Enable Secure Boot in Windows

This document shows how to enable secure boot to launch Windows 10 as a guest through OVMF on ACRNGT, including:

  • Generate Platform Key

  • Get KEK and DB from Microsoft

  • Inject PK, KEK and DB into OVMF

Generate Platform Key (PK)

In UEFI secure boot, the Platform Key establishes a trust relationship between the platform owner and the platform firmware. According to Microsoft’s secure boot documentation, section 1.5, the PK is a self-signed certificate owned by the OEM, and the OEM can generate their own PK.

Here we show two ways to generate a PK: openssl and Microsoft tools.

Generate PK Using OpenSSL

  • Generate a Self-Signed Certificate as PK from a new key using the openssl req command. You will need to answer the Certificate Signing Request (CSR) information prompts to complete the process; use your country, state, and other information as appropriate.

    For example:

    $ openssl req -newkey rsa:2048 -nodes -keyout PKpriv.key -x509 -days 365 -out PK.crt
Generating a 2048 bit RSA private key
....+++
.+++
writing new private key to 'PKpriv.key'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:CN
State or Province Name (full name) [Some-State]:Shanghai
Locality Name (eg, city) []:Shanghai
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Intel
Organizational Unit Name (eg, section) []:Intel
Common Name (e.g. server FQDN or YOUR name) []:
Email Address []:

  • You can also generate the self-signed certificate from an existing key, using the openssl req command, for example:

    openssl req -key testpriv.key -new -x509 -days 365 -out PK.crt

  • View the content of certificate using the openssl x509 command:

    $ openssl x509 -text -noout -in PK2.crt

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 10097816361374596362 (0x8c22a67aeadc3d0a)
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=CN, ST=Shanghai, L=Shanghai, O=Intel, OU=Intel
        Validity
            Not Before: Jun 26 06:29:14 2019 GMT
            Not After : Jun 25 06:29:14 2020 GMT
        Subject: C=CN, ST=Shanghai, L=Shanghai, O=Intel, OU=Intel
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
            Public-Key: (2048 bit)
            Modulus:
                00:9e:15:70:40:8c:b0:a7:c2:dd:45:15:e9:ab:c2:
                d9:3d:d7:32:1e:7f:ec:1d:26:e3:d3:07:2c:5c:40:
                8a:42:12:d3:31:59:2c:f0:b0:f7:3d:94:51:ae:b8:
                25:16:ab:98:97:60:68:67:80:e1:77:85:aa:f2:70:
                f3:47:fc:39:8c:9c:25:46:a8:ca:4f:aa:8f:d1:db:
                f1:50:9b:d9:b6:3d:28:bf:5c:bf:1a:52:12:4c:e2:
                04:dd:fe:04:f1:98:3a:9f:a7:ff:f9:43:43:f7:8b:
                48:48:ee:d8:2e:b1:25:26:97:ca:1f:94:1c:00:1e:
                68:8f:e1:30:3d:3c:1d:99:32:d0:d3:08:0b:ed:4c:
                4b:b4:7c:42:b9:1c:e4:ef:df:47:cf:52:37:7e:6e:
                a1:87:02:f9:23:6b:f4:22:e7:a8:8a:40:4c:5d:ff:
                f2:9f:bd:05:68:15:5c:1a:03:e3:4b:80:55:08:38:
                78:1f:e7:4c:dc:cd:49:22:ef:c0:60:4a:c2:b2:c9:
                cb:2b:5c:e2:c8:1d:ec:9e:2d:eb:ed:b1:d7:53:54:
                ea:ce:1a:f2:1c:f9:19:2e:c4:6f:fa:f2:46:bd:48:
                bc:84:f2:a7:b4:1c:0c:60:26:eb:b1:31:d2:76:24:
                df:21:0d:4e:fb:80:3d:ce:8e:a4:5c:8f:8d:b5:51:
                88:a3
            Exponent: 65537 (0x10001)
    X509v3 extensions:
        X509v3 Subject Key Identifier:
            4D:A0:DC:F6:6C:56:1E:D2:25:C5:E3:EE:5D:0C:70:ED:71:E7:72:AA
    X509v3 Authority Key Identifier:
        keyid:4D:A0:DC:F6:6C:56:1E:D2:25:C5:E3:EE:5D:0C:70:ED:71:E7:72:AA

