Postgres: Add support for scram sha 256 authentication (#18397)

Allow datasource connection to postgres with password "scram-sha-256" 
authentification.

Fixes #14662

go.mod

@@ -44,7 +44,7 @@ require (
 	github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 // indirect
 	github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 // indirect
 	github.com/klauspost/compress v1.4.1 // indirect
 	github.com/klauspost/compress v1.4.1 // indirect
 	github.com/klauspost/cpuid v1.2.0 // indirect
 	github.com/klauspost/cpuid v1.2.0 // indirect
-	github.com/lib/pq v1.0.0
+	github.com/lib/pq v1.2.0
 	github.com/mattn/go-colorable v0.1.1 // indirect
 	github.com/mattn/go-colorable v0.1.1 // indirect
 	github.com/mattn/go-isatty v0.0.7
 	github.com/mattn/go-isatty v0.0.7
 	github.com/mattn/go-sqlite3 v1.10.0
 	github.com/mattn/go-sqlite3 v1.10.0
@@ -52,7 +52,7 @@ require (
 	github.com/onsi/gomega v1.5.0 // indirect
 	github.com/onsi/gomega v1.5.0 // indirect
 	github.com/opentracing/opentracing-go v1.1.0
 	github.com/opentracing/opentracing-go v1.1.0
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/patrickmn/go-cache v2.1.0+incompatible
-	github.com/pkg/errors v0.8.1
+	github.com/pkg/errors v0.8.1 // indirect
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
 	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
 	github.com/prometheus/common v0.2.0
 	github.com/prometheus/common v0.2.0

go.sum

@@ -132,6 +132,8 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/lib/pq v1.0.0 h1:X5PMW56eZitiTeO7tKzZxFCSpbFZJtkMMooicw2us9A=
 github.com/lib/pq v1.0.0 h1:X5PMW56eZitiTeO7tKzZxFCSpbFZJtkMMooicw2us9A=
 github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
+github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
+github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
 github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
 github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
 github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=

vendor/github.com/lib/pq/.travis.sh

@@ -70,17 +70,4 @@ postgresql_uninstall() {
 	sudo rm -rf /var/lib/postgresql
 	sudo rm -rf /var/lib/postgresql
 }
 }
 
 
-megacheck_install() {
-	# Lock megacheck version at $MEGACHECK_VERSION to prevent spontaneous
-	# new error messages in old code.
-	go get -d honnef.co/go/tools/...
-	git -C $GOPATH/src/honnef.co/go/tools/ checkout $MEGACHECK_VERSION
-	go install honnef.co/go/tools/cmd/megacheck
-	megacheck --version
-}
-
-golint_install() {
-	go get github.com/golang/lint/golint
-}
-
 $1
 $1

vendor/github.com/lib/pq/README.md

@@ -10,7 +10,7 @@
 ## Docs
 ## Docs
 
 
 For detailed documentation and basic usage examples, please see the package
 For detailed documentation and basic usage examples, please see the package
-documentation at <http://godoc.org/github.com/lib/pq>.
+documentation at <https://godoc.org/github.com/lib/pq>.
 
 
 ## Tests
 ## Tests
 
 

vendor/github.com/lib/pq/buf.go

@@ -66,7 +66,7 @@ func (b *writeBuf) int16(n int) {
 }
 }
 
 
 func (b *writeBuf) string(s string) {
 func (b *writeBuf) string(s string) {
-	b.buf = append(b.buf, (s + "\000")...)
+	b.buf = append(append(b.buf, s...), '\000')
 }
 }
 
 
 func (b *writeBuf) byte(c byte) {
 func (b *writeBuf) byte(c byte) {

vendor/github.com/lib/pq/conn_go18.go

-// +build go1.8
-
 package pq
 package pq
 
 
 import (
 import (
@@ -9,6 +7,7 @@ import (
 	"fmt"
 	"fmt"
 	"io"
 	"io"
 	"io/ioutil"
 	"io/ioutil"
+	"time"
 )
 )
 
 
 // Implement the "QueryerContext" interface
 // Implement the "QueryerContext" interface
@@ -76,13 +75,32 @@ func (cn *conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx,
 	return tx, nil
 	return tx, nil
 }
 }
 
