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

[Frediano Ziglio <frediano.ziglio@cloud.com>]

From: Ross Lagerwall <ross.lagerwall@citrix.com>

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@citrix.com>
---
 xen/include/xen/sha2.h | 10 ++++++++++
 xen/lib/sha2-256.c     | 14 ++++----------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/xen/include/xen/sha2.h b/xen/include/xen/sha2.h
index 47d97fbf01..ea8bad67e4 100644
--- a/xen/include/xen/sha2.h
+++ b/xen/include/xen/sha2.h
@@ -9,6 +9,16 @@
 
 #define SHA2_256_DIGEST_SIZE 32
 
+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, void *_dst);
 void sha2_256_digest(uint8_t digest[SHA2_256_DIGEST_SIZE],
                      const void *msg, size_t len);
 
diff --git a/xen/lib/sha2-256.c b/xen/lib/sha2-256.c
index 19e8252188..896a257ed9 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;
 
@@ -177,7 +171,7 @@ 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, void *_dst)
 {
     uint32_t *dst = _dst;
     unsigned int i, partial = s->count & 63;
-- 
2.43.0