1 files changed, 24 insertions, 10 deletions
diff --git a/include/crypto/hmac.h b/include/crypto/hmac.h
index c69a0dfab3..da8a1e3ceb 100644
--- a/include/crypto/hmac.h
+++ b/include/crypto/hmac.h
@@ -77,11 +77,18 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(QCryptoHmac, qcrypto_hmac_free)
  * @errp: pointer to a NULL-initialized error object
  *
  * Computes the hmac across all the memory regions
- * present in @iov. The @result pointer will be
- * filled with raw bytes representing the computed
- * hmac, which will have length @resultlen. The
- * memory pointer in @result must be released
- * with a call to g_free() when no longer required.
+ * present in @iov.
+ *
+ * If @result_len is set to a non-zero value by the caller, then
+ * @result must hold a pointer that is @result_len in size, and
+ * @result_len match the size of the hash output. The digest will
+ * be written into @result.
+ *
+ * If @result_len is set to zero, then this function will allocate
+ * a buffer to hold the hash output digest, storing a pointer to
+ * the buffer in @result, and setting @result_len to its size.
+ * The memory referenced in @result must be released with a call
+ * to g_free() when no longer required by the caller.
  *
  * Returns:
  *  0 on success, -1 on error
@@ -103,11 +110,18 @@ int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
  * @errp: pointer to a NULL-initialized error object
  *
  * Computes the hmac across all the memory region
- * @buf of length @len. The @result pointer will be
- * filled with raw bytes representing the computed
- * hmac, which will have length @resultlen. The
- * memory pointer in @result must be released
- * with a call to g_free() when no longer required.
+ * @buf of length @len.
+ *
+ * If @result_len is set to a non-zero value by the caller, then
+ * @result must hold a pointer that is @result_len in size, and
+ * @result_len match the size of the hash output. The digest will
+ * be written into @result.
+ *
+ * If @result_len is set to zero, then this function will allocate
+ * a buffer to hold the hash output digest, storing a pointer to
+ * the buffer in @result, and setting @result_len to its size.
+ * The memory referenced in @result must be released with a call
+ * to g_free() when no longer required by the caller.
  *
  * Returns:
  *  0 on success, -1 on error