first commit -> move some files from one-api

vendor/aws_v3/Aws/Crypto/Polyfill/AesGcm.php

@@ -0,0 +1,228 @@
+<?php
+namespace Aws\Crypto\Polyfill;
+
+use Aws\Exception\CryptoPolyfillException;
+use InvalidArgumentException;
+use RangeException;
+
+/**
+ * Class AesGcm
+ *
+ * This provides a polyfill for AES-GCM encryption/decryption, with caveats:
+ *
+ * 1. Only 96-bit nonces are supported.
+ * 2. Only 128-bit authentication tags are supported. (i.e. non-truncated)
+ *
+ * Supports AES key sizes of 128-bit, 192-bit, and 256-bit.
+ *
+ * @package Aws\Crypto\Polyfill
+ */
+class AesGcm
+{
+    use NeedsTrait;
+
+    /** @var Key $aesKey */
+    private $aesKey;
+
+    /** @var int $keySize */
+    private $keySize;
+
+    /** @var int $blockSize */
+    protected $blockSize = 8192;
+
+    /**
+     * AesGcm constructor.
+     *
+     * @param Key $aesKey
+     * @param int $keySize
+     * @param int $blockSize
+     *
+     * @throws CryptoPolyfillException
+     * @throws InvalidArgumentException
+     * @throws RangeException
+     */
+    public function __construct(Key $aesKey, $keySize = 256, $blockSize = 8192)
+    {
+        /* Preconditions: */
+        self::needs(
+            \in_array($keySize, [128, 192, 256], true),
+            "Key size must be 128, 192, or 256 bits; {$keySize} given",
+            InvalidArgumentException::class
+        );
+        self::needs(
+            \is_int($blockSize) && $blockSize > 0 && $blockSize <= PHP_INT_MAX,
+            'Block size must be a positive integer.',
+            RangeException::class
+        );
+        self::needs(
+            $aesKey->length() << 3 === $keySize,
+            'Incorrect key size; expected ' . $keySize . ' bits, got ' . ($aesKey->length() << 3) . ' bits.'
+        );
+        $this->aesKey = $aesKey;
+        $this->keySize = $keySize;
+    }
+
+    /**
+     * Encryption interface for AES-GCM
+     *
+     * @param string $plaintext  Message to be encrypted
+     * @param string $nonce      Number to be used ONCE
+     * @param Key $key           AES Key
+     * @param string $aad        Additional authenticated data
+     * @param string &$tag       Reference to variable to hold tag
+     * @param int $keySize       Key size (bits)
+     * @param int $blockSize     Block size (bytes) -- How much memory to buffer
+     * @return string
+     * @throws InvalidArgumentException
+     */
+    public static function encrypt(
+        $plaintext,
+        $nonce,
+        Key $key,
+        $aad,
+        &$tag,
+        $keySize = 256,
+        $blockSize = 8192
+    ) {
+        self::needs(
+            self::strlen($nonce) === 12,
+            'Nonce must be exactly 12 bytes',
+            InvalidArgumentException::class
+        );
+
+        $encryptor = new AesGcm($key, $keySize, $blockSize);
+        list($aadLength, $gmac) = $encryptor->gmacInit($nonce, $aad);
+
+        $ciphertext = \openssl_encrypt(
+            $plaintext,
+            "aes-{$encryptor->keySize}-ctr",
+            $key->get(),
+            OPENSSL_NO_PADDING | OPENSSL_RAW_DATA,
+            $nonce . "\x00\x00\x00\x02"
+        );
+
+        /* Calculate auth tag in a streaming fashion to minimize memory usage: */
+        $ciphertextLength = self::strlen($ciphertext);
+        for ($i = 0; $i < $ciphertextLength; $i += $encryptor->blockSize) {
+            $cBlock = new ByteArray(self::substr($ciphertext, $i, $encryptor->blockSize));
+            $gmac->update($cBlock);
+        }
+        $tag = $gmac->finish($aadLength, $ciphertextLength)->toString();
+        return $ciphertext;
+    }
+
+    /**
+     * Decryption interface for AES-GCM
