/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019-2021, Google Inc.
 *
 * camera_request.cpp - libcamera Android Camera Request Descriptor
 */

#include "camera_request.h"

#include <libcamera/base/span.h>

#include "camera_buffer.h"

using namespace libcamera;

/*
 * \class Camera3RequestDescriptor
 *
 * A utility class that groups information about a capture request to be later
 * reused at request complete time to notify the framework.
 *
 *******************************************************************************
 * Lifetime of a Camera3RequestDescriptor tracking a capture request placed by
 * Android Framework
 *******************************************************************************
 *
 *
 *  Android Framework
 *     │
 *     │    ┌──────────────────────────────────┐
 *     │    │camera3_capture_request_t         │
 *     │    │                                  │
 *     │    │Requested output streams          │
 *     │    │  stream1   stream2   stream3 ... │
 *     │    └──────────────────────────────────┘
 *     ▼
 * ┌─────────────────────────────────────────────────────────────┐
 * │ libcamera HAL                                               │
 * ├─────────────────────────────────────────────────────────────┤
 * │  CameraDevice                                               │
 * │                                                             │
 * │  processCaptureRequest(camera3_capture_request_t request)   │
 * │                                                             │
 * │   - Create Camera3RequestDescriptor tracking this request   │
 * │   - Streams requiring post-processing are stored in the     │
 * │     pendingStreamsToProcess map                             │
 * │   - Add this Camera3RequestDescriptor to descriptors' queue │
 * │     CameraDevice::descriptors_                              │
 * │                                                             │ ┌─────────────────────────┐
 * │   - Queue the capture request to libcamera core ────────────┤►│libcamera core           │
 * │                                                             │ ├─────────────────────────┤
 * │                                                             │ │- Capture from Camera    │
 * │                                                             │ │                         │
 * │                                                             │ │- Emit                   │
 * │                                                             │ │  Camera::requestComplete│
 * │  requestCompleted(Request *request) ◄───────────────────────┼─┼────                     │
 * │                                                             │ │                         │
 * │   - Check request completion status                         │ └─────────────────────────┘
 * │                                                             │
 * │   - if (pendingStreamsToProcess > 0)                        │
 * │      Queue all entries from pendingStreamsToProcess         │
 * │    else                                   │                 │
 * │      completeDescriptor()                 │                 └──────────────────────┐
 * │                                           │                                        │
 * │                ┌──────────────────────────┴───┬──────────────────┐                 │
 * │                │                              │                  │                 │
 * │     ┌──────────▼────────────┐     ┌───────────▼─────────┐        ▼                 │
 * │     │CameraStream1          │     │CameraStream2        │      ....                │
 * │     ├┬───┬───┬──────────────┤     ├┬───┬───┬────────────┤                          │
 * │     ││   │   │              │     ││   │   │            │                          │
 * │     │▼───▼───▼──────────────┤     │▼───▼───▼────────────┤                          │
 * │     │PostProcessorWorker    │     │PostProcessorWorker  │                          │
 * │     │                       │     │                     │                          │
 * │     │ +------------------+  │     │ +------------------+│                          │
 * │     │ | PostProcessor    |  │     │ | PostProcessor    |│                          │
 * │     │ |     process()    |  │     │ |     process()    |│                          │
 * │     │ |                  |  │     │ |                  |│                          │
 * │     │ | Emit             |  │     │ | Emit             |│                          │
 * │     │ | processComplete  |  │     │ | processComplete  |│                          │
 * │     │ |                  |  │     │ |                  |│                          │
 * │     │ +--------------│---+  │     │ +--------------│---+│                          │
 * │     │                │      │     │                │    │                          │
 * │     │                │      │     │                │    │                          │
 * │     └────────────────┼──────┘     └────────────────┼────┘                          │
 * │                      │                             │                               │
 * │                      │                             │                               │
 * │                      │                             │                               │
 * │                      ▼                             ▼                               │
 * │ +---------------------------------------+     +--------------+                     │
 * │ | CameraDevice                          |     |              |                     │
 * │ |                                       |     |              |                     │
 * │ | streamProcessingComplete()            |     |              |                     │
 * │ |                                       |     |              |                     │
 * │ | - Check and set buffer status         |     |     ....     |                     │
 * │ | - Remove post+processing entry        |     |              |           </span>
<span class="hl com"> */</span>

