Signature::buildCustomUrl() - Code Metrics - Inspection of "Add option to handle s3 compatible solutions #13" - eddturtle/direct-upload - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( fa499c...038a73 )

by Edd

created 2017-02-11 15:04 UTC

Signature::buildCustomUrl() A

↳ Parent: Signature

Complexity

Conditions	3
Paths	3

Size

Total Lines	12
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	12
rs	9.4285
cc	3
eloc	6
nc	3
nop	0

<?php

namespace EddTurtle\DirectUpload;

/**
 * Class Signature
 *
 * Build an AWS Signature, ready for direct upload. This will support AWS's signature v4 so should be
 * accepted by all regions.
 *
 * @package EddTurtle\DirectUpload
 */
class Signature
{

    CONST ALGORITHM = "AWS4-HMAC-SHA256";
    CONST SERVICE = "s3";
    CONST REQUEST_TYPE = "aws4_request";

    /**
     * Default options, these can be overwritten within the constructor.
     *
     * @var array
     */
    protected $options = [

        // If the upload is a success, this is the http code we get back from S3.
        // By default this will be a 201 Created.
        'success_status' => 201,

        // If the file should be private/public-read/public-write.
        // This is file specific, not bucket. More info: http://amzn.to/1SSOgwO
        'acl' => 'private',

        // The file's name on s3, can be set with JS by changing the input[name="key"].
        // ${filename} will just mean the original filename of the file being uploaded.
        'default_filename' => '${filename}',

        // The maximum file size of an upload in MB. Will refuse with a EntityTooLarge
        // and 400 Bad Request if you exceed this limit.
        'max_file_size' => 500,

        // Request expiration time, specified in relative time format or in seconds.
        // minimum of 1 (+1 second), maximum of 604800 (+7 days)
        'expires' => '+6 hours',

        // Server will check that the filename starts with this prefix and fail
        // with a AccessDenied 403 if not.
        'valid_prefix' => '',

        // Strictly only allow a single content type, blank will allow all. Will fail
        // with a AccessDenied 403 is this condition is not met.
        'content_type' => '',

        // Sets whether AWS server side encryption should be applied to the uploaded files,
        // so that files will be encrypted with AES256 when at rest.
        'encryption' => false,

        //
        'custom_url' => null,

        // Any additional inputs to add to the form. This is an array of name => value
        // pairs e.g. ['Content-Disposition' => 'attachment']
        'additional_inputs' => []

    ];

    /**
     * @var string the AWS Key
     */
    private $key;

    /**
     * @var string the AWS Secret
     */
    private $secret;

    /**
     * @var string
     */
    private $bucket;

    /**
     * @var Region
     */
    private $region;

    /**
     * @var int the current unix timestamp
     */
    private $time = null;

    private $credentials = null;
    private $base64Policy = null;
    private $signature = null;

    /**
     * Signature constructor.
     *
     * @param string $key     the AWS API Key to use.
     * @param string $secret  the AWS API Secret to use.
     * @param string $bucket  the bucket to upload the file into.
     * @param string $region  the s3 region this bucket is within. More info: http://amzn.to/1FtPG6r
     * @param array  $options any additional options, like acl and success status.
     */
    public function __construct($key, $secret, $bucket, $region = "us-east-1", $options = [])
    {
        $this->setAwsCredentials($key, $secret);
        $this->populateTime();

        $this->bucket = $bucket;
        $this->region = new Region($region);

        $this->setOptions($options);
    }

    /**
     * Set the AWS Credentials
     *
     * @param string $key    the AWS API Key to use.
     * @param string $secret the AWS API Secret to use.
     */
    protected function setAwsCredentials($key, $secret)
    {
        // Key
        if (empty($key) || $key === "YOUR_S3_KEY") {
            throw new \InvalidArgumentException("Invalid AWS Key");
        }
        $this->key = $key;

