED_REQUEST_RETRY_PERIOD     = 5 * time.Second
	PSIPHON_API_TUNNEL_STATS_MAX_COUNT             = 1000
	FETCH_ROUTES_TIMEOUT                           = 1 * time.Minute
	DOWNLOAD_UPGRADE_TIMEOUT                       = 15 * time.Minute
	DOWNLOAD_UPGRADE_RETRY_PAUSE_PERIOD            = 5 * time.Second
	IMPAIRED_PROTOCOL_CLASSIFICATION_DURATION      = 2 * time.Minute
	IMPAIRED_PROTOCOL_CLASSIFICATION_THRESHOLD     = 3
	TOTAL_BYTES_TRANSFERRED_NOTICE_PERIOD          = 5 * time.Minute
)
View Source 
const (
	URL_PROXY_TUNNELED_REQUEST_PATH = "/tunneled/"
	URL_PROXY_DIRECT_REQUEST_PATH   = "/direct/"
)
View Source 
const (
	MEEK_PROTOCOL_VERSION          = 2
	MEEK_COOKIE_MAX_PADDING        = 32
	MAX_SEND_PAYLOAD_LENGTH        = 65536
	FULL_RECEIVE_BUFFER_LENGTH     = 4194304
	READ_PAYLOAD_CHUNK_LENGTH      = 65536
	MIN_POLL_INTERVAL              = 100 * time.Millisecond
	MAX_POLL_INTERVAL              = 5 * time.Second
	POLL_INTERNAL_MULTIPLIER       = 1.5
	MEEK_ROUND_TRIP_RETRY_DEADLINE = 1 * time.Second
	MEEK_ROUND_TRIP_RETRY_DELAY    = 50 * time.Millisecond
	MEEK_ROUND_TRIP_TIMEOUT        = 20 * time.Second
)
View Source 
const (
	OBFUSCATION_READ_STATE_SERVER_IDENTIFICATION_LINE = iota
	OBFUSCATION_READ_STATE_SERVER_KEX_PACKETS
	OBFUSCATION_READ_STATE_FLUSH
	OBFUSCATION_READ_STATE_FINISHED
)
View Source 
const (
	OBFUSCATION_WRITE_STATE_SEND_CLIENT_SEED_MESSAGE = iota
	OBFUSCATION_WRITE_STATE_CLIENT_IDENTIFICATION_LINE
	OBFUSCATION_WRITE_STATE_CLIENT_KEX_PACKETS
	OBFUSCATION_WRITE_STATE_FINISHED
)
View Source 
const (
	SSH_MAX_SERVER_LINE_LENGTH = 1024
	SSH_PACKET_PREFIX_LENGTH   = 5          // uint32 + byte
	SSH_MAX_PACKET_LENGTH      = 256 * 1024 // OpenSSH max packet length
	SSH_MSG_NEWKEYS            = 21
	SSH_MAX_PADDING_LENGTH     = 255 // RFC 4253 sec. 6
	SSH_PADDING_MULTIPLE       = 16  // Default cipher block size
)
View Source 
const (
	OBFUSCATE_SEED_LENGTH         = 16
	OBFUSCATE_KEY_LENGTH          = 16
	OBFUSCATE_HASH_ITERATIONS     = 6000
	OBFUSCATE_MAX_PADDING         = 8192
	OBFUSCATE_MAGIC_VALUE         = 0x0BF5CA7E
	OBFUSCATE_CLIENT_TO_SERVER_IV = "client_to_server"
	OBFUSCATE_SERVER_TO_CLIENT_IV = "server_to_client"
)
View Source 
const (
	TUNNEL_PROTOCOL_SSH            = "SSH"
	TUNNEL_PROTOCOL_OBFUSCATED_SSH = "OSSH"
	TUNNEL_PROTOCOL_UNFRONTED_MEEK = "UNFRONTED-MEEK-OSSH"
	TUNNEL_PROTOCOL_FRONTED_MEEK   = "FRONTED-MEEK-OSSH"
)
View Source 
const DNS_PORT = 53

Variables

View Source 
var SupportedTunnelProtocols = []string{
	TUNNEL_PROTOCOL_FRONTED_MEEK,
	TUNNEL_PROTOCOL_UNFRONTED_MEEK,
	TUNNEL_PROTOCOL_OBFUSCATED_SSH,
	TUNNEL_PROTOCOL_SSH,
}

Functions

func ClearReportedTunnelStats 

func ClearReportedTunnelStats(tunnelStats [][]byte) error

ClearReportedTunnelStats deletes a list of tunnel stats records that were succesdfully reported.

func Contains 

func Contains(list []string, target string) bool

Contains is a helper function that returns true if the target string is in the list.

func ContextError 

func ContextError(err error) error

ContextError prefixes an error message with the current function name

func CountServerEntries 

func CountServerEntries(region, protocol string) int

CountServerEntries returns a count of stored servers for the specified region and protocol.

func CountUnreportedTunnelStats 

func CountUnreportedTunnelStats() int

CountUnreportedTunnelStats returns the number of tunnel stats records in StateUnreported.

func CustomTLSDial 

func CustomTLSDial(network, addr string, config *CustomTLSConfig) (net.Conn, error)

CustomTLSDialWithDialer is a customized replacement for tls.Dial. Based on tlsdialer.DialWithDialer which is based on crypto/tls.DialWithDialer.

tlsdialer comment: 

Note - if sendServerName is false, the VerifiedChains field on the
connection's ConnectionState will never get populated.

func DecodeCertificate 

func DecodeCertificate(encodedCertificate string) (certificate *x509.Certificate, err error)

func DialTCP 

func DialTCP(addr string, config *DialConfig) (conn net.Conn, err error)

DialTCP creates a new, connected TCPConn.

func DownloadUpgrade 

func DownloadUpgrade(config *Config, clientUpgradeVersion string, tunnel *Tunnel) error

DownloadUpgrade performs a tunneled, resumable download of client upgrade files. While downloading/resuming, a temporary file is used. Once the download is complete, a notice is issued and the upgrade is available at the destination specified in config.UpgradeDownloadFilename. NOTE: this code does not check that any existing file at config.UpgradeDownloadFilename is actually the version specified in clientUpgradeVersion.

func FetchRemoteServerList 

func FetchRemoteServerList(config *Config, dialConfig *DialConfig) (err error)

FetchRemoteServerList downloads a remote server list JSON record from config.RemoteServerListUrl; validates its digital signature using the public key config.RemoteServerListSignaturePublicKey; and parses the data field into ServerEntry records.

func FilterUrlError 

func FilterUrlError(err error) error

FilterUrlError transforms an error, when it is a url.Error, removing the URL value. This is to avoid logging private user data in cases where the URL may be a user input value. This function is used with errors returned by net/http and net/url, which are (currently) of type url.Error. In particular, the round trip function used by our HttpProxy, http.Client.Do, returns errors of type url.Error, with the URL being the url sent from the user's tunneled applications: https://github.com/golang/go/blob/release-branch.go1.4/src/net/http/client.go#L394

func GetInterfaceIPAddress 

func GetInterfaceIPAddress(listenInterface string) (string, error)

Take in an interface name ("lo", "eth0", "any") passed from either a config setting or by -interface command line flag and return the IP address associated with it. If no interface is provided use the default loopback interface (127.0.0.1). If "any" is passed then listen on 0.0.0.0

func GetKeyValue 

func GetKeyValue(key string) (value string, err error)

GetKeyValue retrieves the value for a given key. If not found, it returns an empty string value.

func GetNotice 

func GetNotice(notice []byte) (
	noticeType string, payload map[string]interface{}, err error)

GetNotice receives a JSON encoded object and attempts to parse it as a Notice. The type is returned as a string and the payload as a generic map.

func GetServerEntryIpAddresses 

func GetServerEntryIpAddresses() (ipAddresses []string, err error)

GetServerEntryIpAddresses returns an array containing all stored server IP addresses.

func GetSplitTunnelRoutesData 

func GetSplitTunnelRoutesData(region string) (data []byte, err error)

GetSplitTunnelRoutesData retrieves the cached routes data for the specified region. If not found, it returns a nil value.

func GetSplitTunnelRoutesETag 

func GetSplitTunnelRoutesETag(region string) (etag string, err error)

GetSplitTunnelRoutesETag retrieves the etag for cached routes data for the specified region. If not found, it returns an empty string value.

func GetUrlETag 

func GetUrlETag(url string) (etag string, err error)

GetUrlETag retrieves a previously stored an ETag for the specfied URL. If not found, it returns an empty string value.

func InitDataStore 

func InitDataStore(config *Config) (err error)

InitDataStore initializes the singleton instance of dataStore. This function uses a sync.Once and is safe for use by concurrent goroutines. The underlying sql.DB connection pool is also safe.

