Add an HKDF (RFC 5869) implementation
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
new file mode 100644
index 0000000..c6cd870
--- /dev/null
+++ b/tests/suites/test_suite_hkdf.function
@@ -0,0 +1,39 @@
+/* BEGIN_HEADER */
+#include "mbedtls/hkdf.h"
+/* END_HEADER */
+
+/* BEGIN_DEPENDENCIES
+ * depends_on:MBEDTLS_HKDF_C
+ * END_DEPENDENCIES
+ */
+
+/* BEGIN_CASE */
+void test_hkdf( int md_alg, char *hex_ikm_string, char *hex_salt_string,
+ char *hex_info_string, char *hex_okm_string )
+{
+ int ret;
+ size_t ikm_len, salt_len, info_len, okm_len;
+ unsigned char ikm[1024] = { '\0' };
+ unsigned char salt[1024] = { '\0' };
+ unsigned char info[1024] = { '\0' };
+ unsigned char expected_okm[1024] = { '\0' };
+ unsigned char okm[1024] = { '\0' };
+ unsigned char okm_string[1000] = { '\0' };
+
+ const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
+ TEST_ASSERT( md != NULL );
+
+ ikm_len = unhexify( ikm, hex_ikm_string );
+ salt_len = unhexify( salt, hex_salt_string );
+ info_len = unhexify( info, hex_info_string );
+ okm_len = unhexify( expected_okm, hex_okm_string );
+
+ ret = mbedtls_hkdf( md, salt, salt_len, ikm, ikm_len, info, info_len, okm,
+ okm_len);
+ TEST_ASSERT( ret == 0 );
+
+ // Run hexify on it so that it looks nicer if the assertion fails
+ hexify( okm_string, okm, okm_len );
+ TEST_ASSERT( !strcmp( (char *)okm_string, hex_okm_string ) );
+}
+/* END_CASE */