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Re: Patch Request: Bug #978


Chronological Thread 
  • From: Wytze van der Raay <wytze AT cacert.org>
  • To: Benny Baumann <benbe AT cacert.org>
  • Cc: critical-admin AT cacert.org, cacert-devel AT lists.cacert.org, Michael Tänzer <michael.taenzer AT cacert.org>, Ulrich Schröter <ulrich AT cacert.org>
  • Subject: Re: Patch Request: Bug #978
  • Date: Wed, 31 Oct 2012 11:32:25 +0100
  • Organization: CAcert

Hi Benny,

On 30.10.2012 22:38, Benny Baumann wrote:
> We have a fix for https://bugs.cacert.org/view.php?id=978
> "Invalid SPKAC requests are not properly validated"
> 
> The fix was reviewed by Michael Tänzer 
> (NEO@NHNG)
>  and me (BenBE).
> Tests were performed by Ulrich Schröter (Uli60) and JensK.
> 
> The patch containing the changes is attached. Please also run the
> makefile so our translators see the new strings (if present) on
> https://translations.cacert.org/ and new translation get imported into
> the system.
> 
> Changed Files (+410/-359):
> - includes/account.php (+1/-0)
> - includes/account_stuff.php (+0/-358)
> - includes/lib/check_weak_key.php (+323/-0) [NEW]
> - includes/lib/general.php (+83/-1)
> - www/api/ccsr.php (+3/-0)

The patch has been installed on the production server on October 31, 2012.
See also the attached log message.
Note that one unusual event occurred during the application of the patch:
we received a rejection of the patch for includes/account.php:

***************
*** 16,21 ****
      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301  USA
  */
        require_once("../includes/loggedin.php");

        loadem("account");

--- 16,22 ----
      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301  USA
  */
        require_once("../includes/loggedin.php");
+       require_once('lib/check_weak_key.php');

        loadem("account");


While it is clear what is intended by the patch, it concerns me that the
patch as delivered did *not* match the current production version of the
application code. This should *not* happen. Please re-check your procedures
in order to prevent a reoccurrence (with possibly worse consequences) in
the future.

The translation upload and downloads were performed as requested, and the
Apache webserver has been restarted to effectuate the changes.

Regards,
-- wytze





> 
> Have a nice day,
> Benny Baumann
> CAcert SoftWare Assessment Team
> 

--- Begin Message ---
  • From: Wytze van der Raay <wytze AT cacert.org>
  • To: cacert-systemlog AT lists.cacert.org
  • Subject: Fwd: [cvs.cacert.org checkin notification]
  • Date: Wed, 31 Oct 2012 11:06:52 +0100
  • Organization: CAcert
Fix for https://bugs.cacert.org/view.php?id=978
"Invalid SPKAC requests are not properly validated"

In conjunction with the attached CVS changes a new tarball has been
made available incorporating all updates. The new tarball is available
through http://www.cacert.org/src-lic.php

-- end
--- Begin Message ---
  • From: "root" <root AT cvs.cacert.org>
  • To: critical-admin AT cacert.org
  • Subject: cvs.cacert.org checkin notification
  • Date: Wed, 31 Oct 2012 11:03:11 +0100 (CET)

uid=0(root) gid=0(root) groups=0(root)
check_weak_key.php NONE 1.1 general.php 1.1 1.2
Wed Oct 31 11:03:10 CET 2012
Update of /var/lib/cvs/cacert/includes/lib
In directory hlin:/home/cacert/www/includes/lib

Modified Files:
        general.php 
Added Files:
        check_weak_key.php 
Log Message:
Fix for https://bugs.cacert.org/view.php?id=978
"Invalid SPKAC requests are not properly validated"

===================================================================
RCS file: /var/lib/cvs/cacert/includes/lib/general.php,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- general.php 2011/09/07 10:30:12     1.1
+++ general.php 2012/10/31 10:03:10     1.2
@@ -47,4 +47,86 @@
        return -1;
 }
 