    X509v3 Basic Constraints:
        CA:TRUE
    Signature Algorithm: sha256WithRSAEncryption
        24:0a:38:57:49:e5:35:05:58:d9:88:03:eb:3a:8c:5b:0d:88:
        70:58:ea:77:b2:4c:37:ff:87:52:b7:f3:bd:0f:6f:5e:7c:fc:
        28:16:37:19:23:d0:90:af:ed:1e:f3:36:ee:9d:66:0e:7c:07:
        5b:7d:0a:2a:fa:80:8c:6a:35:48:2d:50:9e:d2:f4:fc:d1:2a:
        ed:f5:7f:e4:d9:ec:ac:09:10:52:5c:b9:c7:68:4a:91:98:33:
        95:c3:23:4a:06:ca:ec:d3:ef:46:94:92:61:88:e4:e2:f5:db:
        c1:7a:a7:98:9d:59:0d:43:c2:2a:46:11:74:53:44:37:08:cd:
        b1:99:36:b6:3f:5e:51:f2:8c:d7:a0:0c:c5:9f:68:ba:2b:ab:
        7a:57:1f:fd:c9:44:0d:b9:39:6e:52:8c:09:8b:eb:5f:ea:3d:
        d4:3d:05:17:1a:7f:47:92:38:94:1d:e0:59:d2:66:bb:37:95:
        1d:11:4b:70:a1:89:1f:09:5a:25:dc:80:ee:27:17:7e:4a:cc:
        32:63:1d:e2:89:27:b1:44:99:9f:fb:4d:45:31:23:49:7b:ba:
        21:05:eb:d8:8a:b3:d0:72:c0:19:97:2a:59:4b:d1:12:ce:04:
        c4:c6:61:6f:19:e4:c2:fa:6a:0f:c7:70:c9:08:85:0c:65:97:
        83:41:c6:4b

  • Convert certificate from PEM to DER using the openssl x509 command.

    Only a DER format encoded certificate is supported. After conversion, save PK.der for use:

    openssl x509 -in PK.crt -outform der -out PK.der

Using Microsoft Tools

Microsoft documents explain how to use Microsoft tools to generate a secure boot key, which we’ll summarize below.

  • Using certutil.exe to list the Cryptographic Service Providers (CSP)

    For the detailed information of each Microsoft Cryptographic Service Provider, check the Microsoft CRP document

    Here, we chose “Microsoft Strong Cryptographic Provider” for example:

    C:\\CertReq\\test> certutil -csplist
Provider Name: Microsoft Base Cryptographic Provider v1.0
Provider Type: 1 - PROV_RSA_FULL

Provider Name: Microsoft Base DSS and Diffie-Hellman Cryptographic Provider
Provider Type: 13 - PROV_DSS_DH

Provider Name: Microsoft Base DSS Cryptographic Provider
Provider Type: 3 - PROV_DSS

Provider Name: Microsoft Base Smart Card Crypto Provider
Provider Type: 1 - PROV_RSA_FULL

Provider Name: Microsoft DH SChannel Cryptographic Provider
Provider Type: 18 - PROV_DH_SCHANNEL

Provider Name: Microsoft Enhanced Cryptographic Provider v1.0
Provider Type: 1 - PROV_RSA_FULL

Provider Name: Microsoft Enhanced DSS and Diffie-Hellman Cryptographic Provider
Provider Type: 13 - PROV_DSS_DH

Provider Name: Microsoft Enhanced RSA and AES Cryptographic Provider
Provider Type: 24 - PROV_RSA_AES

Provider Name: Microsoft RSA SChannel Cryptographic Provider
Provider Type: 12 - PROV_RSA_SCHANNEL

Provider Name: Microsoft Strong Cryptographic Provider
Provider Type: 1 - PROV_RSA_FULL

Provider Name: Microsoft Software Key Storage Provider

Provider Name: Microsoft Passport Key Storage Provider

Provider Name: Microsoft Platform Crypto Provider

Provider Name: Microsoft Smart Card Key Storage Provider
CertUtil: -csplist command completed successfully.

