• Registered: 2018-04-01
  • Posts: 4

Topic: [SOLVED] SGX with WolfSSL error

Hi,

In having trouble verifying a certificate chain with a CA certificate inside an SGX enclave.

When I build libwolfssl with default configuration and with following code with

g++ -g -c -o main.o main.cpp
g++ -o app main.o -Wall -g -fPIC -lwolfssl

The verification works perfectly.

When I build libwolfssl.sgx.static.lib.a for SGX (with default configuration, wolfssl/IDE/LINUX-SGX/sgx_t_static.mk) and an enclave which contains the same code behaves differently.

wolfSSL_CertManagerVerifyBuffer returns ASN_SIG_CONFIRM_E which means the signature could not be verified.

#include <wolfssl/ssl.h>

//This is Intel's AttestationReportSigningCACert.pem
const char* caCertBuf = "-----BEGIN CERTIFICATE-----\n"
"MIIFSzCCA7OgAwIBAgIJANEHdl0yo7CUMA0GCSqGSIb3DQEBCwUAMH4xCzAJBgNV\n"
"BAYTAlVTMQswCQYDVQQIDAJDQTEUMBIGA1UEBwwLU2FudGEgQ2xhcmExGjAYBgNV\n"
"BAoMEUludGVsIENvcnBvcmF0aW9uMTAwLgYDVQQDDCdJbnRlbCBTR1ggQXR0ZXN0\n"
"YXRpb24gUmVwb3J0IFNpZ25pbmcgQ0EwIBcNMTYxMTE0MTUzNzMxWhgPMjA0OTEy\n"
"MzEyMzU5NTlaMH4xCzAJBgNVBAYTAlVTMQswCQYDVQQIDAJDQTEUMBIGA1UEBwwL\n"
"U2FudGEgQ2xhcmExGjAYBgNVBAoMEUludGVsIENvcnBvcmF0aW9uMTAwLgYDVQQD\n"
"DCdJbnRlbCBTR1ggQXR0ZXN0YXRpb24gUmVwb3J0IFNpZ25pbmcgQ0EwggGiMA0G\n"
"CSqGSIb3DQEBAQUAA4IBjwAwggGKAoIBgQCfPGR+tXc8u1EtJzLA10Feu1Wg+p7e\n"
"LmSRmeaCHbkQ1TF3Nwl3RmpqXkeGzNLd69QUnWovYyVSndEMyYc3sHecGgfinEeh\n"
"rgBJSEdsSJ9FpaFdesjsxqzGRa20PYdnnfWcCTvFoulpbFR4VBuXnnVLVzkUvlXT\n"
"L/TAnd8nIZk0zZkFJ7P5LtePvykkar7LcSQO85wtcQe0R1Raf/sQ6wYKaKmFgCGe\n"
"NpEJUmg4ktal4qgIAxk+QHUxQE42sxViN5mqglB0QJdUot/o9a/V/mMeH8KvOAiQ\n"
"byinkNndn+Bgk5sSV5DFgF0DffVqmVMblt5p3jPtImzBIH0QQrXJq39AT8cRwP5H\n"
"afuVeLHcDsRp6hol4P+ZFIhu8mmbI1u0hH3W/0C2BuYXB5PC+5izFFh/nP0lc2Lf\n"
"6rELO9LZdnOhpL1ExFOq9H/B8tPQ84T3Sgb4nAifDabNt/zu6MmCGo5U8lwEFtGM\n"
"RoOaX4AS+909x00lYnmtwsDVWv9vBiJCXRsCAwEAAaOByTCBxjBgBgNVHR8EWTBX\n"
"MFWgU6BRhk9odHRwOi8vdHJ1c3RlZHNlcnZpY2VzLmludGVsLmNvbS9jb250ZW50\n"
"L0NSTC9TR1gvQXR0ZXN0YXRpb25SZXBvcnRTaWduaW5nQ0EuY3JsMB0GA1UdDgQW\n"
"BBR4Q3t2pn680K9+QjfrNXw7hwFRPDAfBgNVHSMEGDAWgBR4Q3t2pn680K9+Qjfr\n"
"NXw7hwFRPDAOBgNVHQ8BAf8EBAMCAQYwEgYDVR0TAQH/BAgwBgEB/wIBADANBgkq\n"
"hkiG9w0BAQsFAAOCAYEAeF8tYMXICvQqeXYQITkV2oLJsp6J4JAqJabHWxYJHGir\n"
"IEqucRiJSSx+HjIJEUVaj8E0QjEud6Y5lNmXlcjqRXaCPOqK0eGRz6hi+ripMtPZ\n"
"sFNaBwLQVV905SDjAzDzNIDnrcnXyB4gcDFCvwDFKKgLRjOB/WAqgscDUoGq5ZVi\n"
"zLUzTqiQPmULAQaB9c6Oti6snEFJiCQ67JLyW/E83/frzCmO5Ru6WjU4tmsmy8Ra\n"
"Ud4APK0wZTGtfPXU7w+IBdG5Ez0kE1qzxGQaL4gINJ1zMyleDnbuS8UicjJijvqA\n"
"152Sq049ESDz+1rRGc2NVEqh1KaGXmtXvqxXcTB+Ljy5Bw2ke0v8iGngFBPqCTVB\n"
"3op5KBG3RjbF6RRSzwzuWfL7QErNC8WEy5yDVARzTA5+xmBc388v9Dm21HGfcC8O\n"
"DD+gT9sSpssq0ascmvH49MOgjt1yoysLtdCtJW/9FZpoOypaHx0R+mJTLwPXVMrv\n"
"DaVzWh5aiEx+idkSGMnX\n"
"-----END CERTIFICATE-----";

