gotosocial/vendor/github.com/jackc/pgconn/config.go
tobi 2dc9fc1626
Pg to bun (#148)
* start moving to bun

* changing more stuff

* more

* and yet more

* tests passing

* seems stable now

* more big changes

* small fix

* little fixes
2021-08-25 15:34:33 +02:00

729 lines
22 KiB
Go

package pgconn
import (
"context"
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"io"
"io/ioutil"
"math"
"net"
"net/url"
"os"
"path/filepath"
"strconv"
"strings"
"time"
"github.com/jackc/chunkreader/v2"
"github.com/jackc/pgpassfile"
"github.com/jackc/pgproto3/v2"
"github.com/jackc/pgservicefile"
)
type AfterConnectFunc func(ctx context.Context, pgconn *PgConn) error
type ValidateConnectFunc func(ctx context.Context, pgconn *PgConn) error
// Config is the settings used to establish a connection to a PostgreSQL server. It must be created by ParseConfig. A
// manually initialized Config will cause ConnectConfig to panic.
type Config struct {
Host string // host (e.g. localhost) or absolute path to unix domain socket directory (e.g. /private/tmp)
Port uint16
Database string
User string
Password string
TLSConfig *tls.Config // nil disables TLS
ConnectTimeout time.Duration
DialFunc DialFunc // e.g. net.Dialer.DialContext
LookupFunc LookupFunc // e.g. net.Resolver.LookupHost
BuildFrontend BuildFrontendFunc
RuntimeParams map[string]string // Run-time parameters to set on connection as session default values (e.g. search_path or application_name)
Fallbacks []*FallbackConfig
// ValidateConnect is called during a connection attempt after a successful authentication with the PostgreSQL server.
// It can be used to validate that the server is acceptable. If this returns an error the connection is closed and the next
// fallback config is tried. This allows implementing high availability behavior such as libpq does with target_session_attrs.
ValidateConnect ValidateConnectFunc
// AfterConnect is called after ValidateConnect. It can be used to set up the connection (e.g. Set session variables
// or prepare statements). If this returns an error the connection attempt fails.
AfterConnect AfterConnectFunc
// OnNotice is a callback function called when a notice response is received.
OnNotice NoticeHandler
// OnNotification is a callback function called when a notification from the LISTEN/NOTIFY system is received.
OnNotification NotificationHandler
createdByParseConfig bool // Used to enforce created by ParseConfig rule.
}
// Copy returns a deep copy of the config that is safe to use and modify.
// The only exception is the TLSConfig field:
// according to the tls.Config docs it must not be modified after creation.
func (c *Config) Copy() *Config {
newConf := new(Config)
*newConf = *c
if newConf.TLSConfig != nil {
newConf.TLSConfig = c.TLSConfig.Clone()
}
if newConf.RuntimeParams != nil {
newConf.RuntimeParams = make(map[string]string, len(c.RuntimeParams))
for k, v := range c.RuntimeParams {
newConf.RuntimeParams[k] = v
}
}
if newConf.Fallbacks != nil {
newConf.Fallbacks = make([]*FallbackConfig, len(c.Fallbacks))
for i, fallback := range c.Fallbacks {
newFallback := new(FallbackConfig)
*newFallback = *fallback
if newFallback.TLSConfig != nil {
newFallback.TLSConfig = fallback.TLSConfig.Clone()
}
newConf.Fallbacks[i] = newFallback
}
}
return newConf
}
// FallbackConfig is additional settings to attempt a connection with when the primary Config fails to establish a
// network connection. It is used for TLS fallback such as sslmode=prefer and high availability (HA) connections.
type FallbackConfig struct {
Host string // host (e.g. localhost) or path to unix domain socket directory (e.g. /private/tmp)
Port uint16
TLSConfig *tls.Config // nil disables TLS
}
// NetworkAddress converts a PostgreSQL host and port into network and address suitable for use with
// net.Dial.
func NetworkAddress(host string, port uint16) (network, address string) {
if strings.HasPrefix(host, "/") {
network = "unix"
address = filepath.Join(host, ".s.PGSQL.") + strconv.FormatInt(int64(port), 10)
} else {
network = "tcp"
address = net.JoinHostPort(host, strconv.Itoa(int(port)))
}
return network, address
}
// ParseConfig builds a *Config with similar behavior to the PostgreSQL standard C library libpq. It uses the same
