1 files changed, 54 insertions, 31 deletions

diff --git a/include/crypto/sm3.h b/include/crypto/sm3.h
index 1f021ad0533f..371e8a661705 100644
--- a/include/crypto/sm3.h
+++ b/include/crypto/sm3.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Common values for SM3 algorithm
+ * SM3 hash algorithm
  *
  * Copyright (C) 2017 ARM Limited or its affiliates.
  * Copyright (C) 2017 Gilad Ben-Yossef <gilad@benyossef.com>
@@ -15,9 +15,6 @@
 #define SM3_DIGEST_SIZE	32
 #define SM3_BLOCK_SIZE	64
 
-#define SM3_T1		0x79CC4519
-#define SM3_T2		0x7A879D8A
-
 #define SM3_IVA		0x7380166f
 #define SM3_IVB		0x4914b2b9
 #define SM3_IVC		0x172442d7
@@ -27,38 +24,64 @@
 #define SM3_IVG		0xe38dee4d
 #define SM3_IVH		0xb0fb0e4e
 
-extern const u8 sm3_zero_message_hash[SM3_DIGEST_SIZE];
+/* State for the SM3 compression function */
+struct sm3_block_state {
+	u32 h[SM3_DIGEST_SIZE / 4];
+};
 
-struct sm3_state {
-	u32 state[SM3_DIGEST_SIZE / 4];
-	u64 count;
-	u8 buffer[SM3_BLOCK_SIZE];
+/**
+ * struct sm3_ctx - Context for hashing a message with SM3
+ * @state: the compression function state
+ * @bytecount: number of bytes processed so far
+ * @buf: partial block buffer; bytecount % SM3_BLOCK_SIZE bytes are valid
+ */
+struct sm3_ctx {
+	struct sm3_block_state state;
+	u64 bytecount;
+	u8 buf[SM3_BLOCK_SIZE] __aligned(__alignof__(__be64));
 };
 
-/*
- * Stand-alone implementation of the SM3 algorithm. It is designed to
- * have as little dependencies as possible so it can be used in the
- * kexec_file purgatory. In other cases you should generally use the
- * hash APIs from include/crypto/hash.h. Especially when hashing large
- * amounts of data as those APIs may be hw-accelerated.
+/**
+ * sm3_init() - Initialize an SM3 context for a new message
+ * @ctx: the context to initialize
+ *
+ * If you don't need incremental computation, consider sm3() instead.
+ *
+ * Context: Any context.
+ */
+void sm3_init(struct sm3_ctx *ctx);
+
+/**
+ * sm3_update() - Update an SM3 context with message data
+ * @ctx: the context to update; must have been initialized
+ * @data: the message data
+ * @len: the data length in bytes
+ *
+ * This can be called any number of times.
  *
- * For details see lib/crypto/sm3.c
+ * Context: Any context.
  */
+void sm3_update(struct sm3_ctx *ctx, const u8 *data, size_t len);
 
-static inline void sm3_init(struct sm3_state *sctx)
-{
-	sctx->state[0] = SM3_IVA;
-	sctx->state[1] = SM3_IVB;
-	sctx->state[2] = SM3_IVC;
-	sctx->state[3] = SM3_IVD;
-	sctx->state[4] = SM3_IVE;
-	sctx->state[5] = SM3_IVF;
-	sctx->state[6] = SM3_IVG;
-	sctx->state[7] = SM3_IVH;
-	sctx->count = 0;
-}
+/**
+ * sm3_final() - Finish computing an SM3 message digest
+ * @ctx: the context to finalize; must have been initialized
+ * @out: (output) the resulting SM3 message digest
+ *
+ * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
+ *
+ * Context: Any context.
+ */
+void sm3_final(struct sm3_ctx *ctx, u8 out[at_least SM3_DIGEST_SIZE]);
 
-void sm3_update(struct sm3_state *sctx, const u8 *data, unsigned int len);
-void sm3_final(struct sm3_state *sctx, u8 *out);
+/**
+ * sm3() - Compute SM3 message digest in one shot
+ * @data: the message data
+ * @len: the data length in bytes
+ * @out: (output) the resulting SM3 message digest
+ *
+ * Context: Any context.
+ */
+void sm3(const u8 *data, size_t len, u8 out[at_least SM3_DIGEST_SIZE]);
 
-#endif
+#endif /* _CRYPTO_SM3_H */