  • Create request inf file, for example:

    [Version]
Signature= "$Windows NT$"
[NewRequest]
ValidityPeriod = Years
ValidityPeriodUnits = 6
Subject = "CN=Corporation TODO Platform Key,O=TODO Corporation,L=TODO_City,S=TODO_State,C=TODO_Country"
MachineKeySet = true
RequestType=Cert
Exportable = FALSE
HashAlgorithm = SHA256
KeyAlgorithm = RSA
KeyLength = 2048
ProviderName = "Microsoft Strong Cryptographic Provider"
KeyUsage = 0xf0

  • Generate the Platform Key using certreq.exe:

    C:\WINDOWS\system32>certreq.exe -v -new -binary request.inf PKtestDER.cer
Cert: 4 -> 4
Years: 6 -> 6
Installed Certificate:
Serial Number: 285c6f1ec39cc186495f8e55fa053593
Subject: CN=Intel Platform Key, O=Intel, L=Shanghai, S=Shanghai, C=CN
NotBefore: 3/30/2021 10:30 55.000s
NotAfter: 3/30/2027 10:40 55.000s
Thumbprint: 8d79139f90b9fa47200eedbc8c29039869cc4adc
Microsoft Strong Cryptographic Provider
c387aac7266d5db5d81da8a6aa21c703_163d773d-a567-4430-aabf-893dc207fa3d

CertReq: Certificate Created and Installed

  • Validate the Platform Key certificate has been generated correctly:

    C:\\PKtest> certutil -store -v my "3f675d4b64156f9c48ccf30793121147"
my "Personal"
================ Certificate 0 ================
X509 Certificate:
Version: 3
Serial Number: 3f675d4b64156f9c48ccf30793121147
Signature Algorithm:
    Algorithm ObjectId: 1.2.840.113549.1.1.11 sha256RSA
    Algorithm Parameters:
    05 00
Issuer:
    CN=Intel Platform Key
    O=Intel
    L=Shanghai
    S=Shanghai
    C=CN
    Name Hash(sha1): 732312795479b01208e0ade51c695eddd8f2b2d7
    Name Hash(md5): 9264adf01062b20e8fe4351369c55cc4

 NotBefore: 6/26/2019 10:40 AM
 NotAfter: 6/26/2025 10:50 AM

Subject:
    CN=Intel Platform Key
    O=Intel
    L=Shanghai
    S=Shanghai
    C=CN
    Name Hash(sha1): 732312795479b01208e0ade51c695eddd8f2b2d7
    Name Hash(md5): 9264adf01062b20e8fe4351369c55cc4

Public Key Algorithm:
    Algorithm ObjectId: 1.2.840.113549.1.1.1 RSA
    Algorithm Parameters:
    05 00
Public Key Length: 2048 bits
Public Key: UnusedBits = 0
    0000 30 82 01 0a 02 82 01 01 00 b9 72 bb ae ff 44 55
    0010 01 a5 53 6c bd b1 6e b1 32 4a e5 07 04 f9 97 41
    0020 49 a5 95 c9 77 b7 db c0 b0 0d 51 6a 17 d4 a1 91
    0030 21 8b 1c 14 8a 29 f2 45 78 c0 d3 d3 99 19 b6 de
    0040 8b cd 43 05 61 95 d1 c1 84 97 83 c7 ce 93 c7 9a
    0050 90 37 ba 9d 7a 2a d1 6b ad f6 ba da 6d 18 1a ae
    0060 ec 16 80 fe 29 4e 25 8a 2d 22 bd fb 25 02 f3 f3
    0070 ad ae 0e df 37 4b 9d e0 b1 cb b8 40 d2 ff c8 bd
    0080 6b bc 9f 61 68 be d4 33 61 01 b7 b9 ef f3 32 ee
    0090 7e b4 24 c3 68 9c 19 85 4a d6 7f e6 8b 28 81 5f
    00a0 7a 41 fa f7 0c 21 c2 10 1f df b2 89 9d 2d 1a b8
    00b0 ac 9f 09 11 c9 85 1d fb 96 00 55 95 73 d9 d5 ae
    00c0 c2 9e 10 8b c8 7d ec 6c d9 b1 15 80 50 3d 4e 25
    00d0 cb 8a d7 fc 22 27 a7 be 71 15 22 86 0e 88 e9 c0
    00e0 b6 af e6 9b 56 0a 99 6f 88 c7 4c e3 15 dc 6f 03
    00f0 8a b3 21 cc 09 df 8c 3b aa c0 2d 31 0b 39 01 13
    0100 29 e4 f4 85 8e f7 69 db 05 02 03 01 00 01
Certificate Extensions: 2
    2.5.29.15: Flags = 1(Critical), Length = 4
    Key Usage
        Digital Signature, Non-Repudiation, Key Encipherment, Data Encipherment (f0)

