Add support for calculating hashes with watchdog triggering
Implement watchodg-aware variants of hash calculation functions:
- crc32_wd()
- md5_wd()
- sha1_csum_wd()
The above functions calculate the hash of the input buffer in chunks,
triggering the watchdog after processing each chunk. The chunk size
is given as a function call parameter.
Signed-off-by: Bartlomiej Sieka <tur@semihalf.com>
diff --git a/lib_generic/md5.c b/lib_generic/md5.c
index 3cee431..20178b8 100644
--- a/lib_generic/md5.c
+++ b/lib_generic/md5.c
@@ -272,3 +272,39 @@
MD5Update(&context, input, len);
MD5Final(output, &context);
}
+
+
+/*
+ * Calculate and store in 'output' the MD5 digest of 'len' bytes at 'input'.
+ * 'output' must have enough space to hold 16 bytes. If 'chunk' Trigger the
+ * watchdog every 'chunk_sz' bytes of input processed.
+ */
+void
+md5_wd (unsigned char *input, int len, unsigned char output[16],
+ unsigned int chunk_sz)
+{
+ struct MD5Context context;
+#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+ unsigned char *end, *curr;
+ int chunk;
+#endif
+
+ MD5Init(&context);
+
+#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+ curr = input;
+ end = input + len;
+ while (curr < end) {
+ chunk = end - curr;
+ if (chunk > chunk_sz)
+ chunk = chunk_sz;
+ MD5Update(&context, curr, chunk);
+ curr += chunk;
+ WATCHDOG_RESET ();
+ }
+#else
+ MD5Update(&context, input, len);
+#endif
+
+ MD5Final(output, &context);
+}