-?>
+/**
+ * Produces a log entry with the error message with log level E_USER_WARN
+ * and a random ID an returns a message that can be displayed to the user
+ * including the generated ID
+ *
+ * @param $errormessage string
+ *             The error message that should be logged
+ * @return string containing the generated ID that can be displayed to the
+ *             user
+ */
+function failWithId($errormessage) {
+       $errorId = rand();
+       trigger_error("$errormessage. ID: $errorId", E_USER_WARNING);
+       return sprintf(_("Something went wrong when processing your request. 
".
+                               "Please contact %s for help and provide them 
with the ".
+                               "following ID: %d"),
+                       "<a 
href='mailto:support AT cacert.org?subject=System%20Error%20-%20".
+                               
"ID%3A%20$errorId'>support AT cacert.org</a>",
+       $errorId);
+}
+
+
+/**
+ * Runs a command on the shell and return it's exit code and output
+ * 
+ * @param string $command
+ *             The command to run. Make sure that you escapeshellarg() any 
non-constant
+ *             parts as this is executed on a shell!
+ * @param string|bool $input
+ *             The input that is passed to the command via STDIN, if true 
the real
+ *             STDIN is passed through
+ * @param string|bool $output
+ *             The output the command wrote to STDOUT (this is passed as 
reference),
+ *             if true the output will be written to the real STDOUT. Output 
is ignored
+ *             by default
+ * @param string|bool $errors
+ *             The output the command wrote to STDERR (this is passed as 
reference),
+ *             if true (default) the output will be written to the real 
STDERR
+ * 
+ * @return int|bool
+ *             The exit code of the command, true if the execution of the 
command
+ *             failed (true because then
+ *             <code>if (runCommand('echo "foo"')) handle_error();</code> 
will work)
+ */
+function runCommand($command, $input = "", &$output = null, &$errors = true) 
{
+       $descriptorspec = array();
+       
+       if ($input !== true) {
+               $descriptorspec[0] = array("pipe", "r"); // STDIN for child
+       }
+       
+       if ($output !== true) {
+               $descriptorspec[1] = array("pipe", "w"); // STDOUT for child
+       }
+       
+       if ($errors !== true) {
+               $descriptorspec[2] = array("pipe", "w"); // STDERR for child
+       }
+       
+       $proc = proc_open($command, $descriptorspec, $pipes);
+       
+       if (is_resource($proc))
+       {
+               if ($input !== true) {
+                       fwrite($pipes[0], $input);
+                       fclose($pipes[0]);
+               }
+               
+               if ($output !== true) {
+                       $output = stream_get_contents($pipes[1]);
+               }
+               
+               if ($errors !== true) {
+                       $errors = stream_get_contents($pipes[2]);
+               }
+               
+               return proc_close($proc);
+               
+       } else {
+               return true;
+       }
+}
+
===================================================================
RCS file: /var/lib/cvs/cacert/includes/lib/check_weak_key.php,v  -->  
standard output
revision 1.1
<?php /*
    LibreSSL - CAcert web application
    Copyright (C) 2004-2011  CAcert Inc.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; version 2 of the License.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 
 USA
*/

// failWithId()
require_once 'general.php';


/**
* Checks whether the given CSR contains a vulnerable key
*
* @param $csr string
*               The CSR to be checked
* @param $encoding string [optional]
*               The encoding the CSR is in (for the "-inform" parameter of 
OpenSSL,
*               currently only "PEM" (default) or "DER" allowed)
* @return string containing the reason if the key is considered weak,
*               empty string otherwise
*/
function checkWeakKeyCSR($csr, $encoding = "PEM")
{
        $encoding = escapeshellarg($encoding);
        $status = runCommand("openssl req -inform $encoding -text -noout",
                             $csr, $csrText);
        if ($status === true) {
                return failWithId("checkWeakKeyCSR(): Failed to start 
OpenSSL");
        }
        
        if ($status !== 0 || $csrText === "") {
                return _("I didn't receive a valid Certificate Request. Hit ".
                        "the back button and try again.");
        }
        
        return checkWeakKeyText($csrText);
}

/**
 * Checks whether the given X509 certificate contains a vulnerable key
 *
 * @param $cert string
 *              The X509 certificate to be checked
 * @param $encoding string [optional]
 *              The encoding the certificate is in (for the "-inform" 
parameter of
 *              OpenSSL, currently only "PEM" (default), "DER" or "NET" 
allowed)
 * @return string containing the reason if the key is considered weak,
 *              empty string otherwise
 */
function checkWeakKeyX509($cert, $encoding = "PEM")
{
        $encoding = escapeshellarg($encoding);
        $status = runCommand("openssl x509 -inform $encoding -text -noout",
                             $cert, $certText);
        if ($status === true) {
                return failWithId("checkWeakKeyX509(): Failed to start 
OpenSSL");
        }
        
