Documentation
¶
Index ¶
- Constants
- Variables
- type Report
- type ReportAuthorizationKey
- func (r *ReportAuthorizationKey) CreateReport(memoType uint8, memoData []uint8, j1, j2 uint16) (*Report, error)
- func (r *ReportAuthorizationKey) CreateSignedReport(memoType uint8, memoData []uint8, j1, j2 uint16) (*SignedReport, error)
- func (r *ReportAuthorizationKey) InitialTCK() (*TemporaryContactKey, error)
- type SignedReport
- type TemporaryContactKey
- type TemporaryContactNumber
Constants ¶
const ( // The CoEpi symptom self-report format, version 1 CoEpiV1Code = 0x0 // The CovidWatch test data format, version 1 CovidWatchV1Code = 0x1 // ITOMemoCode is the code that marks a report as an ito report in the // memo. ITOMemoCode = 0x2 // ReportMinLength is the minimum length of a TCN report (with memo data // of length 0) in bytes. ReportMinLength = 70 )
Describes the intended type of the contents of a memo field.
const ( // SignedReportMinLength defines a signed report's minimum length in bytes SignedReportMinLength = ReportMinLength + ed25519.SignatureSize )
Variables ¶
var HTCKDomainSep = []byte("H_TCK")
HTCKDomainSep is the domain separator used for the TCK domain-separated hash function.
var HTCNDomainSep = []byte("H_TCN")
HTCNDomainSep is the domain separator for the TCN domain-separated hash function.
Functions ¶
This section is empty.
Types ¶
type Report ¶
type Report struct {
RVK ed25519.PublicKey
TCKBytes [32]byte
J1 uint16
J2 uint16
MemoType uint8
MemoData []uint8
}
Report represents a report as described in the TCN protocol: https://github.com/TCNCoalition/TCN#reporting
func (Report) TemporaryContactNumbers ¶
func (r Report) TemporaryContactNumbers() (map[uint16]TemporaryContactNumber, error)
TemporaryContactNumbers returns a slice over all temporary contact numbers included in the report.
type ReportAuthorizationKey ¶
type ReportAuthorizationKey struct {
RAK ed25519.PrivateKey
RVK ed25519.PublicKey
}
ReportAuthorizationKey authorizes publication of a report of potential exposure.
func NewReportAuthorizationKey ¶
func NewReportAuthorizationKey() (*ReportAuthorizationKey, error)
NewReportAuthorizationKey initialize a new report authorization key from a random number generator.
func (*ReportAuthorizationKey) CreateReport ¶
func (r *ReportAuthorizationKey) CreateReport(memoType uint8, memoData []uint8, j1, j2 uint16) (*Report, error)
CreateReport creates a report of potential exposure.
Inputs ¶
- `memoType`, `memoData`: the type and data for the report's memo field. - `j_1 > 0`: the ratchet index of the first temporary contact number in the report. - `j_2`: the ratchet index of the last temporary contact number other users should check.
Notes ¶
Creating a report reveals *all* temporary contact numbers subsequent to `j_1`, not just up to `j_2`, which is included for convenience.
The `memo_data` must be less than 256 bytes long.
Reports are unlinkable from each other **only up to the memo field**. In other words, adding the same high-entropy data to the memo fields of multiple reports will cause them to be linkable.
func (*ReportAuthorizationKey) CreateSignedReport ¶
func (r *ReportAuthorizationKey) CreateSignedReport(memoType uint8, memoData []uint8, j1, j2 uint16) (*SignedReport, error)
CreateSignedReport creates a signed exposure report, whose source integrity can be verified to produce a `Report`.
func (*ReportAuthorizationKey) InitialTCK ¶
func (r *ReportAuthorizationKey) InitialTCK() (*TemporaryContactKey, error)
InitialTCK computes the initial temporary contact key derived from this report authorization key. Note: this function returns `tck_1`, the first temporary contact key that can be used to generate tcks.
type SignedReport ¶
type SignedReport struct {
*Report
// This is an ed25519 signature in byte array form
// The ed25519 package returns a byte array as the signature
// here: https://golang.org/pkg/crypto/ed25519/#PrivateKey.Sign
Sig []byte
}
SignedReport contains a report and the corresponding signature. The client sends this to the server.
func GenerateSignedReport ¶
func GenerateSignedReport(rak *ed25519.PrivateKey, report *Report) (*SignedReport, error)
GenerateSignedReport signs a report with rak and returns the signed report.
func GetSignedReport ¶
func GetSignedReport(data []byte) (*SignedReport, error)
GetSignedReport interprets data as a signed report and returns it as a parsed structure.
func (*SignedReport) Bytes ¶
func (sr *SignedReport) Bytes() ([]byte, error)
Bytes converts sr to a concatenated byte array representation.
func (*SignedReport) Verify ¶
func (sr *SignedReport) Verify() (bool, error)
Verify checks the source integrity of this report.
type TemporaryContactKey ¶
TemporaryContactKey is a ratcheting key used to derive temporary contact numbers.
func (*TemporaryContactKey) Ratchet ¶
func (tck *TemporaryContactKey) Ratchet() (*TemporaryContactKey, error)
Ratchet the key forward, producing a new key for a new temporary contact number.
func (*TemporaryContactKey) TemporaryContactNumber ¶
func (tck *TemporaryContactKey) TemporaryContactNumber() (*TemporaryContactNumber, error)
TemporaryContactNumber computes the temporary contact number derived from this key.
type TemporaryContactNumber ¶
type TemporaryContactNumber [16]uint8
TemporaryContactNumber is a pseudorandom 128-bit value broadcast to nearby devices over Bluetooth.
func (TemporaryContactNumber) ToString ¶
func (tcn TemporaryContactNumber) ToString() string
ToString dumps TCN to string
Source Files