feat(优化兼容): 添加ofdgo_sign.go文件

ofdgo_doc.go

@@ -24,6 +24,7 @@ type Document struct {
 	Outlines    Outlines    `xml:"Outlines"`
 	Permissions Permissions `xml:"Permissions"`
 	Annotations string      `xml:"Annotations"`
+	Signatures  string      `xml:"Signatures"`
 	Attachments Attachments `xml:"Attachments"`
 	Extensions  Extensions  `xml:"Extensions"`
 }

ofdgo_page.go

@@ -19,6 +19,7 @@ import "encoding/xml"
 // PageContent 页面内容
 type PageContent struct {
 	XMLName  xml.Name   `xml:"Page"`
+	ID       string     `xml:"-"`
 	Area     PageArea   `xml:"Area"`
 	Template []Template `xml:"Template"`
 	Content  Content    `xml:"Content"`

ofdgo_reader.go

@@ -34,6 +34,7 @@ type Reader struct {
 	fontCache      map[string]*Font
 	drawParamCache map[string]*DrawParam
 	doc            *Document
+	Stamps         map[string][]Stamp
 }
 
 // Close 关闭阅读器
@@ -73,6 +74,19 @@ func (r *Reader) readFile(name string) ([]byte, error) {
 	return nil, fmt.Errorf("file not found: %s", name)
 }
 
+// openFile 打开压缩包内的文件流
+// 入参: name 文件名
+// 返回: io.ReadCloser 文件流, error 错误信息
+func (r *Reader) openFile(name string) (io.ReadCloser, error) {
+	name = strings.ReplaceAll(name, "\\", "/")
+	for _, f := range r.Zip.File {
+		if f.Name == name {
+			return f.Open()
+		}
+	}
+	return nil, fmt.Errorf("file not found: %s", name)
+}
+
 // readZipFile 读取zip文件内容
 // 入参: f zip文件对象
 // 返回: []byte 文件内容, error 错误信息
@@ -116,7 +130,8 @@ func (r *Reader) Doc() (*Document, error) {
 		r.loadRes(doc.CommonData.PublicRes)
 	}
 	r.doc = &doc
-	return &doc, nil
+	_ = r.parseSignatures(&doc)
+	return r.doc, nil
 }
 
 // loadRes 加载资源文件
@@ -183,6 +198,7 @@ func (r *Reader) PageContent(page Page) (*PageContent, error) {
 	if err := xml.Unmarshal(data, &content); err != nil {
 		return nil, fmt.Errorf("failed to unmarshal page content: %w", err)
 	}
+	content.ID = page.ID
 	return &content, nil
 }
 

ofdgo_renderer.go

@@ -81,6 +81,11 @@ func (r *Renderer) RenderPage(page *PageContent) (*canvas.Canvas, error) {
 			r.renderLayer(ctx, layer, pageH, nil, nil, 0)
 		}
 	}
+	if stamps, ok := r.Reader.Stamps[page.ID]; ok {
+		for _, s := range stamps {
+			r.renderStamp(ctx, s, pageH)
+		}
+	}
 	return c, nil
 }
 
@@ -570,6 +575,56 @@ func (r *Renderer) loadFont(fontID string) *canvas.FontFamily {
 				return ff
 			}
 		}
+		winFontDir := `C:\Windows\Fonts`
+		matches, _ := filepath.Glob(filepath.Join(winFontDir, "*"+targetName+"*"))
+		if len(matches) == 0 {
+			if targetName == "SimSun" {
+				matches, _ = filepath.Glob(filepath.Join(winFontDir, "simsun.ttc"))
+			} else if targetName == "KaiTi" {
+				matches, _ = filepath.Glob(filepath.Join(winFontDir, "simkai.ttf"))
+			} else if targetName == "SimHei" {
+				matches, _ = filepath.Glob(filepath.Join(winFontDir, "simhei.ttf"))
+			} else if targetName == "FangSong" {
+				matches, _ = filepath.Glob(filepath.Join(winFontDir, "simfang.ttf"))
+			}
+		}
+		for _, m := range matches {
+			if err := ff.LoadFontFile(m, canvas.FontRegular); err == nil {
+				r.FontMap[fontID] = ff
+				return ff
+			}
+		}
 	}
 	return defaultFont
 }
+
+// renderStamp 渲染印章
+// 入参: ctx 画布上下文, s 印章对象, pageH 页面高度
+func (r *Renderer) renderStamp(ctx *canvas.Context, s Stamp, pageH float64) {
+	x, y, w, h := s.Box.X, s.Box.Y, s.Box.W, s.Box.H
+	if len(s.Data) > 0 {
+		img, _, err := image.Decode(bytes.NewReader(s.Data))
+		if err == nil {
+			ctx.Push()
+			screenY := pageH - (y + h)
+			ctx.Translate(x, screenY)
+			ctx.Scale(w/float64(img.Bounds().Dx()), h/float64(img.Bounds().Dy()))
+			ctx.DrawImage(0, 0, img, canvas.DPMM(1.0))
+			ctx.Pop()
+			return
+		}
+	}
+	ctx.Push()
+	screenY := pageH - (y + h)
+	ctx.SetStrokeColor(canvas.Red)
+	ctx.SetStrokeWidth(0.5)
+	ctx.SetFillColor(canvas.Transparent)
+	ctx.DrawPath(x, screenY, canvas.Rectangle(w, h))
+	ctx.SetFillColor(canvas.Red)
+	fontSize := 3.0
+	if r.fontFamily != nil {
+		font := r.fontFamily.Face(fontSize*2.83465, canvas.Red, canvas.FontRegular, canvas.FontNormal)
+		ctx.DrawText(x+w/2-font.TextWidth("Signature")/2, screenY+h/2-fontSize/2, canvas.NewTextLine(font, "Signature", canvas.Left))
+	}
+	ctx.Pop()
+}

