使用与 conda 一起安装的 R 时，install.packages 不适用于代理答案

【问题标题】：install.packages doesn't work with proxy when using R installed with conda使用与 conda 一起安装的 R 时，install.packages 不适用于代理
【发布时间】：2017-08-05 23:39:45
【问题描述】：

我正在使用 Linux 服务器 RHEL6 并安装了 anaconda。我有以下设置

 conda-env version : 4.3.13
 conda-build version : 2.1.4
 python version : 2.7.13.final.0
 rpy2 : 2.8.5

我安装了 rpy2 以在 python 中使用 R

> R.home()
[1] "/anaconda2/envs/py27CCA/lib/R"
> R.version 
version.string R version 3.3.2 (2016-10-31)

我通过以下方式设置代理：

> Sys.getenv("https_proxy")
[1] "https://login:pwd@xxx.net:8080/"

但是下载 R 包不起作用

> options(internet.info = 0)
> install.packages("httr")

* error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
....
Warning: unable to access index for repository https://stat.ethz.ch/CRAN/src/contrib:
  cannot download all files
Warning message:
package 'httr' is not available (for R version 3.3.2)

但如果我使用完全相同的代理设置安装了相同的独立 R 版本，它可以正常工作

> R.version 
version.string R version 3.3.2 (2016-10-31) 
> install.packages("httr")
...
** testing if installed package can be loaded
* DONE (httr)
Making 'packages.html' ... done
...

是什么造成了这个问题？我检查了 openssl 版本，我在 2 个环境中有相同的版本！此链接解释了此类代理问题link stackoverflow discussion 的可能原因。

如果我在 python 中执行此操作，我会遇到相同的问题和错误消息

>>> from rpy2.robjects.packages import importr
>>> utils = importr('utils')
>>> utils.install_packages('httr')

【问题讨论】：

不要将https_proxy设置为https://login:pwd@xxx.ch.doleni.net:8080/，而是尝试将其设置为http://login:pwd@xxx.ch.doleni.net:8080/
@Nehal J Wani：这项工作，谢谢。当我们使用 conda 时，您了解为什么需要此设置吗？顺便说一句，如果您发表评论作为答案，我将标记为解决我的问题。谢谢

标签： r linux conda rpy2 install.packages

【解决方案1】：

TL;DR:

而不是将https_proxy 设置为...：

https://login:pwd@xxx.net:8080/

...尝试将其设置为：

http://login:pwd@xxx.net:8080/

此外，通过这样做，如果有人嗅探您与代理服务器建立的初始连接的数据包，您将泄露您的凭据。进一步阅读以了解更多信息。

IMO，这个问题与 Conda 无关。这是一个非常常见的错误，我发现它在互联网上非常普遍。

之所以会发生这种情况，是因为“HTTPS 代理”一词的混淆。

IIUC，这两个环境变量是什么意思：

http_proxy|HTTP_PROXY：您希望使用的代理服务器，适用于所有您对外界的 HTTP 请求。

https_proxy|HTTPS_PROXY：您希望使用的代理服务器，用于您对外界的所有 HTTPS 请求。

http(s?)://proxy.mydomain.com:3128
 ^^^^^          ^^^^^         ^^^^   
   |              |             |    
scheme    proxy domain/IP   proxy port

现在，理想情况下，这些环境变量的值中指定的方案决定了客户端应该连接到代理服务器的协议。

让我们看一下 HTTPS 代理的定义。从手册页窃取curl >= v7.53：

An HTTPS proxy receives all transactions over an SSL/TLS connection.
Once a secure connection with the proxy is established, the user agent
uses the proxy as usual, including sending CONNECT requests to instruct
the proxy to establish a [usually secure] TCP tunnel with an origin
server. HTTPS proxies protect nearly all aspects of user-proxy
communications as opposed to HTTP proxies that receive all requests
(including CONNECT requests) in vulnerable clear text.

With HTTPS proxies, it is possible to have two concurrent _nested_
SSL/TLS sessions: the "outer" one between the user agent and the proxy
and the "inner" one between the user agent and the origin server
(through the proxy). This change adds supports for such nested sessions
as well.

