SDK 2.0.1's UserNameIdentityTokenHandler encrypts a password longer than 64 bytes
(a private RsaEncryptedSecretPasswordThreshold, no setting) as an RsaEncryptedSecret
with EncryptionAlgorithm=null. SDK 1.5.378 (.106 and .182) decrypts only the legacy
format under RSA policies; its SecurityPolicies.Decrypt answers a null algorithm with
BadIdentityTokenInvalid ("Unexpected encryption algorithm") before any key check.
Every production API key is 65 chars, so no SDK 2 OtOpcUa client could use one
against QA (b8b4c18f), a rollback target or an older third-party server.
LegacyRsaUserNameIdentityTokenHandler (Driver.OpcUaClient.Session, plugged in through
the public UserIdentity(IUserIdentityTokenHandler) ctor) always uses the legacy
format, RSA-OAEP(len|password|serverNonce) under the server certificate, under an RSA
policy. That is what SDK 2 sends for passwords of 64 bytes or less and what SDK 1.5
clients always send. The legacy format has no size limit (the plaintext is
length-framed over as many RSA blocks as it needs), and an SDK 2 server reads both
formats. Policy None, the ECC policies and a missing certificate go to the SDK
handler unchanged.
OpcUaUserIdentityFactory.UserName is now the one UserName identity the driver, the
AdminUI browse and Client.Shared (CLI/UI) present. Client.Shared references .Session
for it.
Tests: handler unit tests (all three RSA policies, the 1.5-required algorithm URI,
SDK 2 server-side decrypt, the session Copy() keeps the type, None unchanged, and an
SDK control pinning the 64/65-byte switch); a Client.Shared identity test; and an
SDK2<->SDK2 integration test where a 65-char key is admitted in both formats and a
wrong 65-char key reaches the key check (BadIdentityTokenRejected). The #800 Windows
gate's SDK 2 CLI 65-char case now gates against the 1.5 server too.
Claude-Session: https://claude.ai/code/session_01GT67ACmpMR7b9LGRPLijMi
The host handed the SDK a provider-less telemetry context, so SDK-side
refusals — identity-token decryption (the SDK 2 RsaEncryptedSecret clock
window, #873), certificate validation, secure-channel faults — left no server
log line (found on windev during the #800 Windows validation). The hosted
service now creates one ServerSdkTelemetry context from its ILoggerFactory
(Warning and above, SDK categories, rate-limited 20/min per category) and
shares it between OtOpcUaSdkServer and the ApplicationInstance; released on
dispose. Test: an untrusted client's rejection reaches the captured log.
Claude-Session: https://claude.ai/code/session_01GT67AD99zQQqpLCVm3p7xk
Joseph Doherty