openssl_cms_decrypt

(PHP 8)

openssl_cms_decrypt — Decrypt a CMS message

说明

openssl_cms_decrypt ( string $input_filename , string $output_filename , OpenSSLCertificate|string $certificate , OpenSSLAsymmetricKey|OpenSSLCertificate|array|string|null $private_key = null , int $encoding = OPENSSL_ENCODING_SMIME ) : bool

Decrypts a CMS message.

参数

input_filename

The name of a file containing encrypted content.

output_filename

The name of the file to deposit the decrypted content.

certificate

The name of the file containing a certificate of the recipient.

private_key

The name of the file containing a PKCS#8 key.

encoding

The encoding of the input file. One of OPENSSL_CMS_SMIME, OPENSLL_CMS_DER or OPENSSL_CMS_PEM.

返回值

成功时返回 true， 或者在失败时返回 false。

User Contributed Notes

Sebastian 28-Feb-2021 09:25
It took me a while to find out the correct way how to decrypt and verify data with these functions.
I needed that to communicate with German Health Insurance Providers as part of a DiGA. Maybe someone finds that useful.

<?php
function decryptAndVerify($signedAndEncryptedRawData): string
{
    $tempDir = __DIR__ . '/tmp';
    $originalFile = tempnam($tempDir, 'original');
    $decryptedFile = tempnam($tempDir, 'decrypted');
    $verifiedFile = tempnam($tempDir, 'verified');

    file_put_contents($originalFile, $signedAndEncryptedRawData);
   
    // One file with all possible certificates one after the other
    // -----BEGIN CERTIFICATE----- ...-----END CERTIFICATE-----
    $allPossibleSenderCertificates = __DIR__ . '/untrusted.pem';

    // Certificate:
    //    Data:
    //        Version: 3 (0x2)...
    $myCertificate = file_get_contents(__DIR__ . '/my.crt');
    $myPrivateKey = openssl_pkey_get_private(
    // -----BEGIN RSA PRIVATE KEY----- ... -----END RSA PRIVATE KEY-----
        file_get_contents(__DIR__ . '/my.prv.key.pem')
    );
   
    openssl_cms_decrypt(
        input_filename: $originalFile,
        output_filename: $decryptedFile,
        certificate: $myCertificate,
        private_key: $myPrivateKey,
        encoding: OPENSSL_ENCODING_DER
    );

    openssl_cms_verify(
        input_filename: $decryptedFile,
        flags: OPENSSL_CMS_BINARY | OPENSSL_CMS_NOSIGS | OPENSSL_CMS_NOVERIFY,
        ca_info: [],
        untrusted_certificates_filename: $allPossibleSenderCertificates,
        content: $verifiedFile,
        encoding: OPENSSL_ENCODING_DER
    );
    return file_get_contents($verifiedFile);
}