go auth_error ai_generated true

rpc error: code = Unavailable desc = connection error: desc = "transport: authentication handshake failed: tls: first record does not look like a TLS handshake"

ID: go/grpc-permission-denied-tls-mismatch

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-11-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.40+ active — — —

Root Cause

The client is attempting TLS but the server is serving plaintext (or vice versa). Common when mixing grpc.WithInsecure() with a TLS server or dialing a plaintext port with credentials.

generic

中文

客户端尝试使用 TLS，但服务端提供明文（或反之）。常见于将 grpc.WithInsecure() 与 TLS 服务端混用，或使用凭证拨号明文端口时。

Workarounds

  1. 93% success 
    // TLS server
creds, _ := credentials.NewServerTLSFromFile("server.crt", "server.key")
s := grpc.NewServer(grpc.Creds(creds))
// TLS client
creds, _ := credentials.NewClientTLSFromFile("ca.crt", "")
conn, _ := grpc.Dial(addr, grpc.WithTransportCredentials(creds))
  2. 90% success 
    import "google.golang.org/grpc/credentials/insecure"
conn, _ := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Silences TLS but breaks against a TLS-only server; also disables security in production

  2. 85% fail

    Does not help when the server isn't speaking TLS at all; and it weakens security