1 files changed, 102 insertions, 0 deletions
diff --git a/library/Icinga/Util/ASN1.php b/library/Icinga/Util/ASN1.php
new file mode 100644
index 0000000..9e00258
--- /dev/null
+++ b/library/Icinga/Util/ASN1.php
@@ -0,0 +1,102 @@
+<?php
+/* Icinga Web 2 | (c) 2018 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Util;
+
+use DateInterval;
+use DateTime;
+use InvalidArgumentException;
+
+/**
+ * Parsers for ASN.1 types
+ */
+class ASN1
+{
+    /**
+     * Parse the given value based on the "3.3.13. Generalized Time" syntax as specified by IETF RFC 4517
+     *
+     * @param   string  $value
+     *
+     * @return  DateTime
+     *
+     * @throws  InvalidArgumentException
+     *
+     * @see https://tools.ietf.org/html/rfc4517#section-3.3.13
+     */
+    public static function parseGeneralizedTime($value)
+    {
+        $generalizedTimePattern = <<<EOD
+/\A
+    (?P<YmdH>
+        [0-9]{4}                    # century year
+        (?:0[1-9]|1[0-2])           # month
+        (?:0[1-9]|[12][0-9]|3[0-1]) # day
+        (?:[01][0-9]|2[0-3])        # hour
+    )
+    (?:
+        (?P<i>[0-5][0-9])           # minute
+        (?P<s>[0-5][0-9]|60)?       # second or leap-second
+    )?
+    (?:[.,](?P<frac>[0-9]+))?       # fraction
+    (?P<tz>                         # g-time-zone
+            Z
+        |
+            [-+]
+            (?:[01][0-9]|2[0-3])    # hour
+            (?:[0-5][0-9])?         # minute
+    )
+\z/x
+EOD;
+
+        $matches = array();
+
+        if (preg_match($generalizedTimePattern, $value, $matches)) {
+            $dateTimeRaw = $matches['YmdH'];
+            $dateTimeFormat = 'YmdH';
+
+            if ($matches['i'] !== '') {
+                $dateTimeRaw .= $matches['i'];
+                $dateTimeFormat .= 'i';
+
+                if ($matches['s'] !== '') {
+                    $dateTimeRaw .= $matches['s'];
+                    $dateTimeFormat .= 's';
+                    $fractionOfSeconds = 1;
+                } else {
+                    $fractionOfSeconds = 60;
+                }
+            } else {
+                $fractionOfSeconds = 3600;
+            }
+
+            $dateTimeFormat .= 'O';
+
+            if ($matches['tz'] === 'Z') {
+                $dateTimeRaw .= '+0000';
+            } else {
+                $dateTimeRaw .= $matches['tz'];
+
+                if (strlen($matches['tz']) === 3) {
+                    $dateTimeRaw .= '00';
+                }
+            }
+
+            $dateTime = DateTime::createFromFormat($dateTimeFormat, $dateTimeRaw);
+
+            if ($dateTime !== false) {
+                if (isset($matches['frac'])) {
+                    $dateTime->add(new DateInterval(
+                        'PT' . round((float) ('0.' . $matches['frac']) * $fractionOfSeconds) . 'S'
+                    ));
+                }
+
+                return $dateTime;
+            }
+        }
+
+        throw new InvalidArgumentException(sprintf(
+            'Failed to parse %s based on the ASN.1 standard (GeneralizedTime)',
+            var_export($value, true)
+        ));
+    }
+}