Note: the sync.Once was more useful when initDataStore was private and called on-demand by the public functions below. Now we require an explicit InitDataStore() call with the filename passed in. The on-demand calls have been replaced by checkInitDataStore() to assert that Init was called.

func IsAddressInUseError 

func IsAddressInUseError(err error) bool

IsAddressInUseError returns true when the err is due to EADDRINUSE/WSAEADDRINUSE.

func LocalProxyRelay 

func LocalProxyRelay(proxyType string, localConn, remoteConn net.Conn)

LocalProxyRelay sends to remoteConn bytes received from localConn, and sends to localConn bytes received from remoteConn.

func LookupIP 

func LookupIP(host string, config *DialConfig) (addrs []net.IP, err error)

LookupIP resolves a hostname. When BindToDevice is not required, it simply uses net.LookupIP. When BindToDevice is required, LookupIP explicitly creates a UDP socket, binds it to the device, and makes an explicit DNS request to the specified DNS resolver.

func MakeRandomPeriod 

func MakeRandomPeriod(min, max time.Duration) (duration time.Duration)

MakeRandomPeriod returns a random duration, within a given range. In the unlikely case where an underlying MakeRandom functions fails, the period is the minimum.

func MakeSecureRandomBytes 

func MakeSecureRandomBytes(length int) ([]byte, error)

MakeSecureRandomBytes is a helper function that wraps crypto/rand.Read.

func MakeSecureRandomInt 

func MakeSecureRandomInt(max int) (int, error)

MakeSecureRandomInt is a helper function that wraps MakeSecureRandomInt64.

func MakeSecureRandomInt64 

func MakeSecureRandomInt64(max int64) (int64, error)

MakeSecureRandomInt64 is a helper function that wraps crypto/rand.Int, which returns a uniform random value in [0, max).

func MakeSecureRandomPadding 

func MakeSecureRandomPadding(minLength, maxLength int) []byte

MakeSecureRandomPadding selects a random padding length in the indicated range and returns a random byte array of the selected length. In the unlikely case where an underlying MakeRandom functions fails, the padding is length 0.

func MakeSessionId 

func MakeSessionId() (sessionId string, err error)

MakeSessionId creates a new session ID. The same session ID is used across multi-tunnel controller runs, where each tunnel has its own ServerContext instance. In server-side stats, we now consider a "session" to be the lifetime of the Controller (e.g., the user's commanded start and stop) and we measure this duration as well as the duration of each tunnel within the session.

func MakeUntunneledHttpsClient 

func MakeUntunneledHttpsClient(
	dialConfig *DialConfig,
	verifyLegacyCertificate *x509.Certificate,
	requestUrl string,
	requestTimeout time.Duration) (*http.Client, string, error)

MakeUntunneledHttpsClient returns a net/http.Client which is configured to use custom dialing features -- including BindToDevice, UseIndistinguishableTLS, etc. -- for a specific HTTPS request URL. If verifyLegacyCertificate is not nil, it's used for certificate verification. Because UseIndistinguishableTLS requires a hack to work with net/http, MakeUntunneledHttpClient may return a modified request URL to be used. Callers should always use this return value to make requests, not the input value.

func NewNetworkList 

func NewNetworkList(routesData []byte) (networkList, error)

NewNetworkList parses text routes data and produces a networkList for fast ContainsIpAddress lookup. The input format is expected to be text lines where each line is, e.g., "1.2.3.0\t255.255.255.0\n"

func NoticeActiveTunnel 

func NoticeActiveTunnel(ipAddress, protocol string)

NoticeActiveTunnel is a successful connection that is used as an active tunnel for port forwarding

func NoticeAlert 

func NoticeAlert(format string, args ...interface{})

NoticeAlert is an alert message; typically a recoverable error condition

func NoticeAvailableEgressRegions 

func NoticeAvailableEgressRegions(regions []string)

NoticeAvailableEgressRegions is what regions are available for egress from. Consecutive reports of the same list of regions are suppressed.

func NoticeBuildInfo 

func NoticeBuildInfo()

func NoticeBytesTransferred 

func NoticeBytesTransferred(ipAddress string, sent, received int64)

NoticeBytesTransferred reports how many tunneled bytes have been transferred since the last NoticeBytesTransferred, for the tunnel to the server at ipAddress.

func NoticeCandidateServers 

func NoticeCandidateServers(region, protocol string, count int)

NoticeCandidateServers is how many possible servers are available for the selected region and protocol

func NoticeClientRegion 

func NoticeClientRegion(region string)

NoticeClientRegion is the client's region, as determined by the server and reported to the client in the handshake.

func NoticeClientUpgradeAvailable 

func NoticeClientUpgradeAvailable(version string)

NoticeClientUpgradeAvailable is an available client upgrade, as per the handshake. The client should download and install an upgrade.

func NoticeClientUpgradeDownloaded 

func NoticeClientUpgradeDownloaded(filename string)

NoticeClientUpgradeDownloaded indicates that a client upgrade download is complete and available at the destination specified.

func NoticeConnectingServer 

func NoticeConnectingServer(ipAddress, region, protocol, frontingAddress string)

NoticeConnectingServer is details on a connection attempt

func NoticeError 

func NoticeError(format string, args ...interface{})

NoticeError is an error message; typically an unrecoverable error condition

func NoticeHomepage 

func NoticeHomepage(url string)

NoticeClientUpgradeAvailable is a sponsor homepage, as per the handshake. The client should display the sponsor's homepage.

func NoticeHttpProxyPortInUse 

func NoticeHttpProxyPortInUse(port int)

NoticeSocksProxyPortInUse is a failure to use the configured LocalHttpProxyPort

func NoticeInfo 

func NoticeInfo(format string, args ...interface{})

NoticeInfo is an informational message

func NoticeListeningHttpProxyPort 

func NoticeListeningHttpProxyPort(port int)

NoticeListeningSocksProxyPort is the selected port for the listening local HTTP proxy

func NoticeListeningSocksProxyPort 

func NoticeListeningSocksProxyPort(port int)

NoticeListeningSocksProxyPort is the selected port for the listening local SOCKS proxy

func NoticeLocalProxyError 

func NoticeLocalProxyError(proxyType string, err error)

NoticeLocalProxyError reports a local proxy error message. Repetitive errors for a given proxy type are suppressed.

func NoticeSocksProxyPortInUse 

func NoticeSocksProxyPortInUse(port int)

NoticeSocksProxyPortInUse is a failure to use the configured LocalSocksProxyPort

func NoticeSplitTunnelRegion 

func NoticeSplitTunnelRegion(region string)

NoticeSplitTunnelRegion reports that split tunnel is on for the given region.

func NoticeTotalBytesTransferred 

func NoticeTotalBytesTransferred(ipAddress string, sent, received int64)

NoticeTotalBytesTransferred reports how many tunneled bytes have been transferred in total up to this point, for the tunnel to the server at ipAddress.

func NoticeTunnels 

func NoticeTunnels(count int)

NoticeTunnels is how many active tunnels are available. The client should use this to determine connecting/unexpected disconnect state transitions. When count is 0, the core is disconnected; when count > 1, the core is connected.

func NoticeUntunneled 

func NoticeUntunneled(address string)

NoticeUntunneled indicates than an address has been classified as untunneled and is being accessed directly.

