feat(admin): add atomic task claim leases

admin/internal/config/config.go

@@ -2,6 +2,8 @@
 package config
 
 import (
+	"bytes"
+	"encoding/hex"
 	"errors"
 	"fmt"
 	"os"
@@ -23,6 +25,8 @@ const (
 	maxTaskQuantityEnv     = "CMBUYER_MAX_TASK_QUANTITY"
 	maxTotalPriceEnv       = "CMBUYER_MAX_TOTAL_PRICE"
 	evidenceDirectoryEnv   = "CMBUYER_EVIDENCE_DIR"
+	claimTokenSecretEnv    = "CMBUYER_CLAIM_TOKEN_SECRET"
+	claimLeaseTTLEnv       = "CMBUYER_CLAIM_LEASE_TTL"
 	minimumSecretLength    = 32
 )
 
@@ -37,6 +41,8 @@ type Config struct {
 	MaxTaskQuantity     int
 	MaxTotalPrice       string
 	EvidenceDirectory   string
+	ClaimTokenSecret    []byte
+	ClaimLeaseTTL       time.Duration
 }
 
 // LoadFromEnv 从进程环境读取配置。错误只指出缺失或非法的变量名，绝不回显秘密。
@@ -112,6 +118,27 @@ func Load(lookup func(string) (string, bool)) (Config, error) {
 	if strings.TrimSpace(evidenceDirectory) != evidenceDirectory || !filepath.IsAbs(evidenceDirectory) {
 		return Config{}, fmt.Errorf("%s must be an absolute path without surrounding whitespace", evidenceDirectoryEnv)
 	}
+	claimSecretText, err := required(lookup, claimTokenSecretEnv)
+	if err != nil {
+		return Config{}, err
+	}
+	claimSecret, err := hex.DecodeString(claimSecretText)
+	if err != nil || len(claimSecret) != 32 || hex.EncodeToString(claimSecret) != claimSecretText {
+		return Config{}, fmt.Errorf("%s must be exactly 64 lowercase hexadecimal characters", claimTokenSecretEnv)
+	}
+	// Claim ownership, admin sessions and device authentication are separate security domains.
+	// Reject both identical configuration text and identical effective key bytes.
+	if claimSecretText == secret || bytes.Equal(claimSecret, []byte(secret)) {
+		return Config{}, fmt.Errorf("%s must be isolated from %s", claimTokenSecretEnv, sessionSecretEnv)
+	}
+	claimTTLText, err := required(lookup, claimLeaseTTLEnv)
+	if err != nil {
+		return Config{}, err
+	}
+	claimTTL, err := time.ParseDuration(claimTTLText)
+	if err != nil || claimTTL <= 0 || claimTTL >= ttl {
+		return Config{}, fmt.Errorf("%s must be positive and shorter than %s", claimLeaseTTLEnv, authorizationTTLEnv)
+	}
 
 	return Config{
 		AdminUsername:       username,
@@ -121,6 +148,8 @@ func Load(lookup func(string) (string, bool)) (Config, error) {
 		DatabaseSource:      databaseSource,
 		AuthorizationTTL:    ttl, MaxTaskQuantity: maxQuantity, MaxTotalPrice: maxPrice,
 		EvidenceDirectory: evidenceDirectory,
+		ClaimTokenSecret:  claimSecret,
+		ClaimLeaseTTL:     claimTTL,
 	}, nil
 }
 

admin/internal/config/config_test.go

@@ -3,6 +3,7 @@ package config_test
 import (
 	"strings"
 	"testing"
+	"time"
 
 	"cmbuyer/admin/internal/config"
 
@@ -25,13 +26,15 @@ func TestLoad(t *testing.T) {
 		"CMBUYER_MAX_TASK_QUANTITY":     "99",
 		"CMBUYER_MAX_TOTAL_PRICE":       "999.99",
 		"CMBUYER_EVIDENCE_DIR":          t.TempDir(),
+		"CMBUYER_CLAIM_TOKEN_SECRET":    strings.Repeat("ab", 32),
+		"CMBUYER_CLAIM_LEASE_TTL":       "1m",
 	}
 
 	got, err := config.Load(lookup(values))
 	if err != nil {
 		t.Fatalf("Load: %v", err)
 	}
-	if got.AdminUsername != "admin" || !got.CookieSecure {
+	if got.AdminUsername != "admin" || !got.CookieSecure || len(got.ClaimTokenSecret) != 32 || got.ClaimLeaseTTL != time.Minute {
 		t.Fatalf("Load returned unexpected public configuration: %#v", got)
 	}
 }
@@ -51,6 +54,8 @@ func TestLoadRejectsMissingOrInvalidConfiguration(t *testing.T) {
 		"CMBUYER_MAX_TASK_QUANTITY":     "99",
 		"CMBUYER_MAX_TOTAL_PRICE":       "999.99",
 		"CMBUYER_EVIDENCE_DIR":          t.TempDir(),
+		"CMBUYER_CLAIM_TOKEN_SECRET":    strings.Repeat("ab", 32),
+		"CMBUYER_CLAIM_LEASE_TTL":       "1m",
 	}
 
 	tests := []struct {
@@ -68,6 +73,12 @@ func TestLoadRejectsMissingOrInvalidConfiguration(t *testing.T) {
 		{"invalid maximum total price", func(values map[string]string) { values["CMBUYER_MAX_TOTAL_PRICE"] = "1" }, "CMBUYER_MAX_TOTAL_PRICE"},
 		{"missing evidence directory", func(values map[string]string) { delete(values, "CMBUYER_EVIDENCE_DIR") }, "CMBUYER_EVIDENCE_DIR"},
 		{"relative evidence directory", func(values map[string]string) { values["CMBUYER_EVIDENCE_DIR"] = "evidence" }, "CMBUYER_EVIDENCE_DIR"},
+		{"invalid claim secret", func(values map[string]string) { values["CMBUYER_CLAIM_TOKEN_SECRET"] = strings.Repeat("A", 64) }, "CMBUYER_CLAIM_TOKEN_SECRET"},
+		{"claim secret same raw session secret", func(values map[string]string) {
+			values["CMBUYER_SESSION_SECRET"] = values["CMBUYER_CLAIM_TOKEN_SECRET"]
+		}, "CMBUYER_CLAIM_TOKEN_SECRET"},
+		{"claim secret same decoded session secret", func(values map[string]string) { values["CMBUYER_SESSION_SECRET"] = strings.Repeat("\xab", 32) }, "CMBUYER_CLAIM_TOKEN_SECRET"},
+		{"invalid claim lease ttl", func(values map[string]string) { values["CMBUYER_CLAIM_LEASE_TTL"] = "10m" }, "CMBUYER_CLAIM_LEASE_TTL"},
 	}
 
 	for _, test := range tests {