api: add OpenSSLDialer implementation

To disable SSL by default we want to transfer OpenSSLDialer
and any other SSL logic to the new go-tlsdialer repository.

go-tlsdialer serves as an interlayer between go-tarantool and
go-openssl. All SSL logic from go-tarantool is moved to the
go-tlsdialer.

go-tlsdialer still uses tarantool connection, but also
types and methods from go-openssl. This way we are
removing the direct go-openssl dependency from go-tarantool,
without creating a tarantool dependency in go-openssl.

Moved all SSL code from go-tarantool, some test helpers.

Part of tarantool/go-tarantool#301

Author: DerekBum

CHANGELOG.md

@@ -10,6 +10,9 @@ Versioning](http://semver.org/spec/v2.0.0.html) except to the first release.
 
 ### Added
 
+* `OpenSSLDialer` type to use SSL transport for `tarantool/go-tarantool/v2`
+  connection (#1).
+
 ### Changed
 
 ### Removed

README.md

@@ -18,6 +18,151 @@ To run a default set of tests:
 go test -v ./...
 ```
 
+## OpenSSLDialer
+
+User can create a dialer by filling the struct:
+```go
+// OpenSSLDialer allows to use SSL transport for connection.
+type OpenSSLDialer struct {
+	// Address is an address to connect.
+	// It could be specified in following ways:
+	//
+	// - TCP connections (tcp://192.168.1.1:3013, tcp://my.host:3013,
+	// tcp:192.168.1.1:3013, tcp:my.host:3013, 192.168.1.1:3013, my.host:3013)
+	//
+	// - Unix socket, first '/' or '.' indicates Unix socket
+	// (unix:///abs/path/tt.sock, unix:path/tt.sock, /abs/path/tt.sock,
+	// ./rel/path/tt.sock, unix/:path/tt.sock)
+	Address string
+	// Auth is an authentication method.
+	Auth tarantool.Auth
+	// Username for logging in to Tarantool.
+	User string
+	// User password for logging in to Tarantool.
+	Password string
+	// RequiredProtocol contains minimal protocol version and
+	// list of protocol features that should be supported by
+	// Tarantool server. By default, there are no restrictions.
+	RequiredProtocolInfo tarantool.ProtocolInfo
+	// SslKeyFile is a path to a private SSL key file.
+	SslKeyFile string
+	// SslCertFile is a path to an SSL certificate file.
+	SslCertFile string
+	// SslCaFile is a path to a trusted certificate authorities (CA) file.
+	SslCaFile string
+	// SslCiphers is a colon-separated (:) list of SSL cipher suites the connection
+	// can use.
+	//
+	// We don't provide a list of supported ciphers. This is what OpenSSL
+	// does. The only limitation is usage of TLSv1.2 (because other protocol
+	// versions don't seem to support the GOST cipher). To add additional
+	// ciphers (GOST cipher), you must configure OpenSSL.
+	//
+	// See also
+	//
+	// * https://www.openssl.org/docs/man1.1.1/man1/ciphers.html
+	SslCiphers string
+	// SslPassword is a password for decrypting the private SSL key file.
+	// The priority is as follows: try to decrypt with SslPassword, then
+	// try SslPasswordFile.
+	SslPassword string
+	// SslPasswordFile is a path to the list of passwords for decrypting
+	// the private SSL key file. The connection tries every line from the
+	// file as a password.
+	SslPasswordFile string
+}
+```
+To create a connection from the created dialer a `Dial` function could be used:
+```go
+package tarantool
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/tarantool/go-tarantool/v2"
+	"github.com/tarantool/go-tlsdialer"
+)
+
+func main() {
+	dialer := tlsdialer.OpenSSLDialer{
+		Address: "127.0.0.1:3301",
+		User:    "guest",
+	}
+	opts := tarantool.Opts{
+		Timeout: 5 * time.Second,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
+	defer cancel()
+
+	conn, err := tarantool.Connect(ctx, dialer, opts)
+	if err != nil {
+		fmt.Printf("Failed to create an example connection: %s", err)
+		return
+	}
+
+	// Use the connection.
+	data, err := conn.Do(tarantool.NewInsertRequest(999).
+		Tuple([]interface{}{99999, "BB"}),
+	).Get()
+	if err != nil {
