feat(签名展示): OFDGo WebUI支持签名展示

assets/webui/index.html

@@ -80,11 +80,22 @@
 						<dt>类型</dt>
 						<dd id="metaType">-</dd>
 					</div>
+					<div>
+						<dt>签名</dt>
+						<dd id="metaSignatures">0</dd>
+					</div>
 					<div>
 						<dt>字体</dt>
 						<dd id="metaFonts">0</dd>
 					</div>
 				</dl>
+				<section id="signaturePanel" class="signature-panel" aria-labelledby="signaturePanelTitle" hidden>
+					<div class="panel-row">
+						<div id="signaturePanelTitle" class="panel-title compact">签名</div>
+						<span id="signatureSummary" class="count-pill">0</span>
+					</div>
+					<div id="signatureList" class="signature-list"></div>
+				</section>
 				<section class="doc-font-panel" aria-labelledby="docFontPanelTitle">
 					<div class="panel-row">
 						<div id="docFontPanelTitle" class="panel-title compact">OFD 字体</div>

assets/webui/ofdgo.css

@@ -519,6 +519,23 @@ body[data-hide-meta] .meta-panel {
 	display: none;
 }
 
+.stamp-highlight {
+	position: absolute;
+	z-index: 4;
+	border: 2px solid var(--accent);
+	background: rgba(15, 123, 104, 0.08);
+	box-shadow: 0 0 0 3px rgba(15, 123, 104, 0.16);
+	pointer-events: none;
+	animation: stampPulse 0.9s ease-in-out 2;
+}
+
+@keyframes stampPulse {
+	50% {
+		border-color: var(--accent-strong);
+		box-shadow: 0 0 0 5px rgba(15, 123, 104, 0.18);
+	}
+}
+
 .ofd-svg {
 	display: block;
 	max-width: none;
@@ -548,7 +565,8 @@ body[data-hide-meta] .meta-panel {
 }
 
 .font-panel,
-.doc-font-panel {
+.doc-font-panel,
+.signature-panel {
 	margin-top: 18px;
 	padding-top: 12px;
 	border-top: 1px solid var(--line);
@@ -569,12 +587,14 @@ body[data-hide-meta] .meta-panel {
 	white-space: nowrap;
 }
 
-.doc-font-list {
+.doc-font-list,
+.signature-list {
 	display: grid;
 	gap: 8px;
 }
 
-.doc-font-row {
+.doc-font-row,
+.signature-row {
 	display: grid;
 	gap: 6px;
 	padding: 9px;
@@ -585,6 +605,7 @@ body[data-hide-meta] .meta-panel {
 
 .page-list-item:not(:disabled):hover,
 .doc-font-row:hover,
+.signature-row:hover,
 .font-row:hover {
 	border-color: var(--line-strong);
 	background: #ffffff;
@@ -600,14 +621,26 @@ body[data-hide-meta] .meta-panel {
 	background: #fffdf7;
 }
 
-.doc-font-head {
+.signature-row.valid {
+	border-color: #bdd8cc;
+	background: #fbfefd;
+}
+
+.signature-row.invalid {
+	border-color: #e2c7c4;
+	background: #fffdfc;
+}
+
+.doc-font-head,
+.signature-head {
 	display: grid;
 	grid-template-columns: minmax(0, 1fr) auto;
 	align-items: start;
 	gap: 8px;
 }
 
-.doc-font-name {
+.doc-font-name,
+.signature-name {
 	overflow: hidden;
 	color: #1f2428;
 	font-size: 13px;
@@ -616,7 +649,51 @@ body[data-hide-meta] .meta-panel {
 	white-space: nowrap;
 }
 
