measurement

Documentation

Overview

Package measurement provides different collectors to hash files, disks, dmi info and cpuid info.

Index

• func HashBytes(b []byte, eventDesc string) error
• func HashFile(inputVal string) error
• type CPUIDCollector
  • func (s *CPUIDCollector) Collect() error
• type Collector
  • func GetCollector(config []byte) (Collector, error)
  • func NewCPUIDCollector(config []byte) (Collector, error)
  • func NewDmiCollector(config []byte) (Collector, error)
  • func NewFileCollector(config []byte) (Collector, error)
  • func NewStorageCollector(config []byte) (Collector, error)
• type DmiCollector
  • func (s *DmiCollector) Collect() error
• type FileCollector
  • func (s *FileCollector) Collect() error
• type StorageCollector
  • func (s *StorageCollector) Collect() error

Functions

func HashBytes

func HashBytes(b []byte, eventDesc string) error

HashBytes extends PCR with a byte array and sends an event to sysfs. the sent event is described via eventDesc.

func HashFile

func HashFile(inputVal string) error

* HashFile reads file input by user and calls TPM to measure it and store the hash. * * inputVal is of format <block device identifier>:<path> * E.g sda:/path/to/file _OR UUID:/path/to/file * Performs following actions * 1. mount device * 2. Read file on device into a byte slice. * 3. Unmount device * 4. Call tpm package which measures byte slice and stores it.

Types

type CPUIDCollector

type CPUIDCollector struct {
	Type     string `json:"type"`
	Location string `json:"location"`
}

describes the "cpuid" portion of policy file

func (*CPUIDCollector) Collect

func (s *CPUIDCollector) Collect() error

* Collect satisfies collector interface. It calls various functions to * 1. get the cpuid info from cpuid package * 2. stores hash of the result in the tpm device. * 3. also keeps a copy of the result on disk at location provided in policy file.

type Collector

type Collector interface {
	Collect() error
}

* all collectors (storage, dmi, cpuid, files) should satisfy this * collectors get information and store the hash of that information in pcr * owned by the tpm device.

func GetCollector

func GetCollector(config []byte) (Collector, error)

* GetCollector calls the appropriate init handlers for a particular * collector JSON object argument and returns a new Collector Interface. * - error is returned if unmarshalling fails or an unsupported collector is * passed as an argument.

func NewCPUIDCollector

func NewCPUIDCollector(config []byte) (Collector, error)

* NewCPUIDCollector extracts the "cpuid" portion from the policy file, * initializes a new CPUIDCollector structure and returns error * if unmarshalling of CPUIDCollector fails

func NewDmiCollector

func NewDmiCollector(config []byte) (Collector, error)

* NewDmiCollector extracts the "dmi" portion from the policy file. * initializes a new DmiCollector structure. * returns error if unmarshalling of DmiCollector fails

func NewFileCollector

func NewFileCollector(config []byte) (Collector, error)

* NewFileCollector extracts the "files" portion from the policy file. * initializes a new FileCollector structure. * returns error if unmarshalling of FileCollector fails

func NewStorageCollector

func NewStorageCollector(config []byte) (Collector, error)

* NewStorageCollector extracts the "storage" portion from the policy file. * initializes a new StorageCollector structure. * returns error if unmarshalling of StorageCollector fails

type DmiCollector

type DmiCollector struct {
	Type     string         `json:"type"`
	Clusters []fieldCluster `json:"events"`
}

describes the "dmi" portion of policy file

func (*DmiCollector) Collect

func (s *DmiCollector) Collect() error

* Collect satisfies collector interface. It calls * 1. smbios package to get all smbios data, * 2. then, filters smbios data based on type provided in policy file, and * 3. the filtered data is then measured into the tpm device.

type FileCollector

type FileCollector struct {
	Type  string   `json:"type"`
	Paths []string `json:"paths"`
}

describes the "files" portion of policy file

func (*FileCollector) Collect

func (s *FileCollector) Collect() error

* Collect satisfies Collector Interface. It loops over all file paths provided by user * and for each file path, calls HashFile. HashFile measures each file on * that path and stores the result in TPM.

type StorageCollector

type StorageCollector struct {
	Type  string   `json:"type"`
	Paths []string `json:"paths"`
}

describes the "storage" portion of policy file

func (*StorageCollector) Collect

func (s *StorageCollector) Collect() error

* Collect satisfies Collector Interface. It loops over all storage paths provided * by user and calls measureStorageDevice for each storage path. storage path is of * form /dev/sda. measureStorageDevice in turn calls tpm * package which further hashes this buffer and extends pcr.