doc/man3/SSL_alert_type_string.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 SSL_alert_type_string, SSL_alert_type_string_long, SSL_alert_desc_string, SSL_alert_desc_string_long - get textual description of alert information

 =head1 SYNOPSIS

  #include <openssl/ssl.h>

  const char *SSL_alert_type_string(int value);
  const char *SSL_alert_type_string_long(int value);

  const char *SSL_alert_desc_string(int value);
  const char *SSL_alert_desc_string_long(int value);

 =head1 DESCRIPTION

 SSL_alert_type_string() returns a one letter string indicating the
 type of the alert specified by B<value>.

 SSL_alert_type_string_long() returns a string indicating the type of the alert
 specified by B<value>.

 SSL_alert_desc_string() returns a two letter string as a short form
 describing the reason of the alert specified by B<value>.

 SSL_alert_desc_string_long() returns a string describing the reason
 of the alert specified by B<value>.

 =head1 NOTES

 When one side of an SSL/TLS communication wants to inform the peer about
 a special situation, it sends an alert. The alert is sent as a special message
 and does not influence the normal data stream (unless its contents results
 in the communication being canceled).

 A warning alert is sent, when a non-fatal error condition occurs. The
 "close notify" alert is sent as a warning alert. Other examples for
 non-fatal errors are certificate errors ("certificate expired",
 "unsupported certificate"), for which a warning alert may be sent.
 (The sending party may however decide to send a fatal error.) The
 receiving side may cancel the connection on reception of a warning
 alert on it discretion.

 Several alert messages must be sent as fatal alert messages as specified
 by the TLS RFC. A fatal alert always leads to a connection abort.

 =head1 RETURN VALUES

 The following strings can occur for SSL_alert_type_string() or
 SSL_alert_type_string_long():

 =over 4

 =item "W"/"warning"

 =item "F"/"fatal"

 =item "U"/"unknown"

 This indicates that no support is available for this alert type.
 Probably B<value> does not contain a correct alert message.

 =back

 The following strings can occur for SSL_alert_desc_string() or
 SSL_alert_desc_string_long():

 =over 4

 =item "CN"/"close notify"

 The connection shall be closed. This is a warning alert.

 =item "UM"/"unexpected message"

 An inappropriate message was received. This alert is always fatal
 and should never be observed in communication between proper
 implementations.

 =item "BM"/"bad record mac"

 This alert is returned if a record is received with an incorrect
 MAC. This message is always fatal.

 =item "DF"/"decompression failure"

 The decompression function received improper input (e.g. data
 that would expand to excessive length). This message is always
 fatal.

 =item "HF"/"handshake failure"

 Reception of a handshake_failure alert message indicates that the
 sender was unable to negotiate an acceptable set of security
 parameters given the options available. This is a fatal error.

 =item "NC"/"no certificate"

 A client, that was asked to send a certificate, does not send a certificate
 (SSLv3 only).

 =item "BC"/"bad certificate"

 A certificate was corrupt, contained signatures that did not
 verify correctly, etc

 =item "UC"/"unsupported certificate"

 A certificate was of an unsupported type.

 =item "CR"/"certificate revoked"

 A certificate was revoked by its signer.

 =item "CE"/"certificate expired"

 A certificate has expired or is not currently valid.

 =item "CU"/"certificate unknown"

 Some other (unspecified) issue arose in processing the
 certificate, rendering it unacceptable.

 =item "IP"/"illegal parameter"

 A field in the handshake was out of range or inconsistent with
 other fields. This is always fatal.

 =item "DC"/"decryption failed"

 A TLSCiphertext decrypted in an invalid way: either it wasn't an
 even multiple of the block length or its padding values, when
 checked, weren't correct. This message is always fatal.

 =item "RO"/"record overflow"

 A TLSCiphertext record was received which had a length more than
 2^14+2048 bytes, or a record decrypted to a TLSCompressed record
 with more than 2^14+1024 bytes. This message is always fatal.