Note: "address" should remain private; this notice should only be used for alerting users, not for diagnostics logs.

func NoticeUpstreamProxyError 

func NoticeUpstreamProxyError(err error)

NoticeUpstreamProxyError reports an error when connecting to an upstream proxy. The user may have input, for example, an incorrect address or incorrect credentials.

func PromoteServerEntry 

func PromoteServerEntry(ipAddress string) error

PromoteServerEntry assigns the top rank (one more than current max rank) to the specified server entry. Server candidates are iterated in decending rank order, so this server entry will be the first candidate in a subsequent tunnel establishment.

func PutBackUnreportedTunnelStats 

func PutBackUnreportedTunnelStats(tunnelStats [][]byte) error

PutBackUnreportedTunnelStats restores a list of tunnel stats records to StateUnreported.

func ReadAuthenticatedDataPackage 

func ReadAuthenticatedDataPackage(
	rawPackage []byte, signingPublicKey string) (data string, err error)

func RecordTunnelStats 

func RecordTunnelStats(
	sessionId string,
	tunnelNumber int64,
	tunnelServerIpAddress string,
	serverHandshakeTimestamp, duration string,
	totalBytesSent, totalBytesReceived int64) error

RecordTunnelStats records a tunnel duration and bytes sent and received for subsequent reporting and quality analysis.

Tunnel durations are precisely measured client-side and reported in status requests. As the duration is not determined until the tunnel is closed, tunnel stats records are stored in the persistent datastore and reported via subsequent status requests sent to any Psiphon server.

Since the status request that reports a tunnel stats record is not necessarily handled by the same server, the tunnel stats records include the original server ID.

Other fields that may change between tunnel stats recording and reporting include client geo data, propagation channel, sponsor ID, client version. These are not stored in the datastore (client region, in particular, since that would create an on-disk record of user location). TODO: the server could encrypt, with a nonce and key unknown to the client, a blob containing this data; return it in the handshake response; and the client could store and later report this blob with its tunnel stats records.

Multiple "status" requests may be in flight at once (due to multi-tunnel, asynchronous final status retry, and aggressive status requests for pre-registered tunnels), To avoid duplicate reporting, tunnel stats records are "taken-out" by a status request and then "put back" in case the request fails.

Note: since tunnel stats records have a globally unique identifier (sessionId + tunnelNumber), we could tolerate duplicate reporting and filter our duplicates on the server-side. Permitting duplicate reporting could increase the velocity of reporting (for example, both the asynchronous untunneled final status requests and the post-connected immediate startus requests could try to report the same tunnel stats). Duplicate reporting may also occur when a server receives and processes a status request but the client fails to receive the response.

func ReportAvailableRegions 

func ReportAvailableRegions()

ReportAvailableRegions prints a notice with the available egress regions. Note that this report ignores config.TunnelProtocol.

func ResolveIP 

func ResolveIP(host string, conn net.Conn) (addrs []net.IP, ttls []time.Duration, err error)

ResolveIP uses a custom dns stack to make a DNS query over the given TCP or UDP conn. This is used, e.g., when we need to ensure that a DNS connection bypasses a VPN interface (BindToDevice) or when we need to ensure that a DNS connection is tunneled. Caller must set timeouts or interruptibility as required for conn.

func SetKeyValue 

func SetKeyValue(key, value string) error

SetKeyValue stores a key/value pair.

func SetNoticeOutput 

func SetNoticeOutput(output io.Writer)

SetNoticeOutput sets a target writer to receive notices. By default, notices are written to stderr.

Notices are encoded in JSON. Here's an example:

{"data":{"message":"shutdown operate tunnel"},"noticeType":"Info","showUser":false,"timestamp":"2015-01-28T17:35:13Z"}

All notices have the following fields: - "noticeType": the type of notice, which indicates the meaning of the notice along with what's in the data payload. - "data": additional structured data payload. For example, the "ListeningSocksProxyPort" notice type has a "port" integer data in its payload. - "showUser": whether the information should be displayed to the user. For example, this flag is set for "SocksProxyPortInUse" as the user should be informed that their configured choice of listening port could not be used. Core clients should anticipate that the core will add additional "showUser"=true notices in the future and emit at least the raw notice. - "timestamp": UTC timezone, RFC3339 format timestamp for notice event

See the Notice* functions for details on each notice meaning and payload.

func SetSplitTunnelRoutes 

func SetSplitTunnelRoutes(region, etag string, data []byte) error

SetSplitTunnelRoutes updates the cached routes data for the given region. The associated etag is also stored and used to make efficient web requests for updates to the data.

func SetUrlETag 

func SetUrlETag(url, etag string) error

SetUrlETag stores an ETag for the specfied URL. Note: input URL is treated as a string, and is not encoded or decoded or otherwise canonicalized.

func StoreServerEntries 

func StoreServerEntries(serverEntries []*ServerEntry, replaceIfExists bool) error

StoreServerEntries shuffles and stores a list of server entries. Shuffling is performed on imported server entrues as part of client-side load balancing. There is an independent transaction for each entry insert/update.

func StoreServerEntry 

func StoreServerEntry(serverEntry *ServerEntry, replaceIfExists bool) error

StoreServerEntry adds the server entry to the data store. A newly stored (or re-stored) server entry is assigned the next-to-top rank for iteration order (the previous top ranked entry is promoted). The purpose of inserting at next-to-top is to keep the last selected server as the top ranked server. When replaceIfExists is true, an existing server entry record is overwritten; otherwise, the existing record is unchanged. If the server entry data is malformed, an alert notice is issued and the entry is skipped; no error is returned.

func StoreTunnelStats 

func StoreTunnelStats(tunnelStats []byte) error

StoreTunnelStats adds a new tunnel stats record, which is set to StateUnreported and is an immediate candidate for reporting. tunnelStats is a JSON byte array containing fields as required by the Psiphon server API (see RecordTunnelStats). It's assumed that the JSON value contains enough unique information for the value to function as a key in the key/value datastore. This assumption is currently satisfied by the fields sessionId + tunnelNumber.

func TakeOutUnreportedTunnelStats 

func TakeOutUnreportedTunnelStats(maxCount int) ([][]byte, error)

TakeOutUnreportedTunnelStats returns up to maxCount tunnel stats records that are in StateUnreported. The records are set to StateReporting. If the records are successfully reported, clear them with ClearReportedTunnelStats. If the records are not successfully reported, restore them with PutBackUnreportedTunnelStats.

func TrimError 

func TrimError(err error) error

TrimError removes the middle of over-long error message strings

func TryUntunneledStatusRequest 

func TryUntunneledStatusRequest(tunnel *Tunnel, isShutdown bool) error

TryUntunneledStatusRequest makes direct connections to the specified server (if supported) in an attempt to send useful bytes transferred and tunnel duration stats after a tunnel has alreay failed. The tunnel is assumed to be closed, but its config, protocol, and context values must still be valid. TryUntunneledStatusRequest emits notices detailing failed attempts.

func ValidateServerEntry 

func ValidateServerEntry(serverEntry *ServerEntry) error

ValidateServerEntry checks for malformed server entries. Currently, it checks for a valid ipAddress. This is important since handshake requests submit back to the server a list of known server IP addresses and the handshake API expects well-formed inputs. TODO: validate more fields

func WaitForNetworkConnectivity 

func WaitForNetworkConnectivity(
	connectivityChecker NetworkConnectivityChecker, stopBroadcasts ...<-chan struct{}) bool

WaitForNetworkConnectivity uses a NetworkConnectivityChecker to periodically check for network connectivity. It returns true if no NetworkConnectivityChecker is provided (waiting is disabled) or when NetworkConnectivityChecker.HasNetworkConnectivity() indicates connectivity. It waits and polls the checker once a second. If any stop is broadcast, false is returned immediately.

