How can i perform a CRL check to a certificate with Security.h

Question

Created Mar ’18

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I am trying to check a certificate whether it is revoked or not with CRL. I downloaded CRL file from the host but I can't find any examples how I can create a trust object or check the certificate. I can validate my certificate with OCSP method but i am stuck in CRL. Appreciate any help 🙂.

Answered by DTS Engineer in 297866022

You should be able to do this by:

Creating a policy object that does whatever standard checking you want; if you don’t need anything special, use
```
SecPolicyCreateBasicX509
```

Calling

SecPolicyCreateRevocation

to create a second policy to check revocation with

kSecRevocationRequirePositiveResponse

and

kSecRevocationCRLMethod

Passing both of those, along with the certificate in question and any intermediate certificates, to
```
SecTrustCreateWithCertificates
```
Doing any extra configuration of the trust object; for example, if certificate was issued by a custom CA, call
```
SecTrustSetAnchorCertificates
```
to trust that CA’s root certificate
Evaluating trust on the trust object

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

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Answer 1

DTS Engineer OP

Apple

Mar ’18

Accepted Answer

You should be able to do this by:

Creating a policy object that does whatever standard checking you want; if you don’t need anything special, use
```
SecPolicyCreateBasicX509
```

Calling

SecPolicyCreateRevocation

to create a second policy to check revocation with

kSecRevocationRequirePositiveResponse

and

kSecRevocationCRLMethod

Passing both of those, along with the certificate in question and any intermediate certificates, to
```
SecTrustCreateWithCertificates
```
Doing any extra configuration of the trust object; for example, if certificate was issued by a custom CA, call
```
SecTrustSetAnchorCertificates
```
to trust that CA’s root certificate
Evaluating trust on the trust object

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

0

Answer 2

digitizedx OP

Nov ’20

Hi,
I did the exact same steps. I can see the request for CRL file going to the distribution point and getting a positive response in Wireshark. But the evaluation is leading to

Code Block INCOMPLETE_REVOCATION_CHECK

for leaf certificate. I cant find any documentation for this. What could this mean. It works fine on non apple OS.

5