support p12 extraction in format command

command/certificate/format.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/x509"
 	"encoding/pem"
+	"github.com/smallstep/cli/crypto/pemutil"
 	"os"
 
 	"github.com/pkg/errors"
@@ -13,23 +14,28 @@ import (
 	"github.com/smallstep/cli/ui"
 	"github.com/smallstep/cli/utils"
 	"github.com/urfave/cli"
+
+	"software.sslmate.com/src/go-pkcs12"
 )
 
 func formatCommand() cli.Command {
 	return cli.Command{
-		Name:      "format",
-		Action:    command.ActionFunc(formatAction),
-		Usage:     `reformat certificate`,
-		UsageText: `**step certificate format** <crt_file> [**--out**=<file>]`,
+		Name:   "format",
+		Action: command.ActionFunc(formatAction),
+		Usage:  `reformat certificate`,
+		UsageText: `**step certificate format** <src_file> [**--crt**=<file>] [**--key**=<file>]
+[**--ca**=<file>] [**--out**=<file>]`,
 		Description: `**step certificate format** prints the certificate or CSR in a different format.
 
-Only 2 formats are currently supported; PEM and ASN.1 DER. This tool will convert
+If either PEM or ASN.1 DER is provided as a positional argument, this tool will convert
 a certificate or CSR in one format to the other.
 
+If PFX / PKCS12 file is provided, it extracts a certificate and private key from the input.
+
 ## POSITIONAL ARGUMENTS
 
-<crt_file>
-:  Path to a certificate or CSR file.
+<src_file>
+:  Path to a certificate or CSR file, or .p12 file when you specify --crt option.
 
 ## EXIT CODES
 
@@ -51,12 +57,50 @@ Convert PEM format to DER and write to disk:
 '''
 $ step certificate format foo.pem --out foo.der
 '''
+
+Convert a .p12 file to a certificate and private key:
+
+'''
+$ step certificate format foo.p12 --crt foo.crt --key foo.key
+'''
+
+Convert a .p12 file to a certificate, private key and intermediate certificates:
+
+'''
+$ step certificate format foo.p12 --crt foo.crt --key foo.key --ca intermediate.crt
+'''
+
+Get certificates from "trust store" for Java applications:
+
+'''
+$ step certificate format trust.p12 --ca ca.crt
+'''
 `,
 		Flags: []cli.Flag{
+			cli.StringFlag{
+				Name: "crt",
+				Usage: `The destination path to the <file>
+to which a certificate will be extracted from .p12 file.`,
+			},
+			cli.StringFlag{
+				Name: "key",
+				Usage: `The destination path to the <file>
+to which a key will be extracted from .p12 file.`,
+			},
+			cli.StringFlag{
+				Name: "ca",
+				Usage: `The destination path to the <file>
+to which intermediate certificates will be extracted from .p12 file.`,
+			},
+			cli.StringFlag{
+				Name:  "password-file",
+				Usage: `The path to the <file> containing the password to decrypt the .p12 file.`,
+			},
 			cli.StringFlag{
 				Name:  "out",
 				Usage: `Path to write the reformatted result.`,
 			},
+			flags.NoPassword,
 			flags.Force,
 		},
 	}
@@ -67,6 +111,16 @@ func formatAction(ctx *cli.Context) error {
 		return err
 	}
 
+	targetCrtFile := ctx.String("crt")
+	targetCAFile := ctx.String("ca")
+	// if --crt or --ca option are set, the input is .p12 file
+	if targetCrtFile != "" || targetCAFile != "" {
+		if err := formatP12Action(ctx); err != nil {
+			return err
+		}
+		return nil
+	}
+
 	var (
 		out = ctx.String("out")
 		ob  []byte
@@ -151,3 +205,96 @@ func decodeCertificatePem(b []byte) ([]byte, error) {
 
 	return nil, errors.Errorf("error decoding certificate: invalid PEM block")
 }
+
+func formatP12Action(ctx *cli.Context) error {
+
+	p12File := ctx.Args().Get(0)
+	crtFile := ctx.String("crt")
+	keyFile := ctx.String("key")
+	caFile := ctx.String("ca")
+
+	var err error
+	var password string
+	if passwordFile := ctx.String("password-file"); passwordFile != "" {
+		password, err = utils.ReadStringPasswordFromFile(passwordFile)
+		if err != nil {
+			return err
+		}
+	}
+
+	if password == "" && !ctx.Bool("no-password") {
+		pass, err := ui.PromptPassword("Please enter a password to decrypt the .p12 file")
+		if err != nil {
+			return errs.Wrap(err, "error reading password")
+		}
+		password = string(pass)
+	}
+
+	p12Data, err := utils.ReadFile(p12File)
+	if err != nil {
+		return errs.Wrap(err, "error reading file %s", p12File)
+	}
+
+	if crtFile != "" && keyFile != "" {
+		// If we have a destination crt path and a key path,
+		// we are extracting those two from the .p12 file
+		key, crt, CAs, err := pkcs12.DecodeChain(p12Data, password)
+		if err != nil {
+			return errs.Wrap(err, "failed to decode PKCS12 data")
+		}
+
+		_, err = pemutil.Serialize(key, pemutil.ToFile(keyFile, 0600))
+		if err != nil {
+			return errs.Wrap(err, "failed to serialize private key")
+		}
+
+		_, err = pemutil.Serialize(crt, pemutil.ToFile(crtFile, 0600))
+		if err != nil {
+			return errs.Wrap(err, "failed to serialize certificate")
+		}
+
+		if caFile != "" {
+			if err := extractCerts(CAs, caFile); err != nil {
+				return errs.Wrap(err, "failed to serialize CA certificates")
+			}
+		}
+
+	} else {
+		// If we have only --ca flags,
+		// we are extracting from trust store
+		certs, err := pkcs12.DecodeTrustStore(p12Data, password)
+		if err != nil {
+			return errs.Wrap(err, "failed to decode trust store")
+		}
+		if err := extractCerts(certs, caFile); err != nil {
+			return errs.Wrap(err, "failed to serialize CA certificates")
+		}
+	}
+
+	if crtFile != "" {
+		ui.Printf("Your certificate has been saved in %s.\n", crtFile)
+	}
+	if keyFile != "" {
+		ui.Printf("Your private key has been saved in %s.\n", keyFile)
+	}
+	if caFile != "" {
+		ui.Printf("Your CA certificate has been saved in %s.\n", caFile)
+	}
+
+	return nil
+}
+
+func extractCerts(certs []*x509.Certificate, filename string) error {
+	var data []byte
+	for _, cert := range certs {
+		pemblk, err := pemutil.Serialize(cert)
+		if err != nil {
+			return err
+		}
+		data = append(data, pem.EncodeToMemory(pemblk)...)
+	}
+	if err := utils.WriteFile(filename, data, 0600); err != nil {
+		return err
+	}
+	return nil
+}