 
+func (cn *conn) Ping(ctx context.Context) error {
+	if finish := cn.watchCancel(ctx); finish != nil {
+		defer finish()
+	}
+	rows, err := cn.simpleQuery("SELECT 'lib/pq ping test';")
+	if err != nil {
+		return driver.ErrBadConn // https://golang.org/pkg/database/sql/driver/#Pinger
+	}
+	rows.Close()
+	return nil
+}
+
 func (cn *conn) watchCancel(ctx context.Context) func() {
 func (cn *conn) watchCancel(ctx context.Context) func() {
 	if done := ctx.Done(); done != nil {
 	if done := ctx.Done(); done != nil {
 		finished := make(chan struct{})
 		finished := make(chan struct{})
 		go func() {
 		go func() {
 			select {
 			select {
 			case <-done:
 			case <-done:
-				_ = cn.cancel()
+				// At this point the function level context is canceled,
+				// so it must not be used for the additional network
+				// request to cancel the query.
+				// Create a new context to pass into the dial.
+				ctxCancel, cancel := context.WithTimeout(context.Background(), time.Second*10)
+				defer cancel()
+
+				_ = cn.cancel(ctxCancel)
 				finished <- struct{}{}
 				finished <- struct{}{}
 			case <-finished:
 			case <-finished:
 			}
 			}
@@ -97,8 +115,8 @@ func (cn *conn) watchCancel(ctx context.Context) func() {
 	return nil
 	return nil
 }
 }
 
 
-func (cn *conn) cancel() error {
-	c, err := dial(cn.dialer, cn.opts)
+func (cn *conn) cancel(ctx context.Context) error {
+	c, err := dial(ctx, cn.dialer, cn.opts)
 	if err != nil {
 	if err != nil {
 		return err
 		return err
 	}
 	}

vendor/github.com/lib/pq/connector.go

-// +build go1.10
-
 package pq
 package pq
 
 
 import (
 import (
 	"context"
 	"context"
 	"database/sql/driver"
 	"database/sql/driver"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
 )
 )
 
 
 // Connector represents a fixed configuration for the pq driver with a given
 // Connector represents a fixed configuration for the pq driver with a given
@@ -14,30 +16,95 @@ import (
 //
 //
 // See https://golang.org/pkg/database/sql/driver/#Connector.
 // See https://golang.org/pkg/database/sql/driver/#Connector.
 // See https://golang.org/pkg/database/sql/#OpenDB.
 // See https://golang.org/pkg/database/sql/#OpenDB.
-type connector struct {
-	name string
+type Connector struct {
+	opts   values
+	dialer Dialer
 }
 }
 
 
 // Connect returns a connection to the database using the fixed configuration
 // Connect returns a connection to the database using the fixed configuration
 // of this Connector. Context is not used.
 // of this Connector. Context is not used.
-func (c *connector) Connect(_ context.Context) (driver.Conn, error) {
-	return (&Driver{}).Open(c.name)
+func (c *Connector) Connect(ctx context.Context) (driver.Conn, error) {
+	return c.open(ctx)
 }
 }
 
 
 // Driver returnst the underlying driver of this Connector.
 // Driver returnst the underlying driver of this Connector.
-func (c *connector) Driver() driver.Driver {
+func (c *Connector) Driver() driver.Driver {
 	return &Driver{}
 	return &Driver{}
 }
 }
 
