[PATCH] crypto: lib/sha256 - add sha256_value function

From: Chen Li
Date: Fri Aug 06 2021 - 23:05:10 EST


Add a function sha256_value() which accepts a string and store SHA256 hash
of this string into dest.

Signed-off-by: Chen Li <chenli@xxxxxxxxxxxxx>
---
include/crypto/sha2.h | 1 +
lib/crypto/sha256.c | 23 +++++++++++++++++++++++
2 files changed, 24 insertions(+)

diff --git a/include/crypto/sha2.h b/include/crypto/sha2.h
index 2838f529f31e..ce17954cab38 100644
--- a/include/crypto/sha2.h
+++ b/include/crypto/sha2.h
@@ -115,6 +115,7 @@ static inline void sha256_init(struct sha256_state *sctx)
void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len);
void sha256_final(struct sha256_state *sctx, u8 *out);
void sha256(const u8 *data, unsigned int len, u8 *out);
+int sha256_value(u8 **dest, const u8 *src);

static inline void sha224_init(struct sha256_state *sctx)
{
diff --git a/lib/crypto/sha256.c b/lib/crypto/sha256.c
index 72a4b0b1df28..ce1de7a3e32e 100644
--- a/lib/crypto/sha256.c
+++ b/lib/crypto/sha256.c
@@ -13,6 +13,8 @@

#include <linux/bitops.h>
#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
#include <linux/module.h>
#include <linux/string.h>
#include <crypto/sha2.h>
@@ -206,4 +208,25 @@ void sha256(const u8 *data, unsigned int len, u8 *out)
}
EXPORT_SYMBOL(sha256);

+int sha256_value(u8 **dest, const u8 *src)
+{
+ u8 out[SHA256_DIGEST_SIZE];
+ int i, k;
+ unsigned char hex[2];
+
+ *dest = kvmalloc(sizeof(u8) * (SHA256_BLOCK_SIZE + 1), GFP_KERNEL);
+ if (ZERO_OR_NULL_PTR(*dest))
+ return -ENOMEM;
+ sha256(src, strlen(src), out);
+
+ for (i = 0, k = 0; i < SHA256_DIGEST_SIZE; i++) {
+ sprintf(hex, "%02x", out[i]);
+ (*dest)[k++] = hex[0];
+ (*dest)[k++] = hex[1];
+ }
+ (*dest)[k] = '\0';
+ return 0;
+}
+EXPORT_SYMBOL(sha256_value);
+
MODULE_LICENSE("GPL");
--
2.32.0.93.g670b81a890