Types

type AuthenticatedDataPackage 

type AuthenticatedDataPackage struct {
	Data                   string `json:"data"`
	SigningPublicKeyDigest string `json:"signingPublicKeyDigest"`
	Signature              string `json:"signature"`
}

AuthenticatedDataPackage is a JSON record containing some Psiphon data payload, such as list of Psiphon server entries. As it may be downloaded from various sources, it is digitally signed so that the data may be authenticated.

type Config 

type Config struct {
	// LogFilename specifies a file to receive event notices (JSON format)
	// By default, notices are emitted to stdout.
	LogFilename string

	// DataStoreDirectory is the directory in which to store the persistent
	// database, which contains information such as server entries.
	// By default, current working directory.
	DataStoreDirectory string

	// DataStoreTempDirectory is the directory in which to store temporary
	// work files associated with the persistent database.
	// This parameter is deprecated and may be removed.
	DataStoreTempDirectory string

	// PropagationChannelId is a string identifier which indicates how the
	// Psiphon client was distributed. This parameter is required.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	PropagationChannelId string

	// PropagationChannelId is a string identifier which indicates who
	// is sponsoring this Psiphon client. One purpose of this value is to
	// determine the home pages for display. This parameter is required.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	SponsorId string

	// RemoteServerListUrl is a URL which specifies a location to fetch
	// out-of-band server entries. This facility is used when a tunnel cannot
	// be established to known servers.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	RemoteServerListUrl string

	// RemoteServerListSignaturePublicKey specifies a public key that's
	// used to authenticate the remote server list payload.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	RemoteServerListSignaturePublicKey string

	// ClientVersion is the client version number that the client reports
	// to the server. The version number refers to the host client application,
	// not the core tunnel library. One purpose of this value is to enable
	// automatic updates.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	// Note that sending a ClientPlatform string which includes "windows"
	// (case insensitive) and a ClientVersion of <= 44 will cause an
	// error in processing the response to DoConnectedRequest calls.
	ClientVersion string

	// ClientPlatform is the client platform ("Windows", "Android", etc.) that
	// the client reports to the server.
	ClientPlatform string

	// TunnelWholeDevice is a flag that is passed through to the handshake
	// request for stats purposes. Set to 1 when the host application is tunneling
	// the whole device, 0 otherwise.
	TunnelWholeDevice int

	// EgressRegion is a ISO 3166-1 alpha-2 country code which indicates which
	// country to egress from. For the default, "", the best performing server
	// in any country is selected.
	EgressRegion string

	// TunnelProtocol indicates which protocol to use. Valid values include:
	// "SSH", "OSSH", "UNFRONTED-MEEK-OSSH", "FRONTED-MEEK-OSSH". For the default,
	// "", the best performing protocol is used.
	TunnelProtocol string

	// EstablishTunnelTimeoutSeconds specifies a time limit after which to halt
	// the core tunnel controller if no tunnel has been established. By default,
	// the controller will keep trying indefinitely.
	EstablishTunnelTimeoutSeconds *int

	// ListenInterface specifies which interface to listen on.  If no interface
	// is provided then listen on 127.0.0.1.
	// If an invalid interface is provided then listen on localhost (127.0.0.1).
	// If 'any' is provided then use 0.0.0.0.
	// If there are multiple IP addresses on an interface use the first IPv4 address.
	ListenInterface string

	// LocalSocksProxyPort specifies a port number for the local SOCKS proxy
	// running at 127.0.0.1. For the default value, 0, the system selects a free
	// port (a notice reporting the selected port is emitted).
	LocalSocksProxyPort int

	// LocalHttpProxyPort specifies a port number for the local HTTP proxy
	// running at 127.0.0.1. For the default value, 0, the system selects a free
	// port (a notice reporting the selected port is emitted).
	LocalHttpProxyPort int

	// ConnectionWorkerPoolSize specifies how many connection attempts to attempt
	// in parallel. The default, 0, uses CONNECTION_WORKER_POOL_SIZE which is
	// recommended.
	ConnectionWorkerPoolSize int

	// TunnelPoolSize specifies how many tunnels to run in parallel. Port forwards
	// are multiplexed over multiple tunnels. The default, 0, uses TUNNEL_POOL_SIZE
	// which is recommended.
	TunnelPoolSize int

	// UpstreamProxyUrl is a URL specifying an upstream proxy to use for all
	// outbound connections. The URL should include proxy type and authentication
	// information, as required. See example URLs here:
	// https://github.com/Psiphon-Labs/psiphon-tunnel-core/tree/master/psiphon/upstreamproxy
	UpstreamProxyUrl string

	// NetworkConnectivityChecker is an interface that enables the core tunnel to call
	// into the host application to check for network connectivity. This parameter is
	// only applicable to library deployments.
	NetworkConnectivityChecker NetworkConnectivityChecker

	// DeviceBinder is an interface that enables the core tunnel to call
	// into the host application to bind sockets to specific devices. This is used
	// for VPN routing exclusion. This parameter is only applicable to library
	// deployments.
	DeviceBinder DeviceBinder

	// DnsServerGetter is an interface that enables the core tunnel to call
	// into the host application to discover the native network DNS server settings.
	// This parameter is only applicable to library deployments.
	DnsServerGetter DnsServerGetter

	// TargetServerEntry is an encoded server entry. When specified, this server entry
	// is used exclusively and all other known servers are ignored.
	TargetServerEntry string

	// DisableApi disables Psiphon server API calls including handshake, connected,
	// status, etc. This is used for special case temporary tunnels (Windows VPN mode).
	DisableApi bool

	// DisableRemoteServerListFetcher disables fetching remote server lists. This is
	// used for special case temporary tunnels.
	DisableRemoteServerListFetcher bool

	// SplitTunnelRoutesUrlFormat is an URL which specifies the location of a routes
	// file to use for split tunnel mode. The URL must include a placeholder for the
	// client region to be supplied. Split tunnel mode uses the routes file to classify
	// port forward destinations as foreign or domestic and does not tunnel domestic
	// destinations. Split tunnel mode is on when all the SplitTunnel parameters are
	// supplied.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	SplitTunnelRoutesUrlFormat string

	// SplitTunnelRoutesSignaturePublicKey specifies a public key that's
	// used to authenticate the split tunnel routes payload.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	SplitTunnelRoutesSignaturePublicKey string

	// SplitTunnelDnsServer specifies a DNS server to use when resolving port
	// forward target domain names to IP addresses for classification. The DNS
	// server must support TCP requests.
	SplitTunnelDnsServer string

	// UpgradeDownloadUrl specifies a URL from which to download a host client upgrade
	// file, when one is available. The core tunnel controller provides a resumable
	// download facility which downloads this resource and emits a notice when complete.
	// This value is supplied by and depends on the Psiphon Network, and is
	// typically embedded in the client binary.
	UpgradeDownloadUrl string

	// UpgradeDownloadFilename is the local target filename for an upgrade download.
	// This parameter is required when UpgradeDownloadUrl is specified.
	UpgradeDownloadFilename string

