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package internal
import (
"encoding/json"
"fmt"
)
type DiscoFileError struct {
URL string
Err error
}
func (e *DiscoFileError) Error() string {
return fmt.Sprintf("failed obtaining disco file %s with error %v", e.URL, e.Err)
}
type DiscoSigFileError struct {
URL string
Err error
}
func (e *DiscoSigFileError) Error() string {
return fmt.Sprintf("failed obtaining disco signature file %s with error %v", e.URL, e.Err)
}
type DiscoVerifyError struct {
File string
Sigfile string
Err error
}
func (e *DiscoVerifyError) Error() string {
return fmt.Sprintf("failed verifying file %s with signature %s due to error %v", e.File, e.Sigfile, e.Err)
}
type DiscoJSONError struct {
Body string
Err error
}
func (e *DiscoJSONError) Error() string {
return fmt.Sprintf("failed parsing JSON for contents %s with error %v", e.Body, e.Err)
}
type OrganizationList struct {
JSON json.RawMessage `json:"organization_list"`
Version uint64 `json:"v"`
Timestamp int64 `json:"-"`
}
type ServersList struct {
JSON json.RawMessage `json:"server_list"`
Version uint64 `json:"v"`
Timestamp int64 `json:"-"`
}
type Discovery struct {
Organizations OrganizationList
Servers ServersList
FSM *FSM
Logger *FileLogger
}
// Helper function that gets a disco json
func getDiscoFile(jsonFile string, previousVersion uint64, structure interface{}) error {
// Get json data
discoURL := "https://disco.eduvpn.org/v2/"
fileURL := discoURL + jsonFile
_, fileBody, fileErr := HTTPGet(fileURL)
if fileErr != nil {
return &DiscoFileError{fileURL, fileErr}
}
// Get signature
sigFile := jsonFile + ".minisig"
sigURL := discoURL + sigFile
_, sigBody, sigFileErr := HTTPGet(sigURL)
if sigFileErr != nil {
return &DiscoSigFileError{URL: sigURL, Err: sigFileErr}
}
// Verify signature
// Set this to true when we want to force prehash
forcePrehash := false
verifySuccess, verifyErr := Verify(string(sigBody), fileBody, jsonFile, previousVersion, forcePrehash)
if !verifySuccess || verifyErr != nil {
return &DiscoVerifyError{File: jsonFile, Sigfile: sigFile, Err: verifyErr}
}
// Parse JSON to extract version and list
jsonErr := json.Unmarshal(fileBody, structure)
if jsonErr != nil {
return &DiscoJSONError{Body: string(fileBody), Err: jsonErr}
}
return nil
}
type GetListError struct {
File string
Err error
}
func (e *GetListError) Error() string {
return fmt.Sprintf("failed getting disco list file %s with error %v", e.File, e.Err)
}
func (discovery *Discovery) Init(fsm *FSM, logger *FileLogger) {
discovery.FSM = fsm
discovery.Logger = logger
}
// FIXME: Implement based on
// https://github.com/eduvpn/documentation/blob/v3/SERVER_DISCOVERY.md
// - [IMPLEMENTED] on "first launch" when offering the search for "Institute Access" and "Organizations";
// - [TODO] when the user tries to add new server AND the user did NOT yet choose an organization before;
// - [TODO] when the authorization for the server associated with an already chosen organization is triggered, e.g. after expiry or revocation.
func (discovery *Discovery) DetermineOrganizationsUpdate() bool {
return string(discovery.Organizations.JSON) == ""
}
// https://github.com/eduvpn/documentation/blob/v3/SERVER_DISCOVERY.md
// - [Implemented] The application MUST always fetch the server_list.json at application start.
// - The application MAY refresh the server_list.json periodically, e.g. once every hour.
func (discovery *Discovery) DetermineServersUpdate() bool {
// No servers, we should update
if string(discovery.Servers.JSON) == "" {
return true
}
// 1 hour from the last update
should_update_time := discovery.Servers.Timestamp + 3600
now := GenerateTimeSeconds()
if now >= should_update_time {
return true
}
discovery.Logger.Log(LOG_INFO, "No update needed for servers, 1h is not passed yet")
return false
}
// Get the organization list
func (discovery *Discovery) GetOrganizationsList() (string, error) {
if !discovery.DetermineOrganizationsUpdate() {
return string(discovery.Organizations.JSON), nil
}
file := "organization_list.json"
err := getDiscoFile(file, discovery.Organizations.Version, &discovery.Organizations)
if err != nil {
// Return previous with an error
return string(discovery.Organizations.JSON), &GetListError{File: file, Err: err}
}
return string(discovery.Organizations.JSON), nil
}
// Get the server list
func (discovery *Discovery) GetServersList() (string, error) {
if !discovery.DetermineServersUpdate() {
return string(discovery.Servers.JSON), nil
}
file := "server_list.json"
err := getDiscoFile(file, discovery.Servers.Version, &discovery.Servers)
if err != nil {
// Return previous with an error
return string(discovery.Servers.JSON), &GetListError{File: file, Err: err}
}
// Update servers timestamp
discovery.Servers.Timestamp = GenerateTimeSeconds()
return string(discovery.Servers.JSON), nil
}
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