Generate Public And Private Key Php

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(PHP 4 >= 4.2.0, PHP 5, PHP 7)

Getting the public key corresponding to a particular private key, through the methods provided for by OpenSSL, is a bit cumbersome. An easier way to do it is to use phpseclib, a pure PHP RSA implementation.

Mar 31, 2018 In this post I will demonstrate how to regenerate a public key from the corresponding private key that you still have. Generate public key and store into a file. It is a simple one liner command to generate a public key from a private key, so lets say our private key is named ‘user@myserver.key’ and we want to generate the public key. Aug 13, 2014  A web based method to register and authenticate user using public/private keys. Technical details Source code htt. Opensslpkeygetpublic (PHP 4 = 4.2.0, PHP 5, PHP 7) opensslpkeygetpublic — Extract public key from certificate and prepare it for use.

openssl_pkey_get_public — Extract public key from certificate and prepare it for use

Description

openssl_pkey_get_public ( mixed$certificate ) : resource

openssl_pkey_get_public() extracts the public key from certificate and prepares it for use by other functions.

How to unlock password. Not useless at all.What the author is describing is a method to use if the one time boot menu option (F12 on an Acer) has been disabled in CMOS as well as a BIOS PWD set.Alternatively, if USB HDD has.not. Type DIR - ENTER. In this case USB HDD.Then just copy the clnpwd.exe to the root directory of the bootable thumbdrive.Put the thumbdrive into a USB port and boot the system. It should bring you to a DOS prompt. been disabled in CMOS you can make a DOS bootable USB thumbdrive using RUFUS (using the freedos method) ( )You would first physically remove the HDD from the system This will force the system to boot from another valid bootable source.

Parameters

certificate

certificate can be one of the following:

  1. an X.509 certificate resource
  2. a string having the format file://path/to/file.pem. The named file must contain a PEM encoded certificate/public key (it may contain both).
  3. A PEM formatted public key.

Return Values

Returns a positive key resource identifier on success, or FALSE on error.