        if ($status !== 0 || $certText === "") {
                return _("I didn't receive a valid Certificate Request. Hit ".
                        "the back button and try again.");
        }
        
        return checkWeakKeyText($certText);
}

/**
 * Checks whether the given SPKAC contains a vulnerable key
 *
 * @param $spkac string
 *              The SPKAC to be checked
 * @param $spkacname string [optional]
 *              The name of the variable that contains the SPKAC. The default 
is
 *              "SPKAC"
 * @return string containing the reason if the key is considered weak,
 *              empty string otherwise
 */
function checkWeakKeySPKAC($spkac, $spkacname = "SPKAC")
{
        $spkacname = escapeshellarg($spkacname);
        $status = runCommand("openssl spkac -spkac $spkacname", $spkac, 
$spkacText);
        if ($status === true) {
                return failWithId("checkWeakKeySPKAC(): Failed to start 
OpenSSL");
        }
        
        if ($status !== 0 || $spkacText === "") {
                return _("I didn't receive a valid Certificate Request. Hit 
the ".
                        "back button and try again.");
        }
        
        return checkWeakKeyText($spkacText);
}

/**
 * Checks whether the given text representation of a CSR or a SPKAC contains
 * a weak key
 *
 * @param $text string
 *              The text representation of a key as output by the
 *              "openssl <foo> -text -noout" commands
 * @return string containing the reason if the key is considered weak,
 *              empty string otherwise
 */
function checkWeakKeyText($text)
{
        /* Which public key algorithm? */
        if (!preg_match('/^\s*Public Key Algorithm: ([^\s]+)$/m', $text,
        $algorithm))
        {
                return failWithId("checkWeakKeyText(): Couldn't extract the ".
                                        "public key algorithm 
used.\nData:\n$text");
        } else {
                $algorithm = $algorithm[1];
        }


        if ($algorithm === "rsaEncryption")
        {
                if (!preg_match('/^\s*RSA Public Key: \((\d+) bit\)$/m', 
$text,
                $keysize))
                {
                        return failWithId("checkWeakKeyText(): Couldn't parse 
the RSA ".
                                                "key size.\nData:\n$text");
                } else {
                        $keysize = intval($keysize[1]);
                }
                        
                if ($keysize < 1024)
                {
                        return sprintf(_("The keys that you use are very 
small ".
                                                "and therefore insecure. 
Please generate stronger ".
                                                "keys. More information about 
this issue can be ".
                                                "found in %sthe wiki%s"),
                                        "<a 
href='//wiki.cacert.org/WeakKeys#SmallKey'>",
                                        "</a>");
                } elseif ($keysize < 2048) {
                        // not critical but log so we have some statistics 
about
                        // affected users
                        trigger_error("checkWeakKeyText(): Certificate for 
small ".
                                                "key (< 2048 bit) requested", 
E_USER_NOTICE);
                }
                        
                        
                $debianVuln = checkDebianVulnerability($text, $keysize);
                if ($debianVuln === true)
                {
                        return sprintf(_("The keys you use have very likely 
been ".
                                                "generated with a vulnerable 
version of OpenSSL which ".
                                                "was distributed by debian. 
Please generate new keys. ".
                                                "More information about this 
issue can be found in ".
                                                "%sthe wiki%s"),
                                        "<a 
href='//wiki.cacert.org/WeakKeys#DebianVulnerability'>",
                                        "</a>");
                } elseif ($debianVuln === false) {
                        // not vulnerable => do nothing
                } else {
                        return failWithId("checkWeakKeyText(): Something went 
wrong in".
                                        
"checkDebianVulnerability().\nKeysize: $keysize\n".
                                        "Data:\n$text");
                }
                        
                if (!preg_match('/^\s*Exponent: (\d+) \(0x[0-9a-fA-F]+\)$/m', 
$text,
                $exponent))
                {
                        return failWithId("checkWeakKeyText(): Couldn't parse 
the RSA ".
                                                "exponent.\nData:\n$text");
                } else {
                        $exponent = $exponent[1]; // exponent might be very 
big =>
                        //handle as string using bc*()