    2.5.29.14: Flags = 0, Length = 16
    Subject Key Identifier
        29c42c8b73d48fb46118895ae59806eac7bf0098

Signature Algorithm:
    Algorithm ObjectId: 1.2.840.113549.1.1.11 sha256RSA
    Algorithm Parameters:
    05 00

Signature: UnusedBits=0
    0000 d4 89 92 e6 e1 ef 7e ce d3 c6 c2 b2 15 63 5c 68
    0010 ea 16 13 7e 90 81 e3 75 64 75 da ac 85 fc c6 3a
    0020 65 3b 60 1e 81 2d 20 58 ec b3 07 3c a3 a8 8a 57
    0030 cf 33 a2 8c 08 fe 74 2b c5 d9 e7 f2 f7 69 8d ca
    0040 68 81 33 3d 5c 25 63 60 17 51 4e 0c 1d bd de 68
    0050 07 52 c6 50 da d9 5e 5b bd 4f 33 84 0c f8 ea 61
    0060 f9 c3 00 db 78 f6 b2 4f 4e 4b 8d cf c9 0f d6 8a
    0070 5c f2 8b 87 0d a5 a5 5e ab ce ac a4 ff dd d2 aa
    0080 4c 22 8a c2 3e 23 7c de 4e 1c 18 f5 f9 a3 c1 4e
    0090 b5 1e 9a af 92 0e 20 0e 17 82 2f 0c b4 c4 a3 f1
    00a0 32 5a 0f e8 63 3e 5e 36 a2 8c ea de 02 78 58 b8
    00b0 5a 0d d3 82 e4 b1 a6 72 9a dc 4a dc 5b 93 de 3c
    00c0 2c ea b0 8d a5 6e 5c d6 c7 f8 78 ef 56 16 ed 7f
    00d0 1e a5 5b a2 35 87 41 4d 5c 9d 34 c9 5b 82 68 94
    00e0 8a 52 9c 8e 80 50 0d d7 10 34 cb 9c 96 8a b3 5e
    00f0 9c bb bd 07 b5 18 b0 ea d2 93 8f 79 e9 dd 32 7a
Signature matches Public Key
Root Certificate: Subject matches Issuer
Key Id Hash(rfc-sha1): 29c42c8b73d48fb46118895ae59806eac7bf0098
Key Id Hash(sha1): 2e442e6469555a714423002b2e0748b373a27952
Key Id Hash(bcrypt-sha1): 66f3c2ecf18079b65d6de0b85be1786749a9eb75
Key Id Hash(bcrypt-sha256): edd9c90796d56e97db92f506953da26c44d7e8640875c3b60e5788f4cd5f7058
Key Id Hash(md5): 99e508cd7c5c5e2077648312097c18ab
Key Id Hash(sha256): 3401abc0a80dc1731990b0a99a1b5c7e1e60e107a667b295ced40a2056e43ce4
Key Id Hash(pin-sha256): 0wf9owhuRaJxiwsN4Mt8zAaXgTrp3dMJFopvr+oB1wA=
Key Id Hash(pin-sha256-hex): d307fda3086e45a2718b0b0de0cb7ccc0697813ae9ddd309168a6fafea01d700
Cert Hash(md5): e95f4760524981cf90bc3198e3075f44
Cert Hash(sha1): ff2771bd5bd1f7086ab96fb9532b594ed8619c3b
Cert Hash(sha256): 3abc3ab573d67e1fb491b2fd7e4ae0e5d9941ac7d55ee085c1d73d684891001a
Signature Hash: 4106dbf78737c3b54009b231eb9fe00e57a1ac6c94e0d5046e9bc7a62febde85

