From cce06e8c501c3cec7d9e8318d36a504b92d6369a Mon Sep 17 00:00:00 2001
From: Hideki Miyazaki <hide@wolfssl.com>
Date: Tue, 26 Feb 2019 12:10:29 +0900
Subject: [PATCH] Addressed to review comments

---
 wolfcrypt/src/port/Espressif/esp32_mp.c | 23 ++++++++++++++++++-----
 wolfcrypt/src/tfm.c                     |  2 +-
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/wolfcrypt/src/port/Espressif/esp32_mp.c b/wolfcrypt/src/port/Espressif/esp32_mp.c
index 3b527e57f..0b231e2d1 100644
--- a/wolfcrypt/src/port/Espressif/esp32_mp.c
+++ b/wolfcrypt/src/port/Espressif/esp32_mp.c
@@ -57,9 +57,16 @@ static int espmp_CryptHwMutexInit = 0;
 /*
 * check if the hw is ready before accessing it
 */
-static void esp_mp_hw_wait_clean()
+static int esp_mp_hw_wait_clean()
 {
-    while(DPORT_REG_READ(RSA_CLEAN_REG) != 1){}
+    int timeout = 0;
+    while(++timeout < ESP_RSA_TIMEOUT && DPORT_REG_READ(RSA_CLEAN_REG) != 1){}
+
+    if(timeout >= ESP_RSA_TIMEOUT) {
+        ESP_LOGE(TAG, "waiting hw ready is time-outed.");
+        return MP_NG;
+    }
+    return MP_OKAY; 
 }
 /*
 * lock hw engine.
@@ -263,7 +270,9 @@ int esp_mp_mul(fp_int* X, fp_int* Y, fp_int* Z)
     if((ret = esp_mp_hw_lock()) != MP_OKAY)
         return ret;
 
-    esp_mp_hw_wait_clean();
+    if((ret = esp_mp_hw_wait_clean()) != MP_OKAY){
+        return ret;
+    }
 
     /* step.1  (2*N/512) => N/256. 512 bits => 16 words */
     DPORT_REG_WRITE(RSA_MULT_MODE_REG, (hwWords_sz >> 3) - 1 + 8);
@@ -364,7 +373,9 @@ int esp_mp_mulmod(fp_int* X, fp_int* Y, fp_int* M, fp_int* Z)
     * 13. Release the hw engine
     */
 
-    esp_mp_hw_wait_clean();
+    if((ret = esp_mp_hw_wait_clean()) != MP_OKAY){
+        return ret;
+    }
     /* step.1                     512 bits => 16 words */
     DPORT_REG_WRITE(RSA_MULT_MODE_REG, (hwWords_sz >> 4) - 1);
 
@@ -471,7 +482,9 @@ int esp_mp_exptmod(fp_int* X, fp_int* Y, word32 Ys, fp_int* M, fp_int* Z)
     * 6. Read the result Z(=Y) from Z_MEM
     * 7. Write 1 to INTERRUPT_REG to clear the interrupt.
     */
-    esp_mp_hw_wait_clean();
+    if((ret = esp_mp_hw_wait_clean()) != MP_OKAY){
+        return ret;
+    }
 
     /* step.1                                         */
     DPORT_REG_WRITE(RSA_MODEXP_MODE_REG, (hwWords_sz >> 4) - 1);
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
index 25dd05e36..c34e5fb8b 100644
--- a/wolfcrypt/src/tfm.c
+++ b/wolfcrypt/src/tfm.c
@@ -3026,7 +3026,7 @@ int mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
     int B = fp_count_bits (b);
 
     if( A >= ESP_RSA_MULM_BITS && B >= ESP_RSA_MULM_BITS)
-     return esp_mp_mulmod(a, b, c, d);
+        return esp_mp_mulmod(a, b, c, d);
     else
  #endif
    return fp_mulmod(a, b, c, d);