                        if (bccomp($exponent, "3") === 0)
                        {
                                return sprintf(_("The keys you use might be 
insecure. ".
                                                        "Although there is 
currently no known attack for ".
                                                        "reasonable 
encryption schemes, we're being ".
                                                        "cautious and don't 
allow certificates for such ".
                                                        "keys. Please 
generate stronger keys. More ".
                                                        "information about 
this issue can be found in ".
                                                        "%sthe wiki%s"),
                                                "<a 
href='//wiki.cacert.org/WeakKeys#SmallExponent'>",
                                                "</a>");
                        } elseif (!(bccomp($exponent, "65537") >= 0 &&
                        (bccomp($exponent, "100000") === -1 ||
                        // speed things up if way smaller than 2^256
                        bccomp($exponent, bcpow("2", "256")) === -1) )) {
                                // 65537 <= exponent < 2^256 recommended by 
NIST
                                // not critical but log so we have some 
statistics about
                                // affected users
                                trigger_error("checkWeakKeyText(): 
Certificate for ".
                                                        "unsuitable exponent 
'$exponent' requested",
                                E_USER_NOTICE);
                        }
                }
        }

        /* No weakness found */
        return "";
}

/**
 * Reimplement the functionality of the openssl-vulnkey tool
 *
 * @param $text string
 *              The text representation of a key as output by the
 *              "openssl <foo> -text -noout" commands
 * @param $keysize int [optional]
 *              If the key size is already known it can be provided so it 
doesn't
 *              have to be parsed again. This also skips the check whether 
the key
 *              is an RSA key => use wisely
 * @return TRUE if key is vulnerable, FALSE otherwise, NULL in case of error
 */
function checkDebianVulnerability($text, $keysize = 0)
{
        $keysize = intval($keysize);

        if ($keysize === 0)
        {
                /* Which public key algorithm? */
                if (!preg_match('/^\s*Public Key Algorithm: ([^\s]+)$/m', 
$text,
                $algorithm))
                {
                        trigger_error("checkDebianVulnerability(): Couldn't 
extract ".
                                        "the public key algorithm 
used.\nData:\n$text",
                                        E_USER_WARNING);
                        return null;
                } else {
                        $algorithm = $algorithm[1];
                }
                        
                if ($algorithm !== "rsaEncryption") return false;
                        
                /* Extract public key size */
                if (!preg_match('/^\s*RSA Public Key: \((\d+) bit\)$/m', 
$text,
                $keysize))
                {
                        trigger_error("checkDebianVulnerability(): Couldn't 
parse the ".
                                        "RSA key size.\nData:\n$text", 
E_USER_WARNING);
                        return null;
                } else {
                        $keysize = intval($keysize[1]);
                }
        }

        // $keysize has been made sure to contain an int
        $blacklist = "/usr/share/openssl-blacklist/blacklist.RSA-$keysize";
        if (!(is_file($blacklist) && is_readable($blacklist)))
        {
                if (in_array($keysize, array(512, 1024, 2048, 4096)))
                {
                        trigger_error("checkDebianVulnerability(): Blacklist 
for ".
                                                "$keysize bit keys not 
accessible. Expected at ".
                                                "$blacklist", E_USER_ERROR);
                        return null;
                }
                        
                trigger_error("checkDebianVulnerability(): $blacklist is not 
".
                                "readable. Unsupported key size?", 
E_USER_WARNING);
                return false;
        }


        /* Extract RSA modulus */
        if (!preg_match('/^\s*Modulus \(\d+ bit\):\n'.
                                
'((?:\s*[0-9a-f][0-9a-f]:(?:\n)?)+[0-9a-f][0-9a-f])$/m',
        $text, $modulus))
        {
                trigger_error("checkDebianVulnerability(): Couldn't extract 
the ".
                                "RSA modulus.\nData:\n$text", E_USER_WARNING);
                return null;
        } else {
                $modulus = $modulus[1];
                // strip whitespace and colon leftovers
                $modulus = str_replace(array(" ", "\t", "\n", ":"), "", 
$modulus);
                        
                // when using "openssl xxx -text" first byte was 00 in all my 
test
                // cases but 00 not present in the "openssl xxx -modulus" 
output
                if ($modulus[0] === "0" && $modulus[1] === "0")
                {
                        $modulus = substr($modulus, 2);
                } else {
                        trigger_error("checkDebianVulnerability(): First byte 
is not ".
                                        "zero", E_USER_NOTICE);
                }
                        
                $modulus = strtoupper($modulus);
        }


        /* calculate checksum and look it up in the blacklist */
        $checksum = substr(sha1("Modulus=$modulus\n"), 20);