  CERT_REQUEST_ORIGINATOR_PROP_ID(71):
    xyzzy.ccr.corp.intel.com

  CERT_KEY_PROV_INFO_PROP_ID(2):
    Key Container = 3d40ebea7d109ee93b238b96721f0e6d_4be58f30-7127-42f5-9b76-f47187495247
    Simple container name: {EA75381E-6D9B-4BDC-B6C7-5144C96507DD}
    Provider = Microsoft Strong Cryptographic Provider
    ProviderType = 1
    Flags = 20 (32)

  CRYPT_MACHINE_KEYSET -- 20 (32)
    KeySpec = 2 -- AT_SIGNATURE

  CERT_SUBJECT_PUB_KEY_BIT_LENGTH_PROP_ID(92):
    0x00000800 (2048)

  CERT_SHA1_HASH_PROP_ID(3):
    ff2771bd5bd1f7086ab96fb9532b594ed8619c3b

  CERT_SUBJECT_PUBLIC_KEY_MD5_HASH_PROP_ID(25):
    99e508cd7c5c5e2077648312097c18ab

  CERT_KEY_IDENTIFIER_PROP_ID(20):
    29c42c8b73d48fb46118895ae59806eac7bf0098

  CERT_SIGNATURE_HASH_PROP_ID(15) disallowedHash:
    4106dbf78737c3b54009b231eb9fe00e57a1ac6c94e0d5046e9bc7a62febde85

  CERT_MD5_HASH_PROP_ID(4):
    e95f4760524981cf90bc3198e3075f44

  CERT_ACCESS_STATE_PROP_ID(14):
    AccessState = 6

  CERT_ACCESS_STATE_SYSTEM_STORE_FLAG -- 2

  CERT_ACCESS_STATE_LM_SYSTEM_STORE_FLAG -- 4
    Provider = Microsoft Strong Cryptographic Provider
    ProviderType = 1
    Simple container name: {EA75381E-6D9B-4BDC-B6C7-5144C96507DD}

  RSA

  PP_KEYSTORAGE = 1

  CRYPT_SEC_DESCR -- 1

  KP_PERMISSIONS = 3b (59)

  CRYPT_ENCRYPT -- 1

  CRYPT_DECRYPT -- 2

  CRYPT_READ -- 8

  CRYPT_WRITE -- 10 (16)

  CRYPT_MAC -- 20 (32)

  D:PAI(A;;GAGR;;;BA)(A;;GAGR;;;SY)

    Allow Full Control BUILTIN\\Administrators
    Allow Full Control NT AUTHORITY\\SYSTEM

Private key is NOT exportable
Signature test passed
CertUtil: -store command completed successfully.

Download KEK and DB From Microsoft

KEK (Key Exchange Key):

Microsoft Corporation KEK CA 2011: allows updates to DB and DBX.

DB (Allowed Signature database):

Microsoft Windows Production CA 2011: This CA in the Signature Database (DB) allows Windows to boot.

Microsoft Corporation UEFI CA 2011: Microsoft signer for third party UEFI binaries via DevCenter program.

Compile OVMF With Secure Boot Support

git clone https://github.com/projectacrn/acrn-edk2.git

cd acrn-edk2

git checkout -b ovmf b64fe247c434e2a4228b9804c522575804550f82

git submodule update --init CryptoPkg/Library/OpensslLib/openssl

source edksetup.sh
make -C BaseTools

Edit the Conf/target.txt file and set these values:

ACTIVE_PLATFORM = OvmfPkg/OvmfPkgX64.dsc
TARGET_ARCH = X64
TOOL_CHAIN_TAG = GCC5

Then continue doing the build:

build -DFD_SIZE_2MB -DDEBUG_ON_SERIAL_PORT=TRUE -DSECURE_BOOT_ENABLE

Notes:

  • source edksetup.sh, this step is needed for compilation every time a shell is created.

  • This will generate the fw section at Build/OvmfX64/DEBUG_GCC5/FV/OVMF_CODE.fd or Build/OvmfX64/RELEASE_GCC5/FV/OVMF_CODE.fd

    This will also generate an empty template VARS file at Build/OvmfX64/DEBUG_GCC5/FV/OVMF_VARS.fd or Build/OvmfX64/RELEASE_GCC5/FV/OVMF_VARS.fd

    Both OVMF_CODE.fd and OVMF_VARS.fd will be used later.