<span class="hl com">/**</span>
<span class="hl com"> * \brief Construct a PubKey from key data</span>
<span class="hl com"> * \param[in] key Key data encoded in DER format</span>
<span class="hl com"> */</span>
<span class="hl kwc">PubKey</span><span class="hl opt">::</span><span class="hl kwd">PubKey</span><span class="hl opt">([[</span>maybe_unused<span class="hl opt">]]</span> Span<span class="hl opt">&lt;</span><span class="hl kwb">const uint8_t</span><span class="hl opt">&gt;</span> key<span class="hl opt">)</span>
	<span class="hl opt">:</span> <span class="hl kwd">valid_</span><span class="hl opt">(</span><span class="hl kwa">false</span><span class="hl opt">)</span>
<span class="hl opt">{</span>
<span class="hl ppc">#if HAVE_GNUTLS</span>
	<span class="hl kwb">int</span> ret <span class="hl opt">=</span> <span class="hl kwd">gnutls_pubkey_init</span><span class="hl opt">(&amp;</span>pubkey_<span class="hl opt">);</span>
	<span class="hl kwa">if</span> <span class="hl opt">(</span>ret <span class="hl opt">&lt;</span> <span class="hl num">0</span><span class="hl opt">)</span>
		<span class="hl kwa">return</span><span class="hl opt">;</span>

	<span class="hl kwb">const</span> gnutls_datum_t gnuTlsKey<span class="hl opt">{</span>
		<span class="hl kwa">const_cast</span><span class="hl opt">&lt;</span><span class="hl kwb">unsigned char</span> <span class="hl opt">*&gt;(</span>key<span class="hl opt">.</span><span class="hl kwd">data</span><span class="hl opt">()),</span>
		<span class="hl kwa">static_cast</span><span class="hl opt">&lt;</span><span class="hl kwb">unsigned int</span><span class="hl opt">&gt;(</span>key<span class="hl opt">.</span><span class="hl kwd">size</span><span class="hl opt">())</span>
	<span class="hl opt">};</span>
	ret <span class="hl opt">=</span> <span class="hl kwd">gnutls_pubkey_import</span><span class="hl opt">(</span>pubkey_<span class="hl opt">, &amp;</span>gnuTlsKey<span class="hl opt">,</span> GNUTLS_X509_FMT_DER<span class="hl opt">);</span>
	<span class="hl kwa">if</span> <span class="hl opt">(</span>ret <span class="hl opt">&lt;</span> <span class="hl num">0</span><span class="hl opt">)</span>
		<span class="hl kwa">return</span><span class="hl opt">;</span>

	valid_ <span class="hl opt">=</span> <span class="hl kwa">true</span><span class="hl opt">;</span>
<span class="hl ppc">#endif</span>
<span class="hl opt">}</span>

<span class="hl kwc">PubKey</span><span class="hl opt">::~</span><span class="hl kwd">PubKey</span><span class="hl opt">()</span>
<span class="hl opt">{</span>
<span class="hl ppc">#if HAVE_GNUTLS</span>
	<span class="hl kwd">gnutls_pubkey_deinit</span><span class="hl opt">(</span>pubkey_<span class="hl opt">);</span>
<span class="hl ppc">#endif</span>
<span class="hl opt">}</span>

<span class="hl com">/**</span>
<span class="hl com"> * \fn bool PubKey::isValid() const</span>
<span class="hl com"> * \brief Check is the public key is valid</span>
<span class="hl com"> * \return True if the public key is valid, false otherwise</span>
<span class="hl com"> */</span>

<span class="hl com">/**</span>
<span class="hl com"> * \brief Verify signature on data</span>
<span class="hl com"> * \param[in] data The signed data</span>
<span class="hl com"> * \param[in] sig The signature</span>
<span class="hl com"> *</span>
<span class="hl com"> * Verify that the signature \a sig matches the signed \a data for the public</span>
<span class="hl com"> * key. The signture algorithm is hardcoded to RSA-SHA256.</span>
<span class="hl com"> *</span>
<span class="hl com"> * \return True if the signature is valid, false otherwise</span>
<span class="hl com"> */</span>
<span class="hl kwb">bool</span> <span class="hl kwc">PubKey</span><span class="hl opt">::</span><span class="hl kwd">verify</span><span class="hl opt">([[</span>maybe_unused<span class="hl opt">]]</span> Span<span class="hl opt">&lt;</span><span class="hl kwb">const uint8_t</span><span class="hl opt">&gt;</span> data<span class="hl opt">,</span>
		    <span class="hl opt">[[</span>maybe_unused<span class="hl opt">]]</span> Span<span class="hl opt">&lt;</span><span class="hl kwb