支付宝wap验签遇到的一点问题

在支付宝回调验签的时，一直验签失败：
异步回调post的数据：

[
‘gmt_create’ => ‘2019-02-22 16:20:37’,
‘charset’ => ‘utf-8’,
‘seller_email’ => ‘xxxxxxxx’,
‘subject’ => ‘走流程-01’,
‘sign’ => ‘mPA4rFddj2ICsfACWJ/tskO8tUfLIzlXP2lH6+3WveBibZapcaBo73++nOm5MJsAQV6BVNDPPxljt3RbDVhdyGs2QTM0IvXoaByRUzwADgDDivxQeZfcCxk6+POm1OtytnJU0yoj410exO4hUB9py/XgR1rvg8t8weMOrrLpg2Re7gIi213lzCp+klra6fv2P4ksHswVFqZULTtU84io5k6TlUNbDxkkDF7xJ+L2hVEtIF7VE6AMjxyWcC6Mmnaxo+ksjA3Of2DoXkoIQKEUKfT2z7svu+ho3mfLA0linXn2p07+dlzdYqW4nCrB0/fvXqZCzaKgDD6vNqO6qjDHww==’,
‘buyer_id’ => ‘2088612008733899’,
‘invoice_amount’ => ‘0.05’,
‘notify_id’ => ‘2019022200222162037033891052182655’,
‘fund_bill_list’ => ‘[{“amount”:“0.05”,“fundChannel”:“ALIPAYACCOUNT”}]’,
‘notify_type’ => ‘trade_status_sync’,
‘trade_status’ => ‘TRADE_SUCCESS’,
‘receipt_amount’ => ‘0.05’,
‘buyer_pay_amount’ => ‘0.05’,
‘app_id’ => ‘xxxxxxxx’,
‘sign_type’ => ‘RSA2’,
‘seller_id’ => ‘xxxxxxxx’,
‘gmt_payment’ => ‘2019-02-22 16:20:37’,
‘notify_time’ => ‘2019-02-22 17:44:10’,
‘version’ => ‘1.0’,
‘out_trade_no’ => ‘alipaywap20190222162023634’,
‘total_amount’ => ‘0.05’,
‘trade_no’ => ‘2019022222001433891021856713’,
‘auth_app_id’ => ‘xxxxxxxx’,
‘buyer_logon_id’ => ‘xxxxxxxx’,
‘point_amount’ => ‘0.00’,
]
在处理验签之前处理如下字段后回调成功。
$params{[}^{\prime }fun{d}_{b}il{l}_{l}is{t}^{\prime }]=stripslashes($params[‘fund_bill_list’]);//转换json串\斜杠