TwitteR、ROAuth和Windows:注册确定，但证书验证失败

Question

我正试图通过twitteR获得大量推特用户的追随者。在我看来，许多other questions贴出的文章对我来说是非常有用的，但似乎没有一个与我的问题直接相关。

我可以将我的OAuth凭证注册到twitter会话，但是我似乎什么也做不了，我只收到了这样的消息：

Error in function (type, msg, asError = TRUE) : SSL certificate problem, verify that the CA cert is OK. Details: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify fail

当我使用twitteR函数而不使用OAuth时，它们可以很好地工作，没有错误或警告，但我遇到了限制和受保护的帐户，我认为使用OAuth可以避免这种情况。

以下是详细信息：

library(twitteR)
library(ROAuth)
library(RCurl)
#
# Here's how I register my credentials
#
requestURL <-  "https://api.twitter.com/oauth/request_token"
accessURL =    "https://api.twitter.com/oauth/access_token"
authURL =      "https://api.twitter.com/oauth/authorize"
consumerKey =   "------------"
consumerSecret = "-----------"
twitCred <- OAuthFactory$new(consumerKey=consumerKey,
                             consumerSecret=consumerSecret,
                             requestURL=requestURL,
                             accessURL=accessURL,
                             authURL=authURL)
download.file(url="http://curl.haxx.se/ca/cacert.pem",
              destfile="cacert.pem")
twitCred$handshake(cainfo="cacert.pem")
To enable the connection, please direct your web browser to: 
https://api.twitter.com/oauth/authorize?oauth_token=xxxx
When complete, record the PIN given to you and provide it here: xxxxxx
registerTwitterOAuth(twitCred)
[1] TRUE
# so the OAuth bit appears to be ok...
#
# save it for a future sessions...
save(list="twitCred", file="twitteR_credentials")
# works, in future I can just
load("twitteR_credentials")
registerTwitterOAuth(twitCred)
#
# try to get follower numbers, here's where it goes south
me <- getUser("Rbloggers")
me$followersCount
Error in function (type, msg, asError = TRUE)  :
SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
#
# another method, same problem
getUser("Rbloggers")$followersCount
Error in function (type, msg, asError = TRUE)  : 
SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
# 
# Here are the packages and versions I'm using
sessionInfo() 
R version 2.14.1 (2011-12-22)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_Australia.1252  LC_CTYPE=English_Australia.1252   
[3] LC_MONETARY=English_Australia.1252 LC_NUMERIC=C                      
[5] LC_TIME=English_Australia.1252    

attached base packages:
[1] stats4    stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] ROAuth_0.9.2      digest_0.5.1      twitteR_0.99.19   rjson_0.2.6       RCurl_1.91-1.1   
 [6] bitops_1.0-4.1    igraph_0.5.5-4    topicmodels_0.1-4 tm_0.5-7          slam_0.1-23      
[11] modeltools_0.2-18 lasso2_1.2-12    

loaded via a namespace (and not attached):
[1] tools_2.14.1

在注册凭据之后，如何使twitteR函数工作？

UPDATE：尝试@Btibert3 3的建议也会出现同样的错误：

> ## Authenticate with Twitter = this is an important peice of code
> registerTwitterOAuth(cred)
[1] TRUE
> ##########################################################################
> ## lets test out what our session limits look like
> ##########################################################################
> rate.limit <- getCurRateLimitInfo()
Error in function (type, msg, asError = TRUE)  : 
  SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

UPDATE遵循@flz关于在任何地方添加cainfo="cacert.pem"的建议，解决了我的问题：

rate.limit <- getCurRateLimitInfo( cainfo="cacert.pem")
rate.limit
                             resource limit remaining               reset
1                  /lists/subscribers   180       180 2013-03-27 09:35:37
2                         /lists/list    15        15 2013-03-27 09:35:37
3                  /lists/memberships    15        15 2013-03-27 09:35:37
4                   /lists/ownerships    15        15 2013-03-27 09:35:37
5                /lists/subscriptions    15        15 2013-03-27 09:35:37
6                      /lists/members   180       180 2013-03-27 09:35:37
7             /lists/subscribers/show    15        15 2013-03-27 09:35:37
8                     /lists/statuses   180       180 2013-03-27 09:35:37
9                         /lists/show    15        15 2013-03-27 09:35:37
10                /lists/members/show    15        15 2013-03-27 09:35:37
11     /application/rate_limit_status   180       179 2013-03-27 09:35:37 (etc)