	// EmitBytesTransferred indicates whether to emit periodic notices showing
	// bytes sent and received.
	EmitBytesTransferred bool

	// UseIndistinguishableTLS enables use of an alternative TLS stack with a less
	// distinct fingerprint (ClientHello content) than the stock Go TLS. This
	// parameter is only supported on platforms built with OpenSSL.
	UseIndistinguishableTLS bool

	// TrustedCACertificatesFilename specifies a file containing trusted CA certs.
	// The file contents should be compatible with OpenSSL's SSL_CTX_load_verify_locations.
	// When specified, this enables use of indistinguishable TLS for HTTPS requests
	// that require typical (system CA) server authentication.
	TrustedCACertificatesFilename string

	// DisablePeriodicSshKeepAlive indicates whether to send an SSH keepalive every
	// 1-2 minutes, when the tunnel is idle. If the SSH keepalive times out, the tunnel
	// is considered to have failed.
	DisablePeriodicSshKeepAlive bool
}

Config is the Psiphon configuration specified by the application. This configuration controls the behavior of the core tunnel functionality.

func LoadConfig 

func LoadConfig(configJson []byte) (*Config, error)

LoadConfig parses and validates a JSON format Psiphon config JSON string and returns a Config struct populated with config values.

type Conns 

type Conns struct {
	// contains filtered or unexported fields
}

Conns is a synchronized list of Conns that is used to coordinate interrupting a set of goroutines establishing connections, or close a set of open connections, etc. Once the list is closed, no more items may be added to the list (unless it is reset).

func (*Conns) Add 

func (conns *Conns) Add(conn net.Conn) bool

func (*Conns) CloseAll 

func (conns *Conns) CloseAll()

func (*Conns) Remove 

func (conns *Conns) Remove(conn net.Conn)

func (*Conns) Reset 

func (conns *Conns) Reset()

type Controller 

type Controller struct {
	// contains filtered or unexported fields
}

Controller is a tunnel lifecycle coordinator. It manages lists of servers to connect to; establishes and monitors tunnels; and runs local proxies which route traffic through the tunnels.

func NewController 

func NewController(config *Config) (controller *Controller, err error)

NewController initializes a new controller.

func (*Controller) Dial 

func (controller *Controller) Dial(
	remoteAddr string, alwaysTunnel bool, downstreamConn net.Conn) (conn net.Conn, err error)

Dial selects an active tunnel and establishes a port forward connection through the selected tunnel. Failure to connect is considered a port foward failure, for the purpose of monitoring tunnel health.

func (*Controller) Run 

func (controller *Controller) Run(shutdownBroadcast <-chan struct{})

Run executes the controller. It launches components and then monitors for a shutdown signal; after receiving the signal it shuts down the controller. The components include: - the periodic remote server list fetcher - the connected reporter - the tunnel manager - a local SOCKS proxy that port forwards through the pool of tunnels - a local HTTP proxy that port forwards through the pool of tunnels

func (*Controller) SignalComponentFailure 

func (controller *Controller) SignalComponentFailure()

SignalComponentFailure notifies the controller that an associated component has failed. This will terminate the controller.

func (*Controller) SignalTunnelFailure 

func (controller *Controller) SignalTunnelFailure(tunnel *Tunnel)

SignalTunnelFailure implements the TunnelOwner interface. This function is called by Tunnel.operateTunnel when the tunnel has detected that it has failed. The Controller will signal runTunnels to create a new tunnel and/or remove the tunnel from the list of active tunnels.

type CustomTLSConfig 

type CustomTLSConfig struct {

	// Dial is the network connection dialer. TLS is layered on
	// top of a new network connection created with dialer.
	Dial Dialer

	// Timeout is and optional timeout for combined network
	// connection dial and TLS handshake.
	Timeout time.Duration

	// FrontingAddr overrides the "addr" input to Dial when specified
	FrontingAddr string

	// SendServerName specifies whether to use SNI
	// (tlsdialer functionality)
	SendServerName bool

	// SkipVerify completely disables server certificate verification.
	SkipVerify bool

	// VerifyLegacyCertificate is a special case self-signed server
	// certificate case. Ignores IP SANs and basic constraints. No
	// certificate chain. Just checks that the server presented the
	// specified certificate. SNI is disbled when this is set.
	VerifyLegacyCertificate *x509.Certificate

	// UseIndistinguishableTLS specifies whether to try to use an
	// alternative stack for TLS. From a circumvention perspective,
	// Go's TLS has a distinct fingerprint that may be used for blocking.
	UseIndistinguishableTLS bool

	// TrustedCACertificatesFilename specifies a file containing trusted
	// CA certs. Directory contents should be compatible with OpenSSL's
	// SSL_CTX_load_verify_locations
	// Only applies to UseIndistinguishableTLS connections.
	TrustedCACertificatesFilename string
}

CustomTLSConfig contains parameters to determine the behavior of CustomTLSDial.

type DeviceBinder 

type DeviceBinder interface {
	BindToDevice(fileDescriptor int) error
}

DeviceBinder defines the interface to the external BindToDevice provider

type DialConfig 

type DialConfig struct {

	// UpstreamProxyUrl specifies a proxy to connect through.
	// E.g., "http://proxyhost:8080"
	//       "socks5://user:password@proxyhost:1080"
	//       "socks4a://proxyhost:1080"
	//       "http://NTDOMAIN\NTUser:password@proxyhost:3375"
	//
	// Certain tunnel protocols require HTTP CONNECT support
	// when a HTTP proxy is specified. If CONNECT is not
	// supported, those protocols will not connect.
	UpstreamProxyUrl string

	ConnectTimeout time.Duration

	// PendingConns is used to track and interrupt dials in progress.
	// Dials may be interrupted using PendingConns.CloseAll(). Once instantiated,
	// a conn is added to pendingConns before the network connect begins and
	// removed from pendingConns once the connect succeeds or fails.
	PendingConns *Conns

	// BindToDevice parameters are used to exclude connections and
	// associated DNS requests from VPN routing.
	// When DeviceBinder is set, any underlying socket is
	// submitted to the device binding servicebefore connecting.
	// The service should bind the socket to a device so that it doesn't route
	// through a VPN interface. This service is also used to bind UDP sockets used
	// for DNS requests, in which case DnsServerGetter is used to get the
	// current active untunneled network DNS server.
	DeviceBinder    DeviceBinder
	DnsServerGetter DnsServerGetter

	// UseIndistinguishableTLS specifies whether to try to use an
	// alternative stack for TLS. From a circumvention perspective,
	// Go's TLS has a distinct fingerprint that may be used for blocking.
	// Only applies to TLS connections.
	UseIndistinguishableTLS bool

	// TrustedCACertificatesFilename specifies a file containing trusted
	// CA certs. The file contents should be compatible with OpenSSL's
	// SSL_CTX_load_verify_locations.
	// Only applies to UseIndistinguishableTLS connections.
	TrustedCACertificatesFilename string
}

DialConfig contains parameters to determine the behavior of a Psiphon dialer (TCPDial, MeekDial, etc.)

type Dialer 

type Dialer func(string, string) (net.Conn, error)

Dialer is a custom dialer compatible with http.Transport.Dial.

func NewCustomTLSDialer 

func NewCustomTLSDialer(config *CustomTLSConfig) Dialer

func NewTCPDialer 

func NewTCPDialer(config *DialConfig) Dialer

NewTCPDialer creates a TCPDialer.

type DnsServerGetter 

type DnsServerGetter interface {
	GetDnsServer() string
}

DnsServerGetter defines the interface to the external GetDnsServer provider

type ExtraParam 

type ExtraParam struct {
	// contains filtered or unexported fields
}

type HttpProxy 

type HttpProxy struct {
	// contains filtered or unexported fields
}

HttpProxy is a HTTP server that relays HTTP requests through the Psiphon tunnel. It includes support for HTTP CONNECT.

