Clarify documentation on is384.
diff --git a/include/mbedtls/sha512.h b/include/mbedtls/sha512.h
index e8d0ab7..b6bee9a 100644
--- a/include/mbedtls/sha512.h
+++ b/include/mbedtls/sha512.h
@@ -103,7 +103,11 @@
*
* \param ctx The SHA-512 context to use. This must be initialized.
* \param is384 Determines which function to use. This must be
- * either \c for SHA-512, or \c 1 for SHA-384.
+ * either \c 0 for SHA-512, or \c 1 for SHA-384.
+ *
+ * \note When MBEDTLS_SHA512_NO_SHA384 is defined, \p is384 must be
+ * 0, or the function will return
+ * MBEDTLS_ERR_SHA512_BAD_INPUT_DATA.
*
* \return \c 0 on success.
* \return A negative error code on failure.
@@ -171,6 +175,9 @@
* \param ctx The SHA-512 context to use. This must be initialized.
* \param is384 Determines which function to use. This must be either
* \c 0 for SHA-512 or \c 1 for SHA-384.
+ *
+ * \note When MBEDTLS_SHA512_NO_SHA384 is defined, \p is384 must be
+ * 0, or the function will fail to work.
*/
MBEDTLS_DEPRECATED void mbedtls_sha512_starts( mbedtls_sha512_context *ctx,
int is384 );
@@ -241,6 +248,10 @@
* \param is384 Determines which function to use. This must be either
* \c 0 for SHA-512, or \c 1 for SHA-384.
*
+ * \note When MBEDTLS_SHA512_NO_SHA384 is defined, \p is384 must be
+ * 0, or the function will return
+ * MBEDTLS_ERR_SHA512_BAD_INPUT_DATA.
+ *
* \return \c 0 on success.
* \return A negative error code on failure.
*/
@@ -275,6 +286,9 @@
* be a writable buffer of length \c 64 Bytes.
* \param is384 Determines which function to use. This must be either
* \c 0 for SHA-512, or \c 1 for SHA-384.
+ *
+ * \note When MBEDTLS_SHA512_NO_SHA384 is defined, \p is384 must be
+ * 0, or the function will fail to work.
*/
MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,
size_t ilen,