// defaults as libpq (e.g. port=5432) and understands most PG* environment variables. ParseConfig closely matches
// the parsing behavior of libpq. connString may either be in URL format or keyword = value format (DSN style). See
// https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING for details. connString also may be
// empty to only read from the environment. If a password is not supplied it will attempt to read the .pgpass file.
//
// # Example DSN
// user=jack password=secret host=pg.example.com port=5432 dbname=mydb sslmode=verify-ca
//
// # Example URL
// postgres://jack:secret@pg.example.com:5432/mydb?sslmode=verify-ca
//
// The returned *Config may be modified. However, it is strongly recommended that any configuration that can be done
// through the connection string be done there. In particular the fields Host, Port, TLSConfig, and Fallbacks can be
// interdependent (e.g. TLSConfig needs knowledge of the host to validate the server certificate). These fields should
// not be modified individually. They should all be modified or all left unchanged.
//
// ParseConfig supports specifying multiple hosts in similar manner to libpq. Host and port may include comma separated
// values that will be tried in order. This can be used as part of a high availability system. See
// https://www.postgresql.org/docs/11/libpq-connect.html#LIBPQ-MULTIPLE-HOSTS for more information.
//
// # Example URL
// postgres://jack:secret@foo.example.com:5432,bar.example.com:5432/mydb
//
// ParseConfig currently recognizes the following environment variable and their parameter key word equivalents passed
// via database URL or DSN:
//
// PGHOST
// PGPORT
// PGDATABASE
// PGUSER
// PGPASSWORD
// PGPASSFILE
// PGSERVICE
// PGSERVICEFILE
// PGSSLMODE
// PGSSLCERT
// PGSSLKEY
// PGSSLROOTCERT
// PGAPPNAME
// PGCONNECT_TIMEOUT
// PGTARGETSESSIONATTRS
//
// See http://www.postgresql.org/docs/11/static/libpq-envars.html for details on the meaning of environment variables.
//
// See https://www.postgresql.org/docs/11/libpq-connect.html#LIBPQ-PARAMKEYWORDS for parameter key word names. They are
// usually but not always the environment variable name downcased and without the "PG" prefix.
//
// Important Security Notes:
//
// ParseConfig tries to match libpq behavior with regard to PGSSLMODE. This includes defaulting to "prefer" behavior if
// not set.
//
// See http://www.postgresql.org/docs/11/static/libpq-ssl.html#LIBPQ-SSL-PROTECTION for details on what level of
// security each sslmode provides.
//
// The sslmode "prefer" (the default), sslmode "allow", and multiple hosts are implemented via the Fallbacks field of
// the Config struct. If TLSConfig is manually changed it will not affect the fallbacks. For example, in the case of
// sslmode "prefer" this means it will first try the main Config settings which use TLS, then it will try the fallback
// which does not use TLS. This can lead to an unexpected unencrypted connection if the main TLS config is manually
// changed later but the unencrypted fallback is present. Ensure there are no stale fallbacks when manually setting
// TLCConfig.
//
// Other known differences with libpq:
//
// If a host name resolves into multiple addresses, libpq will try all addresses. pgconn will only try the first.
//
// When multiple hosts are specified, libpq allows them to have different passwords set via the .pgpass file. pgconn
// does not.
//
// In addition, ParseConfig accepts the following options:
//
// min_read_buffer_size
// The minimum size of the internal read buffer. Default 8192.
// servicefile
// libpq only reads servicefile from the PGSERVICEFILE environment variable. ParseConfig accepts servicefile as a
// part of the connection string.
func ParseConfig(connString string) (*Config, error) {
defaultSettings := defaultSettings()
envSettings := parseEnvSettings()
connStringSettings := make(map[string]string)
if connString != "" {
var err error
// connString may be a database URL or a DSN
if strings.HasPrefix(connString, "postgres://") || strings.HasPrefix(connString, "postgresql://") {
connStringSettings, err = parseURLSettings(connString)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "failed to parse as URL", err: err}
