AESGCMFunction.h

// Copyright (c) 2016 Uber Technologies, Inc.
//
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// of this software and associated documentation files (the "Software"), to deal
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// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// THE SOFTWARE.

#ifndef AESGCMFUNCTION_H_INCLUDED
#define AESGCMFUNCTION_H_INCLUDED

#include <Vertica.h>
#include <sodium.h>

#include <string>
#include <limits.h>

#define VERTICA_VARCHAR_MAX 65000
#if defined(PATH_MAX)&&(PATH_MAX<=VERTICA_VARCHAR_MAX)
#   define MAX_KEY_PATH PATH_MAX
#else
#   define MAX_KEY_PATH VERTICA_VARCHAR_MAX
#endif

#define KEY_PATH_PARAM "key"

// AESGCMFunction encapsulates key reading functionality common to the
// encryption and decryption scalar functions. The key is read from a file
// specified by a function parameter (KEY_PATH_PARAM).
class AESGCMFunction: public Vertica::ScalarFunction {
    protected:
        crypto_aead_aes256gcm_state crypto_ctx;
        std::string column_name;

    public:
        // The maximum number of bytes added to the length of the plaintext to
        // accomodate the public nonce and additional data tag.
        static const long int overhead;

        virtual void setup(Vertica::ServerInterface &srvInterface,
                const Vertica::SizedColumnTypes &argTypes);
};

// AESGCMFunctionFactory provides metainformation common to
// AESGCMEncryptFactory and AESGCMDecryptFactory, namely volatility, stability,
// and parameter hints.
class AESGCMFunctionFactory: public Vertica::ScalarFunctionFactory {
    public:
        virtual void getParameterType(Vertica::ServerInterface &srvInterface,
                Vertica::SizedColumnTypes &parameterTypes);
        virtual void getPerInstanceResources(Vertica::ServerInterface &srvInterface,
                Vertica::VResources &res);
};

#endif /* AESGCMFUNCTION_H_INCLUDED */