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请，有人可以告诉我我做错了什么。我必须对我的卡进行 AES 身份验证。该卡是 Mifare DESFire EV1 4K，读卡器是 Omnikey 5121。我在 Stack 上遵循了一些示例，但我总是在最后一步失败，即卡的旋转 RndA 不等于我的旋转 RndA。AES 配置有问题吗？

public static byte[] Authenticate_AES(this SCardReader reader, byte[] key)
    {
        using (var aes = Aes.Create())
        {
            aes.Key = key;
            aes.Padding = PaddingMode.None;
            aes.Mode = CipherMode.CBC;
            aes.BlockSize = 128;
            aes.IV = SCardUtils.StringToByteArray("00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00");

            var decryptor = aes.CreateDecryptor();
            var encryptor = aes.CreateEncryptor();
            var rnd = new Random();

            //Get encrypted RandB from the card
            var rAPDU = reader.Transmit(0x90, 0xAA, 0, 0, SCardUtils.StringToByteArray("00"));

            if (!rAPDU.HasData)
                throw new Exception("RandB_enc is null");

            //Encrypted RndB
            var RndB_enc = new byte[16];
            rAPDU.Data.CopyTo(RndB_enc, 0);
            SCardUtils.ShowBytes(RndB_enc, "RndB_enc");

            //Decrypt encrypted RndB
            var RndB = decryptor.TransformFinalBlock(RndB_enc, 0, RndB_enc.Length);
            SCardUtils.ShowBytes(RndB, "RndB");

            //Rotate RndB 1 byte to the left
            var RndB_rot = SCardUtils.RotateLeft(RndB);
            SCardUtils.ShowBytes(RndB_rot, "RndB_rot");

            //Generate random RndA
            var RndA = new byte[16];
            rnd.NextBytes(RndA);
            SCardUtils.ShowBytes(RndA, "RndA");

            //Concatenate RndA and RndB_rot
            var RndAB_rot = RndA.Concat(RndB_rot).ToArray();
            SCardUtils.ShowBytes(RndAB_rot, "RndAB_rot");

            //Encypt RndAB_rot
            var dataToSend = encryptor.TransformFinalBlock(RndAB_rot, 0, RndAB_rot.Length);
            SCardUtils.ShowBytes(dataToSend, "Encrypted data");

            rAPDU = reader.Transmit(0x90, 0xAF, 0, 0, dataToSend);

            if (!rAPDU.HasData)
                throw new Exception("rAPDU data is null");

            //Encrypted RndA_rot
            var RndA_rot_enc = new byte[16];
            rAPDU.Data.CopyTo(RndA_rot_enc, 0);
            SCardUtils.ShowBytes(RndA_rot_enc, "RndA_rot_enc");

            //Decrypt encrypted RndA_rot
            var RndA_rot_dec = decryptor.TransformFinalBlock(RndA_rot_enc, 0, RndA_rot_enc.Length);
            SCardUtils.ShowBytes(RndA_rot_dec, "RndA_rot_dec");

            var RndA_rot = SCardUtils.RotateLeft(RndA);
            SCardUtils.ShowBytes(RndA_rot, "RndA_rot");

            //Compare RndA_rot with RndA rotated to the left
            if (!SCardUtils.IsEqualTo(RndA_rot_dec, RndA_rot))
                throw new Exception($"Error authenticating card. The values are not equal.");

            var sessionKey = new byte[16];
            Array.Copy(RndA, 0, sessionKey, 0, 4);
            Array.Copy(RndB, 0, sessionKey, 4, 4);
            Array.Copy(RndA, 12, sessionKey, 8, 4);
            Array.Copy(RndB, 12, sessionKey, 12, 4);

            return sessionKey;
        }
    }

这是输出：

Reader name:  OMNIKEY CardMan 5x21-CL 0
RndB_enc:     08 DD A2 12 57 43 6C F7 75 98 78 9E 6C 0A A7 06 
RndB:         16 C8 35 7A 4A 36 29 D2 F0 86 26 AD FA CA 81 9F 
RndB_rot:     C8 35 7A 4A 36 29 D2 F0 86 26 AD FA CA 81 9F 16 
RndA:         77 93 A5 8D 0E 0D 88 88 22 C3 40 9C 26 67 95 35 
RndAB_rot:    77 93 A5 8D 0E 0D 88 88 22 C3 40 9C 26 67 95 35 C8 35 7A 4A 36 29 D2 F0 86 26 AD FA CA 81 9F 16 
Data:         4D BD 7A E8 B8 6C 00 5F E4 B5 B5 42 7B AE 51 39 25 77 CB 60 83 6A E8 15 B9 9D FD A9 FD A7 75 9F 
RndA_rot_enc: D6 CB CF 08 5F 8A E8 6C 30 95 34 6F DD CF 4F FA 
RndA_rot_dec: 6B 70 54 39 CD 8E 97 42 E2 A5 FF E3 90 95 46 E0 
RndA_rot:     93 A5 8D 0E 0D 88 88 22 C3 40 9C 26 67 95 35 77