        // $checksum and $blacklist should be safe, but just to make sure
        $checksum = escapeshellarg($checksum);
        $blacklist = escapeshellarg($blacklist);
        $debianVuln = runCommand("grep $checksum $blacklist");
        if ($debianVuln === 0) // grep returned something => it is on the list
        {
                return true;
        } elseif ($debianVuln === 1) {
                // grep returned nothing
                return false;
        } else {
                trigger_error("checkDebianVulnerability(): Something went 
wrong ".
                                "when looking up the key with checksum 
$checksum in the ".
                                "blacklist $blacklist", E_USER_ERROR);
                return null;
        }

        // Should not get here
        return null;
}

--- End Message ---
--- Begin Message ---
  • From: "root" <root AT cvs.cacert.org>
  • To: critical-admin AT cacert.org
  • Subject: cvs.cacert.org checkin notification
  • Date: Wed, 31 Oct 2012 11:03:26 +0100 (CET)

uid=0(root) gid=0(root) groups=0(root)
account.php 1.158 1.159 account_stuff.php 1.59 1.60
Wed Oct 31 11:03:26 CET 2012
Update of /var/lib/cvs/cacert/includes
In directory hlin:/home/cacert/www/includes

Modified Files:
        account.php account_stuff.php 
Log Message:
Fix for https://bugs.cacert.org/view.php?id=978
"Invalid SPKAC requests are not properly validated"

