_SecBuffer structure

The SecBuffer structure describes a buffer allocated by a transport application to pass to a security package.

Syntax

typedef struct _SecBuffer {
  unsigned long cbBuffer;
  unsigned long BufferType;
#if ...
  char          *pvBuffer;
#else
  void SEC_FAR  *pvBuffer;
#endif
} SecBuffer, *PSecBuffer;

Members

cbBuffer

Specifies the size, in bytes, of the buffer pointed to by the pvBuffer member.

BufferType

Bit flags that indicate the type of buffer. BufferType must be one of the following flags.

Value Meaning
SECBUFFER_ALERT
17 (0x11)
The buffer contains an alert message.
SECBUFFER_ATTRMASK
4026531840 (0xF0000000)
The buffer contains a bitmask for a SECBUFFER_READONLY_WITH_CHECKSUM buffer.
SECBUFFER_CHANNEL_BINDINGS
14 (0xE)
The buffer contains channel binding information.
SECBUFFER_CHANGE_PASS_RESPONSE
15 (0xF)
The buffer contains a DOMAIN_PASSWORD_INFORMATION structure.
SECBUFFER_DATA
1 (0x1)
The buffer contains common data. The security package can read and write this data, for example, to encrypt some or all of it.
SECBUFFER_DTLS_MTU
24 (0x18)
The buffer contains the setting for the maximum transmission unit (MTU) size for DTLS only. The default value is 1096 and the valid configurable range is between 200 and 64*1024.
SECBUFFER_EMPTY
0 (0x0)
This is a placeholder in the buffer array. The caller can supply several such entries in the array, and the security package can return information in them. For more information, see SSPI Context Semantics.
SECBUFFER_EXTRA
5 (0x5)
The security package uses this value to indicate the number of extra or unprocessed bytes in a message.
SECBUFFER_MECHLIST
11 (0xB)
The buffer contains a protocol-specific list of object identifiers (OIDs). It is not usually of interest to callers.
SECBUFFER_MECHLIST_SIGNATURE
12 (0xC)
The buffer contains a signature of a SECBUFFER_MECHLIST buffer. It is not usually of interest to callers.
SECBUFFER_MISSING
4 (0x4)
The security package uses this value to indicate the number of missing bytes in a particular message. The pvBuffer member is ignored in this type.
SECBUFFER_PKG_PARAMS
3 (0x3)
These are transport-to-package–specific parameters. For example, the NetWare redirector may supply the server object identifier, while DCE RPC can supply an association UUID, and so on.
SECBUFFER_PRESHARED_KEY
22 (0x16)
The buffer contains the preshared key. The maximum allowed PSK buffer size is 256 bytes.
SECBUFFER_PRESHARED_KEY_IDENTITY
23 (0x17)
The buffer contains the preshared key identity.
SECBUFFER_SRTP_MASTER_KEY_IDENTIFIER
20 (0x14)
The buffer contains the SRTP master key identifier.
SECBUFFER_SRTP_PROTECTION_PROFILES
19 (0x13)
The buffer contains the list of SRTP protection profiles, in descending order of preference.
SECBUFFER_STREAM_HEADER
7 (0x7)
The buffer contains a protocol-specific header for a particular record. It is not usually of interest to callers.
SECBUFFER_STREAM_TRAILER
6 (0x6)
The buffer contains a protocol-specific trailer for a particular record. It is not usually of interest to callers.
SECBUFFER_TARGET
13 (0xD)
This flag is reserved. Do not use it.
SECBUFFER_TARGET_HOST
16 (0x10)
The buffer specifies the service principal name (SPN) of the target.

This value is supported by the Digest security package when used with channel bindings.

Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP:  This value is not supported.

SECBUFFER_TOKEN
2 (0x2)
The buffer contains the security token portion of the message. This is read-only for input parameters or read/write for output parameters.
SECBUFFER_TOKEN_BINDING
21 (0x15)
The buffer contains the supported token binding protocol version and key parameters, in descending order of preference.
SECBUFFER_APPLICATION_PROTOCOLS
18
The buffer contains a list of application protocol IDs, one list per application protocol negotiation extension type to be enabled.
 

In addition, BufferType can combine the following flags with any of the flags in the preceding table by using a bitwise-OR operation.

Value Meaning
SECBUFFER_READONLY
2147483648 (0x80000000)
The buffer is read-only with no checksum. This flag is intended for sending header information to the security package for computing the checksum. The package can read this buffer, but cannot modify it.
SECBUFFER_READONLY_WITH_CHECKSUM
268435456 (0x10000000)
The buffer is read-only with a checksum.

pvBuffer.#486659332

pvBuffer.#967516563

Requirements

   
Minimum supported client Windows 8.1 [desktop apps only]
Minimum supported server Windows Server 2012 R2 [desktop apps only]
Header sspi.h (include Security.h)

See Also

SecBufferDesc