-.doc-font-badges {
+.signature-name-button {
+	display: inline;
+	padding: 0;
+	border: 0;
+	background: transparent;
+	color: inherit;
+	font: inherit;
+	font-weight: inherit;
+	cursor: pointer;
+	text-align: left;
+}
+
+.signature-name-button:not(:disabled):hover {
+	background: transparent;
+	color: var(--accent-strong);
+	text-decoration: underline;
+}
+
+.signature-name-with-stamps {
+	white-space: normal;
+}
+
+.signature-stamp-group {
+	color: var(--text-muted);
+	font-weight: 400;
+}
+
+.signature-stamp-link {
+	padding: 0;
+	border: 0;
+	background: transparent;
+	color: var(--accent-strong);
+	font: inherit;
+	font-weight: 400;
+	line-height: inherit;
+	cursor: pointer;
+}
+
+.signature-stamp-link:not(:disabled):hover {
+	background: transparent;
+	text-decoration: underline;
+}
+
+.doc-font-badges,
+.signature-badges {
 	display: flex;
 	flex-wrap: wrap;
 	justify-content: flex-end;
@@ -647,11 +724,45 @@ body[data-hide-meta] .meta-panel {
 	color: #705719;
 }
 
-.font-badge.missing {
+.font-badge.missing,
+.font-badge.invalid {
 	background: #f9e8e5;
 	color: #803f38;
 }
 
+.font-badge.valid {
+	background: #e4f3ef;
+	color: var(--accent-strong);
+}
+
+.signature-line {
+	display: grid;
+	grid-template-columns: 30px minmax(0, 1fr);
+	align-items: start;
+	gap: 7px;
+	color: var(--text-muted);
+	font-size: 11px;
+	line-height: 1.35;
+}
+
+.signature-label {
+	color: #7b8791;
+	white-space: nowrap;
+}
+
+.signature-value {
+	min-width: 0;
+	overflow-wrap: anywhere;
+}
+
+.signature-line.ok .signature-value {
+	color: var(--accent-strong);
+}
+
+.signature-line.fail .signature-value {
+	color: #803f38;
+}
+
 .doc-font-detail {
 	color: var(--text-muted);
 	font-size: 11px;

assets/webui/ofdgo.js

@@ -107,6 +107,10 @@ const el = {
 	metaVersion: document.querySelector("#metaVersion"),
 	metaType: document.querySelector("#metaType"),
 	metaFonts: document.querySelector("#metaFonts"),
+	metaSignatures: document.querySelector("#metaSignatures"),
+	signaturePanel: document.querySelector("#signaturePanel"),
+	signatureSummary: document.querySelector("#signatureSummary"),
+	signatureList: document.querySelector("#signatureList"),
 	docFontList: document.querySelector("#docFontList"),
 	docFontSummary: document.querySelector("#docFontSummary"),
 	availableFontSummary: document.querySelector("#availableFontSummary"),
@@ -1500,12 +1504,201 @@ function renderMeta() {
 	el.metaVersion.textContent = doc.version || "-";
 	el.metaType.textContent = doc.docType || "-";
 	el.metaFonts.textContent = String(doc.fontCount || 0);
+	el.metaSignatures.textContent = String(doc.signatureCount || 0);
 	el.pageTotal.textContent = String(doc.pageCount || 0);
+	renderSignatures();
 	renderDocumentFonts();
 	renderFontList();
 	updateLocalFontButton();
 }
 
