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RSAKeyUsageForLocalAnchorsEnabled

Check RSA key usage for server certificates issued by local trust anchors (obsolete)

OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge version 135.

Supported versions

  • On Windows and macOS since 123, until 135

Description

The X.509 key usage extension declares how the key in a certificate can be used. These instructions ensure certificates aren't used in an unintended context, which protects against a class of cross-protocol attacks on HTTPS and other protocols. HTTPS clients must verify that server certificates match the connection's TLS parameters.

Starting in Microsoft Edge 124, this check is always enabled.

Microsoft Edge 123 and earlier have the following behavior:

If this policy is set to enabled, Microsoft Edge will perform this key check. This helps prevent attacks where an attacker manipulates the browser into interpreting a key in ways that the certificate owner did not intend.

If this policy is set to disabled, Microsoft Edge will skip this key check in HTTPS connections that negotiate TLS 1.2 and use an RSA certificate that chains to a local trust anchor. Examples of local trust anchors include policy-provided or user-installed root certificates. In all other cases, the check is performed independent of this policy's setting.

If this policy is not configured, Microsoft Edge will behave as if the policy is enabled.

This policy is available for administrators to preview the behavior of a future release, which will enable this check by default. At that point, this policy will remain temporarily available for administrators that need more time to update their certificates to meet the new RSA key usage requirements.

Connections that fail this check will fail with the error ERR_SSL_KEY_USAGE_INCOMPATIBLE. Sites that fail with this error likely have a misconfigured certificate. Modern ECDHE_RSA cipher suites use the "digitalSignature" key usage option, while legacy RSA decryption cipher suites use the "keyEncipherment" key usage option. If uncertain, administrators should include both in RSA certificates meant for HTTPS.

The policy has been obsoleted starting from Microsoft Edge version 136, but the key check has been always enabled since Microsoft Edge version 124.

Supported features

  • Can be mandatory: Yes
  • Can be recommended: No
  • Dynamic Policy Refresh: Yes
  • Per Profile: No
  • Applies to a profile that is signed in with a Microsoft account: Yes

Data type

  • Boolean

Windows information and settings

Group Policy (ADMX) info

  • GP unique name: RSAKeyUsageForLocalAnchorsEnabled
  • GP name: Check RSA key usage for server certificates issued by local trust anchors (obsolete)
  • GP path (Mandatory): Administrative Templates/Microsoft Edge
  • GP path (Recommended): N/A
  • GP ADMX file name: MSEdge.admx

Example value

Enabled

Registry settings

  • Path (Mandatory): SOFTWARE\Policies\Microsoft\Edge
  • Path (Recommended): N/A
  • Value name: RSAKeyUsageForLocalAnchorsEnabled
  • Value type: REG_DWORD

Example registry value

0x00000001

Mac information and settings

  • Preference Key name: RSAKeyUsageForLocalAnchorsEnabled
  • Example value:
<true/>

See also