所以你可以看到 RndA_rot_dec 和 RndA_rot 不相等，我不知道为什么。

谢谢大家。

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1 回答 1

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我终于得到了解决方案。我还对代码进行了一些修改，以便像我一样遇到问题的每个人都更容易理解。几个星期。

public static byte[] Authenticate_AES(this SCardReader reader, byte[] key, byte[] IV)
    {
        //Get encrypted RndB from the tag
        var rAPDU = reader.Transmit(0x90, 0xAA, 0, 0, SCardUtils.StringToByteArray("00"));

        if (!rAPDU.HasData)
            throw new Exception("RandB_enc is null");

        var aes = Aes.Create();
        aes.Mode = CipherMode.CBC;
        aes.KeySize = 128;
        aes.BlockSize = 128;
        aes.Padding = PaddingMode.None;
        aes.Key = key;
        aes.IV = IV; //16 bytes of zeros

        //Encrypted RndB from the tag
        var RndB_enc = rAPDU.Data.ToArray();
        SCardUtils.ShowBytes(RndB_enc, "RndB_enc");

        var decryptor = aes.CreateDecryptor();

        //Decrypt encrypted RndB
        var RndB = decryptor.TransformFinalBlock(RndB_enc, 0, RndB_enc.Length);
        SCardUtils.ShowBytes(RndB, "RndB");

        //Rotate RndB 1 byte to the left
        var RndB_rot = SCardUtils.RotateLeft(RndB);
        SCardUtils.ShowBytes(RndB_rot, "RndB_rot");

        var rnd = new Random();

        //Generate random RndA
        var RndA = new byte[16];
        rnd.NextBytes(RndA);
        SCardUtils.ShowBytes(RndA, "RndA");

        //Concatenate RndA and RndB_rot
        var RndAB_rot = RndA.Concat(RndB_rot).ToArray();
        SCardUtils.ShowBytes(RndAB_rot, "RndAB_rot");

        //IV is now encrypted RndB received from the tag
        aes.IV = RndB_enc;

        var encryptor = aes.CreateEncryptor();

        //Encypt RndAB_rot
        var RndAB_rot_enc = encryptor.TransformFinalBlock(RndAB_rot, 0, RndAB_rot.Length);
        SCardUtils.ShowBytes(RndAB_rot_enc, "RndAB_rot_enc");

        rAPDU = reader.Transmit(0x90, 0xAF, 0, 0, RndAB_rot_enc);

        if (!rAPDU.HasData)
            throw new Exception("rAPDU data is null");

        //Encrypted RndA_rot from the tag
        var RndA_rot_enc = rAPDU.Data.ToArray();
        SCardUtils.ShowBytes(RndA_rot_enc, "RndA_rot_enc");

        //IV is now the last 16 bytes of RndAB_rot_enc
        aes.IV = RndAB_rot_enc.Skip(16).Take(16).ToArray();

        decryptor = aes.CreateDecryptor();

        //Decrypt encrypted RndA_rot
        var RndA_rot = decryptor.TransformFinalBlock(rAPDU.Data, 0, rAPDU.Data.Length);
        SCardUtils.ShowBytes(RndA_rot, "RndA_rot");

        //Compare RndA_rot_dec with RndA_rot
        if (!SCardUtils.IsEqualTo(RndA_rot, SCardUtils.RotateLeft(RndA)))
            throw new Exception($"Error authenticating card. The values are not equal.");

        var sessionKey = new byte[16];
        Array.Copy(RndA, 0, sessionKey, 0, 4);
        Array.Copy(RndB, 0, sessionKey, 4, 4);
        Array.Copy(RndA, 12, sessionKey, 8, 4);
        Array.Copy(RndB, 12, sessionKey, 12, 4);

        aes.Clear();
        return sessionKey;
    }

问题出在初始化向量上。它正在通过三通认证而改变。

这是最终输出：

   Reader name: OMNIKEY CardMan 5x21-CL 0
      RndB_enc: 6F 40 6D 9D 51 7A 2C 9E 88 C9 2C 84 80 94 E3 F7 
          RndB: FB FB A7 5F 54 97 D7 CA 4B 15 07 F1 A0 D1 A2 68 
      RndB_rot: FB A7 5F 54 97 D7 CA 4B 15 07 F1 A0 D1 A2 68 FB 
          RndA: 87 7B BA 48 4D 01 14 CE 4D 8E 33 A5 1B 0F 00 E9 
     RndAB_rot: 87 7B BA 48 4D 01 14 CE 4D 8E 33 A5 1B 0F 00 E9 FB A7 5F 54 97 D7 CA 4B 15 07 F1 A0 D1 A2 68 FB 
 RndAB_rot_enc: 0B 8B 4E D9 BF 40 51 F0 83 FC 44 E8 B7 A7 21 26 DE A9 B9 CE E5 05 F7 A5 46 FE 91 0F 59 2B 90 E7 
  RndA_rot_enc: 9F 3D E8 90 37 2E 7B F6 1E BA AC 29 6E 94 1C 9E 
      RndA_rot: 7B BA 48 4D 01 14 CE 4D 8E 33 A5 1B 0F 00 E9 87

如您所见，向左旋转 1 个字节的 RndA（第 5 行）等于 RndA_rot（最后一行）。至此认证完成。

于 2022-02-09T08:24:21.397 回答