从R连接到azure blob存储API时出错

Question

我试图通过R中的REST API使用Azure存储。我正在使用覆盖Curl的包httr 。

建立

您可以使用R-fiddle： http ：//www.r-fiddle.org/#/fiddle？ id = vh8uqGmM

library(httr)
requestdate<-format(Sys.time(),"%a, %d %b %Y %H:%M:%S GMT")
url<-"https://preconstuff.blob.core.windows.net/pings?restype=container&comp=list"
sak<-"Q8HvUVJLBJK+wkrIEG6LlsfFo19iDjneTwJxX/KXSnUCtTjgyyhYnH/5azeqa1bluGD94EcPcSRyBy2W2A/fHQ=="
signaturestring<-paste0("GET",paste(rep("\n",12),collapse=""),
"x-ms-date:",requestdate,"
x-ms-version:2009-09-19
/preconstuff/pings
comp:list
restype:container")

headerstuff<-add_headers(Authorization=paste0("SharedKey preconstuff:",
                         RCurl::base64(digest::hmac(key=sak,
                         object=enc2utf8(signaturestring),
                         algo= "sha256"))),
                    `x-ms-date`=requestdate,
                    `x-ms-version`= "2009-09-19")

试图列出blob：

content(GET(url,config = headerstuff, verbose() ))

错误

顶级消息

在HTTP请求'Q8HvUVJLBJK + wkrIEG6LlsfFo19iDjneTwJxX /KXSnUCtTjgyyhYnH / 5azeqa1bluGD94EcPcSRyBy2W2A / fHQ =='中找到的MAC签名与任何计算签名不同。

回复内容

[1] "<?xml version=\"1.0\" encoding=\"utf-8\"?><Error>
<Code>AuthenticationFailed</Code><Message>Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.\nRequestId:1ab26da5-0001-00dc-6ddb-15e35c000000\nTime:2015-03-26T17:51:42.7190620Z</Message>
<AuthenticationErrorDetail>The MAC signature found in the HTTP request 'NTM1ODZjMjhhZmMyZGM3NDM0YTFjZDgwNGE0ODVmMzVjNDhkNjBkNzk1ZjNkZjJjOTNlNjUxYTMwMjRhNzNlYw==' is not the same as any computed signature. Server used following string to sign: 
'GET\n\n\n\n\n\n\n\n\n\n\n\nx-ms-date:Thu, 26 Mar 2015 17:52:37 GMT\nx-ms-version:2009-09-19\n/preconstuff/pings\ncomp:list\nrestype:container'.
</AuthenticationErrorDetail></Error>"

详细输出

-> GET /pings?restype=container&comp=list HTTP/1.1
-> User-Agent: curl/7.39.0 Rcurl/1.95.4.5 httr/0.6.1
-> Host: preconstuff.blob.core.windows.net
-> Accept-Encoding: gzip
-> Accept: application/json, text/xml, application/xml, */*
-> Authorization: SharedKey preconstuff:OTRhNTgzYmY3OTY3M2UzNjk3ODdjMzk3OWM3ZmU0OTA4MWU5NTE2OGYyZGU3YzRjNjQ1M2NkNzY0ZTcyZDRhYQ==
-> x-ms-date: Thu, 26 Mar 2015 17:56:27 GMT
-> x-ms-version: 2009-09-19
-> 
<- HTTP/1.1 403 Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.
<- Content-Length: 719
<- Content-Type: application/xml
<- Server: Microsoft-HTTPAPI/2.0
<- x-ms-request-id: 3d47770c-0001-0085-2313-6d466f000000
<- Date: Thu, 26 Mar 2015 17:56:27 GMT
<- 