integration/certificate_p12_test.go

@@ -0,0 +1,94 @@
+//go:build integration
+
+package integration
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/smallstep/assert"
+	"github.com/smallstep/cli/crypto/pemutil"
+	"github.com/smallstep/cli/utils"
+)
+
+func TestCertificateP12(t *testing.T) {
+	setup()
+	t.Run("extracted cert and key are equal to p12 inputs", func(t *testing.T) {
+		NewCLICommand().
+			setCommand(fmt.Sprintf("../bin/step certificate p12 %s %s %s", temp("foo.p12"), temp("foo.crt"), temp("foo.key"))).
+			setFlag("ca", temp("intermediate-ca.crt")).
+			setFlag("no-password", "").
+			setFlag("insecure", "").
+			run()
+
+		NewCLICommand().
+			setCommand(fmt.Sprintf("../bin/step certificate format %s", temp("foo.p12"))).
+			setFlag("crt", temp("foo_out.crt")).
+			setFlag("key", temp("foo_out.key")).
+			setFlag("ca", temp("intermediate-ca_out0.crt")).
+			setFlag("no-password", "").
+			run()
+
+		foo_crt, _ := pemutil.ReadCertificate(temp("foo.crt"))
+		foo_crt_out, _ := pemutil.ReadCertificate(temp("foo_out.crt"))
+		assert.Equals(t, foo_crt, foo_crt_out)
+
+		foo_key, _ := utils.ReadFile(temp("foo.key"))
+		foo_out_key, _ := utils.ReadFile(temp("foo_out.key"))
+		assert.Equals(t, foo_key, foo_out_key)
+
+		foo_ca, _ := pemutil.ReadCertificate(temp("intermediate-ca_out0.crt"))
+		foo_ca_out, _ := pemutil.ReadCertificate(temp("intermediate-ca_out0.crt"))
+		assert.Equals(t, foo_ca, foo_ca_out)
+	})
+
+	t.Run("extracted trust store is equal to p12 input", func(t *testing.T) {
+		NewCLICommand().
+			setCommand(fmt.Sprintf("../bin/step certificate p12 %s", temp("truststore.p12"))).
+			setFlag("ca", temp("intermediate-ca.crt")).
+			setFlag("no-password", "").
+			setFlag("insecure", "").
+			run()
+
+		NewCLICommand().
+			setCommand(fmt.Sprintf("../bin/step certificate format %s", temp("truststore.p12"))).
+			setFlag("ca", temp("intermediate-ca_out1.crt")).
+			setFlag("no-password", "").
+			run()
+
+		ca, _ := pemutil.ReadCertificate(temp("intermediate-ca.crt"))
+		ca_out, _ := pemutil.ReadCertificate(temp("intermediate-ca_out1.crt"))
+		assert.Equals(t, ca, ca_out)
+	})
+}
+
+func setup() {
+	NewCLICommand().
+		setCommand(fmt.Sprintf("../bin/step certificate create root-ca %s %s", temp("root-ca.crt"), temp("root-ca.key"))).
+		setFlag("profile", "root-ca").
+		setFlag("no-password", "").
+		setFlag("insecure", "").
+		run()
+
+	NewCLICommand().
+		setCommand(fmt.Sprintf("../bin/step certificate create intermediate-ca %s %s", temp("intermediate-ca.crt"), temp("intermediate-ca.key"))).
+		setFlag("profile", "intermediate-ca").
+		setFlag("ca", temp("root-ca.crt")).
+		setFlag("ca-key", temp("root-ca.key")).
+		setFlag("no-password", "").
+		setFlag("insecure", "").
+		run()
+
+	NewCLICommand().
+		setCommand(fmt.Sprintf("../bin/step certificate create foo %s %s", temp("foo.crt"), temp("foo.key"))).
+		setFlag("profile", "leaf").
+		setFlag("ca", temp("intermediate-ca.crt")).
+		setFlag("ca-key", temp("intermediate-ca.key")).
+		setFlag("no-password", "").
+		setFlag("insecure", "").
+		run()
+}
+
+func temp(filename string) string {
+	return fmt.Sprintf("%s/%s", TempDirectory, filename)
+}