Code Quality: Auth token parsing errors silently discarded

[drmingdrmer]

Summary

Authentication token parsing silently discards errors using .ok(), making debugging auth failures difficult.

Location

crates/service/src/api/grpc/grpc_service.rs:201-202

.and_then(|v| v.to_bytes().ok())
.and_then(|b| String::from_utf8(b.to_vec()).ok())

Problem

When token parsing fails, users get a generic "unauthenticated" error with no context about WHY the token was invalid:

• Malformed binary tokens (could indicate protocol issues)
• Invalid UTF-8 in tokens (could indicate corruption)
• Buffer issues

Developers debugging auth failures have no clue whether the token was malformed, corrupted, or simply wrong.

Impact

• Difficult to debug authentication issues
• Silent masking of protocol/encoding problems
• Poor observability for security events

Suggested Fix

Log the specific parsing failures before converting to Status:

let token = metadata
    .get_bin("auth-token-bin")
    .and_then(|v| v.to_bytes().map_err(|e| {
        warn!("Token bytes error: {}", e);
        e
    }).ok())
    .and_then(|b| String::from_utf8(b.to_vec()).map_err(|e| {
        warn!("Token UTF-8 error: {}", e);
        e
    }).ok())
    .ok_or_else(|| Status::unauthenticated("Invalid or missing auth-token-bin"))?;

Priority

P3 - Observability improvement