会话信息：

sessionInfo()
R version 2.15.3 (2013-03-01)
Platform: x86_64-w64-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] ROAuth_0.9.2   digest_0.6.3   twitteR_1.1.0  rjson_0.2.12   RCurl_1.95-4.1 bitops_1.0-5  

loaded via a namespace (and not attached):
[1] tools_2.15.3

Answer 1

尝试：

getUser("Rbloggers")$followersCount
Error in function (type, msg, asError = TRUE)  : 
  SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
getUser("Rbloggers",cainfo="cacert.pem")$followersCount
[1] 2752

每个get/update操作都需要在后面追加一个cainfo="cacert.pem"。太烦人了。

Answer 2

我在过去曾收到过您在上面描述的错误，但这对我来说是有效的。

#=======================================================================================
## ON windows, we need to dowload the certificate for OAUTH
## NOTE:  you will need to setup an app on Twitter
## dev.twitter.com <- get your KEY/SECRET
#=======================================================================================


##########################################################################
## Load packages
##########################################################################

library(twitteR)
library(ROAuth)

## set the directory
setwd("~/your/directory/here")


## Windows users need to get this file
download.file(url="http://curl.haxx.se/ca/cacert.pem", destfile="cacert.pem")



##########################################################################
## Authenticate with Twitter
##########################################################################

## authenticate with the API
## requires that you have registered an app
KEY <- "KEY"
SECRET <-"SECRET"


## create an object that will save the authenticated onbject -- we can for later sessions
## will need to navigate to website and type in data to generate the file
## NOTE:  Only need to do this part once!!!
cred <- OAuthFactory$new(consumerKey = KEY, 
    consumerSecret = SECRET,
    requestURL = "https://api.twitter.com/oauth/request_token", 
    accessURL = "https://api.twitter.com/oauth/access_token", 
    authURL = "https://api.twitter.com/oauth/authorize")
cred$handshake(cainfo="cacert.pem")


## load the cred object in later sessions and simply pass to the registerTwitterOAuth
## After this file is saved, you only need to load the cred object back into memory
save(cred, file="twitter authentication.Rdata")


## Authenticate with Twitter = this is an important peice of code
registerTwitterOAuth(cred)


##########################################################################
## lets test out what our session limits look like
##########################################################################
rate.limit <- getCurRateLimitInfo()

## If return 350, Authenticated session = more API calls allowed / hour
rate.limit$hourlyLimit
rate.limit$remainingHits
rate.limit$resetTime

Answer 3

UPDATE --这是一个临时解决方案，请参阅@flz的答案和我编辑的问题，以获得最终解决方案。

自从我发布了这个问题之后，我就一直用这个简单的循环作为解决办法(仍然欢迎适当的解决方案！)这需要很长时间，但至少会给我数据。也许其他人会发现它也是有用的。

# load library
library(twitteR)
#
# Search Twitter for your term
s <- searchTwitter('#rstats', n=1500) 
# convert search results to a data frame
df <- do.call("rbind", lapply(s, as.data.frame)) 
# extract the usernames
users <- unique(df$screenName)
users <- sapply(users, as.character)
# make a data frame for the loop to work with 
users.df <- data.frame(users = users, 
                       followers = "", stringsAsFactors = FALSE)
#
# loop to populate users$followers with follower 
# count obtained from Twitter API
for (i in 1:nrow(users.df)) 
    {
    # tell the loop to skip a user if their account is protected 
    # or some other error occurs  
    result <- try(getUser(users.df$users[i])$followersCount, silent = TRUE);
    if(class(result) == "try-error") next;
    # get the number of followers for each user
    users.df$followers[i] <- getUser(users.df$users[i])$followersCount
    # tell the loop to pause for 60 s between iterations to 
    # avoid exceeding the Twitter API request limit
    print('Sleeping for 60 seconds...')
    Sys.sleep(60); 
    }
#
# Now inspect users.df to see the follower data