This proxy also offers a "URL proxy" mode that relays requests for HTTP or HTTPS or URLs specified in the proxy request path. This mode relays either through the Psiphon tunnel, or directly.

An example use case for tunneled URL proxy relays is to craft proxied URLs to pass to components that don't support HTTP or SOCKS proxy settings. For example, the Android Media Player (http://developer.android.com/reference/android/media/MediaPlayer.html). To make the Media Player use the Psiphon tunnel, construct a URL such as: "http://127.0.0.1:<proxy-port>/tunneled/<origin media URL>"; and pass this to the player. TODO: add ICY protocol to support certain streaming media (e.g., https://gist.github.com/tulskiy/1008126)

An example use case for direct, untunneled, relaying is to make use of Go's TLS stack for HTTPS requests in cases where the native TLS stack is lacking (e.g., WinHTTP on Windows XP). The URL for direct relaying is: "http://127.0.0.1:<proxy-port>/direct/<origin URL>".

Origin URLs must include the scheme prefix ("http://" or "https://") and must be URL encoded.

func NewHttpProxy 

func NewHttpProxy(
	config *Config,
	untunneledDialConfig *DialConfig,
	tunneler Tunneler,
	listenIP string) (proxy *HttpProxy, err error)

NewHttpProxy initializes and runs a new HTTP proxy server.

func (*HttpProxy) Close 

func (proxy *HttpProxy) Close()

Close terminates the HTTP server.

func (*HttpProxy) ServeHTTP 

func (proxy *HttpProxy) ServeHTTP(responseWriter http.ResponseWriter, request *http.Request)

ServeHTTP receives HTTP requests and proxies them. CONNECT requests are hijacked and all data is relayed. Other HTTP requests are proxied with explicit round trips. In both cases, the tunnel is used for proxied traffic.

Implementation is based on:

https://github.com/justmao945/mallory Copyright (c) 2014 JianjunMao The MIT License (MIT)

https://golang.org/src/pkg/net/http/httputil/reverseproxy.go Copyright 2011 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.

type MeekConn 

type MeekConn struct {
	// contains filtered or unexported fields
}

MeekConn is a network connection that tunnels TCP over HTTP and supports "fronting". Meek sends client->server flow in HTTP request bodies and receives server->client flow in HTTP response bodies. Polling is used to achieve full duplex TCP.

Fronting is an obfuscation technique in which the connection to a web server, typically a CDN, is indistinguishable from any other HTTPS connection to the generic "fronting domain" -- the HTTP Host header is used to route the requests to the actual destination. See https://trac.torproject.org/projects/tor/wiki/doc/meek for more details.

MeekConn also operates in unfronted mode, in which plain HTTP connections are made without routing through a CDN.

func DialMeek 

func DialMeek(
	serverEntry *ServerEntry, sessionId string,
	frontingAddress string, config *DialConfig) (meek *MeekConn, err error)

DialMeek returns an initialized meek connection. A meek connection is an HTTP session which does not depend on an underlying socket connection (although persistent HTTP connections are used for performance). This function does not wait for the connection to be "established" before returning. A goroutine is spawned which will eventually start HTTP polling. When frontingAddress is not "", fronting is used. This option assumes caller has already checked server entry capabilities.

func (*MeekConn) Close 

func (meek *MeekConn) Close() (err error)

Close terminates the meek connection. Close waits for the relay processing goroutine to stop and releases HTTP transport resources. A mutex is required to support net.Conn concurrency semantics.

func (*MeekConn) LocalAddr 

func (meek *MeekConn) LocalAddr() net.Addr

Stub implementation of net.Conn.LocalAddr

func (*MeekConn) Read 

func (meek *MeekConn) Read(buffer []byte) (n int, err error)

Read reads data from the connection. net.Conn Deadlines are ignored. net.Conn concurrency semantics are supported.

func (*MeekConn) RemoteAddr 

func (meek *MeekConn) RemoteAddr() net.Addr

Stub implementation of net.Conn.RemoteAddr

func (*MeekConn) SetDeadline 

func (meek *MeekConn) SetDeadline(t time.Time) error

Stub implementation of net.Conn.SetDeadline

func (*MeekConn) SetReadDeadline 

func (meek *MeekConn) SetReadDeadline(t time.Time) error

Stub implementation of net.Conn.SetReadDeadline

func (*MeekConn) SetWriteDeadline 

func (meek *MeekConn) SetWriteDeadline(t time.Time) error

Stub implementation of net.Conn.SetWriteDeadline

func (*MeekConn) Write 

func (meek *MeekConn) Write(buffer []byte) (n int, err error)

Write writes data to the connection. net.Conn Deadlines are ignored. net.Conn concurrency semantics are supported.

type NetworkConnectivityChecker 

type NetworkConnectivityChecker interface {
	// TODO: change to bool return value once gobind supports that type
	HasNetworkConnectivity() int
}

NetworkConnectivityChecker defines the interface to the external HasNetworkConnectivity provider

type NoticeReceiver 

type NoticeReceiver struct {
	// contains filtered or unexported fields
}

NoticeReceiver consumes a notice input stream and invokes a callback function for each discrete JSON notice object byte sequence.

func NewNoticeConsoleRewriter 

func NewNoticeConsoleRewriter(writer io.Writer) *NoticeReceiver

NewNoticeConsoleRewriter consumes JSON-format notice input and parses each notice and rewrites in a more human-readable format more suitable for console output. The data payload field is left as JSON.

func NewNoticeReceiver 

func NewNoticeReceiver(callback func([]byte)) *NoticeReceiver

NewNoticeReceiver initializes a new NoticeReceiver

func (*NoticeReceiver) Write 

func (receiver *NoticeReceiver) Write(p []byte) (n int, err error)

Write implements io.Writer.

type ObfuscatedSshConn 

type ObfuscatedSshConn struct {
	net.Conn
	// contains filtered or unexported fields
}

ObfuscatedSshConn wraps a Conn and applies the obfuscated SSH protocol to the traffic on the connection: https://github.com/brl/obfuscated-openssh/blob/master/README.obfuscation ObfuscatedSshConn is used to add obfuscation to go's stock ssh client without modification to that standard library code. The underlying connection must be used for SSH client traffic. This code injects the obfuscated seed message, applies obfuscated stream cipher transformations, and performs minimal parsing of the SSH protocol to determine when to stop obfuscation (after the first SSH_MSG_NEWKEYS is sent by the client and received from the server).

WARNING: doesn't fully conform to net.Conn concurrency semantics: there's no synchronization of access to the read/writeBuffers, so concurrent calls to one of Read or Write will result in undefined behavior.

func NewObfuscatedSshConn 

func NewObfuscatedSshConn(conn net.Conn, obfuscationKeyword string) (*ObfuscatedSshConn, error)

NewObfuscatedSshConn creates a new ObfuscatedSshConn. The underlying conn must be used for SSH client traffic and must have transferred no traffic.

func (*ObfuscatedSshConn) Read 

func (conn *ObfuscatedSshConn) Read(buffer []byte) (n int, err error)

Read wraps standard Read, transparently applying the obfusation transformations.

func (*ObfuscatedSshConn) Write 

func (conn *ObfuscatedSshConn) Write(buffer []byte) (n int, err error)

Write wraps standard Write, transparently applying the obfuscation transformations.

type ObfuscatedSshReadState 

type ObfuscatedSshReadState int

type ObfuscatedSshWriteState 

type ObfuscatedSshWriteState int

type Obfuscator 

type Obfuscator struct {
	// contains filtered or unexported fields
}

Obfuscator implements the seed message, key derivation, and stream ciphers for: https://github.com/brl/obfuscated-openssh/blob/master/README.obfuscation

func NewObfuscator 

func NewObfuscator(config *ObfuscatorConfig) (obfuscator *Obfuscator, err error)

