[PATCH v2 1/4] xen/lib: Export additional sha256 functions

[Frediano Ziglio <freddy77@xxxxxxxxx>]

From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

In future, some code needs to generate a digest over several separate buffers
so export the necessary functions to do so.

Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
---
 xen/include/xen/sha2.h | 12 ++++++++++++
 xen/lib/sha2-256.c     | 17 ++++++-----------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/xen/include/xen/sha2.h b/xen/include/xen/sha2.h
index 47d97fbf01..cb30e8f8d7 100644
--- a/xen/include/xen/sha2.h
+++ b/xen/include/xen/sha2.h
@@ -12,4 +12,16 @@
 void sha2_256_digest(uint8_t digest[SHA2_256_DIGEST_SIZE],
                      const void *msg, size_t len);
 
+struct sha2_256_state {
+    uint32_t state[SHA2_256_DIGEST_SIZE / sizeof(uint32_t)];
+    uint8_t buf[64];
+    size_t count; /* Byte count. */
+};
+
+void sha2_256_init(struct sha2_256_state *s);
+void sha2_256_update(struct sha2_256_state *s, const void *msg,
+                     size_t len);
+void sha2_256_final(struct sha2_256_state *s,
+                    uint8_t digest[SHA2_256_DIGEST_SIZE]);
+
 #endif /* XEN_SHA2_H */
diff --git a/xen/lib/sha2-256.c b/xen/lib/sha2-256.c
index 19e8252188..e55e297eff 100644
--- a/xen/lib/sha2-256.c
+++ b/xen/lib/sha2-256.c
@@ -10,12 +10,6 @@
 #include <xen/string.h>
 #include <xen/unaligned.h>
 
-struct sha2_256_state {
-    uint32_t state[SHA2_256_DIGEST_SIZE / sizeof(uint32_t)];
-    uint8_t buf[64];
-    size_t count; /* Byte count. */
-};
-
 static uint32_t choose(uint32_t x, uint32_t y, uint32_t z)
 {
     return z ^ (x & (y ^ z));
@@ -131,7 +125,7 @@ static void sha2_256_transform(uint32_t *state, const void 
*_input)
     state[4] += e; state[5] += f; state[6] += g; state[7] += h;
 }
 
-static void sha2_256_init(struct sha2_256_state *s)
+void sha2_256_init(struct sha2_256_state *s)
 {
     *s = (struct sha2_256_state){
         .state = {
@@ -147,8 +141,8 @@ static void sha2_256_init(struct sha2_256_state *s)
     };
 }
 
-static void sha2_256_update(struct sha2_256_state *s, const void *msg,
-                            size_t len)
+void sha2_256_update(struct sha2_256_state *s, const void *msg,
+                     size_t len)
 {
     unsigned int partial = s->count & 63;
 
@@ -177,9 +171,10 @@ static void sha2_256_update(struct sha2_256_state *s, 
const void *msg,
     memcpy(s->buf + partial, msg, len);
 }
 
-static void sha2_256_final(struct sha2_256_state *s, void *_dst)
+void sha2_256_final(struct sha2_256_state *s,
+                    uint8_t digest[SHA2_256_DIGEST_SIZE])
 {
-    uint32_t *dst = _dst;
+    uint32_t *dst = (uint32_t *)digest;
     unsigned int i, partial = s->count & 63;
 
     /* Start padding */
-- 
2.43.0