+function renderSignatures() {
+	const signatures = state.doc?.signatures || [];
+	const showPanel = Boolean(state.doc?.signatureError || signatures.length);
+	el.signaturePanel.hidden = !showPanel;
+	el.signatureList.replaceChildren();
+	el.signatureSummary.textContent = signatureSummary(signatures);
+	if (!showPanel) {
+		return;
+	}
+	if (state.doc?.signatureError) {
+		const empty = document.createElement("div");
+		empty.className = "font-empty";
+		empty.textContent = state.doc.signatureError;
+		el.signatureList.append(empty);
+		return;
+	}
+	const fragment = document.createDocumentFragment();
+	for (const signature of signatures) {
+		const row = document.createElement("div");
+		row.className = `signature-row ${signature.valid ? "valid" : "invalid"}`;
+
+		const head = document.createElement("div");
+		head.className = "signature-head";
+
+		const name = signatureNameNode(signature);
+
+		const badges = document.createElement("div");
+		badges.className = "signature-badges";
+		badges.append(fontBadge(signature.valid ? "有效" : "无效", signature.valid ? "valid" : "invalid"));
+
+		head.append(name, badges);
+		row.append(head);
+		appendSignatureLine(row, "签者", signature.signer);
+		appendSignatureLine(row, "时间", formatSignatureTime(signature.signatureDateTime));
+		appendSignatureLine(row, "机构", signatureAgency(signature));
+		appendSignatureLine(row, "版本", signature.version);
+		appendSignatureLine(row, "保护", `${signature.referencePassed || 0}/${signature.referenceCount || 0}`);
+		appendSignatureCheck(row, "原文", signature.dataHashOK);
+		appendSignatureCheck(row, "摘要", signature.digestOK);
+		appendSignatureCheck(row, "签名", signature.signedValueOK);
+		appendSignatureCheck(row, "证书", signature.certOK);
+		if (signature.type !== "Sign") {
+			appendSignatureCheck(row, "印章", signature.sealOK && signature.sealMatchOK);
+			appendSignatureCheck(row, "匹配", signature.sealMatchOK);
+		}
+		appendSignatureLine(row, "算法", signature.signatureMethod);
+		appendSignatureLine(row, "散列", signature.digestMethod);
+		appendSignatureLine(row, "主体", signature.signSubject && signature.signSubject !== signature.signer ? signature.signSubject : "");
+		appendSignatureLine(row, "颁发", signature.signIssuer);
+		appendSignatureLine(row, "序列", signature.signSerial);
+		appendSignatureLine(row, "章图", signature.sealType);
+		appendSignatureLine(row, "章证", signature.sealSubject);
+		appendSignatureLine(row, "编号", signature.id);
+		appendSignatureLine(row, "错误", signature.error, "fail");
+		fragment.append(row);
+	}
+	el.signatureList.append(fragment);
+}
+
+function signatureSummary(signatures) {
+	if (!signatures.length) {
+		return "0";
+	}
+	const invalid = signatures.filter((signature) => !signature.valid).length;
+	if (invalid) {
+		return `${signatures.length} · 异常 ${invalid}`;
+	}
+	return `通过 ${signatures.length}`;
+}
+
+function signatureName() {
+	return "签名";
+}
+
+function signatureNameNode(signature) {
+	const stamps = signature.stamps || [];
+	if (!stamps.length) {
+		const name = document.createElement("div");
+		name.className = "signature-name";
+		name.textContent = signatureName();
+		return name;
+	}
+	const name = document.createElement("div");
+	name.className = "signature-name signature-name-with-stamps";
+
+	const button = document.createElement("button");
+	button.type = "button";
+	button.className = "signature-name-button";
+	button.textContent = signatureName();
+	button.addEventListener("click", () => focusSignatureStamp(stamps[0]));
