[PATCH 7/7] crypto: lib/sha1 - fold linux/cryptohash.h into crypto/sha.h

[Eric Biggers]

From: Eric Biggers <ebiggers@xxxxxxxxxx>

<linux/cryptohash.h> sounds very generic and important, like it's the
header to include if you're doing cryptographic hashing in the kernel.
But actually it only includes the library implementation of the SHA-1
compression function (not even the full SHA-1).  This should basically
never be used anymore; SHA-1 is no longer considered secure, and there
are much better ways to do cryptographic hashing in the kernel.

Remove this header and fold it into <crypto/sha.h> which already
contains constants and functions for SHA-1 (along with SHA-2).

Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
 crypto/sha1_generic.c      |  1 -
 drivers/char/random.c      |  2 +-
 include/crypto/sha.h       | 10 ++++++++++
 include/linux/cryptohash.h | 18 ------------------
 include/linux/filter.h     |  2 +-
 lib/sha1.c                 |  2 +-
 6 files changed, 13 insertions(+), 22 deletions(-)
 delete mode 100644 include/linux/cryptohash.h

diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
index a16d9787dcd2c1..1d43472fecbde1 100644
--- a/crypto/sha1_generic.c
+++ b/crypto/sha1_generic.c
@@ -15,7 +15,6 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mm.h>
-#include <linux/cryptohash.h>
 #include <linux/types.h>
 #include <crypto/sha.h>
 #include <crypto/sha1_base.h>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index a19a8984741b60..cae02b2a871c32 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -327,7 +327,6 @@
 #include <linux/spinlock.h>
 #include <linux/kthread.h>
 #include <linux/percpu.h>
-#include <linux/cryptohash.h>
 #include <linux/fips.h>
 #include <linux/ptrace.h>
 #include <linux/workqueue.h>
@@ -337,6 +336,7 @@
 #include <linux/completion.h>
 #include <linux/uuid.h>
 #include <crypto/chacha.h>
+#include <crypto/sha.h>
 
 #include <asm/processor.h>
 #include <linux/uaccess.h>
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index 5c2132c7190095..405dd20419165c 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -113,6 +113,16 @@ 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 sha1_init(__u32 *buf);
+void sha1_transform(__u32 *digest, const char *data, __u32 *W);
+
 /*
  * Stand-alone implementation of the SHA256 algorithm. It is designed to
  * have as little dependencies as possible so it can be used in the
diff --git a/include/linux/cryptohash.h b/include/linux/cryptohash.h
deleted file mode 100644
index c324ffca96e0d5..00000000000000
--- a/include/linux/cryptohash.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __CRYPTOHASH_H
-#define __CRYPTOHASH_H
-
-#include <uapi/linux/types.h>
-
-/*
- * 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 5
-#define SHA1_BLOCK_SIZE 64
-#define SHA1_WORKSPACE_WORDS 16
-void sha1_init(__u32 *buf);
-void sha1_transform(__u32 *digest, const char *data, __u32 *W);
-
-#endif
diff --git a/include/linux/filter.h b/include/linux/filter.h
index f42662adffe47f..ec45fd7992c957 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -16,11 +16,11 @@
 #include <linux/workqueue.h>
 #include <linux/sched.h>
 #include <linux/capability.h>
-#include <linux/cryptohash.h>
 #include <linux/set_memory.h>
 #include <linux/kallsyms.h>
 #include <linux/if_vlan.h>
 #include <linux/vmalloc.h>
+#include <crypto/sha.h>
 
 #include <net/sch_generic.h>
 
diff --git a/lib/sha1.c b/lib/sha1.c
index b381e8cd4fe447..49257a915bb604 100644
--- a/lib/sha1.c
+++ b/lib/sha1.c
@@ -9,7 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/bitops.h>
-#include <linux/cryptohash.h>
+#include <crypto/sha.h>
 #include <asm/unaligned.h>
 
 /*
-- 
2.26.2