export chain with openssl_pkcs12_export in PHP

Question

Is it possible to export a certificate and private key to a .pfx along with the certificate chain (root cert and/or intermediate), using PHP's openssl_pkcs12_export()?

UPDATE: I've taken a look at the source for the php openssl extension, and found that openssl_pkcs12_export() supports 2 args other than the ones in the documentation, friendly_name and extracerts. This is from ext/openssl/openssl.c, check out lines 1914-1920 (PHP-5.4.0):

1878 /* {{{ proto bool openssl_pkcs12_export(mixed x509, string &out, mixed priv_key, string pass[, array args])
1879    Creates and exports a PKCS12 to a var */
1880 PHP_FUNCTION(openssl_pkcs12_export)
1881 {
1882         X509 * cert = NULL;                                                                                                                                                
1883         BIO * bio_out;
1884         PKCS12 * p12 = NULL;
1885         zval * zcert = NULL, *zout = NULL, *zpkey, *args = NULL;
1886         EVP_PKEY *priv_key = NULL;
1887         long certresource, keyresource;
1888         char * pass;
1889         int pass_len;
1890         char * friendly_name = NULL;
1891         zval ** item;
1892         STACK_OF(X509) *ca = NULL;
1893 
1894         if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "zzzs|a", &zcert, &zout, &zpkey, &pass, &pass_len, &args) == FAILURE)
1895                 return;
1896 
1897         RETVAL_FALSE;
1898 
1899         cert = php_openssl_x509_from_zval(&zcert, 0, &certresource TSRMLS_CC);
1900         if (cert == NULL) {
1901                 php_error_docref(NULL TSRMLS_CC, E_WARNING, "cannot get cert from parameter 1");
1902                 return;
1903         }
1904         priv_key = php_openssl_evp_from_zval(&zpkey, 0, "", 1, &keyresource TSRMLS_CC);
1905         if (priv_key == NULL) {
1906                 php_error_docref(NULL TSRMLS_CC, E_WARNING, "cannot get private key from parameter 3");
1907                 goto cleanup;
1908         }
1909         if (cert && !X509_check_private_key(cert, priv_key)) {
1910                 php_error_docref(NULL TSRMLS_CC, E_WARNING, "private key does not correspond to cert");
1911                 goto cleanup;
1912         }
1913 
1914         /* parse extra config from args array, promote this to an extra function */
1915         if (args && zend_hash_find(Z_ARRVAL_P(args), "friendly_name", sizeof("friendly_name"), (void**)&item) == SUCCESS)
1916                 friendly_name = Z_STRVAL_PP(item);
1917 
1918         if (args && zend_hash_find(Z_ARRVAL_P(args), "extracerts", sizeof("extracerts"), (void**)&item) == SUCCESS)
1919                 ca = php_array_to_X509_sk(item TSRMLS_CC);
1920         /* end parse extra config */
1921 
1922         p12 = PKCS12_create(pass, friendly_name, priv_key, cert, ca, 0, 0, 0, 0, 0);
1923 
1924         bio_out = BIO_new(BIO_s_mem());
1925         if (i2d_PKCS12_bio(bio_out, p12))  {
1926                 BUF_MEM *bio_buf;
1927 
1928                 zval_dtor(zout);
1929                 BIO_get_mem_ptr(bio_out, &bio_buf);
1930                 ZVAL_STRINGL(zout, bio_buf->data, bio_buf->length, 1);
1931 
1932                 RETVAL_TRUE;
1933         }
1934 
1935         BIO_free(bio_out);
1936         PKCS12_free(p12);
1937         php_sk_X509_free(ca);
1938 
1939 cleanup:
1940 
1941         if (keyresource == -1 && priv_key) {
1942                 EVP_PKEY_free(priv_key);
1943         }
1944         if (certresource == -1 && cert) {
1945                 X509_free(cert);
1946         }
1947 }
1948 /* }}} */

however, I'm not quite sure how to pass the additional certificates as arguments... any clues?

Let me know if it's easier readable without the line numbers

Answer 1

This is a bug that has been brought up nearly two months ago.

Thankfully he provides a sample patch for the docs:

$args = array(
               'extracerts' => $CAcert,
               'friendly_name' => 'My signed cert by CA certificate'
              );
openssl_pkcs12_export($signed_csr, $cerificate_out, $private_key_resource, $passphrase, $args);

What is $CAcert? Internally it gets passed to a function that takes an array and turns it into a x509 and that function also detects if it's an array of certs or a single cert. Each element should be an x509 Resource if you're passing an array, or $CAcert should be a single resource if you're not passing an array. openssl_x509_read is likely what you want to use here as it returns the x509 resource type that's expected in $CAcert.

Some people say that keeping docs updated is one of the hardest parts of PHP project. If you're not great with C and want to help PHP get better that's a good place to start.