Add projects

backend/internal/pluginstore/direct.go

@@ -0,0 +1,56 @@
+package pluginstore
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
+func SelectArtifact(plan InstallPlan, goos string, goarch string) (Artifact, error) {
+	plan = NormalizeInstallPlan(plan)
+	goos = normalizeGOOS(goos)
+	goarch = normalizeGOARCH(goarch)
+	if plan.Type != InstallTypeDirect {
+		return Artifact{}, fmt.Errorf("install type %q is not direct", plan.Type)
+	}
+	for _, artifact := range plan.Artifacts {
+		if artifact.GOOS == goos && artifact.GOARCH == goarch {
+			return artifact, nil
+		}
+	}
+	return Artifact{}, fmt.Errorf("artifact not found for %s/%s", goos, goarch)
+}
+
+func (c Client) DownloadArtifact(ctx context.Context, artifact Artifact) ([]byte, error) {
+	artifact = NormalizeInstallPlan(InstallPlan{Type: InstallTypeDirect, Artifacts: []Artifact{artifact}}).Artifacts[0]
+	if errValidate := ValidateArtifact(artifact); errValidate != nil {
+		return nil, errValidate
+	}
+	maxSize := int64(0)
+	if artifact.Size > 0 {
+		maxSize = artifact.Size
+	}
+	data, errDownload := c.get(ctx, artifact.URL, "application/octet-stream", RequestKindArtifact, maxSize)
+	if errDownload != nil {
+		return nil, errDownload
+	}
+	if maxSize > 0 && int64(len(data)) > maxSize {
+		return nil, fmt.Errorf("artifact exceeds declared size")
+	}
+	return data, nil
+}
+
+func VerifyArtifactChecksum(artifact Artifact, data []byte) error {
+	expected := strings.ToLower(strings.TrimSpace(artifact.SHA256))
+	if expected == "" {
+		return fmt.Errorf("artifact checksum missing")
+	}
+	actualBytes := sha256.Sum256(data)
+	actual := hex.EncodeToString(actualBytes[:])
+	if actual != expected {
+		return fmt.Errorf("artifact checksum mismatch")
+	}
+	return nil
+}