igniweb dot net at gmail dot com
1 year ago
To complete http://php.net/manual/fr/function.openssl-pkey-get-public.php#101513
Michaela code retranscription can be :
$key = str_replace([
'-----BEGIN RSA PUBLIC KEY-----',
'-----END RSA PUBLIC KEY-----',
'rn',
'n',
], [
',
',
'n',
'
], $key);
$key = 'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A' . trim($key);
$key = '-----BEGIN PUBLIC KEY-----n' . wordwrap($key, 64, 'n', true) . 'n-----END PUBLIC KEY-----';
Joey
3 years ago
I spent a few hours raging with this function and hitting my head on the desk trying to get it to load a public PEM key.
This function can leave errors in openssl_error_string even if it succeeded so this can cause a lot of confusion further down. Especially if you're prototyping and haven't put full checks on return values in yet. The error will not be cleared either when calling other functions successfully.
To avoid confusion, you should always check the return result and only call openssl_error_string after calling an openssl function that returned failure (false).
info at steyla dot com
9 years ago
If you are trying to read a PKCS#1 RSA public key you run into trouble, because openssl wants the public key in X.509 style.
The PKCS#1 RSA public key
-----BEGIN RSA PUBLIC KEY-----
MIIBCgKCAQEAgYxTW5Yj+5QiQtlPMnS9kqQ/HVp+T2KtmvShe68cm8luR7Dampmb
[..]
cbn6n2FsV91BlEnrAKq65PGJxcwcH5+aJwIDAQAB
-----END RSA PUBLIC KEY-----
. is not readable while the X.509 style public key
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAgYxTW5Yj+5QiQtlPMnS9
[.]
JwIDAQAB
-----END PUBLIC KEY-----
is. You can use an easy (and dirty) work around to read the PKCS#1 RSA anyway. The first few bytes of the X.509 style public key contain header information and can shamelessly be copied.
In other words: Delete everything after the first 32 bytes from the above X.509 key (starting behind Q8A) and attach your PKCS#1 data, reformat to 64 bytes length and use it with openssl.
Please note: The above example only works for 2048 bit length.
Like I said - it's kind of dirty - but hey - if you're as desperate as I was.
Michaela
Anonymous
12 years ago
you can get (and save to file) public key using openssl_pkey_get_details(resource $key ) function:
<?php
$pub_key = openssl_pkey_get_public(file_get_contents('./cert.crt'));
$keyData = openssl_pkey_get_details($pub_key);
file_put_contents('./key.pub', $keyData['key']);
?>
dankybastard at hotmail
15 years ago
You must also use the string representation of the certificate to get the public key resource:
$dn = array(); // use defaults
$res_privkey = openssl_pkey_new();
$res_csr = openssl_csr_new($dn, $res_privkey);
$res_cert = openssl_csr_sign($res_csr, null, $res_privkey, $ndays);
openssl_x509_export($res_cert, $str_cert);
$res_pubkey = openssl_pkey_get_public($str_cert);
Anonymous
15 years ago
This documentation notes it can take a PEM-formatted private key, but as per bug #25614, this is not possible in any form. The function simply returns a FALSE.
The only thing you can get public keys out of are X.509 certificates.
Furthermore, there is NO way to export a public key into a PEM-encoded form.
thelen dot shar at gmail dot com
11 years ago
Found it difficult to get my head around this due to lack of documentation.
But the process I followed for all this was:
Generate private key:
openssl genrsa -des3 -out private.pem 1024
Generate public key:
openssl rsa -in private.pem -out public.pem -outform PEM -pubout
Then in PHP:
$passphrase = 'somestring';
$key_private = openssl_get_privatekey(file_get_contents('private.pem'), $passphrase);
$key_public = openssl_get_publickey(file_get_contents('public.pem'));
Probably not the best way of doing it, but a lot simpler than the other examples on the site. I was having trouble getting the pubkey, it wasn't exactly specified very well, and I had made a mistake in generating it so it wasn't working for that reason as well.
VaD
11 years ago
Small error in this code:
$pub_key = openssl_pkey_get_public(file_get_contents('./cert.crt'));
$keyData = openssl_pkey_get_details($pub_key);
file_put_contents('./key.pub', $keyData['key']);
ppostma1
8 years ago
found the cert/public key for 2048 bits is this format:
-----BEGIN PUBLIC KEY-----
X509 signature + PEM sig + modulus + 'ID' + exponent
-----END PUBLIC KEY-----
so the variables are:
-----BEGIN PUBLIC KEY-----
'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A' . 'MIIBCgKCAQEA' . $modulus . 'ID' . $exponent
-----END PUBLIC KEY-----
<?php wordwrap($cert, 64, 'rn', true); ?>
Paul Clark
10 years ago
Note this will read public keys from PEM formatted public keys as well:
<?php
$key = <<<EOF
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXX/MsKEBLcLeKA1d/i7ufG1qs
qS97xFkIRSeX3TwmHic843AfVrzoh2pZUeOvK9ZLZQpHSM7DoHMYDGD1273+FvZX
Ypf5LiFtecfxko/Cku16zy6WAeCYVFjjlveBhwPmPCIk+qDRYeiIW05QE2XK+CuD
nJ7sxxXIJSSgD3Jo5wIDAQAB
-----END PUBLIC KEY-----
EOF;
print $key;
$res = openssl_pkey_get_public($key);
print_r(openssl_pkey_get_details($res));
?>

Note that contrary to the documentation, openssl_pkey_get_details() will *not* read PEM directly, and you have to go through this step.
Rurri
8 years ago
If you have a 4096 bit key pair and are trying to use a public key that begins with:
-----BEGIN RSA PUBLIC KEY-----
and you need to convert it for this function to use, you can convert it by prepending the static header information:
MIICIjANBgkqhkiG9w0BAQEFAAOCAg8A
Such as:
$start_key = str_replace('-----BEGIN RSA PUBLIC KEY-----', ', $start_key);
$start_key = trim(str_replace('-----END RSA PUBLIC KEY-----', ', $start_key));
$key = 'MIICIjANBgkqhkiG9w0BAQEFAAOCAg8A' . str_replace('n', ', $start_key);
$key = '-----BEGIN PUBLIC KEY-----n' . wordwrap($key, 64, 'n', true) . 'n-----END PUBLIC KEY-----';

Generate Public And Private Key Php Download

  • OpenSSL Functions