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Immediate Alert Service not working without security

Hi all,

On SDK 15.0, Immediate Alert Service is not working without a secured BLE link. When peripheral is not paired, this latter doesn't receive any alert from central device.

However, according to BLE specifications, security is not mandatory for this service and its characteristic. This seems to be an issue in SDK 15.0.

In ble_ias.c, changing BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM(&attr_md.write_perm) to BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm) solved my issue.

Best regards,

Joris

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  • Hi Joris,

    The security is specified at the profile level, not for the service or characteristic itself. So for example, the Find Me Profile specification says the following about security:

    This section describes the security requirements for a Find Me Target and Find Me Locator for LE transport. Since there are no topology restrictions imposed by this profile, the requirements are described in terms of GAP Peripheral role (referred to as the Peripheral) and GAP Central role (referred to as the Central).

    The Peripheral shall support LE Security Mode 1 and Security Levels 2 or 3. The Peripheral should use the SM Slave Security Request procedure only when bonded with the Central to inform the Central of its security requirements.

    The Central shall support LE Security Mode 1 and Security Levels 2 and 3.The Central should accept the LE Security Mode and Security Level combination requested by the Peripheral.

Reply
  • Hi Joris,

    The security is specified at the profile level, not for the service or characteristic itself. So for example, the Find Me Profile specification says the following about security:

    This section describes the security requirements for a Find Me Target and Find Me Locator for LE transport. Since there are no topology restrictions imposed by this profile, the requirements are described in terms of GAP Peripheral role (referred to as the Peripheral) and GAP Central role (referred to as the Central).

    The Peripheral shall support LE Security Mode 1 and Security Levels 2 or 3. The Peripheral should use the SM Slave Security Request procedure only when bonded with the Central to inform the Central of its security requirements.

    The Central shall support LE Security Mode 1 and Security Levels 2 and 3.The Central should accept the LE Security Mode and Security Level combination requested by the Peripheral.

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