+	name.append(button, signatureStampGroup(stamps));
+	return name;
+}
+
+function signatureStampGroup(stamps) {
+	const group = document.createElement("span");
+	group.className = "signature-stamp-group";
+	group.append("（");
+	for (const [index, stamp] of stamps.entries()) {
+		if (index > 0) {
+			group.append("、");
+		}
+		const button = document.createElement("button");
+		button.type = "button";
+		button.className = "signature-stamp-link";
+		button.textContent = `第${index + 1}处`;
+		button.addEventListener("click", () => focusSignatureStamp(stamp));
+		group.append(button);
+	}
+	group.append("）");
+	return group;
+}
+
+function signatureAgency(signature) {
+	if (signature.company && signature.provider) {
+		return `${signature.company} · ${signature.provider}`;
+	}
+	return signature.company || signature.provider || "";
+}
+
+function formatSignatureTime(value) {
+	const text = String(value || "").trim();
+	const digits = text.match(/^(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})$/);
+	if (digits) {
+		return `${digits[1]}-${digits[2]}-${digits[3]} ${digits[4]}:${digits[5]}:${digits[6]}`;
+	}
+	return text.replace("T", " ").replace(/(?:Z|[+-]\d{2}:?\d{2})$/, "");
+}
+
+function appendSignatureLine(row, label, value, status = "") {
+	if (!value && value !== 0) {
+		return;
+	}
+	const line = document.createElement("div");
+	line.className = status ? `signature-line ${status}` : "signature-line";
+
+	const key = document.createElement("span");
+	key.className = "signature-label";
+	key.textContent = label;
+
+	const text = document.createElement("span");
+	text.className = "signature-value";
+	text.textContent = String(value);
+
+	line.append(key, text);
+	row.append(line);
+}
+
+function appendSignatureCheck(row, label, ok) {
+	appendSignatureLine(row, label, ok ? "通过" : "失败", ok ? "ok" : "fail");
+}
+
+async function focusSignatureStamp(stamp) {
+	const pageIndex = (stamp.page || 0) - 1;
+	if (!state.doc || pageIndex < 0) {
+		return;
+	}
+	await renderPage(pageIndex);
+	await nextFrame();
+	highlightSignatureStamp(stamp);
+	setStatus(stamp.page ? `已定位签名外观 第 ${stamp.page} 页` : "已定位签名外观");
+}
+
+function highlightSignatureStamp(stamp) {
+	clearStampHighlights();
+	const pageIndex = (stamp.page || 0) - 1;
+	const shell = pageShell(pageIndex);
+	if (!shell || !stamp.width || !stamp.height) {
+		return;
+	}
+	const mark = document.createElement("div");
+	mark.className = "stamp-highlight";
+	mark.style.left = `${stamp.x * MM_TO_PX * state.scale}px`;
+	mark.style.top = `${stamp.y * MM_TO_PX * state.scale}px`;
+	mark.style.width = `${stamp.width * MM_TO_PX * state.scale}px`;
+	mark.style.height = `${stamp.height * MM_TO_PX * state.scale}px`;
+	shell.append(mark);
+	mark.scrollIntoView({ block: "center", inline: "center" });
+	window.setTimeout(() => mark.remove(), 1800);
+}
+
+function clearStampHighlights() {
+	for (const mark of el.svgHost.querySelectorAll(".stamp-highlight")) {
+		mark.remove();
+	}
+}
+
 function renderDocumentFonts() {
 	const fonts = state.doc?.fonts || [];
 	el.docFontList.replaceChildren();
@@ -1654,6 +1847,7 @@ function applyFit(updateStatus = true) {
 function setScale(nextScale, updateStatus = true, fitMode = "free") {
 	state.fitMode = fitMode;
 	state.scale = Math.min(4, Math.max(0.2, nextScale));
+	clearStampHighlights();
 	layoutPages();
 	el.zoomLabel.textContent = `${Math.round(state.scale * 100)}%`;
 	if (updateStatus && state.doc) {