  • Make sure your GCC is 5.X. GCC 6 and above is NOT supported.

Use QEMU to Inject Secure Boot Keys Into OVMF

We follow the openSUSE: UEFI Secure boot using qemu-kvm document to import PK, KEK, and DB into OVMF, Ubuntu 16.04 used.

  1. Install KVM, QEMU

  2. Prepare the environment

    1. Create a OVMFKeys working directory:

      mkdir OVMFKeys

    2. Copy the build out OVMF binary into OVMFKeys:

      cp edk2/Build/OvmfX64/DEBUG_GCC5/FV/OVMF_CODE.fd OVMFKeys
cp edk2/Build/OvmfX64/DEBUG_GCC5/FV/OVMF_VARS.fd OVMFKeys

    3. copy OVMF_CODE_QEMU.fd into OVMFKeys:

      cp OVMF_CODE_QEMU.fd OVMFKeys

    4. Make a working directory for hda-contents:

      cd OVMFKeys
mkdir hda-contents

    5. Copy PK, KEK and DB into hda-contents:

      cp PKtestDER.cer hda-contents
cp MicCorKEKCA2011_2011-06-24.crt hda-contents
cp MicWinProPCA2011_2011-10-19.crt hda-contents

  3. Use QEMU to inject secure boot keys

    1. Run qemu-system-x86_64 to launch virtual machine:

      cd OVMFKeys
qemu-system-x86_64 -L . \
  -drive if=pflash,format=raw,readonly,file=OVMF_CODE_QEMU.fd \
  -drive if=pflash,format=raw,file=OVMF_VARS.fd \
  -hda fat:hda-contents \
  -net none

      After booting, you can see the UEFI shell.

      ../_images/waag_secure_boot_image5.png

    2. Enter “exit” to close UEFI shell and enter UEFI configuration menu.

      ../_images/waag_secure_boot_image6.png

    3. Go to secure boot configuration (Device Manager / Secure Boot Configuration / Secure Boot Mode) and change from “Standard Mode” to “Custom Mode”.

      ../_images/waag_secure_boot_image7.png

      After change to “Custom Mode”, “Custom Secure Boot Options” will show up, click and enter.

      ../_images/waag_secure_boot_image8.png

    4. Import PK

      PK Options / Enroll PK / Enroll PK Using File: select the only one HD, space select PKtestDer.cer. (Note: only DER format certificate is supported.)

      ../_images/waag_secure_boot_image9.png

      Then, select “Commit Changes and Exit”, PK will be imported into OVMF.

    5. Import KEK

      The process is the same as import PK, bit select “KEK options” to inject “Microsoft Corporation KEK CA 2011”.

      KEK Options / Enroll KEK / Enroll KEK Using File: select the only one HD, space select MicCorKEKCA2011_2011-06-24.crt. Commit Changes and Exit.

    6. Import DB

      Use the same process to inject “Microsoft Windows Production CA 2011”.

      DB Options / Enroll Signature / Enroll Signature Using File: select the only one HD, space select MicWinProPCA2011_2011-10-19.crt. Commit Changes and Exit.

      Repeat the steps to inject “Microsoft Corporation UEFI CA 2011”.

      DB Options / Enroll Signature / Enroll Signature Using File: select the only one HD, space select MicCorUEFCA2011_2011-06-27.crt. Commit Changes and Exit.

      After import PK, KEK and DB, the secure boot state is now “Enabled”.

      ../_images/waag_secure_boot_image10.png

  4. Generate OVMF.fd for ACRN with the updated keys manually:

    cat /path/to/OVMF_VARS.fd /path/to/OVMF_CODE.fd > OVMF.fd

  5. Update OVMF.fd into ACRNGT+OVMF+Win10 to start Windows.

Notes:

  1. According to Microsoft documentation, after enabling secure boot, the kernel mode driver must be signed by a trusted certification authority (CA). Specify the acrn-dm parameter --windows to use the Windows ORACLE virtio device driver. The default REDHAT virtio device driver is not signed and may lead to problems in the secure boot process.

  2. A cross-signed driver using a SHA-1 or SHA-256 certificate issued after July 29th, 2015 is not recommended for Windows 10.

  3. After enable secure boot, standard mechanisms such as kernel debugging and test signing will not be permitted.

See these references for more information: