Bug #50713 [PATCH]: openssl_pkcs7_verify() may ignore untrusted CAs

Edit report at https://bugs.php.net/bug.php?id=50713&edit=1 ID: 50713 Patch added by: cmb@php.net Reported by: dark-tranquillity at yandex dot ru Summary: openssl_pkcs7_verify() may ignore untrusted CAs Status: Assigned Type: Bug Package: OpenSSL related Operating System: Win32 PHP Version: 7.4 Assigned To: cmb Block user comment: N Private report: N New Comment: The following pull request has been associated: Patch Name: Fix #50713: openssl_pkcs7_verify() may ignore untrusted CAs On GitHub: https://github.com/php/php-src/pull/6927 Patch: https://github.com/php/php-src/pull/6927.patch Previous Comments: ------------------------------------------------------------------------ [2021-04-29 12:24:20] cmb@php.net I haven't been able to reproduce openssl_pkcs7_verify() to return true in this case, but still, ignoring untrusted CAs appears to be a bug. ------------------------------------------------------------------------ [2016-03-14 08:59:59] allesbesser at gmail dot com The problem comes from the $outfilename argument which allows you to have PHP save the certificates used to sign the message. The PHP source is here: https://github.com/php/php-src/blob/420c7979d5743a4621b334f569c7ae8686f4f85f/ext/openssl/openssl.c First, the function does what it should do and calls PKCS7_verify(). This function verifies the signature using the internal and $extracerts by calling: signers = PKCS7_get0_signers(p7, others, (int)flags); others are the $extracerts. Now, as you speified $extracerts, you also had to specify $outfilename. Hence, the PHP function makes another function call: signers = PKCS7_get0_signers(p7, NULL, (int)flags); this time without the extra certs. Now, as the internal certificates are empty, this function raises an error as there are no certificates. There are several ways to fix this (apart from ignoring the error when $extracerts is not empty): - Modify the OpenSSL code so that it does not raise the error when getting certificates - Change the way PHP gets the certificates so that the error is not raised anymore - Allow $outfilename to be NULL so that the function is not even called Personally, I think passing NULL as $outfilename should be accepted in these OpenSSL functions. ------------------------------------------------------------------------ [2010-01-10 11:52:57] dark-tranquillity at yandex dot ru Description: ------------ I have a private key & self-signed certificate. 1) create a signature (openssl_pkcs7_sign) 2) verify the signature: function openssl_pkcs7_verify returns TRUE (Verification successful), but openssl_error_string() - returns an error message (error:2107C080:PKCS7 routines:PKCS7_get0_signers:signer certificate not found) 3) in the command line are no errors openssl smime -sign -nocerts -signer proc.crt -inkey proc.key -in in.txt -out signed.txt openssl smime -verify -noverify -nointern -nochain -in signed.txt -certfile proc.crt Reproduce code: --------------- <? file_put_contents("in.txt", "demo text"); $certfname='./proc.crt'; $crt =file_get_contents($certfname); $priv_key =file_get_contents('./proc.key'); if(openssl_pkcs7_sign("in.txt", "signed.txt", $crt, $priv_key, array(), PKCS7_NOCERTS)) { $status=openssl_pkcs7_verify("signed.txt", PKCS7_NOVERIFY|PKCS7_NOINTERN|PKCS7_NOCHAIN, "1.tmp", array(), $certfname); while($msg=openssl_error_string()) echo "$msg\n"; echo "status=$status\n"; } else die('failed openssl_pkcs7_sign'); ?> Expected result: ---------------- status=1 Actual result: -------------- error:2107C080:PKCS7 routines:PKCS7_get0_signers:signer certificate not found status=1 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=50713&edit=1