让我们试试看例子(curl >= v7.53):

在这里，我将使用不支持通过 SSL/TLS 进行客户端-代理连接的代理。

确保事先没有设置代理环境变量：

((curl-7_53_1))$ env | grep -i proxy
((curl-7_53_1))$

env：http_proxy，outer_scheme：http，inner_scheme：http

((curl-7_53_1))$ http_proxy="http://proxy.mydomain.com:3128" ./src/curl -s -vvv http://stackoverflow.com -o /dev/null
* Rebuilt URL to: http://stackoverflow.com/
*   Trying 10.1.1.7...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (10.1.1.7) port 3128 (#0)
> GET http://stackoverflow.com/ HTTP/1.1
> Host: stackoverflow.com
> User-Agent: curl/7.53.1-DEV
> Accept: */*
> Proxy-Connection: Keep-Alive
>
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Cache-Control: private
< Content-Type: text/html; charset=utf-8
< X-Frame-Options: SAMEORIGIN
< X-Request-Guid: 539728ee-a91d-4964-bc7e-1d21d91a6f1d
< Content-Length: 228257
< Accept-Ranges: bytes
< Date: Thu, 16 Mar 2017 05:19:31 GMT
< X-Served-By: cache-jfk8137-JFK
< X-Cache: MISS
< X-Cache-Hits: 0
< X-Timer: S1489641571.098286,VS0,VE7
< Vary: Fastly-SSL
< X-DNS-Prefetch-Control: off
< Set-Cookie: prov=b2e2dcb8-c5ff-21d9-5712-a0e012573aa6; domain=.stackoverflow.com; expires=Fri, 01-Jan-2055 00:00:00 GMT; path=/; HttpOnly
< X-Cache: MISS from proxy.mydomain.com
< X-Cache-Lookup: MISS from proxy.mydomain.com:3128
< Via: 1.1 varnish, 1.0 proxy.mydomain.com (squid)
* HTTP/1.0 connection set to keep alive!
< Connection: keep-alive
<
{ [2816 bytes data]
* Connection #0 to host proxy.mydomain.com left intact

env：http_proxy，outer_scheme：https，inner_scheme：http

((curl-7_53_1))$ http_proxy="https://proxy.mydomain.com:3128" ./src/curl -s -vvv http://stackoverflow.com -o /dev/null
* Rebuilt URL to: http://stackoverflow.com/
*   Trying 10.1.1.7...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (10.1.1.7) port 3128 (#0)
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: none
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
* Closing connection 0

env：https_proxy，outer_scheme：http，inner_scheme：https

((curl-7_53_1))$ https_proxy="http://proxy.mydomain.com:3128" ./src/curl -s -vvv https://stackoverflow.com -o /dev/null
* Rebuilt URL to: https://stackoverflow.com/
*   Trying 10.1.1.7...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (10.1.1.7) port 3128 (#0)
* Establish HTTP proxy tunnel to stackoverflow.com:443
> CONNECT stackoverflow.com:443 HTTP/1.1
> Host: stackoverflow.com:443
> User-Agent: curl/7.53.1-DEV
> Proxy-Connection: Keep-Alive
>
< HTTP/1.0 200 Connection established
<
* Proxy replied OK to CONNECT request
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: none
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS handshake, Server hello (2):
{ [108 bytes data]
* TLSv1.2 (IN), TLS handshake, Certificate (11):
{ [3044 bytes data]
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
{ [333 bytes data]
* TLSv1.2 (IN), TLS handshake, Server finished (14):
{ [4 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
} [70 bytes data]
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
} [1 bytes data]
* TLSv1.2 (OUT), TLS handshake, Finished (20):
} [16 bytes data]
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
{ [1 bytes data]
* TLSv1.2 (IN), TLS handshake, Finished (20):
{ [16 bytes data]
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* ALPN, server accepted to use http/1.1
* Server certificate:
*  subject: C=US; ST=NY; L=New York; O=Stack Exchange, Inc.; CN=*.stackexchange.com
*  start date: May 21 00:00:00 2016 GMT
*  expire date: Aug 14 12:00:00 2019 GMT
*  subjectAltName: host "stackoverflow.com" matched cert's "stackoverflow.com"
*  issuer: C=US; O=DigiCert Inc; OU=www.digicert.com; CN=DigiCert SHA2 High Assurance Server CA
*  SSL certificate verify ok.
} [5 bytes data]
> GET / HTTP/1.1
> Host: stackoverflow.com
> User-Agent: curl/7.53.1-DEV
> Accept: */*
>
{ [5 bytes data]
< HTTP/1.1 200 OK
< Cache-Control: private
< Content-Type: text/html; charset=utf-8
< X-Frame-Options: SAMEORIGIN
< X-Request-Guid: 96f8fe3c-058b-479e-8ef2-db6d09f485d3
< Content-Length: 226580
< Accept-Ranges: bytes
< Date: Thu, 16 Mar 2017 05:20:39 GMT
< Via: 1.1 varnish
< Connection: keep-alive
< X-Served-By: cache-jfk8135-JFK
< X-Cache: MISS
< X-Cache-Hits: 0
< X-Timer: S1489641639.425108,VS0,VE9
< Vary: Fastly-SSL
< X-DNS-Prefetch-Control: off
< Set-Cookie: prov=f1a401f1-f1a0-5f09-66ca-9a792543ee82; domain=.stackoverflow.com; expires=Fri, 01-Jan-2055 00:00:00 GMT; path=/; HttpOnly
<
{ [2181 bytes data]
* Connection #0 to host proxy.mydomain.com left intact

env：https_proxy，outer_scheme：https，inner_scheme：https

((curl-7_53_1))$ https_proxy="https://proxy.mydomain.com:3128" ./src/curl -s -vvv https://stackoverflow.com -o /dev/null
* Rebuilt URL to: https://stackoverflow.com/
*   Trying 10.1.1.7...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (10.1.1.7) port 3128 (#0)
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: none
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
* Closing connection 0