}
} else {
connStringSettings, err = parseDSNSettings(connString)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "failed to parse as DSN", err: err}
}
}
}
settings := mergeSettings(defaultSettings, envSettings, connStringSettings)
if service, present := settings["service"]; present {
serviceSettings, err := parseServiceSettings(settings["servicefile"], service)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "failed to read service", err: err}
}
settings = mergeSettings(defaultSettings, envSettings, serviceSettings, connStringSettings)
}
minReadBufferSize, err := strconv.ParseInt(settings["min_read_buffer_size"], 10, 32)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "cannot parse min_read_buffer_size", err: err}
}
config := &Config{
createdByParseConfig: true,
Database: settings["database"],
User: settings["user"],
Password: settings["password"],
RuntimeParams: make(map[string]string),
BuildFrontend: makeDefaultBuildFrontendFunc(int(minReadBufferSize)),
}
if connectTimeoutSetting, present := settings["connect_timeout"]; present {
connectTimeout, err := parseConnectTimeoutSetting(connectTimeoutSetting)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "invalid connect_timeout", err: err}
}
config.ConnectTimeout = connectTimeout
config.DialFunc = makeConnectTimeoutDialFunc(connectTimeout)
} else {
defaultDialer := makeDefaultDialer()
config.DialFunc = defaultDialer.DialContext
}
config.LookupFunc = makeDefaultResolver().LookupHost
notRuntimeParams := map[string]struct{}{
"host": struct{}{},
"port": struct{}{},
"database": struct{}{},
"user": struct{}{},
"password": struct{}{},
"passfile": struct{}{},
"connect_timeout": struct{}{},
"sslmode": struct{}{},
"sslkey": struct{}{},
"sslcert": struct{}{},
"sslrootcert": struct{}{},
"target_session_attrs": struct{}{},
"min_read_buffer_size": struct{}{},
"service": struct{}{},
"servicefile": struct{}{},
}
for k, v := range settings {
if _, present := notRuntimeParams[k]; present {
continue
}
config.RuntimeParams[k] = v
}
fallbacks := []*FallbackConfig{}
hosts := strings.Split(settings["host"], ",")
ports := strings.Split(settings["port"], ",")
for i, host := range hosts {
var portStr string
if i < len(ports) {
portStr = ports[i]
} else {
portStr = ports[0]
}
port, err := parsePort(portStr)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "invalid port", err: err}
}
var tlsConfigs []*tls.Config
// Ignore TLS settings if Unix domain socket like libpq
if network, _ := NetworkAddress(host, port); network == "unix" {
tlsConfigs = append(tlsConfigs, nil)
} else {
var err error
tlsConfigs, err = configTLS(settings, host)
if err != nil {
return nil, &parseConfigError{connString: connString, msg: "failed to configure TLS", err: err}
}
}
for _, tlsConfig := range tlsConfigs {
fallbacks = append(fallbacks, &FallbackConfig{
Host: host,
Port: port,
TLSConfig: tlsConfig,
})
}
}
config.Host = fallbacks[0].Host
config.Port = fallbacks[0].Port
config.TLSConfig = fallbacks[0].TLSConfig
config.Fallbacks = fallbacks[1:]
passfile, err := pgpassfile.ReadPassfile(settings["passfile"])
if err == nil {
if config.Password == "" {
host := config.Host
if network, _ := NetworkAddress(config.Host, config.Port); network == "unix" {
host = "localhost"
}
config.Password = passfile.FindPassword(host, strconv.Itoa(int(config.Port)), config.Database, config.User)
}
}
if settings["target_session_attrs"] == "read-write" {
config.ValidateConnect = ValidateConnectTargetSessionAttrsReadWrite
} else if settings["target_session_attrs"] != "any" {
return nil, &parseConfigError{connString: connString, msg: fmt.Sprintf("unknown target_session_attrs value: %v", settings["target_session_attrs"])}
}
return config, nil
}
func mergeSettings(settingSets ...map[string]string) map[string]string {
settings := make(map[string]string)
for _, s2 := range settingSets {
for k, v := range s2 {
settings[k] = v
}
}
return settings
}
func parseEnvSettings() map[string]string {
settings := make(map[string]string)
nameMap := map[string]string{
"PGHOST": "host",
"PGPORT": "port",
"PGDATABASE": "database",
"PGUSER": "user",
"PGPASSWORD": "password",
"PGPASSFILE": "passfile",
"PGAPPNAME": "application_name",
"PGCONNECT_TIMEOUT": "connect_timeout",