//This is what comes back in X-IASReport-Signing-Certificate header
const char* certChainBuf = "-----BEGIN CERTIFICATE-----\n"
"MIIEoTCCAwmgAwIBAgIJANEHdl0yo7CWMA0GCSqGSIb3DQEBCwUAMH4xCzAJBgNV\n"
"BAYTAlVTMQswCQYDVQQIDAJDQTEUMBIGA1UEBwwLU2FudGEgQ2xhcmExGjAYBgNV\n"
"BAoMEUludGVsIENvcnBvcmF0aW9uMTAwLgYDVQQDDCdJbnRlbCBTR1ggQXR0ZXN0\n"
"YXRpb24gUmVwb3J0IFNpZ25pbmcgQ0EwHhcNMTYxMTIyMDkzNjU4WhcNMjYxMTIw\n"
"MDkzNjU4WjB7MQswCQYDVQQGEwJVUzELMAkGA1UECAwCQ0ExFDASBgNVBAcMC1Nh\n"
"bnRhIENsYXJhMRowGAYDVQQKDBFJbnRlbCBDb3Jwb3JhdGlvbjEtMCsGA1UEAwwk\n"
"SW50ZWwgU0dYIEF0dGVzdGF0aW9uIFJlcG9ydCBTaWduaW5nMIIBIjANBgkqhkiG\n"
"9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqXot4OZuphR8nudFrAFiaGxxkgma/Es/BA+t\n"
"beCTUR106AL1ENcWA4FX3K+E9BBL0/7X5rj5nIgX/R/1ubhkKWw9gfqPG3KeAtId\n"
"cv/uTO1yXv50vqaPvE1CRChvzdS/ZEBqQ5oVvLTPZ3VEicQjlytKgN9cLnxbwtuv\n"
"LUK7eyRPfJW/ksddOzP8VBBniolYnRCD2jrMRZ8nBM2ZWYwnXnwYeOAHV+W9tOhA\n"
"ImwRwKF/95yAsVwd21ryHMJBcGH70qLagZ7Ttyt++qO/6+KAXJuKwZqjRlEtSEz8\n"
"gZQeFfVYgcwSfo96oSMAzVr7V0L6HSDLRnpb6xxmbPdqNol4tQIDAQABo4GkMIGh\n"
"MB8GA1UdIwQYMBaAFHhDe3amfrzQr35CN+s1fDuHAVE8MA4GA1UdDwEB/wQEAwIG\n"
"wDAMBgNVHRMBAf8EAjAAMGAGA1UdHwRZMFcwVaBToFGGT2h0dHA6Ly90cnVzdGVk\n"
"c2VydmljZXMuaW50ZWwuY29tL2NvbnRlbnQvQ1JML1NHWC9BdHRlc3RhdGlvblJl\n"
"cG9ydFNpZ25pbmdDQS5jcmwwDQYJKoZIhvcNAQELBQADggGBAGcIthtcK9IVRz4r\n"
"Rq+ZKE+7k50/OxUsmW8aavOzKb0iCx07YQ9rzi5nU73tME2yGRLzhSViFs/LpFa9\n"
"lpQL6JL1aQwmDR74TxYGBAIi5f4I5TJoCCEqRHz91kpG6Uvyn2tLmnIdJbPE4vYv\n"
"WLrtXXfFBSSPD4Afn7+3/XUggAlc7oCTizOfbbtOFlYA4g5KcYgS1J2ZAeMQqbUd\n"
"ZseZCcaZZZn65tdqee8UXZlDvx0+NdO0LR+5pFy+juM0wWbu59MvzcmTXbjsi7HY\n"
"6zd53Yq5K244fwFHRQ8eOB0IWB+4PfM7FeAApZvlfqlKOlLcZL2uyVmzRkyR5yW7\n"
"2uo9mehX44CiPJ2fse9Y6eQtcfEhMPkmHXI01sN+KwPbpA39+xOsStjhP9N1Y1a2\n"
"tQAVo+yVgLgV2Hws73Fc0o3wC78qPEA+v2aRs/Be3ZFDgDyghc/1fgU+7C+P6kbq\n"
"d4poyb6IW8KCJbxfMJvkordNOgOUUxndPHEi/tb/U7uLjLOgPA==\n"
"-----END CERTIFICATE-----\n"
"-----BEGIN CERTIFICATE-----\n"
