Add different link styles; fixes #73

This commit is contained in:
Marius Lindvall 2019-12-09 00:00:54 +01:00
parent cacc65b481
commit dbfb58a502
2 changed files with 128 additions and 2 deletions

View file

@ -132,6 +132,51 @@
// not be honored.
"reserve_whitelist" => false,
// The type of links to generate when making new links for shares. Can be any
// of the following:
//
// | Link style | Example | No. of combinations | Avg. bruteforce time |
// +----------------------------+---------------------------------------+-----------------------+-------------------------------+
// | LINK_4_PLUS_4_UPPER_CASE | EIRG-0CYE | 2.82 * 10^12 (36^8) | 44.7 years |
// | LINK_4_PLUS_4_LOWER_CASE | qae3-ulna | 2.82 * 10^12 (36^8) | 44.7 years |
// | LINK_4_PLUS_4_MIXED_CASE | WRho-uHLG | 1.68 * 10^14 (60^8) | 2663 years |
// | LINK_UUID_V4 | 09c8a3b1-e78f-48b1-a604-0da49e99cb5d | 5.32 * 10^36 (2^122) | 84.2 septillion years |
// | LINK_16_HEX | 6cde14c4c6551b41 | 1.84 * 10^19 (2^64) | 292 million years |
// | LINK_16_UPPER_CASE | 49OFGRK6SGPU93KV | 7.95 * 10^24 (36^16) | 126 trillion years |
// | LINK_16_LOWER_CASE | bdyslxszs14cj359 | 7.95 * 10^24 (36^16) | 126 trillion years |
// | LINK_16_MIXED_CASE | NTHX2HDsTn0kS3aj | 2.82 * 10^28 (60^16) | 447 quadrillion years |
// | LINK_32_HEX | 22adf21f11491ae8f3ae128e23a6782f | 3.40 * 10^38 (2^128) | 5.39 octillion years |
// | LINK_32_UPPER_CASE | MG42MW2DKIMHM87B4AO0WAB2PIY26TR1 | 6.33 * 10^49 (36^32) | 1 duodecillion years |
// | LINK_32_LOWER_CASE | itgbolrbq1c02eot5o46c5wixhdrdb5m | 6.33 * 10^49 (36^32) | 1 duodecillion years |
// | LINK_32_MIXED_CASE | cTK82MJ7rUOP138WNVznQR0Ck3BwZp6b | 7.96 * 10^57 (60^32) | 12.6 quattuordecillion years |
//
// For any MIXED_CASE variants, upper-case I and lower-case L will not appear
// because they are visually very similar and are easily confused.
//
// The default value is LINK_4_PLUS_4_UPPER_CASE, which is still considered very
// secure. The bruteforce times in the table below are the average time it would
// take to find a valid sharing link, when there is one link active, at 1000
// guesses per second. For the default setting, this means it would take almost
// 45 years to find the link.
//
// This is assuming that the link is active 24/7 for that entire time. If you
// only have a link active 2% of the time, it would take over 2200 years.
//
// At 1000 guesses per second, you will likely notice that your server is
// noticeably slower and rapidly filling up with access logs.
//
// Very long links are also time-consuming to type, should you find yourself
// in need of typing in a link manually on another computer. This is the reason
// that short links are default.
//
// ---- PLEASE NOTE ----
// This option is provided to you only because several people have requested it
// as a convenience. You are free to change it, but you should know that
// changing the default here gives you, for all intents and purposes, no
// security advantage in practice.
//
"link_style" => LINK_4_PLUS_4_UPPER_CASE,
// Leaflet tile URI template for the map frontend. Here are some examples:
//
// - OpenStreetMap directly:

View file

@ -29,6 +29,20 @@ const REDIS = 1;
const PASSWORD = 0;
const HTPASSWD = 1;
// Share link types.
const LINK_4_PLUS_4_UPPER_CASE = 0;
const LINK_4_PLUS_4_LOWER_CASE = 1;
const LINK_4_PLUS_4_MIXED_CASE = 2;
const LINK_UUID_V4 = 3;
const LINK_16_HEX = 4;
const LINK_16_UPPER_CASE = 5;
const LINK_16_LOWER_CASE = 6;
const LINK_16_MIXED_CASE = 7;
const LINK_32_HEX = 8;
const LINK_32_UPPER_CASE = 9;
const LINK_32_LOWER_CASE = 10;
const LINK_32_MIXED_CASE = 11;
const KILOMETERS_PER_HOUR = array(
// Relative distance per second multiplied by number of seconds per hour.
"mpsMultiplier" => 3.6,
@ -114,6 +128,7 @@ const DEFAULTS = array(
"allow_link_req" => true,
"reserved_links" => [],
"reserve_whitelist" => false,
"link_style" => LINK_4_PLUS_4_UPPER_CASE,
"map_tile_uri" => 'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
"map_attribution" => 'Map data &copy; <a href="https://www.openstreetmap.org/">OpenStreetMap</a> contributors, <a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>',
"default_zoom" => 14,
@ -300,8 +315,74 @@ class Share {
protected function generateLinkID() {
$s = "";
do {
$s = strtoupper(base_convert(hash("sha256", openssl_random_pseudo_bytes(LINK_ID_RAND_BYTES)), 16, 36));
$s = substr($s, 0, 4)."-".substr($s, -4);
switch (getConfig("link_style")) {
case LINK_UUID_V4:
// UUID version 4.
$uuid = openssl_random_pseudo_bytes(16);
$uuid[6] = chr(ord($uuid[6]) & 0x0f | 0x40);
$uuid[8] = chr(ord($uuid[8]) & 0x3f | 0x80);
$s = vsprintf("%s%s-%s-%s-%s-%s%s%s", str_split(bin2hex($uuid), 4));
break;
case LINK_16_HEX:
// 16-char (8-byte) hexadecimal string.
$s = bin2hex(openssl_random_pseudo_bytes(8));
break;
case LINK_16_LOWER_CASE:
// 16-char lower-case alphanumeric string.
$alpha = "0123456789abcdefghijklmnopqrstuvwxyz";
for ($i = 0; $i < 16; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_16_MIXED_CASE:
// 16-char mixed-case alphanumeric string.
$alpha = "0123456789ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
for ($i = 0; $i < 16; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_16_UPPER_CASE:
// 16-char upper-case alphanumeric string.
$alpha = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
for ($i = 0; $i < 16; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_32_HEX:
// 32-char (16-byte) hexadecimal string.
$s = bin2hex(openssl_random_pseudo_bytes(16));
break;
case LINK_32_LOWER_CASE:
// 32-char lower-case alphanumeric string.
$alpha = "0123456789abcdefghijklmnopqrstuvwxyz";
for ($i = 0; $i < 32; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_32_MIXED_CASE:
// 32-char mixed-case alphanumeric string.
// 'l' and 'I' not included because of visual similarity.
$alpha = "0123456789ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
for ($i = 0; $i < 32; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_32_UPPER_CASE:
// 32-char upper-case alphanumeric string.
$alpha = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
for ($i = 0; $i < 32; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
break;
case LINK_4_PLUS_4_LOWER_CASE:
// 4+4-char lower-case alphanumeric string.
$alpha = "0123456789abcdefghijklmnopqrstuvwxyz";
for ($i = 0; $i < 8; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
$s = substr($s, 0, 4)."-".substr($s, -4);
break;
case LINK_4_PLUS_4_MIXED_CASE:
// 4+4-char mixed-case alphanumeric string.
// 'l' and 'I' not included because of visual similarity.
$alpha = "0123456789ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
for ($i = 0; $i < 8; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
$s = substr($s, 0, 4)."-".substr($s, -4);
break;
case LINK_4_PLUS_4_UPPER_CASE:
default:
// 4+4-char upper-case alphanumeric string.
$alpha = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
for ($i = 0; $i < 8; $i++) $s .= $alpha[random_int(0, strlen($alpha)-1)];
$s = substr($s, 0, 4)."-".substr($s, -4);
break;
}
} while ($this->memcache->get(PREFIX_LOCDATA.$s) !== false);
return $s;
}