我正在构建一个包含文件上传功能的网络应用程序。我的目标是启动用户直接上传到 S3 存储桶。该策略是预先签署一个将作为表单提交的 POST 请求。
障碍是 SignatureDoesNotMatch 错误 - 据我所知，我已经遵守了文档，并且探索了很多选项，但仍然无法解决。我能够生成预先签名的下载链接。
引用:
boto3 generate_presigned_post reference
生成签名请求:
def s3_upload_creds(name, user):
s3 = boto3.client('s3')
key = '${filename}'
region = 'us-east-1'
date_short = datetime.datetime.utcnow().strftime('%Y%m%d')
date_long = datetime.datetime.utcnow().strftime('%Y%m%dT000000Z')
fields = {
'acl': 'private',
'date': date_short,
'region': region,
'x-amz-algorithm': 'AWS4-HMAC-SHA256',
'x-amz-date': date_long
}
return s3.generate_presigned_post(
Bucket = 'leasy',
Fields = fields,
Key = key,
Conditions = [
{'acl': 'private'},
{'x-amz-algorithm': 'AWS4-HMAC-SHA256'},
{'x-amz-credential': '/'.join(['AKI--snip--', date_short, region, 's3', 'aws4_request'])},
{'x-amz-date': date_long}
]
)
上传表单(用上面的字段填充):
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
{{ creds }}
<form action="{{ creds.url }}" method="post" enctype="multipart/form-data">
Key to upload:
<input type="input" name="key" value="${filename}" /><br />
<input type="input" name="acl" value="{{ creds.fields.acl }}" />
<input type="hidden" name="Policy" value="{{ creds.fields.policy }}" />
<input type="text" name="X-Amz-Algorithm" value="{{ creds.fields['x-amz-algorithm'] }}" />
<input type="input" name="X-Amz-Credential" value="{{ creds.fields.AWSAccessKeyId }}/{{ creds.fields.date }}/us-east-1/s3/aws4_request" />
<input type="input" name="X-Amz-Date" value="{{ creds.fields['x-amz-date'] }}" />
<input type="input" name="X-Amz-Signature" value="{{ creds.fields.signature }}" />
File:
<input type="file" name="file" /> <br />
<!-- The elements after this will be ignored -->
<input type="submit" name="submit" value="Upload to Amazon S3" />
</form>
</html>
响应的相关部分:
<Error>
<Code>SignatureDoesNotMatch</Code>
<Message>
The request signature we calculated does not match the signature you provided. Check your key and signing method.
</Message>
<AWSAccessKeyId>AKI--snip--</AWSAccessKeyId>
<StringToSign>
eyJjb25kaXRpb25zIjogW3siYWNsIjogInByaXZhdGUifSwgeyJ4LWFtei1hbGdvcml0aG0iOiAiQVdTNC1ITUFDLVNIQTI1NiJ9LCB7IngtYW16LWNyZWRlbnRpYWwiOiAiQUtJQUlDVjRNVlBUUlFHU1lLV1EvMjAxNTEyMTgvdXMtZWFzdC0xL3MzL2F3czRfcmVxdWVzdCJ9LCB7IngtYW16LWRhdGUiOiAiMjAxNTEyMThUMDAwMDAwWiJ9LCB7ImJ1Y2tldCI6ICJsZWFzeSJ9LCBbInN0YXJ0cy13aXRoIiwgIiRrZXkiLCAiIl1dLCAiZXhwaXJhdGlvbiI6ICIyMDE1LTEyLTE4VDA1OjEwOjU2WiJ9
</StringToSign>
<SignatureProvided>wDOjsBRc0iIW7JNtz/4GHgfvKaU=</SignatureProvided>
上述错误中 StringToSign 的 Base64 解码:
{u'conditions': [{u'acl': u'private'},
{u'x-amz-algorithm': u'AWS4-HMAC-SHA256'},
{u'x-amz-credential': u'AKI--snip--/20151218/us-east-1/s3/aws4_request'},
{u'x-amz-date': u'20151218T000000Z'},
{u'bucket': u'leasy'},
[u'starts-with', u'$key', u'']],
u'expiration': u'2015-12-18T04:59:32Z'}
最佳答案
找到解决方案:必须显式配置 s3 客户端以使用亚马逊的新签名 v4。发生错误是因为它默认为旧版本，导致不匹配。有点面子 - 当时这还没有写在 boto3 文档中，尽管亚马逊的人说应该很快。
该方法得到了简化，因为它现在准确地返回所需的字段:
def s3_upload_creds(name):
BUCKET = 'mybucket'
REGION = 'us-west-1'
s3 = boto3.client('s3', region_name=REGION, config=Config(signature_version='s3v4'))
key = '${filename}'
return s3.generate_presigned_post(
Bucket = BUCKET,
Key = key
)
这意味着可以轻松生成表单:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
{{ creds }}
<form action="https://mybucket.s3.amazonaws.com" method="post" enctype="multipart/form-data">
{% for key, value in creds.fields.items() %}
<input type="hidden" name="{{ key }}" value="{{ value }}" />
{% endfor %}
File:
<input type="file" name="file" /> <br />
<input type="submit" name="submit" value="Upload to Amazon S3" />
</form>
</html>
干杯
关于python - 亚马逊 AWS S3 基于浏览器的上传使用 POST -，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34348639/