[Credential Offer] It's possible to receive connection-less credential offer from removed contact

[AlexanderShenshin]

Description of problem

It appears to be possible to receive credential offer from already removed contact. It will be handled as connection-less under the hood and will display Unknown contact label in UI. Such message cannot be normally processed by the user.

It looks like the actual reason is following:

• According to implementation, Unknown contact label is displayed in case if there is no connection ID in credential offer record
• It’s possible because AFJ will consider message as connection-less if connection cannot be found by sender/recipient keys
• Scenario where it’s possible - removed contact
• Normally, if contact was already removed, mediator will not send messages from this contact as mobile wallet will remove it’s connection key by sending keylist-update message (notify mediator that connection is removed)
• But if keylist-update message was not delivered to mediator or already sent credential offer is stuck because of network delays just before contact removal, above-mentioned issue will appear

Expected behavior

It's probably makes sense to not accept such connection-less credential offers from removed contact, but it's not obvious how exactly such cases should be handled.

Steps to reproduce (for credential offer)

Note: reproduction may be not 100% stable as it depends on network connection and delays

• Add new contact
• Disable internet connection on a device
• Send credential offer from a contact
• In mobile app, open contact details → enable internet connection and quickly remove contact
• Go to the Home screen, wait for Credential Offer to appear and open it

Screenshots and/or log output

Related AFJ logs:

2023-06-06T11:52:13.097Z | AFJ | DEBUG : No connection record found for encrypted message with recipient key z6Mknc8GXEjQ8sFeG9D3224xF1z7ZD94gFAbxk9dB6UuF9qD and sender key z6Mkkxu7Q1YZ6kCERxBpANUeizpuNhr2mvpNoCMEAfnPUDvA 
2023-06-06T11:52:13.101Z | AFJ | DEBUG : Processing credential offer with id 802ee8b9-c586-43e8-b4bf-ced1d04b6173 
2023-06-06T11:52:13.102Z | AFJ | DEBUG : 
[
  "Processing connection-less message with id 802ee8b9-c586-43e8-b4bf-ced1d04b6173",
  {
    "type": "https://didcomm.org/issue-credential/2.0/offer-credential"
  }
]

Environment

• Occurs on Android
• Occurs on iOS

Build #: https://github.com/hyperledger/aries-mobile-agent-react-native/tree/db3f18af25f554cd5d616e977e08551b77791c09

Android Device Model: POCO X3 NFC / MIUI version 12.5.7 (Android version 11 RKQ1.200826.002)

iOS Device Model: iPhone 8 Plus / iOS 16

Severity

• High
• Medium (corner case)
• Low