"PGSSLMODE": "sslmode",
"PGSSLKEY": "sslkey",
"PGSSLCERT": "sslcert",
"PGSSLROOTCERT": "sslrootcert",
"PGTARGETSESSIONATTRS": "target_session_attrs",
"PGSERVICE": "service",
"PGSERVICEFILE": "servicefile",
}
for envname, realname := range nameMap {
value := os.Getenv(envname)
if value != "" {
settings[realname] = value
}
}
return settings
}
func parseURLSettings(connString string) (map[string]string, error) {
settings := make(map[string]string)
url, err := url.Parse(connString)
if err != nil {
return nil, err
}
if url.User != nil {
settings["user"] = url.User.Username()
if password, present := url.User.Password(); present {
settings["password"] = password
}
}
// Handle multiple host:port's in url.Host by splitting them into host,host,host and port,port,port.
var hosts []string
var ports []string
for _, host := range strings.Split(url.Host, ",") {
if host == "" {
continue
}
if isIPOnly(host) {
hosts = append(hosts, strings.Trim(host, "[]"))
continue
}
h, p, err := net.SplitHostPort(host)
if err != nil {
return nil, fmt.Errorf("failed to split host:port in '%s', err: %w", host, err)
}
if h != "" {
hosts = append(hosts, h)
}
if p != "" {
ports = append(ports, p)
}
}
if len(hosts) > 0 {
settings["host"] = strings.Join(hosts, ",")
}
if len(ports) > 0 {
settings["port"] = strings.Join(ports, ",")
}
database := strings.TrimLeft(url.Path, "/")
if database != "" {
settings["database"] = database
}
nameMap := map[string]string{
"dbname": "database",
}
for k, v := range url.Query() {
if k2, present := nameMap[k]; present {
k = k2
}
settings[k] = v[0]
}
return settings, nil
}
func isIPOnly(host string) bool {
return net.ParseIP(strings.Trim(host, "[]")) != nil || !strings.Contains(host, ":")
}
var asciiSpace = [256]uint8{'\t': 1, '\n': 1, '\v': 1, '\f': 1, '\r': 1, ' ': 1}
func parseDSNSettings(s string) (map[string]string, error) {
settings := make(map[string]string)
nameMap := map[string]string{
"dbname": "database",
}
for len(s) > 0 {
var key, val string
eqIdx := strings.IndexRune(s, '=')
if eqIdx < 0 {
return nil, errors.New("invalid dsn")
}
key = strings.Trim(s[:eqIdx], " \t\n\r\v\f")
s = strings.TrimLeft(s[eqIdx+1:], " \t\n\r\v\f")
if len(s) == 0 {
} else if s[0] != '\'' {
end := 0
for ; end < len(s); end++ {
if asciiSpace[s[end]] == 1 {
break
}
if s[end] == '\\' {
end++
if end == len(s) {
return nil, errors.New("invalid backslash")
}
}
}
val = strings.Replace(strings.Replace(s[:end], "\\\\", "\\", -1), "\\'", "'", -1)
if end == len(s) {
s = ""
} else {
s = s[end+1:]
}
} else { // quoted string
s = s[1:]
end := 0
for ; end < len(s); end++ {
if s[end] == '\'' {
break
}
if s[end] == '\\' {
end++
}
}
if end == len(s) {
return nil, errors.New("unterminated quoted string in connection info string")
}
val = strings.Replace(strings.Replace(s[:end], "\\\\", "\\", -1), "\\'", "'", -1)
if end == len(s) {
s = ""
} else {
s = s[end+1:]
}
}
if k, ok := nameMap[key]; ok {
key = k
}
if key == "" {
return nil, errors.New("invalid dsn")
}
settings[key] = val
}
return settings, nil
}
func parseServiceSettings(servicefilePath, serviceName string) (map[string]string, error) {
servicefile, err := pgservicefile.ReadServicefile(servicefilePath)
if err != nil {
return nil, fmt.Errorf("failed to read service file: %v", servicefilePath)
}
service, err := servicefile.GetService(serviceName)
if err != nil {
return nil, fmt.Errorf("unable to find service: %v", serviceName)
}
nameMap := map[string]string{
"dbname": "database",
}
settings := make(map[string]string, len(service.Settings))
for k, v := range service.Settings {
if k2, present := nameMap[k]; present {
k = k2
}
settings[k] = v
}
return settings, nil
}
// configTLS uses libpq's TLS parameters to construct []*tls.Config. It is
// necessary to allow returning multiple TLS configs as sslmode "allow" and
// "prefer" allow fallback.
func configTLS(settings map[string]string, thisHost string) ([]*tls.Config, error) {
host := thisHost
sslmode := settings["sslmode"]
sslrootcert := settings["sslrootcert"]
sslcert := settings["sslcert"]
sslkey := settings["sslkey"]
// Match libpq default behavior
if sslmode == "" {
sslmode = "prefer"
}
tlsConfig := &tls.Config{}
switch sslmode {
case "disable":
return []*tls.Config{nil}, nil
