re-add command krng-add-entropy

3 files changed, 53 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index b649601..7484342 100644
--- a/.gitignore
+++ b/.gitignore
@@ -40,3 +40,4 @@ rootfs/_build/
 stack.yaml.lock
 samizdat.iso
 TEST_CHILD.*.log
+krng-add-entropy
diff --git a/Makefile b/Makefile
index 80f3ab3..9398787 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 prefix?=/usr/local
 
-cc_files=wait_for_files samizdat-pinentry
+cc_files=wait_for_files samizdat-pinentry krng-add-entropy
 cpp_files=dynmenu
 
 compiled_programs=${cc_files} ${cpp_files}
@@ -28,6 +28,8 @@ dynmenu: src/dynmenu.cpp | build-deps
         $(CXX) $(CFLAGS) $< -o $@ -lcurses
 samizdat-pinentry: src/samizdat-pinentry.c | build-deps
         $(CC) $(CFLAGS)  $< -o $@ -lcurses
+krng-add-entropy: src/krng-add-entropy.c | build-deps
+        $(CC) $(CFLAGS)  $< -o $@
 wait_for_files: src/wait_for_files.c | build-deps
         $(CC) $(CFLAGS)  $< -o $@
 
diff --git a/src/krng-add-entropy.c b/src/krng-add-entropy.c
new file mode 100644
index 0000000..fc81d29
--- /dev/null
+++ b/src/krng-add-entropy.c
@@ -0,0 +1,49 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <asm/types.h>
+#include <linux/random.h>
+#include <errno.h>
+#include <error.h>
+#include <string.h>
+
+char *program_name;
+void usage() 
+{
+  error(1, 0, "usage: %s [--bytes] <bits>", program_name);
+}
+
+int main(int argc, char **argv)
+{
+  argc--, program_name = *argv++;
+  int multiplier = 1;
+  int bits;
+  while (argc > 1) {
+    if (!strcmp(*argv, "--bytes")) {
+      multiplier = 8;
+    } else {
+      usage();
+    }
+    argc--, argv++;
+  }
+  if ((argc != 1) || (bits = multiplier * atoi(*argv)) <= 0)
+    usage();
+
+  struct rand_pool_info *output;
+  int fd = open("/dev/random", O_WRONLY);
+  if (fd < 0)
+    error(1, errno, "opening /dev/random");
+
+  output = (struct rand_pool_info *) malloc(sizeof(struct rand_pool_info));
+  output -> entropy_count = bits;
+  output -> buf_size = 0;
+
+  int r = ioctl(fd, RNDADDENTROPY, output);
+  if (r < 0)
+    error(1, errno, "ioctl(RNDADDENTROPY)");
+
+  return 0;
+}