openssl_pkcs7_decrypt

(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)

openssl_pkcs7_decrypt — Decrypts an S/MIME encrypted message

Description

openssl_pkcs7_decrypt(
    string $input_filename,
    string $output_filename,
    #[\SensitiveParameter] OpenSSLCertificate|string $certificate,
    #[\SensitiveParameter] OpenSSLAsymmetricKey|OpenSSLCertificate|array|string|null $private_key = null
): bool

Decrypts the S/MIME encrypted message contained in the file specified by input_filename using the certificate and its associated private key specified by certificate and private_key.

Parameters

input_filename
output_filename: The decrypted message is written to the file specified by output_filename.
certificate
private_key

Return Values

Returns true on success or false on failure.

Changelog

Version	Description
8.0.0	`private_key` accepts an OpenSSLAsymmetricKey or OpenSSLCertificate instance now; previously, a resource of type `OpenSSL key` or `OpenSSL X.509 CSR` was accepted.

Examples

Example #1 openssl_pkcs7_decrypt() example

<?php
// $cert and $key are assumed to contain your personal certificate and private
// key pair, and that you are the recipient of an S/MIME message
$infilename = "encrypted.msg";  // this file holds your encrypted message
$outfilename = "decrypted.msg"; // make sure you can write to this file

if (openssl_pkcs7_decrypt($infilename, $outfilename, $cert, $key)) {
    echo "decrypted!";
} else {
    echo "failed to decrypt!";
}
?>

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User Contributed Notes 1 note

down

oliver at anonsphere dot com ¶

13 years ago

If you want to decrypt a received email, keep in mind that you need the full encrypted message including the mime header.

<?php

// Get the full message
$encrypted = imap_fetchmime($stream, $msg_number, "1", FT_UID);
$encrypted .= imap_fetchbody($stream, $msg_number, "1", FT_UID);

// Write the needed temporary files
$infile = tempnam("", "enc");
file_put_contents($infile, $encrypted); 
$outfile = tempnam("", "dec");

// The certification stuff
$public = file_get_contents("/path/to/your/cert.pem");
$private = array(file_get_contents("/path/to/your/cert.pem"), "password");

// Ready? Go!
if(openssl_pkcs7_decrypt($infile, $outfile, $public, $private))
{
    // Decryption successful
    echo file_get_contents($outfile);
}
else
{
    // Decryption failed
    echo "Oh oh! Decryption failed!";
}

// Remove the temp files
@unlink($infile);
@unlink($outfile);

?>

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