gnu: Add sshguard.

* gnu/packages/admin.scm (sshguard): New variable.

Change-Id: I551771ff49af3e852322f2518f0758494aaedee3
Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>

gnu/packages/admin.scm

@@ -6349,3 +6349,26 @@ versions of @command{find}, including POSIX, GNU, and *BSD find.")
 their content instead of their file names.  It is useful for compressing
 backup directories or just finding duplicate files.")
     (license license:gpl2+)))
+
+(define-public sshguard
+  (package
+    (name "sshguard")
+    (version "2.4.3")
+    (source
+      (origin
+        (method git-fetch)
+        (uri (git-reference
+               (url "https://bitbucket.org/sshguard/sshguard")
+               (commit (string-append "v" version))))
+        (file-name (git-file-name name version))
+        (sha256 (base32 "1dkijr287zpwdz1bjdchxzmwf1sk6vzpkycz1skm25lkaba6nd9r"))))
+    (build-system gnu-build-system)
+    (native-inputs
+      (list autoconf automake bison flex python-docutils))
+    (home-page "https://sshguard.net/")
+    (synopsis "Daemon to blocks SSH brute-force attacks")
+    (description
+     "SSHGuard protects hosts from brute-force attacks against SSH and other
+services.  It aggregates system logs and blocks repeat offenders using one of
+several firewall backends.")
+    (license license:isc)))