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OpenSSL Functions
PHP Manual

# openssl_csr_sign

Sign a CSR with another certificate (or itself) and generate a certificate

### Description

resource openssl_csr_sign ( mixed `$csr` , mixed `$cacert` , mixed `$priv_key` , int `$days` [, array `$configargs` [, int `$serial` = 0 ]] )

openssl_csr_sign generates an x509 certificate resource from the given CSR.

> Note: You need to have a valid openssl.cnf installed for this function to operate correctly. See the notes under the installation section for more information.

### Parameters

`csr`

  A CSR previously generated by openssl_csr_new. It can also be the path to a PEM encoded CSR when specified as file://path/to/csr or an exported string generated by openssl_csr_export.

`cacert`

  The generated certificate will be signed by `cacert`. If `cacert` is `NULL`, the generated certificate will be a self-signed certificate.

`priv_key`

  `priv_key` is the private key that corresponds to `cacert`.

`days`

  `days` specifies the length of time for which the generated certificate will be valid, in days.

`configargs`

  You can finetune the CSR signing by `configargs`. See openssl_csr_new for more information about `configargs`.

`serial`

  An optional the serial number of issued certificate. If not specified it will default to 0.

### Return Values

Returns an x509 certificate resource on success, `FALSE` on failure.

### Changelog

Version | Description
--- | ---
4.3.3 | The `serial` parameter was added.

### Examples

Example #1 openssl_csr_sign example - signing a CSR (how to implement your own CA)

`<?php
// Let's assume that this script is set to receive a CSR that has
// been pasted into a textarea from another page
$csrdata = $_POST["CSR"];
// We will sign the request using our own "certificate authority"
// certificate. You can use any certificate to sign another, but
// the process is worthless unless the signing certificate is trusted
// by the software/users that will deal with the newly signed certificate
// We need our CA cert and its private key
$cacert = "file://path/to/ca.crt";
$privkey = array("file://path/to/ca.key", "your_ca_key_passphrase");
$usercert = openssl_csr_sign($csrdata, $cacert, $privkey, 365);
// Now display the generated certificate so that the user can
// copy and paste it into their local configuration (such as a file
// to hold the certificate for their SSL server)
openssl_x509_export($usercert, $certout);
echo $certout;
// Show any errors that occurred here
while (($e = openssl_error_string()) !== false) {
echo $e . "\n";
}
?>`