exp/services/webauth: remove old convjwt2jwk command (#2666)

### What
Remove the `convjwt2jwk` command.

### Why
The command was added to convert JWT keys generated with the old `genjwtkey` command into the same format as the new `genjwk` command. We no longer have any keys in the old format and do not need this command anymore.

exp/services/webauth/README.md

@@ -25,12 +25,8 @@ Usage:
   webauth [command]
 
 Available Commands:
-  convjwtkey2jwk Convert a JWT ECDSA private key ASN.1 DER Base64 encoded that was generated with the old genjwtkey command to a JSON Web Key
-  genjwk         Generate a JSON Web Key (ECDSA/ES256) for JWT issuing
-  serve          Run the SEP-10 Web Authentication server
-
-Flags:
-  -h, --help   help for webauth
+  genjwk      Generate a JSON Web Key (ECDSA/ES256) for JWT issuing
+  serve       Run the SEP-10 Web Authentication server
 
 Use "webauth [command] --help" for more information about a command.
 ```

exp/services/webauth/main.go

@@ -21,7 +21,6 @@ func main() {
 
 	rootCmd.AddCommand((&cmd.ServeCommand{Logger: logger}).Command())
 	rootCmd.AddCommand((&cmd.GenJWKCommand{Logger: logger}).Command())
-	rootCmd.AddCommand((&cmd.ConvJWTKeyToJWKCommand{Logger: logger}).Command())
 
 	err := rootCmd.Execute()
 	if err != nil {

exp/support/jwtkey/jwtkey.go

@@ -10,8 +10,6 @@ import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
-	"crypto/x509"
-	"encoding/base64"
 
 	"github.com/stellar/go/support/errors"
 )
@@ -26,55 +24,3 @@ func GenerateKey() (*ecdsa.PrivateKey, error) {
 	}
 	return k, nil
 }
-
-// PrivateKeyToString converts a ECDSA private key into a ASN.1 DER and base64
-// encoded string.
-func PrivateKeyToString(k *ecdsa.PrivateKey) (string, error) {
-	b, err := x509.MarshalECPrivateKey(k)
-	if err != nil {
-		return "", errors.Wrap(err, "marshaling ECDSA private key")
-	}
-	return base64.StdEncoding.EncodeToString(b), nil
-}
-
-// PublicKeyToString converts a ECDSA public key into a ASN.1 DER and base64
-// encoded string.
-func PublicKeyToString(k *ecdsa.PublicKey) (string, error) {
-	b, err := x509.MarshalPKIXPublicKey(k)
-	if err != nil {
-		return "", errors.Wrap(err, "marshaling ECDSA public key")
-	}
-	return base64.StdEncoding.EncodeToString(b), nil
-}
-
-// PrivateKeyFromString converts a ECDSA private key from a ASN.1 DER and
-// base64 encoded string into a type.
-func PrivateKeyFromString(s string) (*ecdsa.PrivateKey, error) {
-	keyBytes, err := base64.StdEncoding.DecodeString(s)
-	if err != nil {
-		return nil, errors.Wrap(err, "base64 decoding ECDSA private key")
-	}
-	key, err := x509.ParseECPrivateKey(keyBytes)
-	if err != nil {
-		return nil, errors.Wrap(err, "unmarshaling ECDSA private key")
-	}
-	return key, nil
-}
-
-// PublicKeyFromString converts a ECDSA public key from a ASN.1 DER and base64
-// encoded string into a type.
-func PublicKeyFromString(s string) (*ecdsa.PublicKey, error) {
-	keyBytes, err := base64.StdEncoding.DecodeString(s)
-	if err != nil {
-		return nil, errors.Wrap(err, "base64 decoding ECDSA public key")
-	}
-	keyI, err := x509.ParsePKIXPublicKey(keyBytes)
-	if err != nil {
-		return nil, errors.Wrap(err, "unmarshaling ECDSA public key")
-	}
-	key, ok := keyI.(*ecdsa.PublicKey)
-	if !ok {
-		return nil, errors.Wrap(err, "public key not ECDSA key")
-	}
-	return key, nil
-}

exp/support/jwtkey/jwtkey_test.go

@@ -1,10 +1,7 @@
 package jwtkey
 
 import (
-	"crypto/ecdsa"
 	"crypto/elliptic"
-	"crypto/rand"
-	"encoding/base64"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -16,51 +13,3 @@ func TestGenerate(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, elliptic.P256(), key.Curve)
 }
-
-func TestToFromStringRoundTrip(t *testing.T) {
-	testCases := []struct {
-		Name  string
-		Curve elliptic.Curve
-	}{
-		{Name: "P224", Curve: elliptic.P224()},
-		{Name: "P256", Curve: elliptic.P256()},
-		{Name: "P384", Curve: elliptic.P384()},
-		{Name: "P521", Curve: elliptic.P521()},
-	}
-	for _, tc := range testCases {
-		t.Run(tc.Name, func(t *testing.T) {
-			privateKey, err := ecdsa.GenerateKey(tc.Curve, rand.Reader)
-			require.NoError(t, err)
-
-			t.Run("private", func(t *testing.T) {
-				privateKeyStr, err := PrivateKeyToString(privateKey)
-				require.NoError(t, err)
-
-				// Private key as string should be valid standard base64
-				_, err = base64.StdEncoding.DecodeString(privateKeyStr)
-				require.NoError(t, err)
-
-				// Private key should decode back to the original
-				privateKeyRoundTripped, err := PrivateKeyFromString(privateKeyStr)
-				require.NoError(t, err)
-				assert.Equal(t, privateKey, privateKeyRoundTripped)
-			})
-
-			publicKey := &privateKey.PublicKey
-
-			t.Run("public", func(t *testing.T) {
-				publicKeyStr, err := PublicKeyToString(publicKey)
-				require.NoError(t, err)
-
-				// Public key as string should be valid standard base64
-				_, err = base64.StdEncoding.DecodeString(publicKeyStr)
-				require.NoError(t, err)
-
-				// Public key should decode back to the original
-				publicKeyRoundTripped, err := PublicKeyFromString(publicKeyStr)
-				require.NoError(t, err)
-				assert.Equal(t, publicKey, publicKeyRoundTripped)
-			})
-		})
-	}
-}