CryptoAlgorithmRSAES_PKCS1_v1_5GCrypt.cpp   [plain text]

/*
 * Copyright (C) 2014 Igalia S.L. All rights reserved.
 *
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 * modification, are permitted provided that the following conditions
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 *    notice, this list of conditions and the following disclaimer in the
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#include "config.h"
#include "CryptoAlgorithmRSAES_PKCS1_v1_5.h"

#if ENABLE(SUBTLE_CRYPTO)

#include "CryptoKeyRSA.h"
#include "ExceptionCode.h"
#include "GCryptUtilities.h"
#include "NotImplemented.h"
#include "ScriptExecutionContext.h"

namespace WebCore {

static std::optional<Vector<uint8_t>> gcryptEncrypt(gcry_sexp_t keySexp, Vector<uint8_t>&& plainText)
{
    // Embed the plain-text data in a `data` s-expression using PKCS#1 padding.
    PAL::GCrypt::Handle<gcry_sexp_t> dataSexp;
    gcry_error_t error = gcry_sexp_build(&dataSexp, nullptr, "(data(flags pkcs1)(value %b))",
        plainText.size(), plainText.data());
    if (error != GPG_ERR_NO_ERROR) {
        PAL::GCrypt::logError(error);
        return std::nullopt;
    }

    // Encrypt data with the provided key. The returned s-expression is of this form:
    // (enc-val
    //   (rsa
    //     (a a-mpi)))
    PAL::GCrypt::Handle<gcry_sexp_t> cipherSexp;
    error = gcry_pk_encrypt(&cipherSexp, dataSexp, keySexp);
    if (error != GPG_ERR_NO_ERROR) {
        PAL::GCrypt::logError(error);
        return std::nullopt;
    }

    // Return MPI data of the embedded `a` integer.
    PAL::GCrypt::Handle<gcry_sexp_t> aSexp(gcry_sexp_find_token(cipherSexp, "a", 0));
    if (!aSexp)
        return std::nullopt;

    return mpiData(aSexp);
}

static std::optional<Vector<uint8_t>> gcryptDecrypt(gcry_sexp_t keySexp, Vector<uint8_t>&& cipherText)
{
    // Embed the cipher-text data in an `enc-val` s-expression using PKCS#1 padding.
    PAL::GCrypt::Handle<gcry_sexp_t> encValSexp;
    gcry_error_t error = gcry_sexp_build(&encValSexp, nullptr, "(enc-val(flags pkcs1)(rsa(a %b)))",
        cipherText.size(), cipherText.data());
    if (error != GPG_ERR_NO_ERROR) {
        PAL::GCrypt::logError(error);
        return std::nullopt;
    }

    // Decrypt data with the provided key. The returned s-expression is of this form:
    // (data
    //   (flags pkcs1)
    //   (value block))
    PAL::GCrypt::Handle<gcry_sexp_t> plainSexp;
    error = gcry_pk_decrypt(&plainSexp, encValSexp, keySexp);
    if (error != GPG_ERR_NO_ERROR) {
        PAL::GCrypt::logError(error);
        return std::nullopt;
    }

    // Return MPI data of the embedded `value` integer.
    PAL::GCrypt::Handle<gcry_sexp_t> valueSexp(gcry_sexp_find_token(plainSexp, "value", 0));
    if (!valueSexp)
        return std::nullopt;

    return mpiData(valueSexp);
}

void CryptoAlgorithmRSAES_PKCS1_v1_5::platformEncrypt(Ref<CryptoKey>&& key, Vector<uint8_t>&& plainText, VectorCallback&& callback, ExceptionCallback&& exceptionCallback, ScriptExecutionContext& context, WorkQueue& workQueue)
{
    context.ref();
    workQueue.dispatch(
        [key = WTFMove(key), plainText = WTFMove(plainText), callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback), &context]() mutable {
            auto& rsaKey = downcast<CryptoKeyRSA>(key.get());

            auto output = gcryptEncrypt(rsaKey.platformKey(), WTFMove(plainText));
            if (!output) {
                // We should only dereference callbacks after being back to the Document/Worker threads.
                context.postTask(
                    [callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback)](ScriptExecutionContext& context) {
                        exceptionCallback(OperationError);
                        context.deref();
                    });
                return;
            }

            // We should only dereference callbacks after being back to the Document/Worker threads.
            context.postTask(
                [output = WTFMove(*output), callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback)](ScriptExecutionContext& context) mutable {
                    callback(WTFMove(output));
                    context.deref();
                });
        });
}

void CryptoAlgorithmRSAES_PKCS1_v1_5::platformDecrypt(Ref<CryptoKey>&& key, Vector<uint8_t>&& cipherText, VectorCallback&& callback, ExceptionCallback&& exceptionCallback, ScriptExecutionContext& context, WorkQueue& workQueue)
{
    context.ref();
    workQueue.dispatch(
        [key = WTFMove(key), cipherText = WTFMove(cipherText), callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback), &context]() mutable {
            auto& rsaKey = downcast<CryptoKeyRSA>(key.get());

            auto output = gcryptDecrypt(rsaKey.platformKey(), WTFMove(cipherText));
            if (!output) {
                // We should only dereference callbacks after being back to the Document/Worker threads.
                context.postTask(
                    [callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback)](ScriptExecutionContext& context) {
                        exceptionCallback(OperationError);
                        context.deref();
                    });
                return;
            }

            // We should only dereference callbacks after being back to the Document/Worker threads.
            context.postTask(
                [output = WTFMove(*output), callback = WTFMove(callback), exceptionCallback = WTFMove(exceptionCallback)](ScriptExecutionContext& context) mutable {
                    callback(WTFMove(output));
                    context.deref();
                });
        });
}

ExceptionOr<void> CryptoAlgorithmRSAES_PKCS1_v1_5::platformEncrypt(const CryptoKeyRSA&, const CryptoOperationData&, VectorCallback&&, VoidCallback&&)
{
    notImplemented();
    return Exception { NOT_SUPPORTED_ERR };
}

ExceptionOr<void> CryptoAlgorithmRSAES_PKCS1_v1_5::platformDecrypt(const CryptoKeyRSA&, const CryptoOperationData&, VectorCallback&&, VoidCallback&&)
{
    notImplemented();
    return Exception { NOT_SUPPORTED_ERR };
}

} // namespace WebCore

#endif // ENABLE(SUBTLE_CRYPTO)