解决错误

谷歌搜索这个问题似乎没有产生一致的原因，但这可能是由于我的格式/请求结构不好。 为此我检查了：

1. 我已经验证了我的密钥是正确的（它只是门户网站的c＆p）
2. 我确保日期格式正确
3. 有一个最近的documentDB SO表明它可能是一个时钟偏差问题，我注意到我的x-ms-date比响应中的Date早了一秒。 我已经尝试发送一个绝对过去的固定值，但是在15分钟的容差范围内。 没有得到消息的改变。
4. 在 headerstuff添加了 encoding="Base64" ，进一步 headerstuff了 MSDN论坛问题，但返回了相同的错误消息
5. 继@ Serdar的回答，我结合了签名字符串的构造（我已经验证这与错误消息中提供的字符串相匹配），然后在base64中编码hmac-sha256（使用辅助访问密钥（ sak ））作为加密密钥）UTF8转换的signaturestring字符串的版本作为要在SharedKey授权中使用的值。
6. 继@ Serdar的评论之后，签名字符串和主要请求中使用的日期必须相同，因此定义一次并重复使用

有什么明显的错误吗？ 还有其他事情要检查吗？ 代码是否适用于其他人？

Answer 1

看起来你的问题是关键。 您提供的密钥字符串实际上是base64编码的。 在使用原始向量对签名请求进行签名之前，需要将其解码。 例如：

url<-"https://preconstuff.blob.core.windows.net/pings?restype=container&comp=list"
sak<-"Q8HvUVJLBJK+wkrIEG6LlsfFo19iDjneTwJxX/KXSnUCtTjgyyhYnH/5azeqa1bluGD94EcPcSRyBy2W2A/fHQ=="

requestdate<-format(Sys.time(),"%a, %d %b %Y %H:%M:%S %Z", tz="GMT")
signaturestring<-paste0("GET",paste(rep("\n",12),collapse=""),
"x-ms-date:",requestdate,"
x-ms-version:2009-09-19
/preconstuff/pings
comp:list
restype:container")

headerstuff<-add_headers(Authorization=paste0("SharedKey preconstuff:",
                         RCurl::base64(digest::hmac(key=RCurl::base64Decode(sak, mode="raw"),
                         object=enc2utf8(signaturestring),
                         algo= "sha256", raw=TRUE))),
                    `x-ms-date`=requestdate,
                    `x-ms-version`= "2009-09-19")

content(GET(url,config = headerstuff, verbose() ))

虽然没有列出blob，但这种方式不再存在身份验证错误。 也许这是一个不同的问题。

此外，我更改了创建日期/时间的方式，以更“安全”地将当地时间更改为GMT。

Answer 2

您似乎直接在Authorization标头中使用了您帐户的密钥。 要对请求进行身份验证，您必须使用发出请求的帐户的密钥对请求进行签名，并将该签名作为请求的一部分传递。 有关如何构建Authorization标头的详细信息，请参阅Azure存储服务的身份验证 。

另请注意，该服务在错误响应中返回StringToSign。 那么，你的代码应该做的是将以下公式应用于StringToSign =“GET \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n \\ n-nx-ms-date：Wed， 2015年3月25日22:24:12 GMT \\ nx-ms-version：2014-02-14 \\ n / preconstuff / pings \\ ncomp：list \\ nrestype：container“（不含引号）：

Signature=Base64(HMAC-SHA256(AccountKey, UTF8(StringToSign)))

服务如何计算StringToSign将在上面共享的链接中详细说明。

Answer 3

通过MrFlick上面的示例代码工作并使其工作我不得不改变一些事情。

日期字符串必须在英语区域设置中设置，例如：

lct <- Sys.getlocale("LC_TIME") 
Sys.setlocale("LC_TIME", "us")
requestdate <- format(Sys.time(),"%a, %d %b %Y %H:%M:%S %Z", tz="GMT")
Sys.setlocale("LC_TIME", lct)

应使用参数之间的\\ n格式化'signaturestring'：

 signaturestring <- paste0("GET", paste(rep("\n", 12), collapse=""),
"x-ms-date:", requestdate, 
"\nx-ms-version:2009-09-19\n/preconstuff/pings\ncomp:list\nrestype:container")

编辑：以下程序适合我。 基于Steph Locke的例子。

library(httr)
library(RCurl)

azureBlobCall <- function(url, verb, key, requestBody=NULL, headers=NULL, ifMatch="", md5="") { 
  urlcomponents <- httr::parse_url(url)
  account <- gsub(".blob.core.windows.net", "", urlcomponents$hostname, fixed = TRUE)
  container <- urlcomponents$path

