(PHP 4 >= 4.2.0, PHP 5)

openssl_csr_new -- Generates a CSR


mixed openssl_csr_new ( array dn, resource &privkey [, array configargs [, array extraattribs]] )

openssl_csr_new() generates a new CSR (Certificate Signing Request) based on the information provided by dn, which represents the Distinguished Name to be used in the certificate.

privkey should be set to a private key that was previously generated by openssl_pkey_new() (or otherwise obtained from the other openssl_pkey family of functions). The corresponding public portion of the key will be used to sign the CSR.

extraattribs is used to specify additional configuration options for the CSR. Both dn and extraattribs are associative arrays whose keys are converted to OIDs and applied to the relevant part of the request.

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.

By default, the information in your system openssl.conf is used to initialize the request; you can specify a configuration file section by setting the config_section_section key of configargs. You can also specify an alternative openssl configuration file by setting the value of the config key to the path of the file you want to use. The following keys, if present in configargs behave as their equivalents in the openssl.conf, as listed in the table below.

Table 1. Configuration overrides

configargs keytypeopenssl.conf equivalentdescription
digest_algstringdefault_mdSelects which digest method to use
x509_extensionsstringx509_extensionsSelects which extensions should be used when creating an x509 certificate
req_extensionsstringreq_extensionsSelects which extensions should be used when creating a CSR
private_key_bitsstringdefault_bitsSpecifies how many bits should be used to generate a private key
private_key_typeintegernoneSpecifies the type of private key to create. This can be one of OPENSSL_KEYTYPE_DSA, OPENSSL_KEYTYPE_DH or OPENSSL_KEYTYPE_RSA. The default value is OPENSSL_KEYTYPE_RSA which is currently the only supported key type.
encrypt_keybooleanencrypt_keyShould an exported key (with passphrase) be encrypted?

Returns TRUE on success or FALSE on failure.

Example 1. openssl_csr_new() example - creating a self-signed-certificate

// Fill in data for the distinguished name to be used in the cert
// You must change the values of these keys to match your name and
// company, or more precisely, the name and company of the person/site
// that you are generating the certificate for.
// For SSL certificates, the commonName is usually the domain name of
// that will be using the certificate, but for S/MIME certificates,
// the commonName will be the name of the individual who will use the
// certificate.
$dn = array(
"countryName" => "UK",
"stateOrProvinceName" => "Somerset",
"localityName" => "Glastonbury",
"organizationName" => "The Brain Room Limited",
"organizationalUnitName" => "PHP Documentation Team",
"commonName" => "Wez Furlong",
"emailAddress" => ""

// Generate a new private (and public) key pair
$privkey = openssl_pkey_new();

// Generate a certificate signing request
$csr = openssl_csr_new($dn, $privkey);

// You will usually want to create a self-signed certificate at this
// point until your CA fulfills your request.
// This creates a self-signed cert that is valid for 365 days
$sscert = openssl_csr_sign($csr, null, $privkey, 365);

// Now you will want to preserve your private key, CSR and self-signed
// cert so that they can be installed into your web server, mail server
// or mail client (depending on the intended use of the certificate).
// This example shows how to get those things into variables, but you
// can also store them directly into files.
// Typically, you will send the CSR on to your CA who will then issue
// you with the "real" certificate.
openssl_csr_export($csr, $csrout) and var_dump($csrout);
openssl_x509_export($sscert, $certout) and var_dump($certout);
openssl_pkey_export($privkey, $pkeyout, "mypassword") and var_dump($pkeyout);

// Show any errors that occurred here
while (($e = openssl_error_string()) !== false) {
$e . "\n";

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