 =item "CA"/"unknown CA"

 A valid certificate chain or partial chain was received, but the
 certificate was not accepted because the CA certificate could not
 be located or couldn't be matched with a known, trusted CA.  This
 message is always fatal.

 =item "AD"/"access denied"

 A valid certificate was received, but when access control was
 applied, the sender decided not to proceed with negotiation.
 This message is always fatal.

 =item "DE"/"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.

 =item "CY"/"decrypt error"

 A handshake cryptographic operation failed, including being
 unable to correctly verify a signature, decrypt a key exchange,
 or validate a finished message.

 =item "ER"/"export restriction"

 A negotiation not in compliance with export restrictions was
 detected; for example, attempting to transfer a 1024 bit
 ephemeral RSA key for the RSA_EXPORT handshake method. This
 message is always fatal.

 =item "PV"/"protocol version"

 The protocol version the client has attempted to negotiate is
 recognized, but not supported. (For example, old protocol
 versions might be avoided for security reasons). This message is
 always fatal.

 =item "IS"/"insufficient security"

 Returned instead of handshake_failure when a negotiation has
 failed specifically because the server requires ciphers more
 secure than those supported by the client. This message is always
 fatal.

 =item "IE"/"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). This message is always fatal.

 =item "US"/"user canceled"

 This handshake is being canceled for some reason 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.

 =item "NR"/"no renegotiation"

 Sent by the client in response to a hello request or 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, etc.) at startup and it might be
 difficult to communicate changes to these parameters after that
 point. This message is always a warning.

 =item "UP"/"unknown PSK identity"

 Sent by the server to indicate that it does not recognize a PSK
 identity or an SRP identity.

 =item "UK"/"unknown"

 This indicates that no description is available for this alert type.
 Probably B<value> does not contain a correct alert message.

 =back

 =head1 SEE ALSO

 L<ssl(7)>, L<SSL_CTX_set_info_callback(3)>

 =head1 COPYRIGHT

 Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.

 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.

 =cut
	=pod

	=head1 NAME

	SSL_alert_type_string, SSL_alert_type_string_long, SSL_alert_desc_string, SSL_alert_desc_string_long - get textual description of alert information

	=head1 SYNOPSIS

	#include <openssl/ssl.h>

	const char *SSL_alert_type_string(int value);
	const char *SSL_alert_type_string_long(int value);

	const char *SSL_alert_desc_string(int value);
	const char *SSL_alert_desc_string_long(int value);

	=head1 DESCRIPTION

	SSL_alert_type_string() returns a one letter string indicating the
	type of the alert specified by B<value>.

	SSL_alert_type_string_long() returns a string indicating the type of the alert
	specified by B<value>.

	SSL_alert_desc_string() returns a two letter string as a short form
	describing the reason of the alert specified by B<value>.

	SSL_alert_desc_string_long() returns a string describing the reason
	of the alert specified by B<value>.

	=head1 NOTES

	When one side of an SSL/TLS communication wants to inform the peer about
	a special situation, it sends an alert. The alert is sent as a special message
	and does not influence the normal data stream (unless its contents results
	in the communication being canceled).

	A warning alert is sent, when a non-fatal error condition occurs. The
	"close notify" alert is sent as a warning alert. Other examples for
	non-fatal errors are certificate errors ("certificate expired",
	"unsupported certificate"), for which a warning alert may be sent.
	(The sending party may however decide to send a fatal error.) The
	receiving side may cancel the connection on reception of a warning
	alert on it discretion.

	Several alert messages must be sent as fatal alert messages as specified
	by the TLS RFC. A fatal alert always leads to a connection abort.

	=head1 RETURN VALUES

	The following strings can occur for SSL_alert_type_string() or
	SSL_alert_type_string_long():

	=over 4

	=item "W"/"warning"

	=item "F"/"fatal"

	=item "U"/"unknown"

	This indicates that no support is available for this alert type.
	Probably B<value> does not contain a correct alert message.

	=back

	The following strings can occur for SSL_alert_desc_string() or
	SSL_alert_desc_string_long():

	=over 4

	=item "CN"/"close notify"

	The connection shall be closed. This is a warning alert.

	=item "UM"/"unexpected message"

	An inappropriate message was received. This alert is always fatal
	and should never be observed in communication between proper
	implementations.

	=item "BM"/"bad record mac"

	This alert is returned if a record is received with an incorrect
	MAC. This message is always fatal.

	=item "DF"/"decompression failure"

	The decompression function received improper input (e.g. data
	that would expand to excessive length). This message is always
	fatal.

	=item "HF"/"handshake failure"

	Reception of a handshake_failure alert message indicates that the
	sender was unable to negotiate an acceptable set of security
	parameters given the options available. This is a fatal error.

	=item "NC"/"no certificate"

	A client, that was asked to send a certificate, does not send a certificate
	(SSLv3 only).

	=item "BC"/"bad certificate"

	A certificate was corrupt, contained signatures that did not
	verify correctly, etc

	=item "UC"/"unsupported certificate"

	A certificate was of an unsupported type.

	=item "CR"/"certificate revoked"

	A certificate was revoked by its signer.

	=item "CE"/"certificate expired"

	A certificate has expired or is not currently valid.

	=item "CU"/"certificate unknown"

	Some other (unspecified) issue arose in processing the
	certificate, rendering it unacceptable.

	=item "IP"/"illegal parameter"

	A field in the handshake was out of range or inconsistent with
	other fields. This is always fatal.

	=item "DC"/"decryption failed"

	A TLSCiphertext decrypted in an invalid way: either it wasn't an
	even multiple of the block length or its padding values, when
	checked, weren't correct. This message is always fatal.

	=item "RO"/"record overflow"

	A TLSCiphertext record was received which had a length more than
	2^14+2048 bytes, or a record decrypted to a TLSCompressed record
	with more than 2^14+1024 bytes. This message is always fatal.

	=item "CA"/"unknown CA"

	A valid certificate chain or partial chain was received, but the
	certificate was not accepted because the CA certificate could not
	be located or couldn't be matched with a known, trusted CA. This
	message is always fatal.

	=item "AD"/"access denied"

	A valid certificate was received, but when access control was
	applied, the sender decided not to proceed with negotiation.
	This message is always fatal.

	=item "DE"/"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.

	=item "CY"/"decrypt error"

	A handshake cryptographic operation failed, including being
	unable to correctly verify a signature, decrypt a key exchange,
	or validate a finished message.

	=item "ER"/"export restriction"

	A negotiation not in compliance with export restrictions was
	detected; for example, attempting to transfer a 1024 bit
	ephemeral RSA key for the RSA_EXPORT handshake method. This
	message is always fatal.

	=item "PV"/"protocol version"

	The protocol version the client has attempted to negotiate is
	recognized, but not supported. (For example, old protocol
	versions might be avoided for security reasons). This message is
	always fatal.

	=item "IS"/"insufficient security"

	Returned instead of handshake_failure when a negotiation has
	failed specifically because the server requires ciphers more
	secure than those supported by the client. This message is always
	fatal.

	=item "IE"/"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). This message is always fatal.

	=item "US"/"user canceled"

	This handshake is being canceled for some reason 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.

	=item "NR"/"no renegotiation"

	Sent by the client in response to a hello request or 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, etc.) at startup and it might be
	difficult to communicate changes to these parameters after that
	point. This message is always a warning.

	=item "UP"/"unknown PSK identity"

	Sent by the server to indicate that it does not recognize a PSK
	identity or an SRP identity.

	=item "UK"/"unknown"

	This indicates that no description is available for this alert type.
	Probably B<value> does not contain a correct alert message.

	=back

	=head1 SEE ALSO

	L<ssl(7)>, L<SSL_CTX_set_info_callback(3)>

	=head1 COPYRIGHT

	Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.

	Licensed under the Apache License 2.0 (the "License"). You may not use
	this file except in compliance with the License. You can obtain a copy
	in the file LICENSE in the source distribution or at
	L<https://www.openssl.org/source/license.html>.

	=cut