 
-var _ driver.Connector = &connector{}
-
 // NewConnector returns a connector for the pq driver in a fixed configuration
 // NewConnector returns a connector for the pq driver in a fixed configuration
-// with the given name. The returned connector can be used to create any number
+// with the given dsn. The returned connector can be used to create any number
 // of equivalent Conn's. The returned connector is intended to be used with
 // of equivalent Conn's. The returned connector is intended to be used with
 // database/sql.OpenDB.
 // database/sql.OpenDB.
 //
 //
 // See https://golang.org/pkg/database/sql/driver/#Connector.
 // See https://golang.org/pkg/database/sql/driver/#Connector.
 // See https://golang.org/pkg/database/sql/#OpenDB.
 // See https://golang.org/pkg/database/sql/#OpenDB.
-func NewConnector(name string) (driver.Connector, error) {
-	return &connector{name: name}, nil
+func NewConnector(dsn string) (*Connector, error) {
+	var err error
+	o := make(values)
+
+	// A number of defaults are applied here, in this order:
+	//
+	// * Very low precedence defaults applied in every situation
+	// * Environment variables
+	// * Explicitly passed connection information
+	o["host"] = "localhost"
+	o["port"] = "5432"
+	// N.B.: Extra float digits should be set to 3, but that breaks
+	// Postgres 8.4 and older, where the max is 2.
+	o["extra_float_digits"] = "2"
+	for k, v := range parseEnviron(os.Environ()) {
+		o[k] = v
+	}
+
+	if strings.HasPrefix(dsn, "postgres://") || strings.HasPrefix(dsn, "postgresql://") {
+		dsn, err = ParseURL(dsn)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := parseOpts(dsn, o); err != nil {
+		return nil, err
+	}
+
+	// Use the "fallback" application name if necessary
+	if fallback, ok := o["fallback_application_name"]; ok {
+		if _, ok := o["application_name"]; !ok {
+			o["application_name"] = fallback
+		}
+	}
+
+	// We can't work with any client_encoding other than UTF-8 currently.
+	// However, we have historically allowed the user to set it to UTF-8
+	// explicitly, and there's no reason to break such programs, so allow that.
+	// Note that the "options" setting could also set client_encoding, but
+	// parsing its value is not worth it.  Instead, we always explicitly send
+	// client_encoding as a separate run-time parameter, which should override
+	// anything set in options.
+	if enc, ok := o["client_encoding"]; ok && !isUTF8(enc) {
+		return nil, errors.New("client_encoding must be absent or 'UTF8'")
+	}
+	o["client_encoding"] = "UTF8"
+	// DateStyle needs a similar treatment.
+	if datestyle, ok := o["datestyle"]; ok {
+		if datestyle != "ISO, MDY" {
+			return nil, fmt.Errorf("setting datestyle must be absent or %v; got %v", "ISO, MDY", datestyle)
+		}
+	} else {
+		o["datestyle"] = "ISO, MDY"
+	}
+
+	// If a user is not provided by any other means, the last
+	// resort is to use the current operating system provided user
+	// name.
+	if _, ok := o["user"]; !ok {
+		u, err := userCurrent()
+		if err != nil {
+			return nil, err
+		}
+		o["user"] = u
+	}
+
+	return &Connector{opts: o, dialer: defaultDialer{}}, nil
 }
 }

vendor/github.com/lib/pq/doc.go

@@ -239,7 +239,7 @@ for more information).  Note that the channel name will be truncated to 63
 bytes by the PostgreSQL server.
 bytes by the PostgreSQL server.
 
 
 You can find a complete, working example of Listener usage at
 You can find a complete, working example of Listener usage at
-http://godoc.org/github.com/lib/pq/example/listen.
+https://godoc.org/github.com/lib/pq/example/listen.
 
 
 */
 */
 package pq
 package pq

vendor/github.com/lib/pq/encode.go

@@ -117,11 +117,10 @@ func textDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) interfa
 		}
 		}
 		return i
 		return i
 	case oid.T_float4, oid.T_float8:
 	case oid.T_float4, oid.T_float8:
-		bits := 64
-		if typ == oid.T_float4 {
-			bits = 32
-		}
-		f, err := strconv.ParseFloat(string(s), bits)
+		// We always use 64 bit parsing, regardless of whether the input text is for
+		// a float4 or float8, because clients expect float64s for all float datatypes
+		// and returning a 32-bit parsed float64 produces lossy results.
+		f, err := strconv.ParseFloat(string(s), 64)
 		if err != nil {
 		if err != nil {
 			errorf("%s", err)
 			errorf("%s", err)
 		}
 		}

