QueryContextAttributes (General) function

Article
10/25/2021

Enables a transport application to query a security package for certain attributes of a security context.

For information about using this function with a specific security support provider (SSP), see the following topics.

Topic	Description
QueryContextAttributes (CredSSP)	Enables a transport application to query the Credential Security Support Provider (CredSSP) for certain attributes of a security context.
QueryContextAttributes (Digest)	Enables a transport application to query the Digest security package for certain attributes of a security context.
QueryContextAttributes (Kerberos)	Enables a transport application to query the Kerberos security package for certain attributes of a security context.
QueryContextAttributes (Negotiate)	Enables a transport application to query the Negotiate security package for certain attributes of a security context.
QueryContextAttributes (NTLM)	Enables a transport application to query the NTLM security package for certain attributes of a security context.
QueryContextAttributes (Schannel)	Enables a transport application to query the Schannel security package for certain attributes of a security context.

Syntax

SECURITY_STATUS SEC_ENTRY QueryContextAttributes(
  _In_  PCtxtHandle phContext,
  _In_  ULONG       ulAttribute,
  _Out_ PVOID       pBuffer
);

Parameters

phContext [in]

A handle to the security context to be queried.

ulAttribute [in]

Specifies the attribute of the context to be returned. This parameter can be one of the following values.

