armor decryptPrivKey should return ErrWrongPassword

[JulianToledano]

Summary of Bug

When trying to import a key with a wrong passphrase a sdkerrors.ErrWrongPassword should be expected (not sure if its good idea to give that information) but a ciphertext decryption failed is returned. Turns out there’s a mistake when checking the error returned by xsalsa20symmetric.DecryptSymmetric. As you can see in the following code snippets one of the strings starts with a capital letter while the other don’t, which makes the comparation to fail.

cosmos-sdk/crypto/armor.go

Lines 202 to 205 in 3c53870

	privKeyBytes, err := xsalsa20symmetric.DecryptSymmetric(encBytes, key)
	if err != nil && err.Error() == "Ciphertext decryption failed" {
	return privKey, sdkerrors.ErrWrongPassword
	} else if err != nil {

cosmos-sdk/crypto/xsalsa20symmetric/symmetric.go

Lines 51 to 53 in 3c53870

	if !ok {
	return nil, errors.New("ciphertext decryption failed")
	}

[vidhanarya]

Hi, I would like to work on this issue, is it available?