vendor/github.com/lib/pq/error.go

@@ -478,13 +478,13 @@ func errRecoverNoErrBadConn(err *error) {
 	}
 	}
 }
 }
 
 
-func (c *conn) errRecover(err *error) {
+func (cn *conn) errRecover(err *error) {
 	e := recover()
 	e := recover()
 	switch v := e.(type) {
 	switch v := e.(type) {
 	case nil:
 	case nil:
 		// Do nothing
 		// Do nothing
 	case runtime.Error:
 	case runtime.Error:
-		c.bad = true
+		cn.bad = true
 		panic(v)
 		panic(v)
 	case *Error:
 	case *Error:
 		if v.Fatal() {
 		if v.Fatal() {
@@ -493,7 +493,7 @@ func (c *conn) errRecover(err *error) {
 			*err = v
 			*err = v
 		}
 		}
 	case *net.OpError:
 	case *net.OpError:
-		c.bad = true
+		cn.bad = true
 		*err = v
 		*err = v
 	case error:
 	case error:
 		if v == io.EOF || v.(error).Error() == "remote error: handshake failure" {
 		if v == io.EOF || v.(error).Error() == "remote error: handshake failure" {
@@ -503,13 +503,13 @@ func (c *conn) errRecover(err *error) {
 		}
 		}
 
 
 	default:
 	default:
-		c.bad = true
+		cn.bad = true
 		panic(fmt.Sprintf("unknown error: %#v", e))
 		panic(fmt.Sprintf("unknown error: %#v", e))
 	}
 	}
 
 
 	// Any time we return ErrBadConn, we need to remember it since *Tx doesn't
 	// Any time we return ErrBadConn, we need to remember it since *Tx doesn't
 	// mark the connection bad in database/sql.
 	// mark the connection bad in database/sql.
 	if *err == driver.ErrBadConn {
 	if *err == driver.ErrBadConn {
-		c.bad = true
+		cn.bad = true
 	}
 	}
 }
 }