Value	Meaning
SECPKG_ATTR_ACCESS_TOKEN 18	The pBuffer parameter contains a pointer to a SecPkgContext_AccessToken structure. Returns a handle to the access token.
SECPKG_ATTR_APP_DATA 0x5e	The pBuffer parameter contains a pointer to a SecPkgContext_SessionAppData structure. Returns or specifies application data for the session. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_AUTHORITY 6	The pBuffer parameter contains a pointer to a SecPkgContext_Authority structure. Queries the name of the authenticating authority.
SECPKG_ATTR_CLIENT_SPECIFIED_TARGET 27	The pBuffer parameter contains a pointer to a SecPkgContext_ClientSpecifiedTarget structure that represents the service principal name (SPN) of the initial target supplied by the client. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_CONNECTION_INFO 0x5a	The pBuffer parameter contains a pointer to a SecPkgContext_ConnectionInfo structure. Returns detailed information on the established connection. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_CREDS_2 0x80000086	The pBuffer parameter contains a pointer to a SecPkgContext_ClientCreds structure that specifies client credentials. If the client credential is user name and password, the buffer is a packed KERB_INTERACTIVE_LOGON structure. If the client credential is user name and smart card PIN, the buffer is a packed KERB_CERTIFICATE_LOGON structure. If the client credential is an online identity credential, the buffer is a marshaled SEC_WINNT_AUTH_IDENTITY_EX2 structure. This attribute is supported only on the CredSSP server. Windows Server 2008 R2, Windows 7, Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_DCE_INFO 3	The pBuffer parameter contains a pointer to a SecPkgContext_DceInfo structure. Queries for authorization data used by DCE services.
SECPKG_ATTR_ENDPOINT_BINDINGS 26	The pBuffer parameter contains a pointer to a SecPkgContext_Bindings structure that specifies channel binding information. This attribute is supported only by the Schannel security package. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_EAP_KEY_BLOCK 0x5b	The pBuffer parameter contains a pointer to a SecPkgContext_EapKeyBlock structure. Queries for key data used by the EAP TLS protocol. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_FLAGS 14	The pBuffer parameter contains a pointer to a SecPkgContext_Flags structure. Returns information about the negotiated context flags.
SECPKG_ATTR_ISSUER_LIST_EX 0x59	The pBuffer parameter contains a pointer to a SecPkgContext_IssuerListInfoEx structure. Returns a list of certificate issuers that are accepted by the server. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_KEY_INFO 5	The pBuffer parameter contains a pointer to a SecPkgContext_KeyInfo structure. Queries information about the keys used in a security context.
SECPKG_ATTR_LAST_CLIENT_TOKEN_STATUS 30	The pBuffer parameter contains a pointer to a SecPkgContext_LastClientTokenStatus structure that specifies whether the token from the most recent call to the InitializeSecurityContext function is the last token from the client. This value is supported only by the Negotiate, Kerberos, and NTLM security packages. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_LIFESPAN 2	The pBuffer parameter contains a pointer to a SecPkgContext_Lifespan structure. Queries the life span of the context.
SECPKG_ATTR_LOCAL_CERT_CONTEXT 0x54	The pBuffer parameter contains a pointer to a PCCERT_CONTEXTstructure. Finds a certificate context that contains a local end certificate. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_LOCAL_CRED	The pBuffer parameter contains a pointer to a SecPkgContext_LocalCredentialInfo structure. (obsolete) Superseded by SECPKG_ATTR_LOCAL_CERT_CONTEXT.
SECPKG_ATTR_NAMES 1	The pBuffer parameter contains a pointer to a SecPkgContext_Names structure. Queries the name associated with the context.
SECPKG_ATTR_NATIVE_NAMES 13	The pBuffer parameter contains a pointer to a SecPkgContext_NativeNames structure. Returns the principal name (CNAME) from the outbound ticket.
SECPKG_ATTR_NEGOTIATION_INFO 12	The pBuffer parameter contains a pointer to a SecPkgContext_NegotiationInfo structure. Returns information about the security package to be used with the negotiation process and the current state of the negotiation for the use of that package.
SECPKG_ATTR_PACKAGE_INFO 10	The pBuffer parameter contains a pointer to a SecPkgContext_PackageInfo structure. Returns information on the SSP in use.
SECPKG_ATTR_PASSWORD_EXPIRY 8	The pBuffer parameter contains a pointer to a SecPkgContext_PasswordExpiry structure. Returns password expiration information.
SECPKG_ATTR_REMOTE_CERT_CONTEXT 0x53	The pBuffer parameter contains a pointer to a PCCERT_CONTEXTstructure. Finds a certificate context that contains the end certificate supplied by the server. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_ROOT_STORE 0x55	The pBuffer parameter contains a pointer to a HCERTCONTEXT. Finds a certificate context that contains a certificate supplied by the Root store.
SECPKG_ATTR_SESSION_KEY 9	The pBuffer parameter contains a pointer to a SecPkgContext_SessionKey structure. Returns information about the session keys.
SECPKG_ATTR_SESSION_INFO 0x5d	The pBuffer parameter contains a pointer to a SecPkgContext_SessionInfo structure. Returns information about the session. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_SIZES 0	The pBuffer parameter contains a pointer to a SecPkgContext_Sizes structure. Queries the sizes of the structures used in the per-message functions.
SECPKG_ATTR_STREAM_SIZES 4	The pBuffer parameter contains a pointer to a SecPkgContext_StreamSizes structure. Queries the sizes of the various parts of a stream used in the per-message functions. This attribute is supported only by the Schannel security package.
SECPKG_ATTR_SUBJECT_SECURITY_ATTRIBUTES 124	The pBuffer parameter contains a pointer to a SecPkgContext_SubjectAttributes structure. This value returns information about the security attributes for the connection. This value is supported only on the CredSSP server. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_SUPPORTED_SIGNATURES 0x66	The pBuffer parameter contains a pointer to a SecPkgContext_SupportedSignatures structure. This value returns information about the signature types that are supported for the connection. This value is supported only by the Schannel constrained delegation. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.
SECPKG_ATTR_TARGET_INFORMATION 17	The pBuffer parameter contains a pointer to a SecPkgContext_TargetInformation structure. Returns information about the name of the remote server.
SECPKG_ATTR_UNIQUE_BINDINGS 25	The pBuffer parameter contains a pointer to a SecPkgContext_Bindings structure that specifies channel binding information. This value is supported only by the Schannel constrained delegation. Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: This value is not supported.

pBuffer [out]

A pointer to a structure that receives the attributes. The type of structure pointed to depends on the value specified in the ulAttribute parameter.

Return value

If the function succeeds, the return value is SEC_E_OK.

If the function fails, the return value is a nonzero error code.

Remarks

The structure pointed to by the pBuffer parameter varies depending on the attribute being queried. The caller must allocate the pBuffer structure itself, but the SSP allocates any memory required to hold variable sized members of the pBuffer structure. Memory allocated by the SSP can be freed by calling the FreeContextBuffer function.

After the SECPKG_ATTR_REMOTE_CERT_CONTEXT or SECPKG_ATTR_LOCAL_CERT_CONTEXT value has been read, the hCertStore member will be set to a handle to a certificate store that contains the intermediate certificates, if any. Also, the application is responsible for calling CertFreeCertificateContext to release the memory used by the certificate context.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Header	Sspi.h (include Security.h)
Library	Secur32.lib
DLL	Secur32.dll
Unicode and ANSI names	QueryContextAttributesW (Unicode) and QueryContextAttributesA (ANSI)