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@@ -0,0 +1,527 @@
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+<?php
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+
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+/**
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+ * 验证支付宝公钥证书是否可信
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+ * @param $alipayCert 支付宝公钥证书
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+ * @param $rootCert 支付宝根证书
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+ */
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+function isTrusted($alipayCert, $rootCert)
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+{
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+ $alipayCerts = readPemCertChain($alipayCert);
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+ $rootCerts = readPemCertChain($rootCert);
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+ if (verifyCertChain($alipayCerts, $rootCerts)) {
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+ return verifySignature($alipayCert, $rootCert);
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+ } else {
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+ return false;
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+ }
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+
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+}
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+
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+function verifySignature($alipayCert, $rootCert)
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+{
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+ $alipayCertArray = explode("-----END CERTIFICATE-----", $alipayCert);
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+ $rootCertArray = explode("-----END CERTIFICATE-----", $rootCert);
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+ $length = count($rootCertArray) - 1;
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+ $checkSign = isCertSigner($alipayCertArray[0] . "-----END CERTIFICATE-----", $alipayCertArray[1] . "-----END CERTIFICATE-----");
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+ if (!$checkSign) {
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+ $checkSign = isCertSigner($alipayCertArray[1] . "-----END CERTIFICATE-----", $alipayCertArray[0] . "-----END CERTIFICATE-----");
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+ if ($checkSign) {
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+ $issuer = openssl_x509_parse($alipayCertArray[0] . "-----END CERTIFICATE-----")['issuer'];
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+ for ($i = 0; $i < $length; $i++) {
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+ $subject = openssl_x509_parse($rootCertArray[$i] . "-----END CERTIFICATE-----")['subject'];
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+ if ($issuer == $subject) {
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+ isCertSigner($alipayCertArray[0] . "-----END CERTIFICATE-----", $rootCertArray[$i] . $rootCertArray);
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+ return $checkSign;
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+ }
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+ }
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+ } else {
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+ return $checkSign;
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+ }
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+ } else {
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+ $issuer = openssl_x509_parse($alipayCertArray[1] . "-----END CERTIFICATE-----")['issuer'];
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+ for ($i = 0; $i < $length; $i++) {
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+ $subject = openssl_x509_parse($rootCertArray[$i] . "-----END CERTIFICATE-----")['subject'];
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+ if ($issuer == $subject) {
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+ $checkSign = isCertSigner($alipayCertArray[1] . "-----END CERTIFICATE-----", $rootCertArray[$i] . "-----END CERTIFICATE-----");
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+ return $checkSign;
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+ }
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+ }
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+ return $checkSign;
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+ }
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+}
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+
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+function readPemCertChain($cert)
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+{
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+ $array = explode("-----END CERTIFICATE-----", $cert);
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+ $certs[] = null;
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+ for ($i = 0; $i < count($array) - 1; $i++) {
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+ $certs[$i] = openssl_x509_parse($array[$i] . "-----END CERTIFICATE-----");
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+ }
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+ return $certs;
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+}
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+
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+function verifyCert($prev, $rootCerts)
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+{
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+ $nowTime = time();
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+ if ($nowTime < $prev['validFrom_time_t']) {
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+ echo "证书未激活";
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+ return false;
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+ }
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+ if ($nowTime > $prev['validTo_time_t']) {
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+ echo "证书已经过期";
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+ return false;
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+ }
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+ $subjectMap = null;
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+ for ($i = 0; $i < count($rootCerts); $i++) {
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+ $subjectDN = array2string($rootCerts[$i]['subject']);
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+ $subjectMap[$subjectDN] = $rootCerts[$i];
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+ }
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+ $issuerDN = array2string(($prev['issuer']));
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+ if (!array_key_exists($issuerDN, $subjectMap)) {
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+ echo "证书链验证失败";
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+ return false;
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+ }
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+ return true;
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+}
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+
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+/**
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+ * 验证证书链是否是信任证书库中证书签发的
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+ * @param $alipayCerts 目标验证证书列表
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+ * @param $rootCerts 可信根证书列表
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+ */
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+function verifyCertChain($alipayCerts, $rootCerts)
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+{
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+ $sorted = sortByDn($alipayCerts);
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+ if (!$sorted) {
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+ echo "证书链验证失败:不是完整的证书链";
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+ return false;
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+ }
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+ //先验证第一个证书是不是信任库中证书签发的
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+ $prev = $alipayCerts[0];
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+ $firstOK = verifyCert($prev, $rootCerts);
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+ $length = count($alipayCerts);
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+ if (!$firstOK || $length == 1) {
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+ return $firstOK;
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+ }
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+
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+ $nowTime = time();
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+ //验证证书链
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+ for ($i = 1; $i < $length; $i++) {
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+ $cert = $alipayCerts[$i];
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+ if ($nowTime < $cert['validFrom_time_t']) {
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+ echo "证书未激活";
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+ return false;
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+ }
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+ if ($nowTime > $cert['validTo_time_t']) {
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+ echo "证书已经过期";
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+ return false;
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+ }
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+ }
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+ return true;
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+}
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+
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+/**
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+ * 将证书链按照完整的签发顺序进行排序,排序后证书链为:[issuerA, subjectA]-[issuerA, subjectB]-[issuerB, subjectC]-[issuerC, subjectD]...
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+ * @param $certs 证书链
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+ */
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+function sortByDn(&$certs)
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+{
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+ //是否包含自签名证书
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+ $hasSelfSignedCert = false;
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+ $subjectMap = null;
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+ $issuerMap = null;
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+ for ($i = 0; $i < count($certs); $i++) {
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+ if (isSelfSigned($certs[$i])) {
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+ if ($hasSelfSignedCert) {
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+ return false;
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+ }
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+ $hasSelfSignedCert = true;
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+ }
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+ $subjectDN = array2string($certs[$i]['subject']);
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+ $issuerDN = array2string(($certs[$i]['issuer']));
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+ $subjectMap[$subjectDN] = $certs[$i];
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+ $issuerMap[$issuerDN] = $certs[$i];
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+ }
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+ $certChain = null;
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+ addressingUp($subjectMap, $certChain, $certs[0]);
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+ addressingDown($issuerMap, $certChain, $certs[0]);
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+
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+ //说明证书链不完整
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+ if (count($certs) != count($certChain)) {
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+ return false;
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+ }
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+ //将证书链复制到原先的数据
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+ for ($i = 0; $i < count($certs); $i++) {
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+ $certs[$i] = $certChain[count($certs) - $i - 1];
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+ }
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+ return true;
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+}
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+
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+/**
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+ * 验证证书是否是自签发的
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+ * @param $cert 目标证书
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+ */
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+function isSelfSigned($cert)
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+{
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+ $subjectDN = array2string($cert['subject']);
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+ $issuerDN = array2string($cert['issuer']);
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+ return ($subjectDN == $issuerDN);
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+}
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+
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+
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+function array2string($array)
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+{
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+ $string = [];
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+ if ($array && is_array($array)) {
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+ foreach ($array as $key => $value) {
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+ $string[] = $key . '=' . $value;
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+ }
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+ }
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+ return implode(',', $string);
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+}
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+
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+/**
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+ * 向上构造证书链
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+ * @param $subjectMap 主题和证书的映射
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+ * @param $certChain 证书链
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+ * @param $current 当前需要插入证书链的证书,include
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+ */
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+function addressingUp($subjectMap, &$certChain, $current)
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+{
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+ $certChain[] = $current;
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+ if (isSelfSigned($current)) {
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+ return;
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+ }
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+ $issuerDN = array2string($current['issuer']);
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+
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+ if (!array_key_exists($issuerDN, $subjectMap)) {
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+ return;
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+ }
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+ addressingUp($subjectMap, $certChain, $subjectMap[$issuerDN]);
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+}
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+
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+/**
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+ * 向下构造证书链
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+ * @param $issuerMap 签发者和证书的映射
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+ * @param $certChain 证书链
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+ * @param $current 当前需要插入证书链的证书,exclude
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+ */
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+function addressingDown($issuerMap, &$certChain, $current)
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+{
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+ $subjectDN = array2string($current['subject']);
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+ if (!array_key_exists($subjectDN, $issuerMap)) {
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+ return $certChain;
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+ }
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+ $certChain[] = $issuerMap[$subjectDN];
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+ addressingDown($issuerMap, $certChain, $issuerMap[$subjectDN]);
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+}
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+
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+
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+/**
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+ * Extract signature from der encoded cert.
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+ * Expects x509 der encoded certificate consisting of a section container
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+ * containing 2 sections and a bitstream. The bitstream contains the
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+ * original encrypted signature, encrypted by the public key of the issuing
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+ * signer.
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+ * @param string $der
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+ * @return string on success
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+ * @return bool false on failures
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+ */
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+function extractSignature($der = false)
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+{
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+ if (strlen($der) < 5) {
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+ return false;
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+ }
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+ // skip container sequence
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+ $der = substr($der, 4);
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+ // now burn through two sequences and the return the final bitstream
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+ while (strlen($der) > 1) {
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+ $class = ord($der[0]);
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+ $classHex = dechex($class);
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+ switch ($class) {
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+ // BITSTREAM
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+ case 0x03:
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+ $len = ord($der[1]);
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+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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+ $len = ($len << 8) | ord($der[$i + 2]);
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+ }
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+ }
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+ return substr($der, 3 + $bytes, $len);
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+ break;
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+ // SEQUENCE
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+ case 0x30:
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+ $len = ord($der[1]);
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+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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+ $len = ($len << 8) | ord($der[$i + 2]);
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+ }
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+ }
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+ $contents = substr($der, 2 + $bytes, $len);
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+ $der = substr($der, 2 + $bytes + $len);
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+ break;
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+ default:
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+ return false;
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+ break;
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+ }
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+ }
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+ return false;
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+}
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+
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+/**
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+ * Get signature algorithm oid from der encoded signature data.
