php - openssl_verify and "error:0906D06C:PEM routines:PEM_read_bio:no start line"

Question

I am trying to use OpenSSL function for RSA sign/verify in PHP. When I try to do openssl_verify using my public key, I am getting this error: error:0906D06C:PEM routines:PEM_read_bio:no start line, but the function itself works correctly (returns 0 if messages was modified, and 1 if intact). openssl_sign works fine.

How can I fix it?

Currently, I use public key generated by openssl:

define("SC_MSG_PUBLIC", <<<EOD
-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALjPcOckMHDVLiUstcRwwx8kF5PzsiEs
rskyndWisbXMLU9BHomXwL7Qg2L91jE+sNSobkzBDF41CbwDiNlofZUCAwEAAQ==
-----END PUBLIC KEY-----
EOD
);

Any ideas why this error triggers, but things works fine?

Tried to generate public key out of private, and use it, but it appeared to be exactly the same, same error message :-S

$pkey = openssl_pkey_get_private(SC_MSG_PRIVATE);
$keyDetails = openssl_pkey_get_details($pkey);
file_put_contents('c:publickey', $keyDetails['key']);

Also, I've tried to install newer versions of everything (PHP 5.3.1, OpenSSL 1.0.0a) - same result. And, I am on windows.

Answer 1

Have you tried to call openssl_verify() with a (maybe self-signed) certificate containing your public key instead of a pure public key ?

As far as I know, some PHP OpenSSL functions do not properly support naked public keys although it seems strange that it does verify correctly in spite of the error.

<?php
$private = openssl_pkey_get_private(file_get_contents('private'), 'passphrase');

// This causes the "no start line" error when using a naked public key:
$public  = openssl_pkey_get_public(file_get_contents('public')); // <-- this should be cert

echo openssl_error_string()."
";

openssl_sign('Test', $sig, $private);
var_dump(openssl_verify('Test', $sig, $public));

echo openssl_error_string()."
";
?>

Example for converting a public key to a simple certificate in a Linux/UNIX shell such as bash (refer to the OpenSSL documentation or some tutorials for more):

# Create certificate request
openssl req -new -days 3600 -key [PRIVATE-KEY-FILE] -out [REQUEST-TMP-FILE]

# Create certificate from request
RANDFILE=[RANDOM-TMP-FILE] openssl x509 -req -in [REQUEST-TMP-FILE] -signkey [PRIVATE-KEY-FILE] -out [CERTIFICATE-OUT-FILE]

This will also create temporary files you might want to delete afterwards, namely [REQUEST-TMP-FILE] and [RANDOM-TMP-FILE].

PHP sample code can be found at http://de.php.net/manual/en/function.openssl-csr-new.php.