Merge branch 'bugfix/mbedtls_sha384' into 'master'

Bugfix mbedtls sha384 clone()

mbedtls_sha512_clone() on a SHA-384 hash caused incorrect digest

Also adds additional mbedtls unit tests into the unit tests project (including one for this bug).

See merge request !252

components/esp32/hwcrypto/sha.c

@@ -82,7 +82,7 @@ inline static size_t sha_engine_index(esp_sha_type type) {
     }
 }
 
-/* Return state & digest length (in bytes) for a given SHA type */
+/* Return digest length (in bytes) for a given SHA type */
 inline static size_t sha_length(esp_sha_type type) {
     switch(type) {
     case SHA1:
@@ -90,7 +90,7 @@ inline static size_t sha_length(esp_sha_type type) {
     case SHA2_256:
         return 32;
     case SHA2_384:
-        return 64;
+        return 48;
     case SHA2_512:
         return 64;
     default:

components/esp32/include/hwcrypto/sha.h

@@ -113,11 +113,14 @@ void esp_sha_block(esp_sha_type sha_type, const void *data_block, bool is_first_
  * value that is read is the SHA digest (in big endian
  * format). Otherwise, the value that is read is an interim SHA state.
  *
+ * @note If sha_type is SHA2_384, only 48 bytes of state will be read.
+ * This is enough for the final SHA2_384 digest, but if you want the
+ * interim SHA-384 state (to continue digesting) then pass SHA2_512 instead.
+ *
  * @param sha_type SHA algorithm in use.
  *
  * @param state Pointer to a memory buffer to hold the SHA state. Size
- * is 20 bytes (SHA1), 64 bytes (SHA2_256), or 128 bytes (SHA2_384 or
- * SHA2_512).
+ * is 20 bytes (SHA1), 32 bytes (SHA2_256), 48 bytes (SHA2_384) or 64 bytes (SHA2_512).
  *
  */
 void esp_sha_read_digest_state(esp_sha_type sha_type, void *digest_state);