Décrire brièvement l'utilisation du cryptage, du déchiffrement et de la vérification des signatures dans l'interface PHP.

<?php
//header(&#39;Content-Type: text/xml; charset=utf-8&#39;);
include_once(dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.&#39;phpsec&#39;.DIRECTORY_SEPARATOR.&#39;Math&#39;.DIRECTORY_SEPARATOR.&#39;BigInteger.php&#39;);
include_once(dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.&#39;phpsec&#39;.DIRECTORY_SEPARATOR.&#39;Crypt&#39;.DIRECTORY_SEPARATOR.&#39;AES.php&#39;);
include_once(dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.&#39;phpsec&#39;.DIRECTORY_SEPARATOR.&#39;Crypt&#39;.DIRECTORY_SEPARATOR.&#39;RSA.php&#39;);
//密文
$crypttext = &#39;v66YKULHFld2JElhm/J9qik2Edr1JHdZIc/k/OesU2GbTX2usXyvF4jGvzvoihrrE8FsfKmllmjsMIjO5fdrS/FD20bYFii4JW3BO3bzshXmz6AEs2DWwG4sK9mNojfOC0IsMoV311X5/JlgUoQXkDy4F5HHpYE9d/xGb0g2XE/hnGSSy2cpQcvQtBlBmixwSckNhsEG92lovlOz8ULwkqG5o7x+qB7P/EMII/WaFAXBJXDXvZX7lmGcOgon6wLhKJLGXorP6BIxOg6LGc6Ux7BAt3i9+0lujNgxIq/sDsl23hsr3yOUpV5C5a813nrHx4HJyd/hBT1UvIUml+eTmJwWCpSfs2cvxIUr0CE57JAZVyXjK13shK3IsZHLPPsm/JcDCrdy0Co/d5uIGJAdzXdsQ56xsju+tlvnA1J6yq2tDIfYK/x6k911A5WXLKYxztD1nq+bTYN3Gv/WFfrzVtgWQBrh06ihS2cwvna0S9EV/YPmhnAjJmrX4trNr9NXQ9xaZaW4lGRg87U5QDV+nQjj1THk0XHFc69N9g2+DsAGyEs9tK6U0ZQ72hJZqZhBCDH1UKw0PLyIhJdxpgPPOWGp8/QVVU2julTeKunvgAAEc3n+GoZfqjsCDi1S6T2MTnjWYWNoFRBhvEZFD/revgpasTOzDQa5NqR1B+mUF70r6uw6MWLJ7cT9Tz3jq+CA&#39;;
$aeskey = base64_decode(&#39;qZe60QZFxuirub2ey4+7+Q==&#39;);
//AES解密，采用ECB模式
$aes = new Crypt_AES(CRYPT_MODE_ECB);
//设置AES密钥
$aes->setKey($aeskey);
//解密AES密文
$plaintext = $aes->decrypt(base64_decode($crypttext));
echo $plaintext;
echo &#39;<hr />&#39;;
//AES加密明文
//echo $aes->encrypt($plaintext);
//rsa公钥
$publickey = &#39;MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCffOeIVYut9jW5w1L5uKX4aDvd837a8JhaWm5S8YqNQfgEmfD9T+rDknXLqMT+DXeQAqGo4hBmcbej1aoMzn6hIJHk3/TfTAToNN8fgwDotHewsTCBbVkQWtDTby3GouWToVsRi1i/A0Vfb0+xM8MnF46DdhhrnZrycERBSbyrcwIDAQAB&#39;;
//echo base64_decode($publickey);
//rsa签名
$signature = &#39;XHin4uUFqrKDEhKBD/hQisXLFFSxM6EZCvCPqnWCQJq3uEp3ayxmFuUgVE0Xoh4AIWjIIsOWdnaToL1bXvAFKwjCtXnkaRwUpvWrk+Q0eqwsoAdywsVQDEceG5stas1CkPtrznAIW2eBGXCWspOj+aumEAcPyYDxLhDN646Krzw=&#39;;
//echo base64_decode($signature);
$rsa = new Crypt_RSA();
//设置RSA签名模式 CRYPT_RSA_SIGNATURE_PSS or CRYPT_RSA_SIGNATURE_PKCS1
$rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
//var_dump($rsa->createKey());
//生成RSA公钥、私钥
//extract($rsa->createKey());
//使用RSA私钥生成签名
//$rsa->loadKey($privatekey);
//$signature = $rsa->sign($plaintext);
//使用RSA公钥验证签名
echo $plaintext;
$rsa->loadKey(base64_decode($publickey));
echo $rsa->verify($plaintext, base64_decode($signature)) ? &#39;verified&#39; : &#39;unverified&#39;;
echo &#39;<hr />&#39;;
//生成RSA公钥、私钥
//var_dump($rsa->createKey());
extract($rsa->createKey());
//使用RSA私钥加密数据
$rsa->loadKey($privatekey);
$ciphertext = $rsa->encrypt($plaintext);
//使用RSA公钥解密数据
$rsa->loadKey($publickey);
echo $rsa->decrypt($ciphertext);