Submitted By: Robert Connolly <robert at linuxfromscratch dot org> (ashes)
Date: 2006-06-04
Initial Package Version: 2.6.16.19
Upstream Status: Rejected
Origin: This patch is based on a portion of the Grsecurity kernel patch:
	http://www.grsecurity.net/
Description: This patch adds configuration options to increase the entropy
pool size of the Linux kernel.

Also see: http://www.linuxfromscratch.org/hints/downloads/files/entropy.txt

diff -Naur linux-2.6.16.19.orig/drivers/char/Kconfig linux-2.6.16.19/drivers/char/Kconfig
--- linux-2.6.16.19.orig/drivers/char/Kconfig	2006-05-31 00:31:44.000000000 +0000
+++ linux-2.6.16.19/drivers/char/Kconfig	2006-06-04 06:43:45.000000000 +0000
@@ -653,6 +653,34 @@
 
 	  If you're not sure, say N.
 
+config SELECT_ENTROPY_POOL_SIZE
+	def_bool y
+choice
+	prompt "Entropy pool size"
+	default SMALL_ENTROPY_POOL
+
+config SMALL_ENTROPY_POOL_SIZE
+	bool "Small size entropy pool"
+	help
+	  This option keeps entropy DEFAULT_POOL_SIZE at the default of
+	  512 bytes.
+
+config MEDIUM_ENTROPY_POOL_SIZE
+	bool "Medium size entropy pool"
+	help
+	  The option increases the DEFAULT_POOL_SIZE from 512 to 1024 bytes,
+	  the SECONDARY_POOL_SIZE from 128 to 256 bytes, and BATCH_ENTROPY_SIZE
+	  from 256 to 512 bytes.
+
+config LARGE_ENTROPY_POOL_SIZE
+	bool "Large size entropy pool"
+	help
+	  The option increases the DEFAULT_POOL_SIZE from 512 to 2048 bytes,
+	  the SECONDARY_POOL_SIZE from 128 to 256 bytes, and BATCH_ENTROPY_SIZE
+	  from 256 to 512 bytes.
+
+endchoice
+
 config HW_RANDOM
 	tristate "Intel/AMD/VIA HW Random Number Generator support"
 	depends on (X86 || IA64) && PCI
diff -Naur linux-2.6.16.19.orig/drivers/char/random.c linux-2.6.16.19/drivers/char/random.c
--- linux-2.6.16.19.orig/drivers/char/random.c	2006-05-31 00:31:44.000000000 +0000
+++ linux-2.6.16.19/drivers/char/random.c	2006-06-04 06:45:33.000000000 +0000
@@ -249,8 +249,17 @@
 /*
  * Configuration information
  */
+#if defined(CONFIG_MEDIUM_ENTROPY_POOL_SIZE)
+#define INPUT_POOL_WORDS 256
+#define OUTPUT_POOL_WORDS 64
+#elif defined(CONFIG_LARGE_ENTROPY_POOL_SIZE)
+#define INPUT_POOL_WORDS 512
+#define OUTPUT_POOL_WORDS 128
+#else
+/* Default to vanilla pool size. */
 #define INPUT_POOL_WORDS 128
 #define OUTPUT_POOL_WORDS 32
+#endif
 #define SEC_XFER_SIZE 512
 
 /*