What do the following SSL alert messages mean?

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Article ID: 167220

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Updated On:

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SG-300 SG-600 SG-510 SG-810 SG-9000 SG-900 ProxySG Software - SGOS

Issue/Introduction

This table provides a description of the different SSL alert messages.

 

Alert Code
Alert Message
Description
0
close_notify
Notifies the recipient that the sender will not send any more messages on this connection.
10
unexpected_message
Received an inappropriate message This alert should never be observed in communication between proper implementations. This message is always fatal.
20
bad_record_mac
Received a record with an incorrect MAC. This message is always fatal.
21
decryption_failed
Decryption of a TLSCiphertext record is decrypted in an invalid way: either it was not an even multiple of the block length or its padding values, when checked, were not correct. This message is always fatal.
22
record_overflow
Received a TLSCiphertext record which had a length more than 2^14+2048bytes, or a record decrypted to a TLSCompressed record with more than2^14+1024 bytes. This message is always fatal.
30
decompression_failure
Received improper input, such as data that would expand to excessive length, from the decompression function. This message is always fatal.
40
handshake_failure
Indicates that the sender was unable to negotiate an acceptable set of security parameters given the options available. This is a fatal error.
42
bad_certificate
There is a problem with the certificate, for example, a certificate is corrupt, or a certificate contains signatures that cannot be verified.
43
unsupported_certificate
Received an unsupported certificate type.
44
certificate_revoked
Received a certificate that was revoked by its signer.
45
certificate_expired
Received a certificate has expired or is not currently valid.
46
certificate_unknown
An unspecified issue took place while processing the certificate that made it unacceptable.
47
illegal_parameter
Violated security parameters, such as a field in the handshake was out of range or inconsistent with other fields. This is always fatal.
48
unknown_ca
Received a valid certificate chain or partial chain, but the certificate was not accepted because the CA certificate could not be located or could not be matched with a known, trusted CA. This message is always fatal.
49
access_denied
Received a valid certificate, but when access control was applied, the sender did not proceed with negotiation. This message is always fatal.
50
decode_error
A message could not be decoded because some field was out of the specified range or the length of the message was incorrect. This message is always fatal.
51
decrypt_error
Failed handshake cryptographic operation, including being unable to correctly verify a signature, decrypt a key exchange, or validate a finished message.
60
export_restriction
Detected a negotiation that was not in compliance with export restrictions; for example, attempting to transfer a 1024 bit ephemeral RSA key for the RSA_EXPORT handshake method. This message is always fatal.
70
protocol_version
The protocol version the client attempted to negotiate is recognized, but not supported. For example, old protocol versions might be avoided for security reasons. This message is always fatal.
71
insufficient_security
Failed negotiation specifically because the server requires ciphers more secure than those supported by the client. Returned instead of handshake_failure. This message is always fatal.
80
internal_error
An internal error unrelated to the peer or the correctness of the protocol makes it impossible to continue, such as a memory allocation failure. The error is not related to protocol. This message is always fatal.
90
user_cancelled
Cancelled handshake for a reason that is unrelated to a protocol failure. If the user cancels an operation after the handshake is complete, just closing the connection by sending a close_notify is more appropriate. This alert should be followed by a close_notify. This message is generally a warning.
100
no_renegotiation
Sent by the client in response to a hello request or sent by the server in response to a client hello after initial handshaking. Either of these would normally lead to renegotiation; when that is not appropriate, the recipient should respond with this alert; at that point, the original requester can decide whether to proceed with the connection. One case where this would be appropriate would be where a server has spawned a process to satisfy a request; the process might receive security parameters (key length, authentication, and so on) at start-up and it might be difficult to communicate changes to these parameters after that point. This message is always a warning.
255
unsupported_extension