Verifies a signed public key and challenge

# openssl_spki_verify

(PHP 5 >= 5.6.0, PHP 7)

openssl_spki_verify — Verifies a signed public key and challenge

### 説明

openssl_spki_verify ( string `&$spkac` ) : string

Validates the supplied signed public key and challenge

### パラメータ

`spkac`

  Expects a valid signed public key and challenge

### 返り値

Returns a boolean on success or failure.

### エラー / 例外

Emits an `E_WARNING` level error if an invalid argument is passed via the `spkac` parameter.

### 例

例1 openssl_spki_verify() example

Validates an existing signed public key and challenge

`<?php
$pkey = openssl_pkey_new('secret password');
$spkac = openssl_spki_new($pkey, 'challenge string');
if (openssl_spki_verify(preg_replace('/SPKAC=/', '', $spkac))) {
echo $spkac;
} else {
echo "SPKAC validation failed";
}
?>`

例2 openssl_spki_verify() example from <keygen>

Validates an existing signed public key and challenge issued from the <keygen> element

`<?php
if (openssl_spki_verify(preg_replace('/SPKAC=/', '', $_POST['spkac']))) {
echo $spkac;
} else {
echo "SPKAC validation failed";
}
?>
<keygen name="spkac" challenge="challenge string" keytype="RSA">`

### 参考

- openssl_spki_new() - 署名された公開鍵とチャレンジを新規に作成する
- openssl_spki_export_challenge() - Exports the challenge assoicated with a signed public key and challenge
- openssl_spki_export() - Exports a valid PEM formatted public key signed public key and challenge
- openssl_md_method()
- openssl_csr_new() - CSR を作成する
- openssl_csr_sign() - CSRに他の証明書（あるいは自分自身）で署名して証明書を作成する