* Function: Used to issue UserSig that is required by the TRTC and IM services.
* <p>
* Parameter description:
*
* @param userid - User ID. The value can be up to 32 bytes in length and contain letters (a-z and A-Z), digits (0-9), underscores (_), and hyphens (-).
* @param expire - UserSig expiration time, in seconds. For example, 86400 indicates that the generated UserSig will expire one day after being generated.
* Used to issue PrivateMapKey that is optional for room entry.
* PrivateMapKey must be used together with UserSig but with more powerful permission control capabilities.
* - UserSig can only control whether a UserID has permission to use the TRTC service. As long as the UserSig is correct, the user with the corresponding UserID can enter or leave any room.
* - PrivateMapKey specifies more stringent permissions for a UserID, including whether the UserID can be used to enter a specific room and perform audio/video upstreaming in the room.
* To enable stringent PrivateMapKey permission bit verification, you need to enable permission key in TRTC console > Application Management > Application Info.
*
* Parameter description:
*
* @param userid - User ID. The value can be up to 32 bytes in length and contain letters (a-z and A-Z), digits (0-9), underscores (_), and hyphens (-).
* @param roomid - ID of the room to which the specified UserID can enter.
* @param expire - PrivateMapKey expiration time, in seconds. For example, 86400 indicates that the generated PrivateMapKey will expire one day after being generated.
* @param privilegeMap - Permission bits. Eight bits in the same byte are used as the permission switches of eight specific features:
* - Bit 1: 0000 0001 = 1, permission for room creation
* - Bit 2: 0000 0010 = 2, permission for room entry
* - Bit 3: 0000 0100 = 4, permission for audio sending
* - Bit 4: 0000 1000 = 8, permission for audio receiving
* - Bit 5: 0001 0000 = 16, permission for video sending
* - Bit 6: 0010 0000 = 32, permission for video receiving
* - Bit 7: 0100 0000 = 64, permission for substream video sending (screen sharing)
* - Bit 8: 1000 0000 = 200, permission for substream video receiving (screen sharing)
* - privilegeMap == 1111 1111 == 255: Indicates that the UserID has all feature permissions of the room specified by roomid.
* - privilegeMap == 0010 1010 == 42: Indicates that the UserID has only the permissions to enter the room and receive audio/video data.
* @return usersig - Generate signature with userbuf
* Used to issue PrivateMapKey that is optional for room entry.
* PrivateMapKey must be used together with UserSig but with more powerful permission control capabilities.
* - UserSig can only control whether a UserID has permission to use the TRTC service. As long as the UserSig is correct, the user with the corresponding UserID can enter or leave any room.
* - PrivateMapKey specifies more stringent permissions for a UserID, including whether the UserID can be used to enter a specific room and perform audio/video upstreaming in the room.
* To enable stringent PrivateMapKey permission bit verification, you need to enable permission key in TRTC console > Application Management > Application Info.
*
* Parameter description:
*
*
* @param userid - User ID. The value can be up to 32 bytes in length and contain letters (a-z and A-Z), digits (0-9), underscores (_), and hyphens (-).
* @param roomid - ID of the room to which the specified UserID can enter.
* @param expire - PrivateMapKey expiration time, in seconds. For example, 86400 indicates that the generated PrivateMapKey will expire one day after being generated.
* @param privilegeMap - Permission bits. Eight bits in the same byte are used as the permission switches of eight specific features:
* - Bit 1: 0000 0001 = 1, permission for room creation
* - Bit 2: 0000 0010 = 2, permission for room entry
* - Bit 3: 0000 0100 = 4, permission for audio sending
* - Bit 4: 0000 1000 = 8, permission for audio receiving
* - Bit 5: 0001 0000 = 16, permission for video sending
* - Bit 6: 0010 0000 = 32, permission for video receiving
* - Bit 7: 0100 0000 = 64, permission for substream video sending (screen sharing)
* - Bit 8: 1000 0000 = 200, permission for substream video receiving (screen sharing)
* - privilegeMap == 1111 1111 == 255: Indicates that the UserID has all feature permissions of the room specified by roomid.
* - privilegeMap == 0010 1010 == 42: Indicates that the UserID has only the permissions to enter the room and receive audio/video data.
* @return usersig - Generate signature with userbuf