NewObfuscator creates a new Obfuscator, initializes it with a seed message, derives client and server keys, and creates RC4 stream ciphers to obfuscate data.

func (*Obfuscator) ConsumeSeedMessage 

func (obfuscator *Obfuscator) ConsumeSeedMessage() []byte

ConsumeSeedMessage returns the seed message created in NewObfuscator, removing the reference so that it may be garbage collected.

func (*Obfuscator) ObfuscateClientToServer 

func (obfuscator *Obfuscator) ObfuscateClientToServer(buffer []byte)

ObfuscateClientToServer applies the client RC4 stream to the bytes in buffer.

func (*Obfuscator) ObfuscateServerToClient 

func (obfuscator *Obfuscator) ObfuscateServerToClient(buffer []byte)

ObfuscateServerToClient applies the server RC4 stream to the bytes in buffer.

type ObfuscatorConfig 

type ObfuscatorConfig struct {
	Keyword    string
	MaxPadding int
}

type ServerContext 

type ServerContext struct {
	// contains filtered or unexported fields
}

ServerContext is a utility struct which holds all of the data associated with a Psiphon server connection. In addition to the established tunnel, this includes data associated with Psiphon API requests and a persistent http client configured to make tunneled Psiphon API requests.

func NewServerContext 

func NewServerContext(tunnel *Tunnel, sessionId string) (*ServerContext, error)

NewServerContext makes the tunnelled handshake request to the Psiphon server and returns a ServerContext struct for use with subsequent Psiphon server API requests (e.g., periodic connected and status requests).

func (*ServerContext) DoConnectedRequest 

func (serverContext *ServerContext) DoConnectedRequest() error

DoConnectedRequest performs the connected API request. This request is used for statistics. The server returns a last_connected token for the client to store and send next time it connects. This token is a timestamp (using the server clock, and should be rounded to the nearest hour) which is used to determine when a connection represents a unique user for a time period.

func (*ServerContext) DoStatusRequest 

func (serverContext *ServerContext) DoStatusRequest(tunnel *Tunnel) error

DoStatusRequest makes a /status request to the server, sending session stats.

func (*ServerContext) StatsRegexps 

func (serverContext *ServerContext) StatsRegexps() *transferstats.Regexps

StatsRegexps gets the Regexps used for the statistics for this tunnel.

type ServerEntry 

type ServerEntry struct {
	IpAddress                     string   `json:"ipAddress"`
	WebServerPort                 string   `json:"webServerPort"` // not an int
	WebServerSecret               string   `json:"webServerSecret"`
	WebServerCertificate          string   `json:"webServerCertificate"`
	SshPort                       int      `json:"sshPort"`
	SshUsername                   string   `json:"sshUsername"`
	SshPassword                   string   `json:"sshPassword"`
	SshHostKey                    string   `json:"sshHostKey"`
	SshObfuscatedPort             int      `json:"sshObfuscatedPort"`
	SshObfuscatedKey              string   `json:"sshObfuscatedKey"`
	Capabilities                  []string `json:"capabilities"`
	Region                        string   `json:"region"`
	MeekServerPort                int      `json:"meekServerPort"`
	MeekCookieEncryptionPublicKey string   `json:"meekCookieEncryptionPublicKey"`
	MeekObfuscatedKey             string   `json:"meekObfuscatedKey"`
	MeekFrontingHost              string   `json:"meekFrontingHost"`
	MeekFrontingDomain            string   `json:"meekFrontingDomain"`
	MeekFrontingAddresses         []string `json:"meekFrontingAddresses"`
	MeekFrontingAddressesRegex    string   `json:"meekFrontingAddressesRegex"`
}

ServerEntry represents a Psiphon server. It contains information about how to estalish a tunnel connection to the server through several protocols. ServerEntry are JSON records downloaded from various sources.

func DecodeAndValidateServerEntryList 

func DecodeAndValidateServerEntryList(encodedServerEntryList string) (serverEntries []*ServerEntry, err error)

DecodeAndValidateServerEntryList extracts server entries from the list encoding used by remote server lists and Psiphon server handshake requests. Each server entry is validated and invalid entries are skipped.

func DecodeServerEntry 

func DecodeServerEntry(encodedServerEntry string) (serverEntry *ServerEntry, err error)

DecodeServerEntry extracts server entries from the encoding used by remote server lists and Psiphon server handshake requests.

func MakeCompatibleServerEntry 

func MakeCompatibleServerEntry(serverEntry *ServerEntry) *ServerEntry

MakeCompatibleServerEntry provides backwards compatibility with old server entries which have a single meekFrontingDomain and not a meekFrontingAddresses array. By copying this one meekFrontingDomain into meekFrontingAddresses, this client effectively uses that single value as legacy clients do.

func (*ServerEntry) DisableImpairedProtocols 

func (serverEntry *ServerEntry) DisableImpairedProtocols(impairedProtocols []string)

DisableImpairedProtocols modifies the ServerEntry to disable the specified protocols. Note: this assumes that protocol capabilities are 1-to-1.

func (*ServerEntry) GetDirectWebRequestPorts 

func (serverEntry *ServerEntry) GetDirectWebRequestPorts() []string

func (*ServerEntry) GetSupportedProtocols 

func (serverEntry *ServerEntry) GetSupportedProtocols() []string

GetSupportedProtocols returns a list of tunnel protocols supported by the ServerEntry's capabilities.

func (*ServerEntry) SupportsProtocol 

func (serverEntry *ServerEntry) SupportsProtocol(protocol string) bool

SupportsProtocol returns true if and only if the ServerEntry has the necessary capability to support the specified tunnel protocol.

type ServerEntryIterator 

type ServerEntryIterator struct {
	// contains filtered or unexported fields
}

ServerEntryIterator is used to iterate over stored server entries in rank order.

func NewServerEntryIterator 

func NewServerEntryIterator(config *Config) (iterator *ServerEntryIterator, err error)

NewServerEntryIterator creates a new ServerEntryIterator

func (*ServerEntryIterator) Close 

func (iterator *ServerEntryIterator) Close()

Close cleans up resources associated with a ServerEntryIterator.

func (*ServerEntryIterator) Next 

func (iterator *ServerEntryIterator) Next() (serverEntry *ServerEntry, err error)

Next returns the next server entry, by rank, for a ServerEntryIterator. Returns nil with no error when there is no next item.

func (*ServerEntryIterator) Reset 

func (iterator *ServerEntryIterator) Reset() error

Reset a NewServerEntryIterator to the start of its cycle. The next call to Next will return the first server entry.

type SocksProxy 

type SocksProxy struct {
	// contains filtered or unexported fields
}

SocksProxy is a SOCKS server that accepts local host connections and, for each connection, establishes a port forward through the tunnel SSH client and relays traffic through the port forward.

func NewSocksProxy 

func NewSocksProxy(
	config *Config,
	tunneler Tunneler,
	listenIP string) (proxy *SocksProxy, err error)

NewSocksProxy initializes a new SOCKS server. It begins listening for connections, starts a goroutine that runs an accept loop, and returns leaving the accept loop running.

func (*SocksProxy) Close 

func (proxy *SocksProxy) Close()

Close terminates the listener and waits for the accept loop goroutine to complete.

type SplitTunnelClassifier 

type SplitTunnelClassifier struct {
	// contains filtered or unexported fields
}

SplitTunnelClassifier determines whether a network destination should be accessed through a tunnel or accessed directly.

The classifier uses tables of IP address data, routes data, to determine if a given IP is to be tunneled or not. If presented with a hostname, the classifier performs a tunneled (uncensored) DNS request to first determine the IP address for that hostname; then a classification is made based on the IP address.