vendor/github.com/lib/pq/scram/scram.go

+// Copyright (c) 2014 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Package scram implements a SCRAM-{SHA-1,etc} client per RFC5802.
+//
+// http://tools.ietf.org/html/rfc5802
+//
+package scram
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"hash"
+	"strconv"
+	"strings"
+)
+
+// Client implements a SCRAM-* client (SCRAM-SHA-1, SCRAM-SHA-256, etc).
+//
+// A Client may be used within a SASL conversation with logic resembling:
+//
+//    var in []byte
+//    var client = scram.NewClient(sha1.New, user, pass)
+//    for client.Step(in) {
+//            out := client.Out()
+//            // send out to server
+//            in := serverOut
+//    }
+//    if client.Err() != nil {
+//            // auth failed
+//    }
+//
+type Client struct {
+	newHash func() hash.Hash
+
+	user string
+	pass string
+	step int
+	out  bytes.Buffer
+	err  error
+
+	clientNonce []byte
+	serverNonce []byte
+	saltedPass  []byte
+	authMsg     bytes.Buffer
+}
+
+// NewClient returns a new SCRAM-* client with the provided hash algorithm.
+//
+// For SCRAM-SHA-256, for example, use:
+//
+//    client := scram.NewClient(sha256.New, user, pass)
+//
+func NewClient(newHash func() hash.Hash, user, pass string) *Client {
+	c := &Client{
+		newHash: newHash,
+		user:    user,
+		pass:    pass,
+	}
+	c.out.Grow(256)
+	c.authMsg.Grow(256)
+	return c
+}
+
+// Out returns the data to be sent to the server in the current step.
+func (c *Client) Out() []byte {
+	if c.out.Len() == 0 {
+		return nil
+	}
+	return c.out.Bytes()
+}
+
+// Err returns the error that ocurred, or nil if there were no errors.
+func (c *Client) Err() error {
+	return c.err
+}
+
+// SetNonce sets the client nonce to the provided value.
+// If not set, the nonce is generated automatically out of crypto/rand on the first step.
+func (c *Client) SetNonce(nonce []byte) {
+	c.clientNonce = nonce
+}
+
+var escaper = strings.NewReplacer("=", "=3D", ",", "=2C")
+
+// Step processes the incoming data from the server and makes the
+// next round of data for the server available via Client.Out.
+// Step returns false if there are no errors and more data is
+// still expected.
+func (c *Client) Step(in []byte) bool {
+	c.out.Reset()
+	if c.step > 2 || c.err != nil {
+		return false
+	}
+	c.step++
+	switch c.step {
+	case 1:
+		c.err = c.step1(in)
+	case 2:
+		c.err = c.step2(in)
+	case 3:
+		c.err = c.step3(in)
+	}
+	return c.step > 2 || c.err != nil
+}
+
+func (c *Client) step1(in []byte) error {
+	if len(c.clientNonce) == 0 {
+		const nonceLen = 16
+		buf := make([]byte, nonceLen+b64.EncodedLen(nonceLen))
+		if _, err := rand.Read(buf[:nonceLen]); err != nil {
+			return fmt.Errorf("cannot read random SCRAM-SHA-256 nonce from operating system: %v", err)
+		}
+		c.clientNonce = buf[nonceLen:]
+		b64.Encode(c.clientNonce, buf[:nonceLen])
+	}
+	c.authMsg.WriteString("n=")
+	escaper.WriteString(&c.authMsg, c.user)
+	c.authMsg.WriteString(",r=")
+	c.authMsg.Write(c.clientNonce)
+
+	c.out.WriteString("n,,")
+	c.out.Write(c.authMsg.Bytes())
+	return nil
+}
+
+var b64 = base64.StdEncoding
+
+func (c *Client) step2(in []byte) error {
+	c.authMsg.WriteByte(',')
+	c.authMsg.Write(in)
+
+	fields := bytes.Split(in, []byte(","))
+	if len(fields) != 3 {
+		return fmt.Errorf("expected 3 fields in first SCRAM-SHA-256 server message, got %d: %q", len(fields), in)
+	}
+	if !bytes.HasPrefix(fields[0], []byte("r=")) || len(fields[0]) < 2 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 nonce: %q", fields[0])
+	}
+	if !bytes.HasPrefix(fields[1], []byte("s=")) || len(fields[1]) < 6 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 salt: %q", fields[1])
+	}
+	if !bytes.HasPrefix(fields[2], []byte("i=")) || len(fields[2]) < 6 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 iteration count: %q", fields[2])
+	}
+
+	c.serverNonce = fields[0][2:]
+	if !bytes.HasPrefix(c.serverNonce, c.clientNonce) {
+		return fmt.Errorf("server SCRAM-SHA-256 nonce is not prefixed by client nonce: got %q, want %q+\"...\"", c.serverNonce, c.clientNonce)
+	}
+
+	salt := make([]byte, b64.DecodedLen(len(fields[1][2:])))
+	n, err := b64.Decode(salt, fields[1][2:])
+	if err != nil {
+		return fmt.Errorf("cannot decode SCRAM-SHA-256 salt sent by server: %q", fields[1])
+	}
+	salt = salt[:n]
+	iterCount, err := strconv.Atoi(string(fields[2][2:]))
+	if err != nil {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 iteration count: %q", fields[2])
+	}
+	c.saltPassword(salt, iterCount)
+
+	c.authMsg.WriteString(",c=biws,r=")
+	c.authMsg.Write(c.serverNonce)
+
+	c.out.WriteString("c=biws,r=")
+	c.out.Write(c.serverNonce)
+	c.out.WriteString(",p=")
+	c.out.Write(c.clientProof())
+	return nil
+}
+
+func (c *Client) step3(in []byte) error {
+	var isv, ise bool
+	var fields = bytes.Split(in, []byte(","))
+	if len(fields) == 1 {
+		isv = bytes.HasPrefix(fields[0], []byte("v="))
+		ise = bytes.HasPrefix(fields[0], []byte("e="))
+	}
+	if ise {
+		return fmt.Errorf("SCRAM-SHA-256 authentication error: %s", fields[0][2:])
+	} else if !isv {
+		return fmt.Errorf("unsupported SCRAM-SHA-256 final message from server: %q", in)
+	}
+	if !bytes.Equal(c.serverSignature(), fields[0][2:]) {
+		return fmt.Errorf("cannot authenticate SCRAM-SHA-256 server signature: %q", fields[0][2:])
+	}
+	return nil
+}
+
+func (c *Client) saltPassword(salt []byte, iterCount int) {
+	mac := hmac.New(c.newHash, []byte(c.pass))
+	mac.Write(salt)
+	mac.Write([]byte{0, 0, 0, 1})
+	ui := mac.Sum(nil)
+	hi := make([]byte, len(ui))
+	copy(hi, ui)
+	for i := 1; i < iterCount; i++ {
+		mac.Reset()
+		mac.Write(ui)
+		mac.Sum(ui[:0])
+		for j, b := range ui {
+			hi[j] ^= b
+		}
+	}
+	c.saltedPass = hi
+}
+
+func (c *Client) clientProof() []byte {
+	mac := hmac.New(c.newHash, c.saltedPass)
+	mac.Write([]byte("Client Key"))
+	clientKey := mac.Sum(nil)
+	hash := c.newHash()
+	hash.Write(clientKey)
+	storedKey := hash.Sum(nil)
+	mac = hmac.New(c.newHash, storedKey)
+	mac.Write(c.authMsg.Bytes())
+	clientProof := mac.Sum(nil)
+	for i, b := range clientKey {
+		clientProof[i] ^= b
+	}
+	clientProof64 := make([]byte, b64.EncodedLen(len(clientProof)))
+	b64.Encode(clientProof64, clientProof)
+	return clientProof64
+}
+
+func (c *Client) serverSignature() []byte {
+	mac := hmac.New(c.newHash, c.saltedPass)
+	mac.Write([]byte("Server Key"))
+	serverKey := mac.Sum(nil)
+
+	mac = hmac.New(c.newHash, serverKey)
+	mac.Write(c.authMsg.Bytes())
+	serverSignature := mac.Sum(nil)
+
+	encoded := make([]byte, b64.EncodedLen(len(serverSignature)))
+	b64.Encode(encoded, serverSignature)
+	return encoded
+}

