Fix wrong description

[polRk]

Remove base64 requirements for ciphertext in SymmetricDecryptRequest.

When I submit ciphertext encoded in base64, I get an error message

rpc error: code = InvalidArgument desc = Bad ciphertext

In raw format, after - OK

Full code

type YCKMS struct {
	sdk   *ycsdk.SDK
	keyID string
}

func New(sdk *ycsdk.SDK, keyID string) KMS {
	return &YCKMS{sdk: sdk, keyID: keyID}
}

func (s *YCKMS) Encrypt(aadContext string, plaintext string) (keyID string, versionID string, ciphertext []byte, err error) {
	aadContextBuf := make([]byte, base64.RawStdEncoding.EncodedLen(len([]byte(aadContext))))
	plaintextBuf := make([]byte, base64.RawStdEncoding.EncodedLen(len(plaintext)))

	base64.RawStdEncoding.Encode(aadContextBuf, []byte(aadContext))
	base64.RawStdEncoding.Encode(plaintextBuf, []byte(plaintext))

	result, err := s.sdk.KMSCrypto().SymmetricCrypto().Encrypt(context.Background(), &kms.SymmetricEncryptRequest{
		KeyId:      s.keyID,
		AadContext: aadContextBuf,
		Plaintext:  plaintextBuf,
	})
	if err != nil {
		return "", "", nil, err
	}

	return result.KeyId, result.VersionId, result.Ciphertext, nil
}

func (s *YCKMS) Decrypt(aadContext string, ciphertext []byte) ([]byte, error) {
        aadContextBuf := make([]byte, base64.RawStdEncoding.EncodedLen(len([]byte(aadContext))))
	// ciphertextBuf := make([]byte, base64.RawStdEncoding.EncodedLen(len(ciphertext)))

	base64.RawStdEncoding.Encode(aadContextBuf, []byte(aadContext))
	// base64.RawStdEncoding.Encode(ciphertextBuf, ciphertext)

	result, err := s.sdk.KMSCrypto().SymmetricCrypto().Decrypt(context.Background(), &kms.SymmetricDecryptRequest{
		KeyId:      s.keyID,
		AadContext: aadContextBuf,
		Ciphertext: ciphertext, 
	})
	if err != nil {
		return nil, err
	}

	return result.Plaintext, nil
}

Usage

	keyID, versionID, ciphertext, err := k.Encrypt(Bot.ID, Bot.Token)
	if err != nil {
		panic(fmt.Errorf("cannot encrypt Bot.Token: %w", err))
	}

	plaintext, err := k.Decrypt(Bot.ID, Bot.TokenCiphertext)
	if err != nil {
		panic(fmt.Errorf("cannot dencrypt Bot.Token: %w", err))
	}

	plaintext, _ = base64.RawStdEncoding.DecodeString(string(plaintext))
        fmt.Println(string(plaintext))