===================================================================
RCS file: /var/lib/cvs/cacert/includes/account_stuff.php,v
retrieving revision 1.59
retrieving revision 1.60
diff -u -r1.59 -r1.60
--- account_stuff.php   2012/08/10 11:06:20     1.59
+++ account_stuff.php   2012/10/31 10:03:26     1.60
@@ -284,361 +284,3 @@
 </body>             
 </html><?
        }
-       
-       /**
-        * Produces a log entry with the error message with log level 
E_USER_WARN
-        * and a random ID an returns a message that can be displayed to the 
user
-        * including the generated ID
-        * 
-        * @param $errormessage string
-        *              The error message that should be logged
-        * @return string containing the generated ID that can be displayed 
to the
-        *              user
-        */
-       function failWithId($errormessage) {
-               $errorId = rand();
-               trigger_error("$errormessage. ID: $errorId", E_USER_WARNING);
-               return sprintf(_("Something went wrong when processing your 
request. ".
-                               "Please contact %s for help and provide them 
with the ".
-                               "following ID: %d"),
-                       "<a 
href='mailto:support AT cacert.org?subject=System%20Error%20-%20".
-                               
"ID%3A%20$errorId'>support AT cacert.org</a>",
-                       $errorId);
-       }
-       
-       /**
-        * Checks whether the given CSR contains a vulnerable key
-        * 
-        * @param $csr string
-        *              The CSR to be checked
-        * @param $encoding string [optional]
-        *              The encoding the CSR is in (for the "-inform" 
parameter of OpenSSL,
-        *              currently only "PEM" (default) or "DER" allowed)
-        * @return string containing the reason if the key is considered weak,
-        *              empty string otherwise
-        */
-       function checkWeakKeyCSR($csr, $encoding = "PEM")
-       {
-               // non-PEM-encodings may be binary so don't use echo
-               $descriptorspec = array(
-                       0 => array("pipe", "r"), // STDIN for child
-                       1 => array("pipe", "w"), // STDOUT for child
-               );
-               $encoding = escapeshellarg($encoding);
-               $proc = proc_open("openssl req -inform $encoding -text 
-noout",
-                       $descriptorspec, $pipes);
-               
-               if (is_resource($proc))
-               {
-                       fwrite($pipes[0], $csr);
-                       fclose($pipes[0]);
-                       
-                       $csrText = ""; 
-                       while (!feof($pipes[1]))
-                       {
-                               $csrText .= fread($pipes[1], 8192);
-                       }
-                       fclose($pipes[1]);
-                       
-                       if (($status = proc_close($proc)) !== 0 || $csrText 
=== "")
-                       {
-                               return _("I didn't receive a valid 
Certificate Request, hit ".
-                               "the back button and try again.");
-                       }
-               } else {
-                       return failWithId("checkWeakKeyCSR(): Failed to start 
OpenSSL");
-               }
-               
-               
-               return checkWeakKeyText($csrText);
-       }
-       
-       /**
-        * Checks whether the given X509 certificate contains a vulnerable key
-        * 
-        * @param $cert string
-        *              The X509 certificate to be checked
-        * @param $encoding string [optional]
-        *              The encoding the certificate is in (for the "-inform" 
parameter of
-        *              OpenSSL, currently only "PEM" (default), "DER" or 
"NET" allowed)
-        * @return string containing the reason if the key is considered weak,
-        *              empty string otherwise
-        */
-       function checkWeakKeyX509($cert, $encoding = "PEM")
-       {
-               // non-PEM-encodings may be binary so don't use echo
-               $descriptorspec = array(
-                       0 => array("pipe", "r"), // STDIN for child
-                       1 => array("pipe", "w"), // STDOUT for child
-               );
-               $encoding = escapeshellarg($encoding);
-               $proc = proc_open("openssl x509 -inform $encoding -text 
-noout",
-                       $descriptorspec, $pipes);
-               
-               if (is_resource($proc))
-               {
-                       fwrite($pipes[0], $cert);
-                       fclose($pipes[0]);
-                       
-                       $certText = ""; 
-                       while (!feof($pipes[1]))
-                       {
-                               $certText .= fread($pipes[1], 8192);
-                       }
-                       fclose($pipes[1]);
-                       
-                       if (($status = proc_close($proc)) !== 0 || $certText 
=== "")
-                       {
-                               return _("I didn't receive a valid 
Certificate Request, hit ".
-                               "the back button and try again.");
-                       }
-               } else {
-                       return failWithId("checkWeakKeyCSR(): Failed to start 
OpenSSL");
-               }
-               
-               
-               return checkWeakKeyText($certText);
-       }
-       
-       /**
-        * Checks whether the given SPKAC contains a vulnerable key
-        * 
-        * @param $spkac string
-        *              The SPKAC to be checked
-        * @param $spkacname string [optional]
-        *              The name of the variable that contains the SPKAC. The 
default is
-        *              "SPKAC"
-        * @return string containing the reason if the key is considered weak,
-        *              empty string otherwise
-        */
-       function checkWeakKeySPKAC($spkac, $spkacname = "SPKAC")
-       {
-               /* Check for the debian OpenSSL vulnerability */
-               
-               $spkac = escapeshellarg($spkac);
-               $spkacname = escapeshellarg($spkacname);
-               $spkacText = `echo $spkac | openssl spkac -spkac $spkacname`;
-               if ($spkacText === null) {
-                       return _("I didn't receive a valid Certificate 
Request, hit the ".
-                               "back button and try again.");
-               }
-               
-               return checkWeakKeyText($spkacText);
-       }
-       
-       /**
-        * Checks whether the given text representation of a CSR or a SPKAC 
contains
-        * a weak key
-        * 
-        * @param $text string
-        *              The text representation of a key as output by the
-        *              "openssl <foo> -text -noout" commands
-        * @return string containing the reason if the key is considered weak,
-        *              empty string otherwise
-        */
-       function checkWeakKeyText($text)
-       {
-               /* Which public key algorithm? */
-               if (!preg_match('/^\s*Public Key Algorithm: ([^\s]+)$/m', 
$text,
-                               $algorithm))
-               {
-                       return failWithId("checkWeakKeyText(): Couldn't 
extract the ".
-                                       "public key algorithm used");
-               } else {
-                       $algorithm = $algorithm[1];
-               }
-               
-               
-               if ($algorithm === "rsaEncryption")
-               {
-                       if (!preg_match('/^\s*RSA Public Key: \((\d+) 
bit\)$/m', $text,
-                                       $keysize))
-                       {
-                               return failWithId("checkWeakKeyText(): 
Couldn't parse the RSA ".
-                                               "key size");
-                       } else {
-                               $keysize = intval($keysize[1]);
-                       }
-                       
-                       if ($keysize < 1024)
-                       {
-                               return sprintf(_("The keys that you use are 
very small ".
-                                               "and therefore insecure. 
Please generate stronger ".
-                                               "keys. More information about 
this issue can be ".
-                                               "found in %sthe wiki%s"),
-                                       "<a 
href='//wiki.cacert.org/WeakKeys#SmallKey'>",
-                                       "</a>");
-                       } elseif ($keysize < 2048) {
-                               // not critical but log so we have some 
statistics about
-                               // affected users
-                               trigger_error("checkWeakKeyText(): 
Certificate for small ".
-                                               "key (< 2048 bit) requested", 
E_USER_NOTICE);
-                       }
-                       
-                       
-                       $debianVuln = checkDebianVulnerability($text, 
$keysize);
-                       if ($debianVuln === true)
-                       {
-                               return sprintf(_("The keys you use have very 
likely been ".
