title: Error installing PKI package in R
body: <p>I'd like to publish a slidify presentation in RPubs but it requires PKI and rsconnect packages.</p>
  
  <p>I'm having this error message when trying to install PKI package in R</p>
  
  <pre><code>Installing package into ‘/home/juanchi/R/x86_64-pc-linux-gnu-library/3.2’
  (as ‘lib’ is unspecified)
  probando la URL 'http://cran.rstudio.com/src/contrib/PKI_0.1-1.tar.gz'
  Content type 'application/x-gzip' length 20334 bytes (19 KB)
  ==================================================
  downloaded 19 KB
  
  * installing *source* package ‘PKI’ ...
  ** package ‘PKI’ successfully unpacked and MD5 sums checked
  ** libs
  gcc -std=gnu99 -I/usr/share/R/include -DNDEBUG      -fpic  -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -g  -c asn1.c -o asn1.o
  gcc -std=gnu99 -I/usr/share/R/include -DNDEBUG      -fpic  -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -g  -c init.c -o init.o
  In file included from init.c:1:0:
  pki.h:11:25: fatal error: openssl/err.h: No existe el archivo o el directorio
   #include &lt;openssl/err.h&gt;
                           ^
  compilation terminated.
  /usr/lib/R/etc/Makeconf:134: recipe for target 'init.o' failed
  make: *** [init.o] Error 1
  ERROR: compilation failed for package ‘PKI’
  * removing ‘/home/juanchi/R/x86_64-pc-linux-gnu-library/3.2/PKI’
  Warning in install.packages :
    installation of package ‘PKI’ had non-zero exit status
  </code></pre>
  
  <p>with this session Info:</p>
  
  <pre><code>&gt; sessionInfo()
  R version 3.2.0 (2015-04-16)
  Platform: x86_64-pc-linux-gnu (64-bit)
  Running under: Ubuntu 15.04
  
  locale:
   [1] LC_CTYPE=pt_BR.UTF-8       LC_NUMERIC=C               LC_TIME=pt_BR.UTF-8       
   [4] LC_COLLATE=es_ES.UTF-8     LC_MONETARY=pt_BR.UTF-8    LC_MESSAGES=es_ES.UTF-8   
   [7] LC_PAPER=pt_BR.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
  [10] LC_TELEPHONE=C             LC_MEASUREMENT=pt_BR.UTF-8 LC_IDENTIFICATION=C       
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base     
  
  other attached packages:
  [1] devtools_1.8.0
  
  loaded via a namespace (and not attached):
   [1] httr_0.6.1        magrittr_1.5      rversions_1.0.0   htmltools_0.2.6   tools_3.2.0      
   [6] RCurl_1.95-4.7    yaml_2.1.13       memoise_0.2.1     stringi_0.4-1     rmarkdown_0.6.2.2
  [11] git2r_0.10.1      stringr_1.0.0     digest_0.6.8      bitops_1.0-6      XML_3.98-1.1    
  </code></pre>
  
  <p>Does someone knows what's happen here?</p>