现在，我将展示支持 SSL/TLS 连接的代理的相同输出。为了运行本地 https 代理，我安装了 squid 版本 4.0.17。我通过在/etc/hosts 中覆盖它来将proxy.mydomain.com 指向localhost。相关的 squid 配置行是：

https_port 3127 cert=/etc/squid/ssl_cert/myCA.pem

请注意，我现在没有使用任何明确指定（复杂？）的模式（sslbump/intercept/accel/tproxy）

我也已将证书添加到信任库：

sudo cp /etc/squid/ssl_cert/myCA.pem /etc/pki/ca-trust/source/anchors/mySquidCA.pem
sudo update-ca-trust

现在，进行真正的测试：

env：http_proxy，outer_scheme：https，inner_scheme：http

/t/curl-curl-7_53_1 ❯❯❯ http_proxy=https://proxy.mydomain.com:3127 ./src/curl -s -vvv http://google.com -o /dev/null
* Rebuilt URL to: http://google.com/
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (127.0.0.1) port 3127 (#0)
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS handshake, Server hello (2):
{ [86 bytes data]
* TLSv1.2 (IN), TLS handshake, Certificate (11):
{ [1027 bytes data]
* TLSv1.2 (IN), TLS handshake, Server finished (14):
{ [4 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
} [262 bytes data]
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
} [1 bytes data]
* TLSv1.2 (OUT), TLS handshake, Finished (20):
} [16 bytes data]
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
{ [1 bytes data]
* TLSv1.2 (IN), TLS handshake, Finished (20):
{ [16 bytes data]
* SSL connection using TLSv1.2 / AES256-GCM-SHA384
* Proxy certificate:
*  subject: C=IN; ST=SomeState; L=SomeLocation; O=Default Company Ltd; CN=proxy.mydomain.com; emailAddress=no-reply@gmail.com
*  start date: Mar 16 06:43:35 2017 GMT
*  expire date: Mar 16 06:43:35 2018 GMT
*  common name: proxy.mydomain.com (matched)
*  issuer: C=IN; ST=SomeState; L=SomeLocation; O=Default Company Ltd; CN=proxy.mydomain.com; emailAddress=no-reply@gmail.com
*  SSL certificate verify ok.
} [5 bytes data]
> GET http://google.com/ HTTP/1.1
> Host: google.com
> User-Agent: curl/7.53.1-DEV
> Accept: */*
> Proxy-Connection: Keep-Alive
> 
{ [5 bytes data]
< HTTP/1.1 302 Found
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Location: http://www.google.co.in/?gfe_rd=cr&ei=ejTKWLGzM-Ts8AepwJyQCg
< Content-Length: 261
< Date: Thu, 16 Mar 2017 06:45:14 GMT
< X-Cache: MISS from lenovo
< X-Cache-Lookup: MISS from lenovo:3128
< Via: 1.1 lenovo (squid/4.0.17)
< Connection: keep-alive
< 
{ [5 bytes data]
* Connection #0 to host proxy.mydomain.com left intact