-                                               "generated with a vulnerable 
version of OpenSSL which ".
-                                               "was distributed by debian. 
Please generate new keys. ".
-                                               "More information about this 
issue can be found in ".
-                                               "%sthe wiki%s"),
-                                       "<a 
href='//wiki.cacert.org/WeakKeys#DebianVulnerability'>",
-                                       "</a>");
-                       } elseif ($debianVuln === false) {
-                               // not vulnerable => do nothing
-                       } else {
-                               return failWithId("checkWeakKeyText(): 
Something went wrong in".
-                                       "checkDebianVulnerability()");
-                       }
-                       
-                       if (!preg_match('/^\s*Exponent: (\d+) 
\(0x[0-9a-fA-F]+\)$/m', $text,
-                                       $exponent))
-                       {
-                               return failWithId("checkWeakKeyText(): 
Couldn't parse the RSA ".
-                                               "exponent");
-                       } else {
-                               $exponent = $exponent[1]; // exponent might 
be very big =>
-                                       //handle as string using bc*()  
-                               
-                               if (bccomp($exponent, "3") === 0)
-                               {
-                                       return sprintf(_("The keys you use 
might be insecure. ".
-                                                       "Although there is 
currently no known attack for ".
-                                                       "reasonable 
encryption schemes, we're being ".
-                                                       "cautious and don't 
allow certificates for such ".
-                                                       "keys. Please 
generate stronger keys. More ".
-                                                       "information about 
this issue can be found in ".
-                                                       "%sthe wiki%s"),
-                                               "<a 
href='//wiki.cacert.org/WeakKeys#SmallExponent'>",
-                                               "</a>");
-                               } elseif (!(bccomp($exponent, "65537") >= 0 &&
-                                               (bccomp($exponent, "100000") 
=== -1 ||
-                                                       // speed things up if 
way smaller than 2^256
-                                               bccomp($exponent, bcpow("2", 
"256")) === -1) )) {
-                                       // 65537 <= exponent < 2^256 
recommended by NIST
-                                       // not critical but log so we have 
some statistics about
-                                       // affected users
-                                       trigger_error("checkWeakKeyText(): 
Certificate for ".
-                                                       "unsuitable exponent 
'$exponent' requested",
-                                                       E_USER_NOTICE);
-                               }
-                       }
-               }
-               
-               /* No weakness found */
-               return "";
-       }
-       
-       /**
-        * Reimplement the functionality of the openssl-vulnkey tool
-        * 
-        * @param $text string
-        *              The text representation of a key as output by the
-        *              "openssl <foo> -text -noout" commands
-        * @param $keysize int [optional]
-        *              If the key size is already known it can be provided 
so it doesn't
-        *              have to be parsed again. This also skips the check 
whether the key
-        *              is an RSA key => use wisely
-        * @return TRUE if key is vulnerable, FALSE otherwise, NULL in case 
of error
-        */
-       function checkDebianVulnerability($text, $keysize = 0)
-       {
-               $keysize = intval($keysize);
-               
-               if ($keysize === 0)
-               {
-                       /* Which public key algorithm? */
-                       if (!preg_match('/^\s*Public Key Algorithm: 
([^\s]+)$/m', $text,
-                               $algorithm))
-                       {
-                               trigger_error("checkDebianVulnerability(): 
Couldn't extract ".
-                                       "the public key algorithm used", 
E_USER_WARNING);
-                               return null;
-                       } else {
-                               $algorithm = $algorithm[1];
-                       }
-                       
-                       if ($algorithm !== "rsaEncryption") return false;
-                       
-                       /* Extract public key size */
-                       if (!preg_match('/^\s*RSA Public Key: \((\d+) 
bit\)$/m', $text,
-                               $keysize))
-                       {
-                               trigger_error("checkDebianVulnerability(): 
Couldn't parse the ".
-                                       "RSA key size", E_USER_WARNING);
-                               return null;
-                       } else {
-                               $keysize = intval($keysize[1]);
-                       }
-               }
-               
-               // $keysize has been made sure to contain an int
-               $blacklist = 
"/usr/share/openssl-blacklist/blacklist.RSA-$keysize";
-               if (!(is_file($blacklist) && is_readable($blacklist)))
-               {
-                       if (in_array($keysize, array(512, 1024, 2048, 4096)))
-                       {
-                               trigger_error("checkDebianVulnerability(): 
Blacklist for ".
-                                               "$keysize bit keys not 
accessible. Expected at ".
-                                               "$blacklist", E_USER_ERROR);
-                               return null;
-                       }
-                       
-                       trigger_error("checkDebianVulnerability(): $blacklist 
is not ".
-                               "readable. Unsupported key size?", 
E_USER_WARNING);
-                       return false;
-               }
-               
-               
-               /* Extract RSA modulus */
-               if (!preg_match('/^\s*Modulus \(\d+ bit\):\n'.
-                               
'((?:\s*[0-9a-f][0-9a-f]:(?:\n)?)+[0-9a-f][0-9a-f])$/m',
-                       $text, $modulus))
-               {
-                       trigger_error("checkDebianVulnerability(): Couldn't 
extract the ".
-                               "RSA modulus", E_USER_WARNING);
-                       return null;
-               } else {
-                       $modulus = $modulus[1];
-                       // strip whitespace and colon leftovers
-                       $modulus = str_replace(array(" ", "\t", "\n", ":"), 
"", $modulus);
-                       
-                       // when using "openssl xxx -text" first byte was 00 
in all my test
-                       // cases but 00 not present in the "openssl xxx 
-modulus" output
-                       if ($modulus[0] === "0" && $modulus[1] === "0")
-                       {
-                               $modulus = substr($modulus, 2);
-                       } else {
-                               trigger_error("checkDebianVulnerability(): 
First byte is not ".
-                                       "zero", E_USER_NOTICE);
-                       }
-                       
-                       $modulus = strtoupper($modulus);
-               }
-               
-               
-               /* calculate checksum and look it up in the blacklist */
-               $checksum = substr(sha1("Modulus=$modulus\n"), 20);
-               
-               // $checksum and $blacklist should be safe, but just to make 
sure
-               $checksum = escapeshellarg($checksum);
-               $blacklist = escapeshellarg($blacklist);
-               exec("grep $checksum $blacklist", $dummy, $debianVuln);
-               if ($debianVuln === 0) // grep returned something => it is on 
the list
-               {
-                       return true;
-               } elseif ($debianVuln === 1) { // grep returned nothing
-                       return false;
-               } else {
-                       trigger_error("checkDebianVulnerability(): Something 
went wrong ".
-                               "when looking up the key with checksum 
$checksum in the ".
-                               "blacklist $blacklist", E_USER_ERROR);
-                       return null;
-               }
-               
-               // Should not get here
-               return null;
-       }
-?>
===================================================================
RCS file: /var/lib/cvs/cacert/includes/account.php,v
retrieving revision 1.158
retrieving revision 1.159
diff -u -r1.158 -r1.159
--- account.php 2012/08/10 11:06:19     1.158
+++ account.php 2012/10/31 10:03:25     1.159
@@ -17,6 +17,7 @@
 */
        require_once("../includes/loggedin.php");
        require_once("../includes/lib/l10n.php");
+       require_once('lib/check_weak_key.php');
 
