syntax = "proto2";
option java_package = "keyexportformat";
message TemporaryExposureKeyExport {
    // Time window of keys in this batch based on arrival to server, in UTC seconds
    optional fixed64 start_timestamp = 1;
    optional fixed64 end_timestamp = 2;
    // Region for which these keys came from (e.g., country)
    optional string region = 3;
    // E.g., File 2 in batch size of 10. Ordinal, 1-based numbering.
    optional int32 batch_num = 4;
    optional int32 batch_size = 5;
    // Information about associated signatures
    repeated SignatureInfo signature_infos = 6;
    // The TemporaryExposureKeys themselves
    repeated TemporaryExposureKey keys = 7;
}
message SignatureInfo {
    // Apple App Store Application Bundle ID
    optional string app_bundle_id = 1;
    // Android App package name
    optional string android_package = 2;
    // Key version for rollovers
    optional string verification_key_version = 3;
    // Additional identifying information
    // E.g., backend might serve app in different countries with different keys
    optional string verification_key_id = 4;
    // E.g. ECDSA using a p-256 curve and SHA-256 as a hash function
    optional string signature_algorithm = 5;
}

message SubmissionPayload {
    repeated TemporaryExposureKey keys = 1;
}

message TemporaryExposureKey {
    // Key of infected user
    optional bytes key_data = 1;
    // Varying risk associated with a key depending on diagnosis method
    optional int32 transmission_risk_level = 2;
    // The interval number since epoch for which a key starts
    optional int32 rolling_start_interval_number = 3;
    // Increments of 10 minutes describing how long a key is valid
    optional int32 rolling_period = 4 [default = 144]; // defaults to 24 hours
    // Data type representing why this key was published.
    enum ReportType {
        UNKNOWN = 0;  // Never returned by the client API.
        CONFIRMED_TEST = 1;
        CONFIRMED_CLINICAL_DIAGNOSIS = 2;
        SELF_REPORT = 3;
        RECURSIVE = 4;  // Reserved for future use.
        REVOKED = 5;  // Used to revoke a key, never returned by client API.
    }
    // Type of diagnosis associated with a key.
    optional ReportType report_type = 5;
    // Number of days elapsed between symptom onset and the TEK being used.
    // E.g. 2 means TEK is 2 days after onset of symptoms.
    optional sint32 days_since_onset_of_symptoms = 6;
}

message TEKSignatureList {
    repeated TEKSignature signatures = 1;
}
message TEKSignature {
    // Info about the signing key, version, algorithm, etc
    optional SignatureInfo signature_info = 1;
    // E.g., File 2 in batch size of 10. Ordinal, 1-based numbering.
    // E.g., Batch 2 of 10
    optional int32 batch_num = 2;
    optional int32 batch_size = 3;
    // Signature in X9.62 format (ASN.1 SEQUENCE of two INTEGER fields)
    optional bytes signature = 4;
}