vendor/github.com/lib/pq/ssl.go

@@ -58,7 +58,13 @@ func ssl(o values) (func(net.Conn) (net.Conn, error), error) {
 	if err != nil {
 	if err != nil {
 		return nil, err
 		return nil, err
 	}
 	}
-	sslRenegotiation(&tlsConf)
+
+	// Accept renegotiation requests initiated by the backend.
+	//
+	// Renegotiation was deprecated then removed from PostgreSQL 9.5, but
+	// the default configuration of older versions has it enabled. Redshift
+	// also initiates renegotiations and cannot be reconfigured.
+	tlsConf.Renegotiation = tls.RenegotiateFreelyAsClient
 
 
 	return func(conn net.Conn) (net.Conn, error) {
 	return func(conn net.Conn) (net.Conn, error) {
 		client := tls.Client(conn, &tlsConf)
 		client := tls.Client(conn, &tlsConf)

vendor/github.com/lib/pq/ssl_go1.7.go

-// +build go1.7
-
-package pq
-
-import "crypto/tls"
-
-// Accept renegotiation requests initiated by the backend.
-//
-// Renegotiation was deprecated then removed from PostgreSQL 9.5, but
-// the default configuration of older versions has it enabled. Redshift
-// also initiates renegotiations and cannot be reconfigured.
-func sslRenegotiation(conf *tls.Config) {
-	conf.Renegotiation = tls.RenegotiateFreelyAsClient
-}

vendor/github.com/lib/pq/ssl_renegotiation.go

-// +build !go1.7
-
-package pq
-
-import "crypto/tls"
-
-// Renegotiation is not supported by crypto/tls until Go 1.7.
-func sslRenegotiation(*tls.Config) {}

vendor/modules.txt

@@ -139,9 +139,10 @@ github.com/klauspost/compress/gzip
 github.com/klauspost/compress/flate
 github.com/klauspost/compress/flate
 # github.com/klauspost/cpuid v1.2.0
 # github.com/klauspost/cpuid v1.2.0
 github.com/klauspost/cpuid
 github.com/klauspost/cpuid
-# github.com/lib/pq v1.0.0
+# github.com/lib/pq v1.2.0
 github.com/lib/pq
 github.com/lib/pq
 github.com/lib/pq/oid
 github.com/lib/pq/oid
+github.com/lib/pq/scram
 # github.com/mattn/go-colorable v0.1.1
 # github.com/mattn/go-colorable v0.1.1
 github.com/mattn/go-colorable
 github.com/mattn/go-colorable
 # github.com/mattn/go-isatty v0.0.7
 # github.com/mattn/go-isatty v0.0.7