ESP32 Forum

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I (327) KEY: bf 9a d2 76 37 a9 48 33 02 de a5 9a 4d 00 f0 3f
I (327) KEY: ac b2 c5 9b a4 2e 4e 54 65 60 22 b1 b1 f7 88 a8
I (337) IV: f7 16 20 b1 79 6c 89 d7 82 1f 4b 06 54 e0 da 29
I (347) ENCRYPTED HEX: 51 9f 43 57 1f fb 7a c5 63 20 78 3f 47 2f c0 55
I (347) DECRYPTED HEX: 74 72 75 65 00 00 00 00 00 00 00 00 00 00 00 00
I (357) DECRYPTED ASCII: true

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void testdecode()
{   

// only CBC requires that input length shall be multiple of 16
#define INPUT_LENGTH 16

mbedtls_aes_context aes;

// key length 32 bytes for 256 bit encrypting, it can be 16 or 24 bytes for 128 and 192 bits encrypting mode
uint8_t key[] = {0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};
uint8_t iv[]  = {0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};
uint8_t iv2[] = {0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};

uint8_t input[INPUT_LENGTH] = {0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x20, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16};
uint8_t encrypt_output[INPUT_LENGTH] = {0};
uint8_t decrypt_output[INPUT_LENGTH] = {0};

    mbedtls_aes_init(&aes);
    mbedtls_aes_setkey_enc(&aes, key, 256);
    
    //sprintf((char*)input, "%s","Hello Testing");

    mbedtls_aes_crypt_cbc(&aes, MBEDTLS_AES_ENCRYPT, INPUT_LENGTH, iv, input, encrypt_output);
    Serial.println("Encrypted Array:");
    for (uint8_t i=0; i<INPUT_LENGTH; i++)
    {
        Serial.print(String(encrypt_output[i])+" ");
    }
    Serial.println();
    
 
    mbedtls_aes_crypt_cbc(&aes, MBEDTLS_AES_DECRYPT, INPUT_LENGTH, iv2, encrypt_output, decrypt_output);
    Serial.println("Decrypted Array:");
    for (uint8_t i=0; i<INPUT_LENGTH; i++)
    {
        Serial.print(String(decrypt_output[i])+" ");
    }
    Serial.println();

    mbedtls_aes_free(&aes);

}

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Encrypted Array:
219 245 170 160 113 80 47 61 200 104 238 191 30 168 127 76
Decrypted Array:
17 18 19 20 21 22 23 24 25 32 17 18 19 20 21 22

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Decrypted Array:
17 18 19 20 21 22 23 24 25 32 17 18 19 20 21 22

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11 12 13 14 15 16 17 18 19 20 11 12 13 14 15 16

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if (true)
        {
            #define BUFFER_SIZE=2048
            mbedtls_aes_context aes;

            const uint8_t key[] = {0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10};
            uint8_t iv[]  = {0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11,0x11};
            uint8_t decrypt_output[BUFFER_SIZE] = {0};

            mbedtls_aes_init(&aes);
            mbedtls_aes_setkey_enc(&aes, key, 256);

            // CODES REMOVED TO SHORTEN

            while (HTTP_Client.connected() && (remaining_len > 0 || remaining_len == -1))
            {
                // get available data size
                remaining_stream_size = stream->available();
                if (remaining_stream_size)
                {
                    // reset buffer to ensure padding
                    memset(buffer, 0, BUFFER_SIZE);
                    memset(decrypt_output, 0, BUFFER_SIZE);
                    // read up to array size
                    read_length = stream->readBytes(buffer, ((remaining_stream_size > sizeof(buffer)) ? sizeof(buffer) : remaining_stream_size));
                    
                    //decrypt the firmware
                    mbedtls_aes_crypt_cbc(&aes, MBEDTLS_AES_DECRYPT,read_length, iv, buffer, decrypt_output);
                    
                    // Write read buffer to Flash Mem
             Update.write(decrypt_output, read_length)
                    // Update.write(buffer, read_length);

                    //CODE REMOVED TO SHORTEN
                    
                    }
                    else
                    {
                        Update.end(true);
                        mbedtls_aes_free(&aes);
                        HTTP_Client.end();
                    }