+		fmt.Printf("Error: %s", err)
+	} else {
+		fmt.Printf("Data: %v", data)
+	}
+}
+```
+
+## Application build
+
+Since tlsdialer uses OpenSSL for connection to the Tarantool-EE, Cgo should be
+enabled while building and OpenSSL libraries and includes should be available
+in build time.
+
+### Building with system OpenSSL
+
+Build your application using the command:
+1. **Static build**.
+   ```shell
+   CGO_ENABLED=1 go build -ldflags "-linkmode external -extldflags '-static -lssl -lcrypto'" -o myapp main.go
+   ```
+2. **Dynamic build**.
+   ```shell
+   CGO_ENABLED=1 go build -o myapp main.go
+   ```
+
+### Building with a custom OpenSSL version
+
+OpenSSL could be build in two ways. Both of them require downloading the source
+code of OpenSSL. It could be done from the [official website](https://www.openssl.org/source/)
+or from the [GitHub repository](https://github.com/openssl/openssl).
+1. **Static build**. Run this command from the installation directory to configure
+   the OpenSSL:
+   ```shell
+   ./config no-shared --prefix=/tmp/openssl/
+   ```
+2. **Dynamic build**. Run this command from the installation directory to configure
+   the OpenSSL:
+   ```shell
+   ./config --prefix=/tmp/openssl/
+   ```
+   After configuring, run this command to install and build OpenSSL:
+   ```shell
+   make install
+   ```
+And then build your application using the command:
+1. **Static build**.
+   ```shell
+   CGO_ENABLED=1 CGO_CFLAGS="-I/tmp/openssl/include" CGO_LDFLAGS="-L/tmp/openssl/lib" PKG_CONFIG_PATH="/tmp/openssl/lib/pkgconfig" go build -ldflags "-linkmode=external -extldflags '-static -lssl -lcrypto'" -o myapp main.go
+   ```
+2. **Dynamic build**.
+   ```shell
+   CGO_ENABLED=1 CGO_CFLAGS="-I/tmp/openssl/include" CGO_LDFLAGS="-L/tmp/openssl/lib" PKG_CONFIG_PATH="/tmp/openssl/lib/pkgconfig" go build -o myapp main.go
+   ```
+After compiling your Go application, you can run it as usual.
+
 [godoc-badge]: https://pkg.go.dev/badge/github.com/tarantool/go-tlsdialer.svg
 [godoc-url]: https://pkg.go.dev/github.com/tarantool/go-tlsdialer
 [coverage-badge]: https://coveralls.io/repos/github/tarantool/go-tlsdialer/badge.svg?branch=master

conn.go

@@ -0,0 +1,66 @@
+package tlsdialer
+
+import (
+	"errors"
+	"io"
+	"net"
+
+	"github.com/tarantool/go-tarantool/v2"
+)
+
+type ttConn struct {
+	net    net.Conn
+	reader io.Reader
+	writer writeFlusher
+}
+
+// writeFlusher is the interface that groups the basic Write and Flush methods.
+type writeFlusher interface {
+	io.Writer
+	Flush() error
+}
+
+// Addr makes ttConn satisfy the Conn interface.
+func (c *ttConn) Addr() net.Addr {
+	return c.net.RemoteAddr()
+}
+
+// Read makes ttConn satisfy the Conn interface.
+func (c *ttConn) Read(p []byte) (int, error) {
+	return c.reader.Read(p)
+}
+
+// Write makes ttConn satisfy the Conn interface.
+func (c *ttConn) Write(p []byte) (int, error) {
+	var (
+		l   int
+		err error
+	)
+
+	if l, err = c.writer.Write(p); err != nil {
+		return l, err
+	} else if l != len(p) {
+		return l, errors.New("wrong length written")
+	}
+	return l, nil
+}
+
+// Flush makes ttConn satisfy the Conn interface.
+func (c *ttConn) Flush() error {
+	return c.writer.Flush()
+}
+
+// Close makes ttConn satisfy the Conn interface.
+func (c *ttConn) Close() error {
+	return c.net.Close()
+}
+
+// Greeting makes ttConn satisfy the Conn interface.
+func (c *ttConn) Greeting() tarantool.Greeting {
+	return tarantool.Greeting{}
+}
+
+// ProtocolInfo makes ttConn satisfy the Conn interface.
+func (c *ttConn) ProtocolInfo() tarantool.ProtocolInfo {
+	return tarantool.ProtocolInfo{}
+}

deadlineio.go

@@ -0,0 +1,31 @@
+package tlsdialer
+
+import (
+	"net"
+	"time"
+)
+
+type deadlineIO struct {
+	to time.Duration
+	c  net.Conn
+}
+
+func (d *deadlineIO) Write(b []byte) (n int, err error) {
+	if d.to > 0 {