case "allow", "prefer":
tlsConfig.InsecureSkipVerify = true
case "require":
// According to PostgreSQL documentation, if a root CA file exists,
// the behavior of sslmode=require should be the same as that of verify-ca
//
// See https://www.postgresql.org/docs/12/libpq-ssl.html
if sslrootcert != "" {
goto nextCase
}
tlsConfig.InsecureSkipVerify = true
break
nextCase:
fallthrough
case "verify-ca":
// Don't perform the default certificate verification because it
// will verify the hostname. Instead, verify the server's
// certificate chain ourselves in VerifyPeerCertificate and
// ignore the server name. This emulates libpq's verify-ca
// behavior.
//
// See https://github.com/golang/go/issues/21971#issuecomment-332693931
// and https://pkg.go.dev/crypto/tls?tab=doc#example-Config-VerifyPeerCertificate
// for more info.
tlsConfig.InsecureSkipVerify = true
tlsConfig.VerifyPeerCertificate = func(certificates [][]byte, _ [][]*x509.Certificate) error {
certs := make([]*x509.Certificate, len(certificates))
for i, asn1Data := range certificates {
cert, err := x509.ParseCertificate(asn1Data)
if err != nil {
return errors.New("failed to parse certificate from server: " + err.Error())
}
certs[i] = cert
}
// Leave DNSName empty to skip hostname verification.
opts := x509.VerifyOptions{
Roots: tlsConfig.RootCAs,
Intermediates: x509.NewCertPool(),
}
// Skip the first cert because it's the leaf. All others
// are intermediates.
for _, cert := range certs[1:] {
opts.Intermediates.AddCert(cert)
}
_, err := certs[0].Verify(opts)
return err
}
case "verify-full":
tlsConfig.ServerName = host
default:
return nil, errors.New("sslmode is invalid")
}
if sslrootcert != "" {
caCertPool := x509.NewCertPool()
caPath := sslrootcert
caCert, err := ioutil.ReadFile(caPath)
if err != nil {
return nil, fmt.Errorf("unable to read CA file: %w", err)
}
if !caCertPool.AppendCertsFromPEM(caCert) {
return nil, errors.New("unable to add CA to cert pool")
}
tlsConfig.RootCAs = caCertPool
tlsConfig.ClientCAs = caCertPool
}
if (sslcert != "" && sslkey == "") || (sslcert == "" && sslkey != "") {
return nil, errors.New(`both "sslcert" and "sslkey" are required`)
}
if sslcert != "" && sslkey != "" {
cert, err := tls.LoadX509KeyPair(sslcert, sslkey)
if err != nil {
return nil, fmt.Errorf("unable to read cert: %w", err)
}
tlsConfig.Certificates = []tls.Certificate{cert}
}
switch sslmode {
case "allow":
return []*tls.Config{nil, tlsConfig}, nil
case "prefer":
return []*tls.Config{tlsConfig, nil}, nil
case "require", "verify-ca", "verify-full":
return []*tls.Config{tlsConfig}, nil
default:
panic("BUG: bad sslmode should already have been caught")
}
}
func parsePort(s string) (uint16, error) {
port, err := strconv.ParseUint(s, 10, 16)
if err != nil {
return 0, err
}
if port < 1 || port > math.MaxUint16 {
return 0, errors.New("outside range")
}
return uint16(port), nil
}
func makeDefaultDialer() *net.Dialer {
return &net.Dialer{KeepAlive: 5 * time.Minute}
}
func makeDefaultResolver() *net.Resolver {
return net.DefaultResolver
}
func makeDefaultBuildFrontendFunc(minBufferLen int) BuildFrontendFunc {
return func(r io.Reader, w io.Writer) Frontend {
cr, err := chunkreader.NewConfig(r, chunkreader.Config{MinBufLen: minBufferLen})
if err != nil {
panic(fmt.Sprintf("BUG: chunkreader.NewConfig failed: %v", err))
}
frontend := pgproto3.NewFrontend(cr, w)
return frontend
}
}
func parseConnectTimeoutSetting(s string) (time.Duration, error) {
timeout, err := strconv.ParseInt(s, 10, 64)
if err != nil {
return 0, err
}
if timeout < 0 {
return 0, errors.New("negative timeout")
}
return time.Duration(timeout) * time.Second, nil
}
func makeConnectTimeoutDialFunc(timeout time.Duration) DialFunc {
d := makeDefaultDialer()
d.Timeout = timeout
return d.DialContext
}
// ValidateConnectTargetSessionAttrsReadWrite is an ValidateConnectFunc that implements libpq compatible
// target_session_attrs=read-write.
func ValidateConnectTargetSessionAttrsReadWrite(ctx context.Context, pgConn *PgConn) error {
result := pgConn.ExecParams(ctx, "show transaction_read_only", nil, nil, nil, nil).Read()
if result.Err != nil {
return result.Err
}
if string(result.Rows[0][0]) == "on" {
return errors.New("read only connection")
}
return nil
}