var_dump($platformCertificateFileContent); //打印看下这个值，按报错看应该是没有读取到证书内容

你的PHP版本低于7.1.2，顾没有，详细<a href="/community/develop/issue/7151" target="_blank"> #7151 </a>serialNumberHex support 说明。

[图片] 这一行说明你用的 $sm3-&gt;signFile 签名的摘要不对；另程序异常捕获写法参考如下： try { $res = $instance-&gt;chain('')-&gt;post([]); } catch ($e) { var_dump((string)$e-&gt;getResponse()-&gt;getBody()); } Sm3杂凑单文件实现参考这里： https://github.com/TheNorthMemory/wechatpay-php/blob/v1.5/src/Crypto/Sm3.php 使用上类似这里的注视示例： https://github.com/TheNorthMemory/wechatpay-openapi/blob/master/src/V3/NewTaxControlFapiao/FapiaoApplications/UploadFapiaoFile.php#L13-L36 // available since wechatpay/wechatpay:&gt;=1.5.0 $digest = \WeChatPay\Crypto\Sm3::file('file:///path/to/fapiao.pdf'); $media = new \WeChatPay\Util\MediaUtil('file:///path/to/fapiao.pdf'); $json &nbsp;= [ &nbsp; &nbsp; 'sub_mchid' &nbsp; &nbsp; &nbsp; &nbsp;=&gt; 'your_sub_mchid', //服务商模式下必传 &nbsp; &nbsp; 'file_type' &nbsp; &nbsp; &nbsp; &nbsp;=&gt; 'PDF', &nbsp; &nbsp; 'digest_algorithm' =&gt; 'SM3', &nbsp; &nbsp; 'digest' &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; =&gt; $digest, ]; $media-&gt;setMeta(\json_encode($json)); $options = [ &nbsp; &nbsp; 'body' &nbsp; &nbsp; &nbsp; =&gt; $media-&gt;getStream(), &nbsp; &nbsp; 'headers' &nbsp; &nbsp;=&gt; ['Content-type' =&gt; $media-&gt;getContentType()] ];

建议看看 https://www.npmjs.com/package/wechatpay-axios-plugin npm包

https://pay.weixin.qq.com/wiki/doc/apiv3_partner/Offline/apis/chapter11_2_1.shtml 这个接口传参是GET方式，而银行卡是密文base64字符串，传输时需要处理特殊字符（一般SDK都会处理）。 PHP参考代码如下： &lt;?php use WeChatPay\Builder; use WeChatPay\Crypto\Rsa; Builder::factory([ 'mchid' =&gt; $mchid, 'privateKey' =&gt; $privateKey = Rsa::fromPkcs8($merchantPrivateKeyString), 'serial' =&gt; $merchantCerificateSerial, 'certs' =&gt; [$platformCertificateSerial =&gt; $publicKey = Rsa::fromSpki($platformPublicKeyString)], ]) -&gt;chain('v3/capital/capitallhh/banks/search-banks-by-bank-account') -&gt;getAsync([ 'headers' =&gt; [ 'Wechatpay-Serial' =&gt; $platformCertificateSerial, ], 'query' =&gt; [ 'account_number' =&gt; Rsa::encrypt('6228481831910000000', $publicKey) ], ]) -&gt;then(fn ($res) =&gt; (string)$res-&gt;getBody()) -&gt;otherwise(fn ($err) =&gt; (string)$err-&gt;getResponse()-&gt;getBody()) -&gt;then(fn ($str) =&gt; fwrite(STDERR, $str)) -&gt;wait(); 打印的json如下： { &nbsp; "data": [ &nbsp; &nbsp; { &nbsp; &nbsp; &nbsp; "account_bank": "农业银行", &nbsp; &nbsp; &nbsp; "account_bank_code": 1005, &nbsp; &nbsp; &nbsp; "bank_alias": "农业银行", &nbsp; &nbsp; &nbsp; "bank_alias_code": "1000009548", &nbsp; &nbsp; &nbsp; "need_bank_branch": false &nbsp; &nbsp; } &nbsp; ], &nbsp; "total_count": 1 }

https://github.com/wechatpay-apiv3/wechatpay-guzzle-middleware 环境要求 我们开发和测试使用的环境如下： PHP 5.5+ / PHP 7.0+guzzlehttp/guzzle ^6.3

微信小程序搜： 微信收款服务商助手

APIv2退款需要在httpclient加载商户私钥以及商户证书

使用Java加载密钥时，抛出异常InvalidKeyException: Illegal key size受到美国法律的约束，早期Java的运行时限制了JCE支持的密钥长度，即默认不支持256位的AES。解决的方法有三个： （推荐）升级Java 8u162+，默认使用ulimited policyJava 8u151和8u152，可以在你的程序中直接放开策略Security.setProperty("crypto.policy", "unlimited"); 其他版本，下载无限强度权限策略文件补丁包，并使用其中的文件覆盖[代码]$JAVA_HOME/lib/security[代码]目录下的对应的[代码]local_policy.jar[代码]&nbsp;和[代码]US_export_policy.jar[代码]Java9及以上，均无限制。 https://pay.weixin.qq.com/wiki/doc/apiv3/wechatpay/wechatpay7_2.shtml

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