Merge branch 'bugfix/aes_dma_align_issue_v4.4' into 'release/v4.4'

aes: fix DMA descriptor calculation for the alignment case (v4.4) See merge request espressif/esp-idf!24095
espressif · Jun 14, 2023 · 6afa8e4 · 6afa8e4
2 parents e33a180 + 98c5323
commit 6afa8e4
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Showing 2 changed files with 58 additions and 2 deletions.
diff --git a/components/mbedtls/port/aes/dma/esp_aes.c b/components/mbedtls/port/aes/dma/esp_aes.c
@@ -362,8 +362,8 @@ static int esp_aes_process_dma(esp_aes_context *ctx, const unsigned char *input,
             return esp_aes_process_dma_ext_ram(ctx, input, output, len, stream_out, input_needs_realloc, output_needs_realloc);
         }
 
-        /* Set up dma descriptors for input and output */
-        lldesc_num = lldesc_get_required_num(block_bytes);
+        /* Set up dma descriptors for input and output considering the 16 byte alignment requirement for EDMA */
+        lldesc_num = lldesc_get_required_num_constrained(block_bytes, LLDESC_MAX_NUM_PER_DESC_16B_ALIGNED);
 
         /* Allocate both in and out descriptors to save a malloc/free per function call */
         block_desc = heap_caps_calloc(lldesc_num * 2, sizeof(lldesc_t), MALLOC_CAP_DMA);

diff --git a/components/mbedtls/test/test_aes.c b/components/mbedtls/test/test_aes.c
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
 /* mbedTLS AES test
 */
 #include <string.h>
@@ -15,6 +21,7 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "freertos/semphr.h"
+#include "soc/lldesc.h"
 
 static const uint8_t key_256[] = {
     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
@@ -108,6 +115,55 @@ TEST_CASE("mbedtls CBC AES-256 test", "[aes]")
     free(decryptedtext);
 }
 
+TEST_CASE("mbedtls CBC AES-256 DMA buffer align test", "[aes]")
+{
+#define ALIGN_DOWN(val, align) ((val) & ~((align) - 1))
+    // Size is taken considering the maximum DMA buffer size
+    const unsigned SZ = ALIGN_DOWN((2*LLDESC_MAX_NUM_PER_DESC), 16);
+    mbedtls_aes_context ctx;
+    uint8_t nonce[16];
+
+    const uint8_t expected_cipher_end[] = {
+        0x9e, 0xcb, 0x1d, 0x24, 0x01, 0xc8, 0x3f, 0xba,
+        0xde, 0x76, 0xea, 0x9c, 0xf3, 0x64, 0x23, 0x19,
+        0x8c, 0x67, 0xd4, 0x1a, 0xd1, 0xe0, 0xbf, 0xc3,
+        0xd2, 0xb8, 0x40, 0x95, 0x89, 0x41, 0x09, 0xdb,
+    };
+
+    memcpy(nonce, iv, 16);
+
+    // allocate internal memory
+    uint8_t *chipertext = heap_caps_malloc(SZ, MALLOC_CAP_8BIT|MALLOC_CAP_INTERNAL);
+    uint8_t *plaintext = heap_caps_malloc(SZ, MALLOC_CAP_8BIT|MALLOC_CAP_INTERNAL);
+    uint8_t *decryptedtext = heap_caps_malloc(SZ, MALLOC_CAP_8BIT|MALLOC_CAP_INTERNAL);
+
+    TEST_ASSERT_NOT_NULL(chipertext);
+    TEST_ASSERT_NOT_NULL(plaintext);
+    TEST_ASSERT_NOT_NULL(decryptedtext);
+
+    mbedtls_aes_init(&ctx);
+    mbedtls_aes_setkey_enc(&ctx, key_256, 256);
+
+    memset(plaintext, 0x3A, SZ);
+    memset(decryptedtext, 0x0, SZ);
+
+    // Encrypt
+    mbedtls_aes_crypt_cbc(&ctx, MBEDTLS_AES_ENCRYPT, SZ, nonce, plaintext, chipertext);
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(expected_cipher_end, chipertext + SZ - 32, 32);
+
+    // Decrypt
+    memcpy(nonce, iv, 16);
+    mbedtls_aes_setkey_dec(&ctx, key_256, 256);
+    mbedtls_aes_crypt_cbc(&ctx, MBEDTLS_AES_DECRYPT, SZ, nonce, chipertext, decryptedtext);
+
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(plaintext, decryptedtext, SZ);
+
+    mbedtls_aes_free(&ctx);
+    free(plaintext);
+    free(chipertext);
+    free(decryptedtext);
+}
+
 TEST_CASE("mbedtls CTR AES-256 test", "[aes]")
 {
     const unsigned SZ = 1000;