env：https_proxy，outer_scheme：https，inner_scheme：https

/t/curl-curl-7_53_1 ❯❯❯ https_proxy=https://proxy.mydomain.com:3127 ./src/curl -s -vvv https://google.com -o /dev/null
* Rebuilt URL to: https://google.com/
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to proxy.mydomain.com (127.0.0.1) port 3127 (#0)
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS handshake, Server hello (2):
{ [86 bytes data]
* TLSv1.2 (IN), TLS handshake, Certificate (11):
{ [1027 bytes data]
* TLSv1.2 (IN), TLS handshake, Server finished (14):
{ [4 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
} [262 bytes data]
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
} [1 bytes data]
* TLSv1.2 (OUT), TLS handshake, Finished (20):
} [16 bytes data]
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
{ [1 bytes data]
* TLSv1.2 (IN), TLS handshake, Finished (20):
{ [16 bytes data]
* SSL connection using TLSv1.2 / AES256-GCM-SHA384
* ALPN, server did not agree to a protocol
* Proxy certificate:
*  subject: C=IN; ST=SomeState; L=SomeLocation; O=Default Company Ltd; CN=proxy.mydomain.com; emailAddress=no-reply@gmail.com
*  start date: Mar 16 06:43:35 2017 GMT
*  expire date: Mar 16 06:43:35 2018 GMT
*  common name: proxy.mydomain.com (matched)
*  issuer: C=IN; ST=SomeState; L=SomeLocation; O=Default Company Ltd; CN=proxy.mydomain.com; emailAddress=no-reply@gmail.com
*  SSL certificate verify ok.
* Establish HTTP proxy tunnel to google.com:443
} [5 bytes data]
> CONNECT google.com:443 HTTP/1.1
> Host: google.com:443
> User-Agent: curl/7.53.1-DEV
> Proxy-Connection: Keep-Alive
> 
{ [5 bytes data]
< HTTP/1.1 200 Connection established
< 
* Proxy replied OK to CONNECT request
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none
} [5 bytes data]
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS handshake, Server hello (2):
{ [102 bytes data]
* TLSv1.2 (IN), TLS handshake, Certificate (11):
{ [3757 bytes data]
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
{ [148 bytes data]
* TLSv1.2 (IN), TLS handshake, Server finished (14):
{ [4 bytes data]
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
} [70 bytes data]
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
} [1 bytes data]
* TLSv1.2 (OUT), TLS handshake, Finished (20):
} [16 bytes data]
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
{ [1 bytes data]
* TLSv1.2 (IN), TLS handshake, Finished (20):
{ [16 bytes data]
* SSL connection using TLSv1.2 / ECDHE-ECDSA-AES128-GCM-SHA256
* ALPN, server accepted to use http/1.1
* Server certificate:
*  subject: C=US; ST=California; L=Mountain View; O=Google Inc; CN=*.google.com
*  start date: Mar  9 02:43:31 2017 GMT
*  expire date: Jun  1 02:20:00 2017 GMT
*  subjectAltName: host "google.com" matched cert's "google.com"
*  issuer: C=US; O=Google Inc; CN=Google Internet Authority G2
*  SSL certificate verify ok.
} [5 bytes data]
> GET / HTTP/1.1
> Host: google.com
> User-Agent: curl/7.53.1-DEV
> Accept: */*
> 
{ [5 bytes data]
< HTTP/1.1 302 Found
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Location: https://www.google.co.in/?gfe_rd=cr&ei=hDTKWJXlMubs8Aek-6WQAg
< Content-Length: 262
< Date: Thu, 16 Mar 2017 06:45:24 GMT
< Alt-Svc: quic=":443"; ma=2592000; v="36,35,34"
< 
{ [262 bytes data]
* Connection #0 to host proxy.mydomain.com left intact

从输出中可以明显看出，在这两种情况下都首先与代理服务器进行 SSL 握手。

现在，我会咆哮一点。

许多客户端（例如：curl = 7.51.0），不支持与代理本身的 SSL/TLS 连接并引发此类错误：

$ https_proxy=https://proxy.mydomain.com:3128 curl -vvvv https://google.com
* Rebuilt URL to: https://google.com/
* Unsupported proxy scheme for 'https://proxy.mydomain.com:3128'
* Closing connection -1
curl: (7) Unsupported proxy scheme for 'https://proxy.mydomain.com:3128'

然后，有些客户端（例如 curl=7.47.0）会忽略代理 URL 中不受支持的方案，这会误导人们相信他们所完成的事情。一般来说，他们永远不会通过 SSL/TLS 连接到代理服务器，即使变量明确指定方案为“https”并回退到使用与代理服务器的未加密连接。

还有其他客户端（例如 wget v1.18），这会让我们更加困惑：

在以下情况下，错误消息具有误导性，因为即使对于向外部世界（如上面的示例所示，使用 squid），因为我们希望与代理服务器的连接通过 SSL/TLS。
```
http_proxy=https://proxy.mydomain.com:3128 wget http://google.com
Error in proxy URL https://proxy.mydomain.com:3128: Must be HTTP.
```

不仅如此，混乱还会增加，当它回落时，我们认为它可能正在连接到代理服务器 SSL/TLS，实际上不是，也让我们认为方案中的 https:// 仅在内部协议为还有 https://

https_proxy=https://proxy.mydomain-research.com:3128 wget https://google.com
--2017-03-16 11:21:06--  https://google.com/
Resolving proxy.mydomain-research.com (proxy.mydomain-research.com)... 10.1.1.7
Connecting to proxy.mydomain-research.com (proxy.mydomain-research.com)|10.1.1.7|:3128... connected.
Proxy request sent, awaiting response... 301 Moved Permanently
Location: https://www.google.com/ [following]
--2017-03-16 11:21:07--  https://www.google.com/
Connecting to proxy.mydomain-research.com (proxy.mydomain-research.com)|10.1.1.7|:3128... connected.
Proxy request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Saving to: ‘index.html’

如需了解有关通过 TLS/SSL 与代理服务器连接（和不连接）的安全方面的更多信息，请访问：https://security.stackexchange.com/a/61336/114965

【讨论】：