+		if err := d.c.SetWriteDeadline(time.Now().Add(d.to)); err != nil {
+			return 0, err
+		}
+	}
+	n, err = d.c.Write(b)
+	return
+}
+
+func (d *deadlineIO) Read(b []byte) (n int, err error) {
+	if d.to > 0 {
+		if err := d.c.SetReadDeadline(time.Now().Add(d.to)); err != nil {
+			return 0, err
+		}
+	}
+	n, err = d.c.Read(b)
+	return
+}

dial.go

@@ -0,0 +1,138 @@
+package tlsdialer
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"net"
+	"os"
+	"strings"
+
+	"github.com/tarantool/go-openssl"
+)
+
+func sslDialContext(ctx context.Context, network, address string,
+	sslOpts opts) (connection net.Conn, err error) {
+	var sslCtx *openssl.Ctx
+	if sslCtx, err = sslCreateContext(sslOpts); err != nil {
+		return
+	}
+
+	return openssl.DialContext(ctx, network, address, sslCtx, 0)
+}
+
+func sslCreateContext(sslOpts opts) (sslCtx *openssl.Ctx, err error) {
+	// Require TLSv1.2, because other protocol versions don't seem to
+	// support the GOST cipher.
+	if sslCtx, err = openssl.NewCtxWithVersion(openssl.TLSv1_2); err != nil {
+		return
+	}
+	sslCtx.SetMaxProtoVersion(openssl.TLS1_2_VERSION)
+	sslCtx.SetMinProtoVersion(openssl.TLS1_2_VERSION)
+
+	if sslOpts.CertFile != "" {
+		if err = sslLoadCert(sslCtx, sslOpts.CertFile); err != nil {
+			return
+		}
+	}
+
+	if sslOpts.KeyFile != "" {
+		if err = sslLoadKey(sslCtx, sslOpts.KeyFile, sslOpts.Password,
+			sslOpts.PasswordFile); err != nil {
+			return
+		}
+	}
+
+	if sslOpts.CaFile != "" {
+		if err = sslCtx.LoadVerifyLocations(sslOpts.CaFile, ""); err != nil {
+			return
+		}
+		verifyFlags := openssl.VerifyPeer | openssl.VerifyFailIfNoPeerCert
+		sslCtx.SetVerify(verifyFlags, nil)
+	}
+
+	if sslOpts.Ciphers != "" {
+		if err = sslCtx.SetCipherList(sslOpts.Ciphers); err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+func sslLoadCert(ctx *openssl.Ctx, certFile string) (err error) {
+	var certBytes []byte
+	if certBytes, err = os.ReadFile(certFile); err != nil {
+		return
+	}
+
+	certs := openssl.SplitPEM(certBytes)
+	if len(certs) == 0 {
+		err = errors.New("No PEM certificate found in " + certFile)
+		return
+	}
+	first, certs := certs[0], certs[1:]
+
+	var cert *openssl.Certificate
+	if cert, err = openssl.LoadCertificateFromPEM(first); err != nil {
+		return
+	}
+	if err = ctx.UseCertificate(cert); err != nil {
+		return
+	}
+
+	for _, pem := range certs {
+		if cert, err = openssl.LoadCertificateFromPEM(pem); err != nil {
+			break
+		}
+		if err = ctx.AddChainCertificate(cert); err != nil {
+			break
+		}
+	}
+	return
+}
+
+func sslLoadKey(ctx *openssl.Ctx, keyFile string, password string,
+	passwordFile string) error {
+	var keyBytes []byte
+	var err, firstDecryptErr error
+
+	if keyBytes, err = os.ReadFile(keyFile); err != nil {
+		return err
+	}
+
+	// If the key is encrypted and password is not provided,
+	// openssl.LoadPrivateKeyFromPEM(keyBytes) asks to enter PEM pass phrase
+	// interactively. On the other hand,
+	// openssl.LoadPrivateKeyFromPEMWithPassword(keyBytes, password) works fine
+	// for non-encrypted key with any password, including empty string. If
+	// the key is encrypted, we fast fail with password error instead of
+	// requesting the pass phrase interactively.
+	passwords := []string{password}
+	if passwordFile != "" {
+		file, err := os.Open(passwordFile)
+		if err == nil {
+			defer file.Close()
+
+			scanner := bufio.NewScanner(file)
+			// Tarantool itself tries each password file line.
+			for scanner.Scan() {
+				password = strings.TrimSpace(scanner.Text())
+				passwords = append(passwords, password)
+			}
+		} else {
+			firstDecryptErr = err
+		}
+	}
+
+	for _, password := range passwords {
+		key, err := openssl.LoadPrivateKeyFromPEMWithPassword(keyBytes, password)
+		if err == nil {
+			return ctx.UsePrivateKey(key)
+		} else if firstDecryptErr == nil {
+			firstDecryptErr = err
+		}
+	}
+
+	return firstDecryptErr
+}