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+ * Expects decrypted signature data from a certificate in der format.
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+ * This ASN1 data should contain the following structure:
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+ * SEQUENCE
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+ * SEQUENCE
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+ * OID (signature algorithm)
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+ * NULL
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+ * OCTET STRING (signature hash)
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+ * @return bool false on failures
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+ * @return string oid
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+ */
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+function getSignatureAlgorithmOid($der = null)
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+{
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+ // Validate this is the der we need...
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+ if (!is_string($der) or strlen($der) < 5) {
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+ return false;
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+ }
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+ $bit_seq1 = 0;
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+ $bit_seq2 = 2;
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+ $bit_oid = 4;
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+ if (ord($der[$bit_seq1]) !== 0x30) {
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+ die('Invalid DER passed to getSignatureAlgorithmOid()');
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+ }
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+ if (ord($der[$bit_seq2]) !== 0x30) {
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+ die('Invalid DER passed to getSignatureAlgorithmOid()');
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+ }
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+ if (ord($der[$bit_oid]) !== 0x06) {
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+ die('Invalid DER passed to getSignatureAlgorithmOid');
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+ }
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+ // strip out what we don't need and get the oid
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+ $der = substr($der, $bit_oid);
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+ // Get the oid
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+ $len = ord($der[1]);
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+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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+ $len = ($len << 8) | ord($der[$i + 2]);
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+ }
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+ }
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+ $oid_data = substr($der, 2 + $bytes, $len);
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+ // Unpack the OID
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+ $oid = floor(ord($oid_data[0]) / 40);
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+ $oid .= '.' . ord($oid_data[0]) % 40;
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+ $value = 0;
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+ $i = 1;
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+ while ($i < strlen($oid_data)) {
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+ $value = $value << 7;
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+ $value = $value | (ord($oid_data[$i]) & 0x7f);
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+ if (!(ord($oid_data[$i]) & 0x80)) {
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+ $oid .= '.' . $value;
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+ $value = 0;
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+ }
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+ $i++;
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+ }
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+ return $oid;
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+}
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+
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+/**
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+ * Get signature hash from der encoded signature data.
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+ * Expects decrypted signature data from a certificate in der format.
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+ * This ASN1 data should contain the following structure:
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+ * SEQUENCE
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+ * SEQUENCE
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+ * OID (signature algorithm)
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+ * NULL
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+ * OCTET STRING (signature hash)
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+ * @return bool false on failures
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+ * @return string hash
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+ */
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+function getSignatureHash($der = null)
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+{
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+ // Validate this is the der we need...
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+ if (!is_string($der) or strlen($der) < 5) {
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+ return false;
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+ }
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+ if (ord($der[0]) !== 0x30) {
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+ die('Invalid DER passed to getSignatureHash()');
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+ }
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+ // strip out the container sequence
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+ $der = substr($der, 2);
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+ if (ord($der[0]) !== 0x30) {
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+ die('Invalid DER passed to getSignatureHash()');
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+ }
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+ // Get the length of the first sequence so we can strip it out.
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+ $len = ord($der[1]);
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+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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+ $len = ($len << 8) | ord($der[$i + 2]);
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+ }
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+ }
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+ $der = substr($der, 2 + $bytes + $len);
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+ // Now we should have an octet string
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+ if (ord($der[0]) !== 0x04) {
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+ die('Invalid DER passed to getSignatureHash()');
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+ }
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+ $len = ord($der[1]);
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+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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+ $len = ($len << 8) | ord($der[$i + 2]);
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+ }
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+ }
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+ return bin2hex(substr($der, 2 + $bytes, $len));
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+}
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+
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+/**
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+ * Determine if one cert was used to sign another
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+ * Note that more than one CA cert can give a positive result, some certs
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+ * re-issue signing certs after having only changed the expiration dates.
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+ * @param string $cert - PEM encoded cert
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+ * @param string $caCert - PEM encoded cert that possibly signed $cert
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+ * @return bool
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+ */
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+function isCertSigner($certPem = null, $caCertPem = null)
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+{
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+ if (!function_exists('openssl_pkey_get_public')) {
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+ die('Need the openssl_pkey_get_public() function.');
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+ }
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+ if (!function_exists('openssl_public_decrypt')) {
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+ die('Need the openssl_public_decrypt() function.');
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+ }
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+ if (!function_exists('hash')) {
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+ die('Need the php hash() function.');
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+ }
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+ if (empty($certPem) or empty($caCertPem)) {
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+ return false;
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+ }
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+ // Convert the cert to der for feeding to extractSignature.
