Add new public function RANDOM-BYTES, an lispy wrapper over the OpenSSL RAND_bytes function.

build.xcvb

@@ -19,7 +19,8 @@
 	       (:cond ((:featurep :clisp) "ffi-buffer-clisp")
                       ((:featurep (:not :clisp)) "ffi-buffer"))
 	       "streams"
-	       "bio")
+	       "bio"
+	       "random")
   :build-depends-on ("flexi-streams" "trivial-gray-streams" "cffi")
   :supersedes-asdf ("cl+ssl")))
 

cl+ssl.asd

@@ -25,4 +25,5 @@
     #-clisp (:file "ffi-buffer")
     #+clisp (:file "ffi-buffer-clisp")
     (:file "streams")
-    (:file "bio")))
+    (:file "bio")
+    (:file "random")))

ffi.lisp

@@ -131,10 +131,6 @@
 (cffi:defcfun ("SSL_CTX_free" ssl-ctx-free)
     :void
   (ctx ssl-ctx))
-(cffi:defcfun ("RAND_seed" rand-seed)
-    :void
-  (buf :pointer)
-  (num :int))
 (cffi:defcfun ("BIO_ctrl" bio-set-fd)
     :long
   (bio :pointer)
@@ -213,6 +209,15 @@
     :void
   (fun :pointer))
 
+(cffi:defcfun ("RAND_seed" rand-seed)
+    :void
+  (buf :pointer)
+  (num :int))
+(cffi:defcfun ("RAND_bytes" rand-bytes)
+    :int
+  (buf :pointer)
+  (num :int))
+
 ;;; Funcall wrapper
 ;;;
 (defvar *socket*)

package.lisp

@@ -15,4 +15,5 @@
            #:stream-fd
            #:make-ssl-client-stream
            #:make-ssl-server-stream
-           #:use-certificate-chain-file))
+           #:use-certificate-chain-file
+           #:random-bytes))

random.lisp

@@ -0,0 +1,32 @@
+#+xcvb
+(module
+ (:depends-on ("package" "conditions" "ffi"
+                         (:cond ((:featurep :clisp) "ffi-buffer-clisp")
+                                (t "ffi-buffer"))
+                         "ffi-buffer-all")))
+
+(in-package :cl+ssl)
+
+(defun random-bytes (count)
+  "Generates COUNT cryptographically strong pseudo-random bytes. Returns
+the bytes as a SIMPLE-ARRAY with ELEMENT-TYPE '(UNSIGNED-BYTE 8). Signals
+an ERROR in case of problems, for example when the OpenSSL random number
+generator has not been seeded with enough randomness to ensure an 
+unpredictable byte sequence."
+  (let* ((result (make-array count :element-type '(unsigned-byte 8)))
+         (buf (make-buffer count))
+         (ret (with-pointer-to-vector-data (ptr buf) 
+                (rand-bytes ptr count))))
+    (when (/= 1 ret)
+      (error "RANDOM-BYTES failed: error reported by the OpenSSL RAND_bytes function. ~A."
+             (with-output-to-string (s) (write-ssl-error-queue s))))
+    (v/b-replace result buf)))
+
+;; TODO: Should we define random-specific constants and condition classes for 
+;; RAND_F_RAND_GET_RAND_METHOD, RAND_F_SSLEAY_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED
+;; (defined in the rand.h file of the OpenSSl sources)?
+;; Where to place these constants/condtitions, here or in the conditions.lisp?
+;; On the other hand, those constants are just numbers defined for C,
+;; for now we jsut report human readable strings, without possibility
+;; to distinguish these error causes programmatically.
+

streams.lisp

@@ -9,7 +9,8 @@
 (module
  (:depends-on ("package" "conditions" "ffi"
                          (:cond ((:featurep :clisp) "ffi-buffer-clisp")
-                                (t "ffi-buffer")))))
+                                (t "ffi-buffer"))
+                         "ffi-buffer-all")))
 
 (eval-when (:compile-toplevel)
   (declaim