/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "CrossOriginEmbedderPolicy.h"

#include "Frame.h"
#include "FrameLoader.h"
#include "HTTPHeaderNames.h"
#include "HTTPParsers.h"
#include "JSFetchRequest.h"
#include "PingLoader.h"
#include "ResourceResponse.h"
#include "ScriptExecutionContext.h"
#include "SecurityOrigin.h"

namespace WebCore {

// https://html.spec.whatwg.org/multipage/origin.html#obtain-an-embedder-policy
CrossOriginEmbedderPolicy obtainCrossOriginEmbedderPolicy(const ResourceResponse& response, const ScriptExecutionContext* context)
{
    auto parseCOEPHeader = [&response](HTTPHeaderName headerName, auto& value, auto& reportingEndpoint) {
        auto coepParsingResult = parseStructuredFieldValue(response.httpHeaderField(headerName));
        if (coepParsingResult && coepParsingResult->first == "require-corp"_s) {
            value = CrossOriginEmbedderPolicyValue::RequireCORP;
            reportingEndpoint = coepParsingResult->second.get<HashTranslatorASCIILiteral>("report-to"_s);
        }
    };

    CrossOriginEmbedderPolicy policy;
    if (context && !context->settingsValues().crossOriginEmbedderPolicyEnabled)
        return policy;
    if (!SecurityOrigin::create(response.url())->isPotentiallyTrustworthy())
        return policy;

    parseCOEPHeader(HTTPHeaderName::CrossOriginEmbedderPolicy, policy.value, policy.reportingEndpoint);
    parseCOEPHeader(HTTPHeaderName::CrossOriginEmbedderPolicyReportOnly, policy.reportOnlyValue, policy.reportOnlyReportingEndpoint);
    return policy;
}

CrossOriginEmbedderPolicy CrossOriginEmbedderPolicy::isolatedCopy() const &
{
    return {
        value,
        reportingEndpoint.isolatedCopy(),
        reportOnlyValue,
        reportOnlyReportingEndpoint.isolatedCopy()
    };
}

CrossOriginEmbedderPolicy CrossOriginEmbedderPolicy::isolatedCopy() &&
{
    return {
        value,
        WTFMove(reportingEndpoint).isolatedCopy(),
        reportOnlyValue,
        WTFMove(reportOnlyReportingEndpoint).isolatedCopy()
    };
}

void addCrossOriginEmbedderPolicyHeaders(ResourceResponse& response, const CrossOriginEmbedderPolicy& coep)
{
    if (coep.value != CrossOriginEmbedderPolicyValue::UnsafeNone) {
        ASSERT(coep.value == CrossOriginEmbedderPolicyValue::RequireCORP);
        if (coep.reportingEndpoint.isEmpty())
            response.setHTTPHeaderField(HTTPHeaderName::CrossOriginEmbedderPolicy, "require-corp"_s);
        else
            response.setHTTPHeaderField(HTTPHeaderName::CrossOriginEmbedderPolicy, makeString("require-corp; report-to=\"", coep.reportingEndpoint, '\"'));
    }
    if (coep.reportOnlyValue != CrossOriginEmbedderPolicyValue::UnsafeNone) {
        ASSERT(coep.reportOnlyValue == CrossOriginEmbedderPolicyValue::RequireCORP);
        if (coep.reportOnlyReportingEndpoint.isEmpty())
            response.setHTTPHeaderField(HTTPHeaderName::CrossOriginEmbedderPolicyReportOnly, "require-corp"_s);
        else
            response.setHTTPHeaderField(HTTPHeaderName::CrossOriginEmbedderPolicyReportOnly, makeString("require-corp; report-to=\"", coep.reportOnlyReportingEndpoint, '\"'));
    }
}

} // namespace WebCore