"MIIFSzCCA7OgAwIBAgIJANEHdl0yo7CUMA0GCSqGSIb3DQEBCwUAMH4xCzAJBgNV\n"
"BAYTAlVTMQswCQYDVQQIDAJDQTEUMBIGA1UEBwwLU2FudGEgQ2xhcmExGjAYBgNV\n"
"BAoMEUludGVsIENvcnBvcmF0aW9uMTAwLgYDVQQDDCdJbnRlbCBTR1ggQXR0ZXN0\n"
"YXRpb24gUmVwb3J0IFNpZ25pbmcgQ0EwIBcNMTYxMTE0MTUzNzMxWhgPMjA0OTEy\n"
"MzEyMzU5NTlaMH4xCzAJBgNVBAYTAlVTMQswCQYDVQQIDAJDQTEUMBIGA1UEBwwL\n"
"U2FudGEgQ2xhcmExGjAYBgNVBAoMEUludGVsIENvcnBvcmF0aW9uMTAwLgYDVQQD\n"
"DCdJbnRlbCBTR1ggQXR0ZXN0YXRpb24gUmVwb3J0IFNpZ25pbmcgQ0EwggGiMA0G\n"
"CSqGSIb3DQEBAQUAA4IBjwAwggGKAoIBgQCfPGR+tXc8u1EtJzLA10Feu1Wg+p7e\n"
"LmSRmeaCHbkQ1TF3Nwl3RmpqXkeGzNLd69QUnWovYyVSndEMyYc3sHecGgfinEeh\n"
"rgBJSEdsSJ9FpaFdesjsxqzGRa20PYdnnfWcCTvFoulpbFR4VBuXnnVLVzkUvlXT\n"
"L/TAnd8nIZk0zZkFJ7P5LtePvykkar7LcSQO85wtcQe0R1Raf/sQ6wYKaKmFgCGe\n"
"NpEJUmg4ktal4qgIAxk+QHUxQE42sxViN5mqglB0QJdUot/o9a/V/mMeH8KvOAiQ\n"
"byinkNndn+Bgk5sSV5DFgF0DffVqmVMblt5p3jPtImzBIH0QQrXJq39AT8cRwP5H\n"
"afuVeLHcDsRp6hol4P+ZFIhu8mmbI1u0hH3W/0C2BuYXB5PC+5izFFh/nP0lc2Lf\n"
"6rELO9LZdnOhpL1ExFOq9H/B8tPQ84T3Sgb4nAifDabNt/zu6MmCGo5U8lwEFtGM\n"
"RoOaX4AS+909x00lYnmtwsDVWv9vBiJCXRsCAwEAAaOByTCBxjBgBgNVHR8EWTBX\n"
"MFWgU6BRhk9odHRwOi8vdHJ1c3RlZHNlcnZpY2VzLmludGVsLmNvbS9jb250ZW50\n"
"L0NSTC9TR1gvQXR0ZXN0YXRpb25SZXBvcnRTaWduaW5nQ0EuY3JsMB0GA1UdDgQW\n"
"BBR4Q3t2pn680K9+QjfrNXw7hwFRPDAfBgNVHSMEGDAWgBR4Q3t2pn680K9+Qjfr\n"
"NXw7hwFRPDAOBgNVHQ8BAf8EBAMCAQYwEgYDVR0TAQH/BAgwBgEB/wIBADANBgkq\n"
"hkiG9w0BAQsFAAOCAYEAeF8tYMXICvQqeXYQITkV2oLJsp6J4JAqJabHWxYJHGir\n"
"IEqucRiJSSx+HjIJEUVaj8E0QjEud6Y5lNmXlcjqRXaCPOqK0eGRz6hi+ripMtPZ\n"
"sFNaBwLQVV905SDjAzDzNIDnrcnXyB4gcDFCvwDFKKgLRjOB/WAqgscDUoGq5ZVi\n"
"zLUzTqiQPmULAQaB9c6Oti6snEFJiCQ67JLyW/E83/frzCmO5Ru6WjU4tmsmy8Ra\n"
"Ud4APK0wZTGtfPXU7w+IBdG5Ez0kE1qzxGQaL4gINJ1zMyleDnbuS8UicjJijvqA\n"
"152Sq049ESDz+1rRGc2NVEqh1KaGXmtXvqxXcTB+Ljy5Bw2ke0v8iGngFBPqCTVB\n"
"3op5KBG3RjbF6RRSzwzuWfL7QErNC8WEy5yDVARzTA5+xmBc388v9Dm21HGfcC8O\n"
"DD+gT9sSpssq0ascmvH49MOgjt1yoysLtdCtJW/9FZpoOypaHx0R+mJTLwPXVMrv\n"
"DaVzWh5aiEx+idkSGMnX\n"
"-----END CERTIFICATE-----";

