From d9e221806b9cb182d9aaacd9efe34b0b013855ca Mon Sep 17 00:00:00 2001
From: kaleb-himes <kaleb@wolfssl.com>
Date: Thu, 27 Feb 2020 09:39:22 -0700
Subject: [PATCH] Fix infinite loop with small sha1 inputs. Thanks to Peter W.
 on ZD9976 for the report

---
 wolfcrypt/src/port/pic32/pic32mz-crypt.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/wolfcrypt/src/port/pic32/pic32mz-crypt.c b/wolfcrypt/src/port/pic32/pic32mz-crypt.c
index 319e6ca3a..1e618c194 100644
--- a/wolfcrypt/src/port/pic32/pic32mz-crypt.c
+++ b/wolfcrypt/src/port/pic32/pic32mz-crypt.c
@@ -427,6 +427,9 @@ static void start_engine(pic32mz_desc *desc)
     bufferLen = desc->dbPtr;
     if (bufferLen % 4)
         bufferLen = (bufferLen + 4) - (bufferLen % 4);
+    /* initialize the MSGLEN on engine startup to avoid infinite loop when
+     * length is less than 257 (size of PIC32_BLOCK_SIZE) */
+    uc_desc->bd[desc->currBd].MSGLEN = desc->msgSize;
     uc_desc->bd[desc->currBd].BD_CTRL.BUFLEN = bufferLen;
     uc_desc->bd[desc->currBd].BD_CTRL.LAST_BD = 1;
     uc_desc->bd[desc->currBd].BD_CTRL.LIFM = 1;