        // Secret
        if (empty($secret) || $secret === "YOUR_S3_SECRET") {
            throw new \InvalidArgumentException("Invalid AWS Secret");
        }
        $this->secret = $secret;
    }

    /**
     * Build the form url for sending files, this will include the bucket and the region name.
     *
     * @return string the s3 bucket's url.
     */
    public function getFormUrl()
    {
        if (!is_null($this->options['custom_url'])) {
            return $this->buildCustomUrl();
        } else {
            return $this->buildAmazonUrl();
        }
    }

    private function buildCustomUrl()
    {
        $url = trim($this->options['custom_url']);

        if (filter_var($url, FILTER_VALIDATE_URL) === false) {
            throw new InvalidOptionException("The custom_url option you have specified is invalid");
        }

        $separator = (substr($url, -1) === "/" ? "" : "/");

        return $url . $separator . urlencode($this->bucket);
    }

    private function buildAmazonUrl()
    {
        $region = (string)$this->region;

        // Only the us-east-1 region is exempt from needing the region in the url.
        if ($region !== "us-east-1") {
            $middle = "-" . $region;
        } else {
            $middle = "";
        }

        return "//" . self::SERVICE . $middle . ".amazonaws.com" . "/" . urlencode($this->bucket);
    }

    /**
     * Get all options.
     *
     * @return array
     */
    public function getOptions()
    {
        return $this->options;
    }

    /**
     * Set/overwrite any default options.
     *
     * @param array $options any options to override.
     */
    public function setOptions($options)
    {
        // Overwrite default options
        $this->options = $options + $this->options;

        $this->options['acl'] = new Acl($this->options['acl']);

        // Return HTTP code must be a string
        $this->options['success_status'] = (string)$this->options['success_status'];
    }

    /**
     * Get an AWS Signature V4 generated.
     *
     * @return string the aws v4 signature.
     */
    public function getSignature()
    {
        if (is_null($this->signature)) {
            $this->generateScope();
            $this->generatePolicy();
            $this->generateSignature();
        }
        return $this->signature;
    }

    /**
     * Generate the necessary hidden inputs to go within the form. These inputs should match what's being send in
     * the policy.
     *
     * @param bool $addKey whether to add the 'key' input (filename), defaults to yes.
     *
     * @return array of the form inputs.
     */
    public function getFormInputs($addKey = true)
    {
        $this->getSignature();

        $inputs = [
            'Content-Type' => $this->options['content_type'],
            'acl' => (string)$this->options['acl'],
            'success_action_status' => $this->options['success_status'],
            'policy' => $this->base64Policy,
            'X-amz-credential' => $this->credentials,
            'X-amz-algorithm' => self::ALGORITHM,
            'X-amz-date' => $this->getFullDateFormat(),
            'X-amz-signature' => $this->signature
        ];

        if ($this->options['encryption']) {
            $inputs['X-amz-server-side-encryption'] = 'AES256';
        }

        $inputs = array_merge($inputs, $this->options['additional_inputs']);

        if ($addKey) {
            // Note: The Key (filename) will need to be populated with JS on upload
            // if anything other than the filename is wanted.
            $inputs['key'] = $this->options['valid_prefix'] . $this->options['default_filename'];
        }

        return $inputs;
    }

    /**
     * Based on getFormInputs(), this will build up the html to go within the form.
     *
     * @param bool $addKey whether to add the 'key' input (filename), defaults to yes.
     *
     * @return string html of hidden form inputs.
     */
    public function getFormInputsAsHtml($addKey = true)
    {
        $inputs = [];
        foreach ($this->getFormInputs($addKey) as $name => $value) {
            $inputs[] = '<input type="hidden" name="' . $name . '" value="' . $value . '" />';
        }
        return implode(PHP_EOL, $inputs);
    }


    // Where the magic begins ;)

