服务端配置使用阿里云 OSS      作为存储。测试中发现安卓端修改用户头像是正常的，但是iOS端修改头像报失败，跟踪后发现mars的dump数据如下：

> HTTP/1.1 403 Forbidden > Server: AliyunOSS > Date: Sat, 03 Oct 2020 14:24:03 GMT > Content-Type: application/xml > Content-Length: 913 > Connection: close > x-oss-request-id: 5F7889838338063136FB903B > x-oss-server-time: 0 > > <?xml version="1.0" encoding="UTF-8"?> > <Error> >  <Code>SignatureDoesNotMatch</Code> >  <Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message> >  <RequestId>5F7889838338063136FB903B</RequestId> >  <HostId>此处隐藏</HostId> >  <OSSAccessKeyId>此处隐藏</OSSAccessKeyId> >  <SignatureProvided>此处隐藏</SignatureProvided> >  <StringToSign>PUT > > image/jpeg > Sat, 03 Oct 2020 14:23:55 GMT > /ddian-tech/SeoZSZ44-5-1601735035-sHaZTl3n_.jpg</StringToSign> >  <StringToSignBytes>50 55 54 0A 0A 69 6D 61 67 65 2F 6A 70 65 67 0A 53 61 74 2C 20 30 33 20 4F 63 74 20 32 30 32 30 20 31 34 3A 32 33 3A 35 35 20 47 4D 54 0A 2F 64 64 69 61 6E 2D 74 65 63 68 2F 53 65 6F 5A 53 5A 34 34 2D 35 2D 31 36 30 31 37 33 35 30 33 35 2D 73 48 61 5A 54 6C 33 6E 5F 2E 6A 70 67 </StringToSignBytes> > </Error>

目前测试，安卓端上传与多媒体相关的内容都正常。iOS端聊天部分涉及多媒体内容上传也是正常，仅头像更新不行。

由于不懂 iOS的代码，目前不知道如何处理。非常感谢您的阅读。