PPML: Initiate doc for verificationCLI (#5770)

* Initiate doc for verificationCLI and refine

* Update README.md

Co-authored-by: xiangyuT <[email protected]>

scala/ppml/src/main/scala/com/intel/analytics/bigdl/ppml/attestation/README.md

@@ -4,16 +4,54 @@ Support Grapmine, Occlum and SGX SDK.
 
 ## Environment
 You should have an available attestation service to attest with. You can use `EHSMAttestationService` and configure eHSM-KMS according to [this link](https://github.com/intel-analytics/BigDL/tree/main/ppml/services/pccs-ehsm/kubernetes), or you can just use `DummyAttestationService` for debug. 
-To enable bi-attestation, you also need SGX SDK to fulfill quote verification. [Here](https://github.com/intel-analytics/BigDL-core/tree/master/ppml#requirements) is the guide to install SGX SDK with verification libs.
+
+### Bidirectional Attestation
+To enable bidirectional attestation, you also need SGX SDK to fulfill quote verification. Here is the guide to install SGX SDK with related libs. 
+
+```bash
+wget https://download.01.org/intel-sgx/sgx-linux/2.16/as.ld.objdump.r4.tar.gz 
+tar -zxf as.ld.objdump.r4.tar.gz
+sudo cp external/toolset/ubuntu20.04/* /usr/local/bin
+
+wget https://download.01.org/intel-sgx/sgx-dcap/1.13/linux/distro/ubuntu20.04-server/sgx_linux_x64_sdk_2.16.100.4.bin
+#choose to install the sdk into the /opt/intel
+chmod a+x ./sgx_linux_x64_sdk_2.16.100.4.bin && sudo ./sgx_linux_x64_sdk_2.16.100.4.bin
+
+source /opt/intel/sgxsdk/environment
+
+cd /opt/intel
+
+wget https://download.01.org/intel-sgx/sgx-dcap/1.13/linux/distro/ubuntu20.04-server/sgx_debian_local_repo.tgz
+
+tar xzf sgx_debian_local_repo.tgz
+
+echo 'deb [trusted=yes arch=amd64] file:///opt/intel/sgx_debian_local_repo focal main' | tee /etc/apt/sources.list.d/intel-sgx.list
+
+wget -qO - https://download.01.org/intel-sgx/sgx_repo/ubuntu/intel-sgx-deb.key | apt-key add -
+
+sudo apt-get update
+
+sudo apt-get install -y libsgx-enclave-common-dev  libsgx-ae-qe3 libsgx-ae-qve libsgx-urts libsgx-dcap-ql libsgx-dcap-default-qpl libsgx-dcap-quote-verify-dev libsgx-dcap-ql-dev libsgx-dcap-default-qpl-dev libsgx-quote-ex-dev libsgx-uae-service libsgx-ra-network libsgx-ra-uefi
+```
+
+And you need to configure PCCS in `/etc/sgx_default_qcnl.conf`.
+
+```bash
+# PCCS server address
+PCCS_URL=https://your_pccs_url/sgx/certification/v3/
+
+# To accept insecure HTTPS certificate, set this option to FALSE
+USE_SECURE_CERT=FALSE
+```
 
 ## Usage
 You can attest your environment with AttestationCLI by command like:
 ```bash
-java -cp [dependent-jars] com.intel.analytics.bigdl.ppml.attestation.AttestationCLI -i <appID> -k <appKey> -u <asURL> -t <asType> -c <challenge> -p <userReport> 
+java -cp [dependent-jars] com.intel.analytics.bigdl.ppml.attestation.AttestationCLI -i <appID> -k <apiKey> -u <asURL> -t <asType> -c <challenge> -p <userReport> 
 ```
 
 ## Parameters
-`-i` **appID** , `-k` **appKey** The appID and appKey pair generated by your attestation service. It is a gap that BigDL names the key as `appkey` while EHSM refers it as `apikey`. We will also turn to `apikey` in the future.
+`-i` **appID** , `-k` **apiKey** The appID and apipey pair generated by your attestation service. 
 
 `-u` **asURL** URL of attestation service. Should match the format `<ip_address>:<port>`, default is `127.0.0.1:9000`
 
@@ -22,3 +60,29 @@ java -cp [dependent-jars] com.intel.analytics.bigdl.ppml.attestation.Attestation
 `-c` **challenge** Challenge to get quote of attestation service which will be verified by local SGX SDK. Used only for bi-attestation. Should be a BASE64 string, default is "" and will skip bi-attestation.
 
 `-p` **userReport** User report to generate quote and attested by attestation service. Default is `test`.
+
+# Attestation Service Verification Interface
+
+You can verify Attestation Service (eHSM for example) with VerificationCLI. It will first get quote from Attestation Service and then verify the quote with SGX SDK.
+
+## Environment 
+You can follow [this guide](#bi-attestation) to install SGX SDK and related DCAP libraries.
+
+## Usage
+You can attest the attestation service with VerificationCLI by command like:
+```bash
+java -cp [dependent-jars] com.intel.analytics.bigdl.ppml.attestation.VerificationCLI -i <appID> -k <apiKey> -u <asURL> -t <asType> -c <challenge>
+```
+Or you can use `verify-attestation-service.sh` to verify the attestation service quote.
+```bash
+bash verify-attestation-service.sh
+```
+
+## Parameters
+`-i` **appID** , `-k` **apiKey** The appID and apiKey pair generated by your attestation service. 
+
+`-u` **asURL** URL of attestation service. Should match the format `<ip_address>:<port>`, default is `127.0.0.1:9000`
+
+`-t` **asType** Type of attestation service. Currently support `EHSMAttestationService`.
+
+`-c` **challenge** Challenge to get quote of attestation service which will be verified by local SGX SDK. Should be a BASE64 string.