ArnEqualsIfExists

Warning:

In spite of the name difference ArnEqualsIfExists behaves exactly the same as ArnLikeIfExists. Switch to ArnLikeIfExists so people don't ask later what in the world you were thinking.

ArnEqualsIfExists

ArnEqualsIfExists compares an ARN in a request to a list of ARN patterns in your policy. The policy values can include asterisks (*) to match multiple characters and question marks (?) to match a single character within an ARN segement. Wildcards cannot be used to span ARN segment, so the partition, service, region, account, and resource must all be present in your policy value, even if they are all wildcards. The comparision is case sensitive.

To match a request, the context key can be absent, but if present it must match at least one of the ARN patterns in your policy.

You can use policy variables in the value of this operator.

ArnEqualsIfExists in an Allow Statement

Click into any of these polices and change them test how they change the result.

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: null

Then the result is:

Allowed Assuming no explicit Deny elsewhere

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: 
    arn:aws:iam::123456789012:role/AdminRole

Then the result is:

Allowed Assuming no explicit Deny elsewhere

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: 
    arn:aws:iam::123456789012:user/User

Then the result is:

Not Allowed Statement does not apply

ArnEqualsIfExists in a Deny Statement

Click into any of these polices and change them test how they change the result.

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: null

Then the result is:

Denied

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: 
    arn:aws:iam::123456789012:role/AdminRole

Then the result is:

Denied

Given the Policy Condition:

"ArnEqualsIfExists": {
  "aws:PrincipalArn": [
    "arn:aws:iam::*:role/*",
    "arn:aws:ec2:*:*:instance/i-?????"
  ]
}

When the Request Context has:

aws:PrincipalArn: 
    arn:aws:iam::123456789012:user/User

Then the result is:

Not Denied May be allowed by another statement