How to authenticate to grails from R using RCurl

	authenticate <- function(baseUrl="http://localhost:8080/GrailsApp/", user, password, verbose=F){
	require(RCurl)
	loginUrl = paste(baseUrl, "login/auth", sep="")
	authenticateUrl = paste(baseUrl, "j_spring_security_check", sep="")
	cat(paste("trying to authenticate user", user))
	agent="Mozilla/5.0"
	#Set RCurl pars
	curl = getCurlHandle()
	curlSetOpt(ssl.verifypeer=FALSE, timeout=60, cookiefile=tempfile(), cookiejar=tempfile(), useragent = agent, followlocation = TRUE, curl=curl, verbose=verbose)
	#open login page
	getURL(loginUrl, curl=curl)
	#Post login form
	postForm(authenticateUrl, .params= list(j_username=user, j_password=password), curl=curl, style="POST")
	return(curl)
	}

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The trick is to open the login page before actually trying to post the login data. I assume something is stored in the cookie, but I only know this is how it works. See also my question on stackoverflow: http://stackoverflow.com/questions/20355874/how-to-use-rcurl-to-authenticate-to-spring-security-grails-app/20370222#20370222