Add gosop supports subcommand

cmd/commands.go

@@ -2,6 +2,8 @@
 package cmd
 
 import (
+	"io"
+
 	"github.com/urfave/cli/v2"
 )
 
@@ -25,6 +27,7 @@ var All = []*cli.Command{
 		Usage:     "List profiles for subcommands",
 		UsageText: "gosop list-profiles SUBCOMMAND",
 		Flags:     []cli.Flag{},
+		Before: BeforeListProfiles,
 		Action: func(c *cli.Context) error {
 			return ListProfiles(c.Args().Slice()...)
 		},
@@ -39,6 +42,7 @@ var All = []*cli.Command{
 			keyPasswordFlag,
 			signingOnlyFlag,
 		},
+		Before: BeforeGenerateKey,
 		Action: func(c *cli.Context) error {
 			return GenerateKey(c.Args().Slice()...)
 		},
@@ -63,6 +67,7 @@ var All = []*cli.Command{
 			asFlag,
 			keyPasswordFlag,
 		},
+		Before: BeforeSign,
 		Action: func(c *cli.Context) error {
 			return Sign(c.Args().Slice()...)
 		},
@@ -75,6 +80,7 @@ var All = []*cli.Command{
 			notBeforeFlag,
 			notAfterFlag,
 		},
+		Before: BeforeVerify,
 		Action: func(c *cli.Context) error {
 			return Verify(c.Args().Slice()...)
 		},
@@ -88,6 +94,7 @@ var All = []*cli.Command{
 			asSignedFlag,
 			keyPasswordFlag,
 		},
+		Before: BeforeInlineSign,
 		Action: func(c *cli.Context) error {
 			return InlineSign(c.Args().Slice()...)
 		},
@@ -101,6 +108,7 @@ var All = []*cli.Command{
 			notAfterFlag,
 			verificationsOutFlag,
 		},
+		Before: BeforeInlineVerify,
 		Action: func(c *cli.Context) error {
 			return InlineVerify(c.Args().Slice()...)
 		},
@@ -129,6 +137,7 @@ var All = []*cli.Command{
 			signWithFlag,
 			keyPasswordFlag,
 		},
+		Before: BeforeEncrypt,
 		Action: func(c *cli.Context) error {
 			return Encrypt(c.Args().Slice()...)
 		},
@@ -147,6 +156,7 @@ var All = []*cli.Command{
 			verifyNotAfterFlag,
 			keyPasswordFlag,
 		},
+		Before: BeforeDecrypt,
 		Action: func(c *cli.Context) error {
 			return Decrypt(c.Args().Slice()...)
 		},
@@ -167,4 +177,20 @@ var All = []*cli.Command{
 			return DearmorComm()
 		},
 	},
+	{
+		Name:      "supports",
+		Usage:     "Check whether gosop supports the given subcommand and options",
+		UsageText: "gosop supports COMMAND",
+		Action: func(c *cli.Context) error {
+			for _, c := range c.App.Commands {
+				c.Action = func(ctx *cli.Context) error {
+					return nil // Don't run the actual action.
+				}
+			}
+			c.App.Writer = io.Discard // Discard help text.
+			args := []string{"gosop"}
+			args = append(args, c.Args().Slice()...)
+			return c.App.Run(args)
+		},
+	},
 }

cmd/decrypt.go

@@ -3,11 +3,14 @@ package cmd
 import (
 	"encoding/hex"
 	"errors"
+	"fmt"
 	"io"
 	"os"
 	"strconv"
 	"strings"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 
 	"github.com/ProtonMail/gopenpgp/v3/constants"
@@ -24,17 +27,27 @@ var symKeyAlgos = map[packet.CipherFunction]string{
 	packet.CipherAES256: constants.AES256,
 }
 
+func BeforeDecrypt(c *cli.Context) error {
+	if !c.Args().Present() && password == "" && sessionKey == "" {
+		fmt.Fprintln(os.Stderr, "Please provide decryption keys, passphrase, or session key.")
+		return Err19
+	}
+	if c.Args().Present() && password != "" ||
+		c.Args().Present() && sessionKey != "" ||
+		password != "" && sessionKey != "" {
+		fmt.Fprintln(os.Stderr, "Can't decrypt with more than one of keys, passphrase and session key.")
+		return Err37
+	}
+	return nil
+}
+
 // Decrypt takes the data from stdin and decrypts it with the key file passed as
 // argument, or a passphrase in a file passed with the --with-password flag.
-// Note: Can't encrypt both symmetrically (passphrase) and keys.
+// Note: Can't decrypt with more than one of keys, passphrase and session key.
 // TODO: Multiple signers?
 //
 // --session-key-out=file flag: Outputs session key byte stream to given file.
 func Decrypt(keyFilenames ...string) error {
-	if len(keyFilenames) == 0 && password == "" && sessionKey == "" {
-		println("Please provide decryption keys, session key, or passphrase")
-		return Err69
-	}
 	var err error
 
 	pgp := crypto.PGP()

cmd/encrypt.go

@@ -1,8 +1,9 @@
 package cmd
 
 import (
-	"io"
 	"bufio"
+	"fmt"
+	"io"
 	"os"
 	"unicode"
 
@@ -17,15 +18,27 @@ const (
 	textOpt = "text"
 )
 
