feat(util): Add ARC4 algorithm to util

components/util/Kconfig

@@ -51,4 +51,19 @@ config ESP_MD5
 
        Disabling the "assert" function at menuconfig can speed up the calculation.
 
+config ESP_ARC4
+   bool "Enable Espressif ARC4"
+   default y
+   help
+       Enable Espressif ARC4 for other components to
+       speed up process speed and save code size.
+
+       ESP8285 is like ESP8266 + 1MB flash, but its internal I/O connection from CPU
+       core to flash is DIO not QIO, which makes it read flash data slower.
+       So the function will speed up ESP8285 obviously.
+
+       The calculation uses "ibus_data" to speed up load data from instruction bus.
+
+       Disabling the "assert" function at menuconfig can speed up the calculation.
+
 endmenu # Util

components/util/include/esp_arc4.h

@@ -0,0 +1,71 @@
+// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+ * @brief                       ARC4 context structure
+ */
+typedef struct
+{
+    int x;                      /*!< permutation index */
+    int y;                      /*!< permutation index */
+    unsigned char m[256];       /*!< permutation table */
+}esp_arc4_context;
+
+/**
+ * @brief          ARC4 key schedule
+ *
+ * @param ctx      ARC4 context to be setup
+ * @param key      the secret key
+ * @param keylen   length of the key, in bytes
+ */
+void esp_arc4_setup(esp_arc4_context *ctx, const uint8_t *key, uint32_t keylen);
+
+/**
+ * @brief          ARC4 cipher function
+ *
+ * @param ctx      ARC4 context
+ * @param length   length of the input data
+ * @param input    buffer holding the input data
+ * @param output   buffer for the output data
+ *
+ * @return         0 if successful
+ */
+int esp_arc4_encrypt(esp_arc4_context *ctx, size_t length, const uint8_t *input, uint8_t *output);
+
+/**
+ * @brief          ARC4 cipher function
+ *
+ * @param ctx      ARC4 context
+ * @param length   length of the input data
+ * @param input    buffer holding the input data
+ * @param output   buffer for the output data
+ *
+ * @return         0 if successful
+ * @Note           When you encrypt or decrypt, must call esp_arc4_setup function to set key. 
+ *                 Encrypt and decrypt will change the ctx value
+ */
+int esp_arc4_decrypt(esp_arc4_context *ctx, size_t length, const uint8_t *input, uint8_t *output );
+
+#ifdef __cplusplus
+}
+#endif
+

components/util/src/arc4.c

@@ -0,0 +1,91 @@
+// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <sys/errno.h>
+#include <string.h>
+#include "esp_arc4.h"
+#include "ibus_data.h"
+#include "util_assert.h"
+
+/*
+ * ARC4 key schedule
+ */
+void esp_arc4_setup(esp_arc4_context *ctx, const uint8_t *key, uint32_t keylen)
+{
+    int i, j, a;
+    uint32_t k;
+    uint8_t *m;
+
+    util_assert(ctx);
+    util_assert(key);
+
+    ctx->x = 0;
+    ctx->y = 0;
+    m = ctx->m;
+
+    for(i = 0; i < 256; i++)
+        m[i] = (uint8_t) i;
+
+    j = k = 0;
+
+    for(i = 0; i < 256; i++, k++)
+    {
+        if(k >= keylen) k = 0;
+
+        a = m[i];
+        j = (j + a + key[k]) & 0xFF;
+        m[i] = m[j];
+        m[j] = (uint8_t) a;
+    }
+}
+
+/*
+ * ARC4 cipher function
+ */
+int esp_arc4_encrypt(esp_arc4_context *ctx, size_t length, const uint8_t *input, uint8_t *output)
+{
+    int x, y, a, b;
+    size_t i;
+    uint8_t *m;
+
+    util_assert(ctx);
+    util_assert(input);
+    util_assert(output);
+    
+    x = ctx->x;
+    y = ctx->y;
+    m = ctx->m;
+
+    for(i = 0; i < length; i++)
+    {
+        x = (x + 1) & 0xFF; a = m[x];
+        y = (y + a) & 0xFF; b = m[y];
+
+        m[x] = (uint8_t) b;
+        m[y] = (uint8_t) a;
+
+        output[i] = (uint8_t)(input[i] ^ m[(uint8_t)(a + b)]);
+    }
+
+    ctx->x = x;
+    ctx->y = y;
+
+    return 0;
+}
+
+int esp_arc4_decrypt(esp_arc4_context *ctx, size_t length, const uint8_t *input, uint8_t *output)
+{
+    return esp_arc4_encrypt(ctx, length, input, output);
+}
+

components/util/test/test_arc4.c

@@ -0,0 +1,74 @@
+
+// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string.h>
+#include <stdio.h>
+#include "esp_arc4.h"
+#include "unity.h"
+
+#define TEST_ARC4_COUNT 512
+#define TEST_ARC4_DEBUG 1
+
+static const uint8_t arc4_test_key[3][8] =
+{
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+};
+
+static const uint8_t arc4_test_pt[3][8] =
+{
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+};
+
+static const uint8_t arc4_test_ct[3][8] =
+{
+    { 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 },
+    { 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 },
+    { 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A }
+};
+
+TEST_CASE("Test ARC4", "[ARC4]")
+{
+    int i, n = 0;
+    uint32_t encode_time = 0;
+    uint8_t ibuf[8];
+    uint8_t obuf[8];
+    extern uint32_t esp_get_time(void);
+
+    for (n = 0; n < TEST_ARC4_COUNT; n++) {
+        for(i = 0; i < 3; i++)
+        {
+            memcpy(ibuf, arc4_test_pt[i], 8);
+
+            uint32_t tmp = esp_get_time();
+            esp_arc4_context ctx;
+            esp_arc4_setup(&ctx, arc4_test_key[i], 8);
+            TEST_ASSERT_TRUE(esp_arc4_encrypt(&ctx, 8, ibuf, obuf) == 0);
+            encode_time += esp_get_time() - tmp;
+
+            TEST_ASSERT_TRUE(memcmp(obuf, arc4_test_ct[i], 8) == 0);
+        }
+    }
+#if TEST_ARC4_DEBUG
+    printf("ARC4 test cost time totally encode %u us , once cost is about encode %u us\n",
+        encode_time, encode_time / (TEST_ARC4_COUNT * 3));
+#endif
+}
+
+// ARC4 test cost time totally encode 794288 us , once cost is about encode 517 us
+