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+ $certDer = pemToDer($certPem);
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+ if (!is_string($certDer)) {
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+ die('invalid certPem');
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+ }
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+ // Grab the encrypted signature from the der encoded cert.
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+ $encryptedSig = extractSignature($certDer);
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+ if (!is_string($encryptedSig)) {
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+ die('Failed to extract encrypted signature from certPem.');
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+ }
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+ // Extract the public key from the ca cert, which is what has
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+ // been used to encrypt the signature in the cert.
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+ $pubKey = openssl_pkey_get_public($caCertPem);
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+ if ($pubKey === false) {
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+ die('Failed to extract the public key from the ca cert.');
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+ }
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+ // Attempt to decrypt the encrypted signature using the CA's public
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+ // key, returning the decrypted signature in $decryptedSig. If
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+ // it can't be decrypted, this ca was not used to sign it for sure...
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+ $rc = openssl_public_decrypt($encryptedSig, $decryptedSig, $pubKey);
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+ if ($rc === false) {
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+ return false;
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+ }
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+ // We now have the decrypted signature, which is der encoded
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+ // asn1 data containing the signature algorithm and signature hash.
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+ // Now we need what was originally hashed by the issuer, which is
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+ // the original DER encoded certificate without the issuer and
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+ // signature information.
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+ $origCert = stripSignerAsn($certDer);
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+ if ($origCert === false) {
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+ die('Failed to extract unsigned cert.');
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+ }
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+ // Get the oid of the signature hash algorithm, which is required
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+ // to generate our own hash of the original cert. This hash is
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+ // what will be compared to the issuers hash.
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+ $oid = getSignatureAlgorithmOid($decryptedSig);
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+ if ($oid === false) {
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+ die('Failed to determine the signature algorithm.');
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+ }
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+ switch ($oid) {
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+ case '1.2.840.113549.2.2':
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+ $algo = 'md2';
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+ break;
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+ case '1.2.840.113549.2.4':
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+ $algo = 'md4';
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+ break;
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+ case '1.2.840.113549.2.5':
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+ $algo = 'md5';
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+ break;
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+ case '1.3.14.3.2.18':
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+ $algo = 'sha';
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+ break;
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+ case '1.3.14.3.2.26':
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+ $algo = 'sha1';
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+ break;
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+ case '2.16.840.1.101.3.4.2.1':
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+ $algo = 'sha256';
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+ break;
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+ case '2.16.840.1.101.3.4.2.2':
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+ $algo = 'sha384';
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+ break;
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+ case '2.16.840.1.101.3.4.2.3':
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+ $algo = 'sha512';
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+ break;
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+ default:
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+ die('Unknown signature hash algorithm oid: ' . $oid);
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+ break;
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+ }
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+ // Get the issuer generated hash from the decrypted signature.
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+ $decryptedHash = getSignatureHash($decryptedSig);
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+ // Ok, hash the original unsigned cert with the same algorithm
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+ // and if it matches $decryptedHash we have a winner.
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+ $certHash = hash($algo, $origCert);
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+ return ($decryptedHash === $certHash);
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+}
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+
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+/**
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+ * Convert pem encoded certificate to DER encoding
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+ * @return string $derEncoded on success
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+ * @return bool false on failures
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|
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+ */
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+function pemToDer($pem = null)
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+{
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+ if (!is_string($pem)) {
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+ return false;
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+ }
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+ $cert_split = preg_split('/(-----((BEGIN)|(END)) CERTIFICATE-----)/', $pem);
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+ if (!isset($cert_split[1])) {
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+ return false;
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|
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+ }
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+ return base64_decode($cert_split[1]);
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+}
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+
|
|
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+/**
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+ * Obtain der cert with issuer and signature sections stripped.
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|
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+ * @param string $der - der encoded certificate
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|
|
+ * @return string $der on success
|
|
|
+ * @return bool false on failures.
|
|
|
+ */
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|
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+function stripSignerAsn($der = null)
|
|
|
+{
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|
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+ if (!is_string($der) or strlen($der) < 8) {
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|
|
+ return false;
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|
|
+ }
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|
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+ $bit = 4;
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|
|
+ $len = ord($der[($bit + 1)]);
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|
|
+ $bytes = 0;
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+ if ($len & 0x80) {
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+ $bytes = $len & 0x0f;
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|
|
+ $len = 0;
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+ for ($i = 0; $i < $bytes; $i++) {
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|
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+ $len = ($len << 8) | ord($der[$bit + $i + 2]);
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|
|
+ }
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|
|
+ }
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|
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+ return substr($der, 4, $len + 4);
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|
|
+}
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