LRNG: Backport to 4.19 kernel

- Required to fix compilation of LRNG on 4.19 kernel

Change-Id: I6a25f657d3ab2ee3f9e44cbe5a9c0314d6ca905f
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>

drivers/char/lrng/lrng_drng_kcapi.c

@@ -38,7 +38,7 @@ static int lrng_kcapi_drng_seed_helper(void *drng, const u8 *inbuf,
 	struct crypto_shash *hash_tfm = lrng_drng_info->hash_tfm;
 	SHASH_DESC_ON_STACK(shash, hash_tfm);
 	u32 digestsize;
-	u8 digest[HASH_MAX_DIGESTSIZE] __aligned(8);
+	u8 digest[64] __aligned(8);
 	int ret;
 
 	if (!hash_tfm)

drivers/char/lrng/lrng_es_irq.c

@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/preempt.h>
 #include <asm/irq_regs.h>
 #include <asm/ptrace.h>
 #include <crypto/hash.h>

drivers/char/lrng/lrng_es_mgr.c

@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/preempt.h>
 #include <linux/random.h>
 #include <linux/utsname.h>
 #include <linux/workqueue.h>

drivers/char/lrng/lrng_interface_random_kernel.c

@@ -32,6 +32,7 @@ int __init rand_initialize(void)
 {
 	return lrng_rand_initialize();
 }
+early_initcall(rand_initialize);
 
 bool lrng_ready_list_has_sleeper(void)
 {

drivers/char/lrng/lrng_internal.h

@@ -6,8 +6,7 @@
 #ifndef _LRNG_INTERNAL_H
 #define _LRNG_INTERNAL_H
 
-#include <crypto/sha1.h>
-#include <crypto/sha2.h>
+#include <crypto/sha.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -15,6 +14,11 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
+#define arch_get_random_seed_long_early arch_get_random_seed_long
+#define arch_get_random_long_early arch_get_random_long
+
+#define kfree_sensitive kzfree
+
 /*************************** General LRNG parameter ***************************/
 
 /* Security strength of LRNG -- this must match DRNG security strength */

drivers/char/lrng/lrng_sha1.c

@@ -30,7 +30,7 @@ static void lrng_sha1_block_fn(struct sha1_state *sctx, const u8 *src,
 	u32 temp[SHA1_WORKSPACE_WORDS];
 
 	while (blocks--) {
-		sha1_transform(sctx->state, src, temp);
+		sha_transform(sctx->state, src, temp);
 		src += SHA1_BLOCK_SIZE;
 	}
 	memzero_explicit(temp, sizeof(temp));

drivers/char/lrng/lrng_sha256.c

@@ -10,7 +10,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/lrng.h>
-#include <crypto/sha.h>
+#include <linux/sha256.h>
 
 #include "lrng_sha.h"
 

include/crypto/sha.h

@@ -112,4 +112,15 @@ extern int crypto_sha512_update(struct shash_desc *desc, const u8 *data,
 
 extern int crypto_sha512_finup(struct shash_desc *desc, const u8 *data,
 			       unsigned int len, u8 *hash);
+ 
+/*
+ * An implementation of SHA-1's compression function.  Don't use in new code!
+ * You shouldn't be using SHA-1, and even if you *have* to use SHA-1, this isn't
+ * the correct way to hash something with SHA-1 (use crypto_shash instead).
+ */
+#define SHA1_DIGEST_WORDS	(SHA1_DIGEST_SIZE / 4)
+#define SHA1_WORKSPACE_WORDS	16
+void sha_init(__u32 *buf);
+void sha_transform(__u32 *digest, const char *data, __u32 *W);
+
 #endif

lib/Kconfig

@@ -636,3 +636,6 @@ config GENERIC_LIB_CMPDI2
 
 config GENERIC_LIB_UCMPDI2
 	bool
+
+config CRYPTO_LIB_SHA256
+	tristate

lib/Makefile

@@ -291,3 +291,6 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
 obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
 obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
 obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
+
+obj-$(CONFIG_CRYPTO_LIB_SHA256) += libsha256.o
+libsha256-y := sha256.o