Classification results (both the hostname resolution and the following IP address classification) are cached for the duration of the DNS record TTL.

Classification is by geographical region (country code). When the split tunnel feature is configured to be on, and if the IP address is within the user's region, it may be accessed untunneled. Otherwise, the IP address must be accessed through a tunnel. The user's current region is revealed to a Tunnel via the Psiphon server API handshake.

When a Tunnel has a blank region (e.g., when DisableApi is set and the tunnel registers without performing a handshake) then no routes data is set and all IP addresses are classified as requiring tunneling.

Split tunnel is made on a best effort basis. After the classifier is started, but before routes data is available for the given region, all IP addresses will be classified as requiring tunneling.

Routes data is fetched asynchronously after Start() is called. Routes data is cached in the data store so it need not be downloaded in full when fresh data is in the cache.

func NewSplitTunnelClassifier 

func NewSplitTunnelClassifier(config *Config, tunneler Tunneler) *SplitTunnelClassifier

func (*SplitTunnelClassifier) IsUntunneled 

func (classifier *SplitTunnelClassifier) IsUntunneled(targetAddress string) bool

IsUntunneled takes a destination hostname or IP address and determines if it should be accessed through a tunnel. When a hostname is presented, it is first resolved to an IP address which can be matched against the routes data. Multiple goroutines may invoke RequiresTunnel simultaneously. Multi-reader locks are used in the implementation to enable concurrent access, with no locks held during network access.

func (*SplitTunnelClassifier) Shutdown 

func (classifier *SplitTunnelClassifier) Shutdown()

Shutdown waits until the background setRoutes() goroutine is finished. There is no explicit shutdown signal sent to setRoutes() -- instead we assume that in an overall shutdown situation, the tunnel used for network access in setRoutes() is closed and network events won't delay the completion of the goroutine.

func (*SplitTunnelClassifier) Start 

func (classifier *SplitTunnelClassifier) Start(fetchRoutesTunnel *Tunnel)

Start resets the state of the classifier. In the default state, all IP addresses are classified as requiring tunneling. With sufficient configuration and region info, this function starts a goroutine to asynchronously fetch and install the routes data.

type SyncFileWriter 

type SyncFileWriter struct {
	// contains filtered or unexported fields
}

SyncFileWriter wraps a file and exposes an io.Writer. At predefined steps, the file is synced (flushed to disk) while writing.

func NewSyncFileWriter 

func NewSyncFileWriter(file *os.File) *SyncFileWriter

NewSyncFileWriter creates a SyncFileWriter.

func (*SyncFileWriter) Write 

func (writer *SyncFileWriter) Write(p []byte) (n int, err error)

Write implements io.Writer with periodic file syncing.

type TCPConn 

type TCPConn struct {
	net.Conn
	// contains filtered or unexported fields
}

TCPConn is a customized TCP connection that:

  • can be interrupted while dialing;
  • implements a connect timeout;
  • uses an upstream proxy when specified, and includes upstream proxy dialing in the connect timeout;
  • can be bound to a specific system device (for Android VpnService routing compatibility, for example);

func (*TCPConn) Close 

func (conn *TCPConn) Close() (err error)

Close terminates a connected TCPConn or interrupts a dialing TCPConn.

type TimeoutError 

type TimeoutError struct{}

TimeoutError implements the error interface

func (TimeoutError) Error 

func (TimeoutError) Error() string

func (TimeoutError) Temporary 

func (TimeoutError) Temporary() bool

func (TimeoutError) Timeout 

func (TimeoutError) Timeout() bool

type Tunnel 

type Tunnel struct {
	// contains filtered or unexported fields
}

Tunnel is a connection to a Psiphon server. An established tunnel includes a network connection to the specified server and an SSH session built on top of that transport.

func EstablishTunnel 

func EstablishTunnel(
	config *Config,
	untunneledDialConfig *DialConfig,
	sessionId string,
	pendingConns *Conns,
	serverEntry *ServerEntry,
	tunnelOwner TunnelOwner) (tunnel *Tunnel, err error)

EstablishTunnel first makes a network transport connection to the Psiphon server and then establishes an SSH client session on top of that transport. The SSH server is authenticated using the public key in the server entry. Depending on the server's capabilities, the connection may use plain SSH over TCP, obfuscated SSH over TCP, or obfuscated SSH over HTTP (meek protocol). When requiredProtocol is not blank, that protocol is used. Otherwise, the a random supported protocol is used. untunneledDialConfig is used for untunneled final status requests.

func (*Tunnel) Close 

func (tunnel *Tunnel) Close(isDiscarded bool)

Close stops operating the tunnel and closes the underlying connection. Supports multiple and/or concurrent calls to Close(). When isDicarded is set, operateTunnel will not attempt to send final status requests.

func (*Tunnel) Dial 

func (tunnel *Tunnel) Dial(
	remoteAddr string, alwaysTunnel bool, downstreamConn net.Conn) (conn net.Conn, err error)

Dial establishes a port forward connection through the tunnel This Dial doesn't support split tunnel, so alwaysTunnel is not referenced

func (*Tunnel) IsDiscarded 

func (tunnel *Tunnel) IsDiscarded() bool

IsDiscarded returns the tunnel's discarded flag.

func (*Tunnel) SignalComponentFailure 

func (tunnel *Tunnel) SignalComponentFailure()

SignalComponentFailure notifies the tunnel that an associated component has failed. This will terminate the tunnel.

type TunnelOwner 

type TunnelOwner interface {
	SignalTunnelFailure(tunnel *Tunnel)
}

TunnerOwner specifies the interface required by Tunnel to notify its owner when it has failed. The owner may, as in the case of the Controller, remove the tunnel from its list of active tunnels.

type TunneledConn 

type TunneledConn struct {
	net.Conn
	// contains filtered or unexported fields
}

TunneledConn implements net.Conn and wraps a port foward connection. It is used to hook into Read and Write to observe I/O errors and report these errors back to the tunnel monitor as port forward failures. TunneledConn optionally tracks a peer connection to be explictly closed when the TunneledConn is closed.

func (*TunneledConn) Close 

func (conn *TunneledConn) Close() error

func (*TunneledConn) Read 

func (conn *TunneledConn) Read(buffer []byte) (n int, err error)

func (*TunneledConn) Write 

func (conn *TunneledConn) Write(buffer []byte) (n int, err error)

type Tunneler 

type Tunneler interface {
	Dial(remoteAddr string, alwaysTunnel bool, downstreamConn net.Conn) (conn net.Conn, err error)
	SignalComponentFailure()
}

Tunneler specifies the interface required by components that use a tunnel. Components which use this interface may be serviced by a single Tunnel instance, or a Controller which manages a pool of tunnels, or any other object which implements Tunneler. alwaysTunnel indicates that the connection should always be tunneled. If this is not set, the connection may be made directly, depending on split tunnel classification, when that feature is supported and active. downstreamConn is an optional parameter which specifies a connection to be explictly closed when the Dialed connection is closed. For instance, this is used to close downstreamConn App<->LocalProxy connections when the related LocalProxy<->SshPortForward connections close.

Source Files

View all Source files

Directories

Path Synopsis
Package stats counts and keeps track of session stats.
 Package stats counts and keeps track of session stats.
go-ntlm/ntlm
Package NTLM implements the interfaces used for interacting with NTLMv1 and NTLMv2.
 Package NTLM implements the interfaces used for interacting with NTLMv1 and NTLMv2.
go-ntlm/ntlm/md4
Package md4 implements the MD4 hash algorithm as defined in RFC 1320.
 Package md4 implements the MD4 hash algorithm as defined in RFC 1320.

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