  # get timestamp in us locale
  lct <- Sys.getlocale("LC_TIME"); Sys.setlocale("LC_TIME", "us")
  `x-ms-date` <- format(Sys.time(),"%a, %d %b %Y %H:%M:%S %Z", tz="GMT")
  Sys.setlocale("LC_TIME", lct)

  # if requestBody exist get content length in bytes and content type
  `Content-Length` <- ""; `Content-Type` <- ""
  if(!is.null(requestBody)) {
    if(class(requestBody) == "form_file") {
      `Content-Length` <- (file.info(requestBody$path))$size
      `Content-Type` <- requestBody$type 
    } else {
      requestBody <- enc2utf8(as.character(requestBody))
      `Content-Length` <- nchar(requestBody, "bytes")
      `Content-Type` <- "text/plain; charset=UTF-8" 
    }
  } 

  # combine timestamp and version headers with any input headers, order and create the CanonicalizedHeaders
  headers <- setNames(c(`x-ms-date`, "2015-04-05",  unlist(headers)), 
                      c("x-ms-date", "x-ms-version", unclass(names(unlist(headers)))))
  headers <- headers[order(names(headers))]
  CanonicalizedHeaders <- paste(names(headers), headers, sep=":", collapse = "\n")

  # create CanonicalizedResource headers and add any queries to it
  if(!is.null(urlcomponents$query)) {
    components <- setNames(unlist(urlcomponents$query), unclass(names(unlist(urlcomponents$query))))
    componentstring <- paste0("\n", paste(names(components[order(names(components))]),
                                          components[order(names(components))], sep=":", collapse = "\n"))
  } else componentstring <- ""
  CanonicalizedResource <- paste0("/",account,"/",container, componentstring)

  # create the authorizationtoken
  signaturestring <- paste0(verb, "\n\n\n", `Content-Length`, "\n", md5, "\n", `Content-Type`, "\n\n\n", 
                            ifMatch, "\n\n\n\n", CanonicalizedHeaders, "\n", CanonicalizedResource)

  requestspecificencodedkey <- RCurl::base64(
    digest::hmac(key=RCurl::base64Decode(key, mode="raw"),
                 object=enc2utf8(signaturestring),
                 algo= "sha256", raw=TRUE)
  )

  authorizationtoken <- paste0("SharedKey ", account, ":", requestspecificencodedkey)

  # make the call
  headers_final <- add_headers(Authorization=authorizationtoken, headers, `Content-Type` = `Content-Type`)
  call <- httr::VERB(verb=verb, url=url, config=headers_final, body=requestBody, verbose())

  print("signaturestring");print(signaturestring); 
  print(headers_final); print(call)
  return(content(call))
} 

## Tests. Replace 'key' and 'accountName' with yours
key <- "YowThr***********RDw=="

# Creates a container named 'test'
azureBlobCall("https://accountName.blob.core.windows.net/test?restype=container", "PUT", key)
# Creates a blob named 'blob' under container 'test' with the content of "Hej världen!"
azureBlobCall("https://accountName.blob.core.windows.net/test/blob", "PUT", key, 
              headers = c("x-ms-blob-type"="BlockBlob"), requestBody = "Hej världen!") #upload_file("blob.txt"))
# List all blob in the container 'test'
azureBlobCall("https://accountName.blob.core.windows.net/test?comp=list&restype=container", "GET", key)
# deletes the blobl named 'blob' 
azureBlobCall("https://accountName.blob.core.windows.net/test/blob", "DELETE", key)
# Creates a blob named 'blob' under container 'test' with and upload the file 'blob.txt'
azureBlobCall("https://accountName.blob.core.windows.net/test/blob", "PUT", key, 
              headers = c("x-ms-blob-type"="BlockBlob"), requestBody = upload_file("blob.txt"))
# deletes the container named 'test' 
azureBlobCall("https://accountName.blob.core.windows.net/test?restype=container", "DELETE", key)