    /**
     * Step 1: Generate the Scope
     */
    protected function generateScope()
    {
        $scope = [
            $this->key,
            $this->getShortDateFormat(),
            $this->region,
            self::SERVICE,
            self::REQUEST_TYPE
        ];
        $this->credentials = implode('/', $scope);
    }

    /**
     * Step 2: Generate a Base64 Policy
     */
    protected function generatePolicy()
    {
        $policy = [
            'expiration' => $this->getExpirationDate(),
            'conditions' => [
                ['bucket' => $this->bucket],
                ['acl' => (string)$this->options['acl']],
                ['starts-with', '$key', $this->options['valid_prefix']],
                $this->getPolicyContentTypeArray(),
                ['content-length-range', 0, $this->mbToBytes($this->options['max_file_size'])],
                ['success_action_status' => $this->options['success_status']],
                ['x-amz-credential' => $this->credentials],
                ['x-amz-algorithm' => self::ALGORITHM],
                ['x-amz-date' => $this->getFullDateFormat()]
            ]
        ];
        $policy = $this->addAdditionalInputs($policy);
        $this->base64Policy = base64_encode(json_encode($policy));
    }

    private function getPolicyContentTypeArray()
    {
        $contentTypePrefix = (empty($this->options['content_type']) ? 'starts-with' : 'eq');
        return [
            $contentTypePrefix,
            '$Content-Type',
            $this->options['content_type']
        ];
    }

    private function addAdditionalInputs($policy)

    {
        foreach ($this->options['additional_inputs'] as $name => $value) {
            $policy['conditions'][] = ['starts-with', '$' . $name, $value];
        }
        return $policy;
    }

    /**
     * Step 3: Generate and sign the Signature (v4)
     */
    protected function generateSignature()
    {
        $signatureData = [
            $this->getShortDateFormat(),
            (string)$this->region,
            self::SERVICE,
            self::REQUEST_TYPE
        ];

        // Iterates over the data (defined in the array above), hashing it each time.
        $initial = 'AWS4' . $this->secret;
        $signingKey = array_reduce($signatureData, function($key, $data) {
            return $this->keyHash($data, $key);
        }, $initial);

        // Finally, use the signing key to hash the policy.
        $this->signature = $this->keyHash($this->base64Policy, $signingKey, false);
    }


    // Helper functions

    private function keyHash($date, $key, $raw = true)
    {
        return hash_hmac('sha256', $date, $key, $raw);
    }

    private function populateTime()
    {
        if (is_null($this->time)) {
            $this->time = time();
        }
    }

    private function mbToBytes($megaByte)
    {
        if (is_numeric($megaByte)) {
            return $megaByte * pow(1024, 2);
        }
        return 0;
    }


    // Dates

    private function getShortDateFormat()
    {
        return gmdate("Ymd", $this->time);
    }

    private function getFullDateFormat()
    {
        return gmdate("Ymd\THis\Z", $this->time);
    }

    private function getExpirationDate()
    {
        // Note: using \DateTime::ISO8601 doesn't work :(

        $exp = strtotime($this->options['expires'], $this->time);
        $diff = $exp - $this->time;

        if (!($diff >= 1 && $diff <= 604800)) {
            throw new \InvalidArgumentException("Expiry must be between 1 and 604800");
        }

        return gmdate('Y-m-d\TG:i:s\Z', $exp);
    }


}


1			<?php
2
3			namespace EddTurtle\DirectUpload;
4
5			/**
6			* Class Signature
7			*
8			* Build an AWS Signature, ready for direct upload. This will support AWS's signature v4 so should be
9			* accepted by all regions.
10			*
11			* @package EddTurtle\DirectUpload
12			*/
13			class Signature
14			{
15
16			CONST ALGORITHM = "AWS4-HMAC-SHA256";
17			CONST SERVICE = "s3";
18			CONST REQUEST_TYPE = "aws4_request";
19
20			/**
21			* Default options, these can be overwritten within the constructor.
22			*
23			* @var array
24			*/
25			protected $options = [
26
27			// If the upload is a success, this is the http code we get back from S3.
28			// By default this will be a 201 Created.
29			'success_status' => 201,
30
31			// If the file should be private/public-read/public-write.
32			// This is file specific, not bucket. More info: http://amzn.to/1SSOgwO
33			'acl' => 'private',
34
35			// The file's name on s3, can be set with JS by changing the input[name="key"].
36			// ${filename} will just mean the original filename of the file being uploaded.
37			'default_filename' => '${filename}',
38
39			// The maximum file size of an upload in MB. Will refuse with a EntityTooLarge
40			// and 400 Bad Request if you exceed this limit.
41			'max_file_size' => 500,
42
43			// Request expiration time, specified in relative time format or in seconds.
44			// minimum of 1 (+1 second), maximum of 604800 (+7 days)
45			'expires' => '+6 hours',
46
47			// Server will check that the filename starts with this prefix and fail
48			// with a AccessDenied 403 if not.
49			'valid_prefix' => '',
50
51			// Strictly only allow a single content type, blank will allow all. Will fail
52			// with a AccessDenied 403 is this condition is not met.
53			'content_type' => '',
54
55			// Sets whether AWS server side encryption should be applied to the uploaded files,
56			// so that files will be encrypted with AES256 when at rest.
57			'encryption' => false,
58
59			//
60			'custom_url' => null,
61
62			// Any additional inputs to add to the form. This is an array of name => value
63			// pairs e.g. ['Content-Disposition' => 'attachment']
64			'additional_inputs' => []
65
66			];
67
68			/**
69			* @var string the AWS Key
70			*/
71			private $key;
72
73			/**
74			* @var string the AWS Secret
75			*/
76			private $secret;
77
78			/**
79			* @var string
80			*/
81			private $bucket;
82
83			/**
84			* @var Region
85			*/
86			private $region;
87
88			/**
89			* @var int the current unix timestamp
90			*/
91			private $time = null;
92
93			private $credentials = null;
94			private $base64Policy = null;
95			private $signature = null;
96
97			/**
98			* Signature constructor.
99			*
100			* @param string $key the AWS API Key to use.
101			* @param string $secret the AWS API Secret to use.
102			* @param string $bucket the bucket to upload the file into.
103			* @param string $region the s3 region this bucket is within. More info: http://amzn.to/1FtPG6r
104			* @param array $options any additional options, like acl and success status.
105			*/
106			public function __construct($key, $secret, $bucket, $region = "us-east-1", $options = [])
107			{
108			$this->setAwsCredentials($key, $secret);
109			$this->populateTime();
110
111			$this->bucket = $bucket;
112			$this->region = new Region($region);
113
114			$this->setOptions($options);
115			}
116
117			/**
118			* Set the AWS Credentials
119			*
120			* @param string $key the AWS API Key to use.
121			* @param string $secret the AWS API Secret to use.
122			*/
123			protected function setAwsCredentials($key, $secret)
124			{
125			// Key
126			if (empty($key) \|\| $key === "YOUR_S3_KEY") {
127			throw new \InvalidArgumentException("Invalid AWS Key");
128			}
129			$this->key = $key;
130
131			// Secret
132			if (empty($secret) \|\| $secret === "YOUR_S3_SECRET") {
133			throw new \InvalidArgumentException("Invalid AWS Secret");
134			}
135			$this->secret = $secret;
136			}
137
138			/**
139			* Build the form url for sending files, this will include the bucket and the region name.
140			*
141			* @return string the s3 bucket's url.
142			*/
143			public function getFormUrl()
144			{
145			if (!is_null($this->options['custom_url'])) {
146			return $this->buildCustomUrl();
147			} else {
148			return $this->buildAmazonUrl();
149			}
150			}
151
152			private function buildCustomUrl()
153			{
154			$url = trim($this->options['custom_url']);
155
156			if (filter_var($url, FILTER_VALIDATE_URL) === false) {
157			throw new InvalidOptionException("The custom_url option you have specified is invalid");
158			}
159
160			$separator = (substr($url, -1) === "/" ? "" : "/");
161
162			return $url . $separator . urlencode($this->bucket);
163			}
164
165			private function buildAmazonUrl()
166			{
167			$region = (string)$this->region;
168
169			// Only the us-east-1 region is exempt from needing the region in the url.
170			if ($region !== "us-east-1") {
171			$middle = "-" . $region;
172			} else {
173			$middle = "";
174			}
175
176			return "//" . self::SERVICE . $middle . ".amazonaws.com" . "/" . urlencode($this->bucket);
177			}
178
179			/**
180			* Get all options.
181			*
182			* @return array
183			*/
184			public function getOptions()
185			{
186			return $this->options;
187			}
188
189			/**
190			* Set/overwrite any default options.
191			*
192			* @param array $options any options to override.
193			*/
194			public function setOptions($options)
195			{
196			// Overwrite default options
197			$this->options = $options + $this->options;
198
199			$this->options['acl'] = new Acl($this->options['acl']);
200
201			// Return HTTP code must be a string
202			$this->options['success_status'] = (string)$this->options['success_status'];
203			}
204
205			/**
206			* Get an AWS Signature V4 generated.
207			*
208			* @return string the aws v4 signature.
209			*/
210			public function getSignature()
211			{
212			if (is_null($this->signature)) {
213			$this->generateScope();
214			$this->generatePolicy();
215			$this->generateSignature();
216			}
217			return $this->signature;
218			}
219
220			/**
221			* Generate the necessary hidden inputs to go within the form. These inputs should match what's being send in
222			* the policy.
223			*
224			* @param bool $addKey whether to add the 'key' input (filename), defaults to yes.
225			*
226			* @return array of the form inputs.
227			*/
228			public function getFormInputs($addKey = true)
229			{
230			$this->getSignature();
231
232			$inputs = [
233			'Content-Type' => $this->options['content_type'],
234			'acl' => (string)$this->options['acl'],
235			'success_action_status' => $this->options['success_status'],
236			'policy' => $this->base64Policy,
237			'X-amz-credential' => $this->credentials,
238			'X-amz-algorithm' => self::ALGORITHM,
239			'X-amz-date' => $this->getFullDateFormat(),
240			'X-amz-signature' => $this->signature
241			];
242
243			if ($this->options['encryption']) {
244			$inputs['X-amz-server-side-encryption'] = 'AES256';
245			}
246
247			$inputs = array_merge($inputs, $this->options['additional_inputs']);
248
249			if ($addKey) {
250			// Note: The Key (filename) will need to be populated with JS on upload
251			// if anything other than the filename is wanted.
252			$inputs['key'] = $this->options['valid_prefix'] . $this->options['default_filename'];
253			}
254
255			return $inputs;
256			}
257
258			/**
259			* Based on getFormInputs(), this will build up the html to go within the form.
260			*
261			* @param bool $addKey whether to add the 'key' input (filename), defaults to yes.
262			*
263			* @return string html of hidden form inputs.
264			*/
265			public function getFormInputsAsHtml($addKey = true)
266			{
267			$inputs = [];
268			foreach ($this->getFormInputs($addKey) as $name => $value) {
269			$inputs[] = '<input type="hidden" name="' . $name . '" value="' . $value . '" />';
270			}
271			return implode(PHP_EOL, $inputs);
272			}
273
274
275			// Where the magic begins ;)
