openssl_seal
The openssl_sign() function seems to be incompatible with openssl comandline and openssl library. For some reason it adds some bytes which lead to a "wrong signature length" error.
If you need to be compatible hashing and encrypting by our own is a feasable way...
Or in case you don't bother about calls to exec() just use the comandline tool direct. However, besides testing purposes I wouldn't recomnd that.
openssl_sign
(PHP 4 >= 4.0.4, PHP 5)
openssl_sign — Generar una firma
Descripción
bool openssl_sign
( string
$data
, string &$signature
, mixed $priv_key_id
[, int $signature_alg = OPENSSL_ALGO_SHA1
] )
openssl_sign() computa una firma para la información
data especificada usando SHA1 para el hash,
seguido por la encriptación usando la clave privada asociada con
priv_key_id. Observe que la información misma no
está encriptada.
Parámetros
-
data -
-
signature -
Si la llamada tuvo éxito, la firma es devuelta en
signature. -
priv_key_id -
-
signature_alg -
Para más información vea la lista de Algoritmos de Firma.
Valores devueltos
Devuelve TRUE en caso de éxito o FALSE en caso de error.
Historial de cambios
| Versión | Descripción |
|---|---|
| 5.0.0 |
Se añadió el parámetro signature_alg.
|
Ejemplos
Ejemplo #1 Ejemplo de openssl_sign()
<?php
// se asume que $data contiene la información que se va a firmar
// traer la clave privada desde el archivo y prepararla
$fp = fopen("/src/openssl-0.9.6/demos/sign/key.pem", "r");
$priv_key = fread($fp, 8192);
fclose($fp);
$pkeyid = openssl_get_privatekey($priv_key);
// computar la firma
openssl_sign($data, $signature, $pkeyid);
// liberar la clave de la memoria
openssl_free_key($pkeyid);
?>
add a note
User Contributed Notes
openssl_sign - [4 notes]
wolfram dot thoma at googlemail dot com ¶
1 year ago
Chris Kistner ¶
2 years ago
The list of Signature Algorithms (constants) is very limited! Fortunately the newer versions of php/openssl allow you to specify the signature algorithm as a string.
You can use the 'openssl_get_md_methods' method to get a list of digest methods. Only some of them may be used to sign with RSA private keys.
Those that can be used to sign with RSA private keys are: md4, md5, ripemd160, sha, sha1, sha224, sha256, sha384, sha512
Here's the modified Example #1 with SHA-512 hash:
<?php
// $data is assumed to contain the data to be signed
// fetch private key from file and ready it
$fp = fopen("/src/openssl-0.9.6/demos/sign/key.pem", "r");
$priv_key = fread($fp, 8192);
fclose($fp);
$pkeyid = openssl_get_privatekey($priv_key);
// compute signature with SHA-512
openssl_sign($data, $signature, $pkeyid, "sha512");
// free the key from memory
openssl_free_key($pkeyid);
?>
edmarw at yahoo dot com ¶
5 years ago
This may help if you just want a real-simple private/public key pair:
<?php
$data = "Beeeeer is really good.. hic...";
// You can get a simple private/public key pair using:
// openssl genrsa 512 >private_key.txt
// openssl rsa -pubout <private_key.txt >public_key.txt
// IMPORTANT: The key pair below is provided for testing only.
// For security reasons you must get a new key pair
// for production use, obviously.
$private_key = <<<EOD
-----BEGIN RSA PRIVATE KEY-----
MIIBOgIBAAJBANDiE2+Xi/WnO+s120NiiJhNyIButVu6zxqlVzz0wy2j4kQVUC4Z
RZD80IY+4wIiX2YxKBZKGnd2TtPkcJ/ljkUCAwEAAQJAL151ZeMKHEU2c1qdRKS9
sTxCcc2pVwoAGVzRccNX16tfmCf8FjxuM3WmLdsPxYoHrwb1LFNxiNk1MXrxjH3R
6QIhAPB7edmcjH4bhMaJBztcbNE1VRCEi/bisAwiPPMq9/2nAiEA3lyc5+f6DEIJ
h1y6BWkdVULDSM+jpi1XiV/DevxuijMCIQCAEPGqHsF+4v7Jj+3HAgh9PU6otj2n
Y79nJtCYmvhoHwIgNDePaS4inApN7omp7WdXyhPZhBmulnGDYvEoGJN66d0CIHra
I2SvDkQ5CmrzkW5qPaE2oO7BSqAhRZxiYpZFb5CI
-----END RSA PRIVATE KEY-----
EOD;
$public_key = <<<EOD
-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANDiE2+Xi/WnO+s120NiiJhNyIButVu6
zxqlVzz0wy2j4kQVUC4ZRZD80IY+4wIiX2YxKBZKGnd2TtPkcJ/ljkUCAwEAAQ==
-----END PUBLIC KEY-----
EOD;
$binary_signature = "";
// At least with PHP 5.2.2 / OpenSSL 0.9.8b (Fedora 7)
// there seems to be no need to call openssl_get_privatekey or similar.
// Just pass the key as defined above
openssl_sign($data, $binary_signature, $private_key, OPENSSL_ALGO_SHA1);
// Check signature
$ok = openssl_verify($data, $binary_signature, $public_key, OPENSSL_ALGO_SHA1);
echo "check #1: ";
if ($ok == 1) {
echo "signature ok (as it should be)\n";
} elseif ($ok == 0) {
echo "bad (there's something wrong)\n";
} else {
echo "ugly, error checking signature\n";
}
$ok = openssl_verify('tampered'.$data, $binary_signature, $public_key, OPENSSL_ALGO_SHA1);
echo "check #2: ";
if ($ok == 1) {
echo "ERROR: Data has been tampered, but signature is still valid! Argh!\n";
} elseif ($ok == 0) {
echo "bad signature (as it should be, since data has beent tampered)\n";
} else {
echo "ugly, error checking signature\n";
}
?>
adam dot mansfeld at gmail dot com ¶
7 years ago
Hello,
the fourth parameter 'signature_alg' to choose the signature algorithm can be one of:
OPENSSL_ALGO_SHA1
OPENSSL_ALGO_MD5
OPENSSL_ALGO_MD4
OPENSSL_ALGO_MD2
Just for the case that somebody needs this.
Regards