int verifyCertChain()
{
    int   ret;
    WOLFSSL_CERT_MANAGER* cm = 0;

    cm = wolfSSL_CertManagerNew();
    if (cm == NULL) {
        printf("wolfSSL_CertManagerNew() failed\n");
        return -1;
    }

    ret = wolfSSL_CertManagerLoadCABuffer(cm, (unsigned char*)caCertBuf, strlen(caCertBuf) ,WOLFSSL_FILETYPE_PEM);
    if (ret != SSL_SUCCESS) {
        printf("wolfSSL_CertManagerLoadCA() failed (%d): %s\n",
                ret, wolfSSL_ERR_reason_error_string(ret));
        return -1;
    }

    ret = wolfSSL_CertManagerVerifyBuffer(cm, (unsigned char*)certChainBuf, strlen(certChainBuf), WOLFSSL_FILETYPE_PEM);
    if (ret != SSL_SUCCESS) {
        printf("wolfSSL_CertManagerVerify() failed (%d): %s\n",
                ret, wolfSSL_ERR_reason_error_string(ret));
        return -1;
    }

    return 0;
}

Help?

Thanks,
Ben

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  • From: Bozeman
  • Registered: 2014-05-09
  • Posts: 777

Re: [SOLVED] SGX with WolfSSL error

Hi bendanon,

How are you invoking these once inside the enclave?

1. Did you add a trusted call to invoke verifyCertChain and compile the above into the enclave?
2. Does the above reside outside the enclave and is making trusted calls to  wolfSSL_CertManagerNew, wolfSSL_CertManagerLoadCABuffer, wolfSSL_CertManagerVerifyBuffer inside the enclave?

I'd be happy to try and reproduce the issue on my end but I need to make sure I correctly understand what is running in the untrusted section and what is running in the trusted section before doing so.


Warm Regards,

- Kaleb

Kaleb J. Himes's Website

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3 Reply by bendanon305 (edited by bendanon305 2018-04-02 13:06:27)

  • Registered: 2018-04-01
  • Posts: 4

Re: [SOLVED] SGX with WolfSSL error

Hi Kaleb,

All the code I attached is inside the enclave. I have a trusted call to verifyCertChain which runs entirely inside the enclave.

Thanks!
Ben

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  • From: Bozeman
  • Registered: 2014-05-09
  • Posts: 777

Re: [SOLVED] SGX with WolfSSL error

Thanks Ben for confirming,

I apologize I didn't get time to test this last week, I'll try to get some time set aside for it this week!

Cheers,

Kaleb

Kaleb J. Himes's Website

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  • Registered: 2018-04-01
  • Posts: 4

Re: [SOLVED] SGX with WolfSSL error

Hi,

Still no idea how to solve this one.

Does anyone have a lead?

Thanks,
Ben

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  • From: Bozeman
  • Registered: 2014-05-09
  • Posts: 777

Re: [SOLVED] SGX with WolfSSL error

Hi bendanon,

I sincerely apologize for the delay in getting back to you on this as I had some other tasks come up.

Could you try adding this setting to the C Pre-processor flags in the sgx_t_static.mk 

Wolfssl_C_Extra_Flags += -DFP_MAX_BITS=8192

The cert is using a 3072-bit RSA key which is too large for the default FP_MAX_BITS=4096 in SGX. The FP_MAX_BITS buffer must be at least twice the length of the largest RSA key so for 3072 you could get away with setting it to 6144 but just in case you end up with a 4096-bit RSA key in the future it's best to just set to 8192.

Cheers,

Kaleb

Kaleb J. Himes's Website

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  • Registered: 2018-04-01
  • Posts: 4

Re: [SOLVED] SGX with WolfSSL error

Worked like a charm smile

Thanks a lot!

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