276
277			/**
278			* Step 1: Generate the Scope
279			*/
280			protected function generateScope()
281			{
282			$scope = [
283			$this->key,
284			$this->getShortDateFormat(),
285			$this->region,
286			self::SERVICE,
287			self::REQUEST_TYPE
288			];
289			$this->credentials = implode('/', $scope);
290			}
291
292			/**
293			* Step 2: Generate a Base64 Policy
294			*/
295			protected function generatePolicy()
296			{
297			$policy = [
298			'expiration' => $this->getExpirationDate(),
299			'conditions' => [
300			['bucket' => $this->bucket],
301			['acl' => (string)$this->options['acl']],
302			['starts-with', '$key', $this->options['valid_prefix']],
303			$this->getPolicyContentTypeArray(),
304			['content-length-range', 0, $this->mbToBytes($this->options['max_file_size'])],
305			['success_action_status' => $this->options['success_status']],
306			['x-amz-credential' => $this->credentials],
307			['x-amz-algorithm' => self::ALGORITHM],
308			['x-amz-date' => $this->getFullDateFormat()]
309			]
310			];
311			$policy = $this->addAdditionalInputs($policy);
312			$this->base64Policy = base64_encode(json_encode($policy));
313			}
314
315			private function getPolicyContentTypeArray()
316			{
317			$contentTypePrefix = (empty($this->options['content_type']) ? 'starts-with' : 'eq');
318			return [
319			$contentTypePrefix,
320			'$Content-Type',
321			$this->options['content_type']
322			];
323			}
324
325			private function addAdditionalInputs($policy)
			0 ignored issues – show Documentation introduced 2016-11-14 19:58 UTC by Report Bug Copy Issue Report The return type could not be reliably inferred; please add a `@return` annotation. Our type inference engine in quite powerful, but sometimes the code does not provide enough clues to go by. In these cases we request you to add a `@return` annotation as described here. Loading history...
326			{
327			foreach ($this->options['additional_inputs'] as $name => $value) {
328			$policy['conditions'][] = ['starts-with', '$' . $name, $value];
329			}
330			return $policy;
331			}
332
333			/**
334			* Step 3: Generate and sign the Signature (v4)
335			*/
336			protected function generateSignature()
337			{
338			$signatureData = [
339			$this->getShortDateFormat(),
340			(string)$this->region,
341			self::SERVICE,
342			self::REQUEST_TYPE
343			];
344
345			// Iterates over the data (defined in the array above), hashing it each time.
346			$initial = 'AWS4' . $this->secret;
347			$signingKey = array_reduce($signatureData, function($key, $data) {
348			return $this->keyHash($data, $key);
349			}, $initial);
350
351			// Finally, use the signing key to hash the policy.
352			$this->signature = $this->keyHash($this->base64Policy, $signingKey, false);
353			}
354
355
356			// Helper functions
357
358			private function keyHash($date, $key, $raw = true)
359			{
360			return hash_hmac('sha256', $date, $key, $raw);
361			}
362
363			private function populateTime()
364			{
365			if (is_null($this->time)) {
366			$this->time = time();
367			}
368			}
369
370			private function mbToBytes($megaByte)
371			{
372			if (is_numeric($megaByte)) {
373			return $megaByte * pow(1024, 2);
374			}
375			return 0;
376			}
377
378
379			// Dates
380
381			private function getShortDateFormat()
382			{
383			return gmdate("Ymd", $this->time);
384			}
385
386			private function getFullDateFormat()
387			{
388			return gmdate("Ymd\THis\Z", $this->time);
389			}
390
391			private function getExpirationDate()
392			{
393			// Note: using \DateTime::ISO8601 doesn't work :(
394
395			$exp = strtotime($this->options['expires'], $this->time);
396			$diff = $exp - $this->time;
397
398			if (!($diff >= 1 && $diff <= 604800)) {
399			throw new \InvalidArgumentException("Expiry must be between 1 and 604800");
400			}
401
402			return gmdate('Y-m-d\TG:i:s\Z', $exp);
403			}
404
405
406			}
407

eddturtle / direct-upload

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Signature::buildCustomUrl() A

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