ofdgo_sign.go

@@ -0,0 +1,167 @@
+// Copyright 2025 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"encoding/asn1"
+	"encoding/xml"
+	"path"
+	"strings"
+)
+
+const (
+	// SignTypeSeal 签章类型: seal
+	SignTypeSeal = "seal"
+	// SignTypeSign 签章类型: sign
+	SignTypeSign = "sign"
+)
+
+// OFDSignatures 签名列表列表
+type OFDSignatures struct {
+	XMLName   xml.Name       `xml:"Signatures"`
+	MaxSignId string         `xml:"MaxSignId"`
+	List      []OFDSignature `xml:"Signature"`
+}
+
+// OFDSignature 签名列表引用
+type OFDSignature struct {
+	ID      string `xml:"ID,attr"`
+	BaseLoc string `xml:"BaseLoc,attr"`
+}
+
+// SignatureFile 签名文件内容描述
+type SignatureFile struct {
+	XMLName     xml.Name `xml:"Signature"`
+	SignedValue string   `xml:"SignedValue"`
+	SignedInfo  struct {
+		StampAnnot []struct {
+			ID       string `xml:"ID,attr"`
+			PageRef  string `xml:"PageRef,attr"`
+			Boundary string `xml:"Boundary,attr"`
+		} `xml:"StampAnnot"`
+	} `xml:"SignedInfo"`
+}
+
+// parseSignatures 解析签名文件
+// 入参: doc 文档结构
+// 返回: error 错误信息
+func (r *Reader) parseSignatures(doc *Document) error {
+	if doc.Signatures == "" {
+		return nil
+	}
+	f, err := r.openFile(doc.Signatures)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	var signatures OFDSignatures
+	if err := xml.NewDecoder(f).Decode(&signatures); err != nil {
+		return err
+	}
+	for _, sigRef := range signatures.List {
+		sigPath := path.Join(path.Dir(doc.Signatures), sigRef.BaseLoc)
+		sf, err := r.openFile(sigPath)
+		if err != nil {
+			continue
+		}
+		var sigFile SignatureFile
+		if err := xml.NewDecoder(sf).Decode(&sigFile); err != nil {
+			sf.Close()
+			continue
+		}
+		sf.Close()
+		signedValuePath := path.Join(path.Dir(sigPath), sigFile.SignedValue)
+		svData, err := r.ResData(signedValuePath)
+		if err != nil {
+			continue
+		}
+		sealType, sealData := extractSeal(svData)
+		for _, annot := range sigFile.SignedInfo.StampAnnot {
+			pageID := annot.PageRef
+			bbox, _ := ParseBox(annot.Boundary)
+			r.addStamp(pageID, bbox, sealType, sealData)
+		}
+	}
+	return nil
+}
+
+// extractSeal 尝试提取印章数据
+// 入参: data 签名值数据
+// 返回: string 印章类型, []byte 印章数据
+func extractSeal(data []byte) (string, []byte) {
+	var raw asn1.RawValue
+	_, err := asn1.Unmarshal(data, &raw)
+	if err != nil {
+		return "", nil
+	}
+	var foundType string
+	var foundData []byte
+	var search func(node asn1.RawValue) bool
+	search = func(node asn1.RawValue) bool {
+		if node.IsCompound {
+			var elements []asn1.RawValue
+			rest, err := asn1.Unmarshal(node.Bytes, &elements)
+			if err == nil && len(rest) == 0 {
+				if len(elements) == 4 {
+					e0, e1, e2, e3 := elements[0], elements[1], elements[2], elements[3]
+					if e1.Tag == 4 && e2.Tag == 2 && e3.Tag == 2 {
+						foundData = e1.Bytes
+						var s string
+						if _, err := asn1.Unmarshal(e0.FullBytes, &s); err == nil {
+							foundType = s
+						} else {
+							foundType = string(e0.Bytes)
+						}
+						foundType = strings.ToLower(strings.TrimSpace(strings.ReplaceAll(foundType, "\x00", "")))
+						if foundType == "es" {
+							foundType = "png"
+						}
+						return true
+					}
+				}
+				for _, child := range elements {
+					if search(child) {
+						return true
+					}
+				}
+			}
+		}
+		return false
+	}
+	if search(raw) {
+		return foundType, foundData
+	}
+	return "", nil
+}
+
+// Stamp 印章信息结构
+type Stamp struct {
+	Box  Box
+	Type string
+	Data []byte
+}
+
+// addStamp 添加印章到页面
+// 入参: pageID 页面ID, box 印章区域, sType 印章类型, data 印章数据
+func (r *Reader) addStamp(pageID string, box Box, sType string, data []byte) {
+	if r.Stamps == nil {
+		r.Stamps = make(map[string][]Stamp)
+	}
+	r.Stamps[pageID] = append(r.Stamps[pageID], Stamp{
+		Box:  box,
+		Type: sType,
+		Data: data,
+	})
+}