+     *
+     * @param string $ciphertext Ciphertext to decrypt
+     * @param string $nonce      Number to be used ONCE
+     * @param Key $key           AES key
+     * @param string $aad        Additional authenticated data
+     * @param string $tag        Authentication tag
+     * @param int $keySize       Key size (bits)
+     * @param int $blockSize     Block size (bytes) -- How much memory to buffer
+     * @return string            Plaintext
+     *
+     * @throws CryptoPolyfillException
+     * @throws InvalidArgumentException
+     */
+    public static function decrypt(
+        $ciphertext,
+        $nonce,
+        Key $key,
+        $aad,
+        &$tag,
+        $keySize = 256,
+        $blockSize = 8192
+    ) {
+        /* Precondition: */
+        self::needs(
+            self::strlen($nonce) === 12,
+            'Nonce must be exactly 12 bytes',
+            InvalidArgumentException::class
+        );
+
+        $encryptor = new AesGcm($key, $keySize, $blockSize);
+        list($aadLength, $gmac) = $encryptor->gmacInit($nonce, $aad);
+
+        /* Calculate auth tag in a streaming fashion to minimize memory usage: */
+        $ciphertextLength = self::strlen($ciphertext);
+        for ($i = 0; $i < $ciphertextLength; $i += $encryptor->blockSize) {
+            $cBlock = new ByteArray(self::substr($ciphertext, $i, $encryptor->blockSize));
+            $gmac->update($cBlock);
+        }
+
+        /* Validate auth tag in constant-time: */
+        $calc = $gmac->finish($aadLength, $ciphertextLength);
+        $expected = new ByteArray($tag);
+        self::needs($calc->equals($expected), 'Invalid authentication tag');
+
+        /* Return plaintext if auth tag check succeeded: */
+        return \openssl_decrypt(
+            $ciphertext,
+            "aes-{$encryptor->keySize}-ctr",
+            $key->get(),
+            OPENSSL_NO_PADDING | OPENSSL_RAW_DATA,
+            $nonce . "\x00\x00\x00\x02"
+        );
+    }
+
+    /**
+     * Initialize a Gmac object with the nonce and this object's key.
+     *
+     * @param string $nonce     Must be exactly 12 bytes long.
+     * @param string|null $aad
+     * @return array
+     */
+    protected function gmacInit($nonce, $aad = null)
+    {
+        $gmac = new Gmac(
+            $this->aesKey,
+            $nonce . "\x00\x00\x00\x01",
+            $this->keySize
+        );
+        $aadBlock = new ByteArray($aad);
+        $aadLength = $aadBlock->count();
+        $gmac->update($aadBlock);
+        $gmac->flush();
+        return [$aadLength, $gmac];
+    }
+
+    /**
+     * Calculate the length of a string.
+     *
+     * Uses the appropriate PHP function without being brittle to
+     * mbstring.func_overload.
+     *
+     * @param string $string
+     * @return int
+     */
+    protected static function strlen($string)
+    {
+        if (\is_callable('\\mb_strlen')) {
+            return (int) \mb_strlen($string, '8bit');
+        }
+        return (int) \strlen($string);
+    }
+
+    /**
+     * Return a substring of the provided string.
+     *
+     * Uses the appropriate PHP function without being brittle to
+     * mbstring.func_overload.
+     *
+     * @param string $string
+     * @param int $offset
+     * @param int|null $length
+     * @return string
+     */
+    protected static function substr($string, $offset = 0, $length = null)
+    {
+        if (\is_callable('\\mb_substr')) {
+            return \mb_substr($string, $offset, $length, '8bit');
+        } elseif (!\is_null($length)) {
+            return \substr($string, $offset, $length);
+        }
+        return \substr($string, $offset);
+    }
+}