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crypto: lib/sha256 - add sha256_value function

PATCH In review Chen Li 2 participants 2 messages Aug 7, 2021

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Crypto API Crypto library
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Chen Li

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#0 lore raw

PATCH 1/1 crypto: lib/sha256 - add sha256_value function

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

Signed-off-by Chen Li <[email protected]>
---
 include/crypto/sha2.h |  1 +
 lib/crypto/sha256.c   | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)
include/crypto/sha2.h +1 -0
index 2838f529f31e..ce17954cab38 100644
@@ -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)
 {
lib/crypto/sha256.c +23 -0
index 72a4b0b1df28..ce1de7a3e32e 100644
@@ -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");
Signature · 1 line
2.32.0.93.g670b81a890
maintainer
#1 lore raw
Quoted 48 lines · Chen Li

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

Signed-off-by Chen Li <[email protected]>
---
 include/crypto/sha2.h |  1 +
 lib/crypto/sha256.c   | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)
include/crypto/sha2.h +1 -0
index 2838f529f31e..ce17954cab38 100644
@@ -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)
 {
lib/crypto/sha256.c +12 -0
index 72a4b0b1df28..ce1de7a3e32e 100644
@@ -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);

lib/crypto/sha256.c void sha256(const u8 *data, unsigned int len, u8 *out) · line 230

Quoted 10 lines
lib/crypto/sha256.c +10 -0
+
+	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);

You forgot to include something that actually calls this function.

Anyway, there should be no need for this. If you're trying to convert a SHA-256 hash value to a string, just use the %*phN printk format specifier which converts bytes to hex.

- Eric