        loadem("account");
 

--- End Message ---
--- Begin Message ---
  • From: "root" <root AT cvs.cacert.org>
  • To: critical-admin AT cacert.org
  • Subject: cvs.cacert.org checkin notification
  • Date: Wed, 31 Oct 2012 11:03:33 +0100 (CET)

uid=0(root) gid=0(root) groups=0(root)
ccsr.php 1.10 1.11
Wed Oct 31 11:03:33 CET 2012
Update of /var/lib/cvs/cacert/www/api
In directory hlin:/home/cacert/www/www/api

Modified Files:
        ccsr.php 
Log Message:
Fix for https://bugs.cacert.org/view.php?id=978
"Invalid SPKAC requests are not properly validated"

===================================================================
RCS file: /var/lib/cvs/cacert/www/api/ccsr.php,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -r1.10 -r1.11
--- ccsr.php    2011/06/16 09:20:24     1.10
+++ ccsr.php    2012/10/31 10:03:33     1.11
@@ -15,6 +15,9 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  
02110-1301  USA
 */
+
+require_once '../../includes/lib/check_weak_key.php';
+
        $username = mysql_real_escape_string($_REQUEST['username']);
        $password = mysql_real_escape_string($_REQUEST['password']);
 

--- End Message ---

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature


--- End Message ---

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature




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