ApiOperations
6 years ago
Checkout
6 years ago
Error
6 years ago
HttpClient
6 years ago
Issuing
6 years ago
Radar
6 years ago
Reporting
6 years ago
Sigma
6 years ago
Terminal
6 years ago
Util
6 years ago
Account.php
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AccountLink.php
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AlipayAccount.php
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ApiRequestor.php
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ApiResource.php
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ApiResponse.php
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ApplePayDomain.php
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ApplicationFee.php
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ApplicationFeeRefund.php
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Balance.php
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BalanceTransaction.php
6 years ago
BankAccount.php
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BitcoinReceiver.php
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BitcoinTransaction.php
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Capability.php
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Card.php
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Charge.php
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Collection.php
6 years ago
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6 years ago
Coupon.php
6 years ago
CreditNote.php
6 years ago
Customer.php
6 years ago
CustomerBalanceTransaction.php
6 years ago
Discount.php
6 years ago
Dispute.php
6 years ago
EphemeralKey.php
6 years ago
Event.php
6 years ago
ExchangeRate.php
6 years ago
File.php
6 years ago
FileLink.php
6 years ago
FileUpload.php
6 years ago
Invoice.php
6 years ago
InvoiceItem.php
6 years ago
InvoiceLineItem.php
6 years ago
IssuerFraudRecord.php
6 years ago
LoginLink.php
6 years ago
OAuth.php
6 years ago
Order.php
6 years ago
OrderItem.php
6 years ago
OrderReturn.php
6 years ago
PaymentIntent.php
6 years ago
PaymentMethod.php
6 years ago
Payout.php
6 years ago
Person.php
6 years ago
Plan.php
6 years ago
Product.php
6 years ago
Recipient.php
6 years ago
RecipientTransfer.php
6 years ago
Refund.php
6 years ago
RequestTelemetry.php
6 years ago
Review.php
6 years ago
SKU.php
6 years ago
SetupIntent.php
6 years ago
SingletonApiResource.php
6 years ago
Source.php
6 years ago
SourceTransaction.php
6 years ago
Stripe.php
6 years ago
StripeObject.php
6 years ago
Subscription.php
6 years ago
SubscriptionItem.php
6 years ago
SubscriptionSchedule.php
6 years ago
TaxId.php
6 years ago
TaxRate.php
6 years ago
ThreeDSecure.php
6 years ago
Token.php
6 years ago
Topup.php
6 years ago
Transfer.php
6 years ago
TransferReversal.php
6 years ago
UsageRecord.php
6 years ago
UsageRecordSummary.php
6 years ago
Webhook.php
6 years ago
WebhookEndpoint.php
6 years ago
WebhookSignature.php
6 years ago
WebhookSignature.php
134 lines
| 1 | <?php |
| 2 | |
| 3 | namespace Stripe; |
| 4 | |
| 5 | abstract class WebhookSignature |
| 6 | { |
| 7 | const EXPECTED_SCHEME = "v1"; |
| 8 | |
| 9 | /** |
| 10 | * Verifies the signature header sent by Stripe. Throws a |
| 11 | * SignatureVerification exception if the verification fails for any |
| 12 | * reason. |
| 13 | * |
| 14 | * @param string $payload the payload sent by Stripe. |
| 15 | * @param string $header the contents of the signature header sent by |
| 16 | * Stripe. |
| 17 | * @param string $secret secret used to generate the signature. |
| 18 | * @param int $tolerance maximum difference allowed between the header's |
| 19 | * timestamp and the current time |
| 20 | * @throws \Stripe\Error\SignatureVerification if the verification fails. |
| 21 | * @return bool |
| 22 | */ |
| 23 | public static function verifyHeader($payload, $header, $secret, $tolerance = null) |
| 24 | { |
| 25 | // Extract timestamp and signatures from header |
| 26 | $timestamp = self::getTimestamp($header); |
| 27 | $signatures = self::getSignatures($header, self::EXPECTED_SCHEME); |
| 28 | if ($timestamp == -1) { |
| 29 | throw new Error\SignatureVerification( |
| 30 | "Unable to extract timestamp and signatures from header", |
| 31 | $header, |
| 32 | $payload |
| 33 | ); |
| 34 | } |
| 35 | if (empty($signatures)) { |
| 36 | throw new Error\SignatureVerification( |
| 37 | "No signatures found with expected scheme", |
| 38 | $header, |
| 39 | $payload |
| 40 | ); |
| 41 | } |
| 42 | |
| 43 | // Check if expected signature is found in list of signatures from |
| 44 | // header |
| 45 | $signedPayload = "$timestamp.$payload"; |
| 46 | $expectedSignature = self::computeSignature($signedPayload, $secret); |
| 47 | $signatureFound = false; |
| 48 | foreach ($signatures as $signature) { |
| 49 | if (Util\Util::secureCompare($expectedSignature, $signature)) { |
| 50 | $signatureFound = true; |
| 51 | break; |
| 52 | } |
| 53 | } |
| 54 | if (!$signatureFound) { |
| 55 | throw new Error\SignatureVerification( |
| 56 | "No signatures found matching the expected signature for payload", |
| 57 | $header, |
| 58 | $payload |
| 59 | ); |
| 60 | } |
| 61 | |
| 62 | // Check if timestamp is within tolerance |
| 63 | if (($tolerance > 0) && (abs(time() - $timestamp) > $tolerance)) { |
| 64 | throw new Error\SignatureVerification( |
| 65 | "Timestamp outside the tolerance zone", |
| 66 | $header, |
| 67 | $payload |
| 68 | ); |
| 69 | } |
| 70 | |
| 71 | return true; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Extracts the timestamp in a signature header. |
| 76 | * |
| 77 | * @param string $header the signature header |
| 78 | * @return int the timestamp contained in the header, or -1 if no valid |
| 79 | * timestamp is found |
| 80 | */ |
| 81 | private static function getTimestamp($header) |
| 82 | { |
| 83 | $items = explode(",", $header); |
| 84 | |
| 85 | foreach ($items as $item) { |
| 86 | $itemParts = explode("=", $item, 2); |
| 87 | if ($itemParts[0] == "t") { |
| 88 | if (!is_numeric($itemParts[1])) { |
| 89 | return -1; |
| 90 | } |
| 91 | return intval($itemParts[1]); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | return -1; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Extracts the signatures matching a given scheme in a signature header. |
| 100 | * |
| 101 | * @param string $header the signature header |
| 102 | * @param string $scheme the signature scheme to look for. |
| 103 | * @return array the list of signatures matching the provided scheme. |
| 104 | */ |
| 105 | private static function getSignatures($header, $scheme) |
| 106 | { |
| 107 | $signatures = []; |
| 108 | $items = explode(",", $header); |
| 109 | |
| 110 | foreach ($items as $item) { |
| 111 | $itemParts = explode("=", $item, 2); |
| 112 | if ($itemParts[0] == $scheme) { |
| 113 | array_push($signatures, $itemParts[1]); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | return $signatures; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Computes the signature for a given payload and secret. |
| 122 | * |
| 123 | * The current scheme used by Stripe ("v1") is HMAC/SHA-256. |
| 124 | * |
| 125 | * @param string $payload the payload to sign. |
| 126 | * @param string $secret the secret used to generate the signature. |
| 127 | * @return string the signature as a string. |
| 128 | */ |
| 129 | private static function computeSignature($payload, $secret) |
| 130 | { |
| 131 | return hash_hmac("sha256", $payload, $secret); |
| 132 | } |
| 133 | } |
| 134 |