+func BeforeEncrypt(c *cli.Context) error {
+	if !c.Args().Present() && password == "" {
+		fmt.Fprintln(os.Stderr, "Please provide encryption keys or passphrase (--with-password).")
+		return Err19
+	}
+	if c.Args().Present() && password != "" {
+		fmt.Fprintln(os.Stderr, "Can't encrypt with both keys and passphrase.")
+		return Err37
+	}
+	profile := utils.SelectEncryptionProfile(selectedProfile)
+	if profile == nil {
+		return Err89
+	}
+	return nil
+}
+
 // Encrypt takes the data from stdin and encrypts it with the keys passed as
 // argument, or a passphrase passed with the --with-password flag. It signs
 // with the given private keys.
 // Note: Can't encrypt both symmetrically (passphrase) and keys.
 func Encrypt(keyFilenames ...string) error {
-	if len(keyFilenames) == 0 && password == "" {
-		println("Please provide recipients and/or passphrase (--with-password)")
-		return Err19
-	}
 	profile := utils.SelectEncryptionProfile(selectedProfile)
 	if profile == nil {
 		return Err89

cmd/generate_key.go

@@ -1,16 +1,41 @@
 package cmd
 
 import (
+	"fmt"
 	"os"
 	"strings"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 
 	"github.com/ProtonMail/gopenpgp/v3/crypto"
 
 	"github.com/ProtonMail/go-crypto/openpgp/v2"
 )
 
+func BeforeGenerateKey(c *cli.Context) error {
+	profile := utils.SelectKeyGenerationProfile(selectedProfile)
+	if profile == nil {
+		return Err89
+	}
+	if !profile.PgpProfile.V6 && !c.Args().Present() {
+		fmt.Fprintln(os.Stderr, "Non-v6 key requires a User ID.")
+		return Err19
+	}
+	for _, userID := range c.Args().Slice() {
+		_, comment, _, err := utils.ParseUserID(userID)
+		if err != nil {
+			return kgErr(err)
+		}
+		if comment != "" {
+			fmt.Fprintln(os.Stderr, "Comments in User IDs are not supported.")
+			return Err37
+		}
+	}
+	return nil
+}
+
 // GenerateKey creates a single default OpenPGP certificate with zero or more
 // User IDs. Given that go-crypto expects name, comment, email parameters, we
 // force the USERID of this implementation to be of the form "name (comment)

cmd/inline_sign.go

@@ -1,10 +1,13 @@
 package cmd
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"unicode/utf8"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 
 	"github.com/ProtonMail/gopenpgp/v3/crypto"
@@ -14,14 +17,20 @@ const (
 	clearsignedOpt = "clearsigned"
 )
 
-// InlineSign takes the data from stdin and signs it with the key passed as argument.
-// TODO: Exactly one signature should be made by each supplied "KEY".
-func InlineSign(keyFilenames ...string) error {
-	if len(keyFilenames) == 0 {
-		println("Please provide keys to create detached signature")
+func BeforeInlineSign(c *cli.Context) error {
+	if !c.Args().Present() {
+		fmt.Fprintln(os.Stderr, "Please provide keys to create detached signature")
 		return Err19
 	}
+	if noArmor && asType == clearsignedOpt {
+		return Err83
+	}
+	return nil
+}
 
+// InlineSign takes the data from stdin and signs it with the key passed as argument.
+// TODO: Exactly one signature should be made by each supplied "KEY".
+func InlineSign(keyFilenames ...string) error {
 	// Signer keyring
 	var keyRing *crypto.KeyRing
 	var err error
@@ -56,10 +65,6 @@ func InlineSign(keyFilenames ...string) error {
 		return Err53
 	}
 
-	if noArmor && asType == clearsignedOpt {
-		return Err83
-	}
-
 	encoding := crypto.Armor
 	if noArmor {
 		encoding = crypto.Bytes

cmd/inline_verify.go

@@ -1,22 +1,28 @@
 package cmd
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"strings"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 
 	"github.com/ProtonMail/gopenpgp/v3/crypto"
 )
 
-// InlineVerify checks the validity of a signed message against a set of certificates.
-func InlineVerify(input ...string) error {
-	if len(input) == 0 {
-		println("Please provide a certificate (public key)")
+func BeforeInlineVerify(c *cli.Context) error {
+	if !c.Args().Present() {
+		fmt.Fprintln(os.Stderr, "Please provide a certificate (public key)")
 		return Err19
 	}
+	return nil
+}
 
+// InlineVerify checks the validity of a signed message against a set of certificates.
+func InlineVerify(input ...string) error {
 	timeFrom, timeTo, err := utils.ParseDates(notBefore, notAfter)
 	if err != nil {
 		return inlineVerErr(err)

cmd/list_profiles.go

@@ -4,16 +4,27 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 )
 
 const encryptCommand = "encrypt"
 const keyGenCommand = "generate-key"
 
-func ListProfiles(commands ...string) error {
-	if len(commands) < 1 {
+func BeforeListProfiles(c *cli.Context) error {
+	if !c.Args().Present() {
+		return Err89
+	}
+	switch c.Args().First() {
+	case keyGenCommand, encryptCommand:
+		return nil
+	default:
 		return Err89
 	}
+}
+
+func ListProfiles(commands ...string) error {
 	command := commands[0]
 	switch command {
 	case keyGenCommand:

cmd/sign.go

@@ -1,21 +1,28 @@
 package cmd
 
 import (
+	"fmt"
 	"io"
 	"os"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ProtonMail/gosop/utils"
 
 	"github.com/ProtonMail/gopenpgp/v3/crypto"
 )
 
+func BeforeSign(c *cli.Context) error {
+	if !c.Args().Present() {
+		fmt.Fprintln(os.Stderr, "Please provide keys to create detached signature")
+		return Err19
+	}
+	return nil
+}
+
 // Sign takes the data from stdin and signs it with the key passed as argument.
 // TODO: Exactly one signature will be made by each supplied "KEY".
 func Sign(keyFilenames ...string) error {
-	if len(keyFilenames) == 0 {
-		println("Please provide keys to create detached signature")
-		return Err19
-	}
 	pgp := crypto.PGP()
 
 	// Signer keyring