internal/webui/webui.go

@@ -39,6 +39,49 @@ type FontFile = ofdgo.FontFile
 // FontInfo OFD字体信息
 type FontInfo = ofdgo.FontInfo
 
+// SignatureInfo 签名验证信息
+type SignatureInfo struct {
+	ID                string               `json:"id"`
+	Type              string               `json:"type"`
+	Valid             bool                 `json:"valid"`
+	Error             string               `json:"error,omitempty"`
+	Provider          string               `json:"provider,omitempty"`
+	Company           string               `json:"company,omitempty"`
+	Version           string               `json:"version,omitempty"`
+	Signer            string               `json:"signer,omitempty"`
+	SignSubject       string               `json:"signSubject,omitempty"`
+	SignIssuer        string               `json:"signIssuer,omitempty"`
+	SignSerial        string               `json:"signSerial,omitempty"`
+	SealSubject       string               `json:"sealSubject,omitempty"`
+	SealIssuer        string               `json:"sealIssuer,omitempty"`
+	SealSerial        string               `json:"sealSerial,omitempty"`
+	SealType          string               `json:"sealType,omitempty"`
+	SignatureMethod   string               `json:"signatureMethod,omitempty"`
+	SignatureDateTime string               `json:"signatureDateTime,omitempty"`
+	DigestMethod      string               `json:"digestMethod,omitempty"`
+	ReferenceCount    int                  `json:"referenceCount"`
+	ReferencePassed   int                  `json:"referencePassed"`
+	DigestOK          bool                 `json:"digestOK"`
+	DataHashOK        bool                 `json:"dataHashOK"`
+	SignedValueOK     bool                 `json:"signedValueOK"`
+	SealOK            bool                 `json:"sealOK"`
+	SealMatchOK       bool                 `json:"sealMatchOK"`
+	CertOK            bool                 `json:"certOK"`
+	Stamps            []SignatureStampInfo `json:"stamps,omitempty"`
+}
+
+// SignatureStampInfo 签名外观信息
+type SignatureStampInfo struct {
+	ID       string  `json:"id,omitempty"`
+	Page     int     `json:"page,omitempty"`
+	PageID   string  `json:"pageId,omitempty"`
+	Boundary string  `json:"boundary,omitempty"`
+	X        float64 `json:"x,omitempty"`
+	Y        float64 `json:"y,omitempty"`
+	Width    float64 `json:"width,omitempty"`
+	Height   float64 `json:"height,omitempty"`
+}
+
 // Session WebUI文档会话
 type Session struct {
 	Reader    *ofdgo.Reader
@@ -59,7 +102,10 @@ type DocumentInfo struct {
 	ModDate        string          `json:"modDate"`
 	PageCount      int             `json:"pageCount"`
 	FontCount      int             `json:"fontCount"`
+	SignatureCount int             `json:"signatureCount"`
+	SignatureError string          `json:"signatureError,omitempty"`
 	Fonts          []FontInfo      `json:"fonts"`
+	Signatures     []SignatureInfo `json:"signatures"`
 	Pages          []PageInfo      `json:"pages"`
 }
 
@@ -179,6 +225,12 @@ func (s *Session) Info() DocumentInfo {
 		info.Fonts = fonts
 	}
 	info.FontCount = len(info.Fonts)
+	if signatures, err := s.signatureInfos(); err == nil {
+		info.Signatures = signatures
+	} else {
+		info.SignatureError = err.Error()
+	}
+	info.SignatureCount = len(info.Signatures)
 	if docInfo, err := s.Reader.DocInfo(); err == nil && docInfo != nil {
 		info.Title = docInfo.Title
 		info.Author = docInfo.Author
@@ -257,6 +309,108 @@ func (s *Session) ExportPage(index int, value string) ([]byte, ExportFormat, err
 	return buf.Bytes(), format, nil
 }
 
+// signatureInfos 获取签名验证信息
+// 返回: []SignatureInfo 签名验证信息, error 错误信息
+func (s *Session) signatureInfos() ([]SignatureInfo, error) {
+	reports, err := s.Reader.VerifySignatures()
+	if err != nil {
+		return nil, err
+	}
+	infos := make([]SignatureInfo, 0, len(reports))
+	for _, report := range reports {
+		positions, err := s.Reader.SignatureStampPositions(report.Stamps)
+		if err != nil {
+			return nil, err
+		}
+		infos = append(infos, signatureInfo(report, positions))
+	}
+	return infos, nil
+}
+
+// signatureInfo 转换签名验证信息
+// 入参: report 签名验证报告, positions 签名外观位置
+// 返回: SignatureInfo 签名验证信息
+func signatureInfo(report ofdgo.SignatureVerifyReport, positions []ofdgo.SignatureStampPosition) SignatureInfo {
+	return SignatureInfo{
+		ID:                report.ID,
+		Type:              string(report.Type),
+		Valid:             report.Valid,
+		Error:             report.Error,
+		Provider:          report.Provider.ProviderName,
+		Company:           report.Provider.Company,
+		Version:           report.Provider.Version,
+		Signer:            signatureSigner(report),
+		SignSubject:       report.SignCert.Subject,
+		SignIssuer:        report.SignCert.Issuer,
+		SignSerial:        report.SignCert.SerialNumber,
+		SealSubject:       report.SealCert.Subject,
+		SealIssuer:        report.SealCert.Issuer,
+		SealSerial:        report.SealCert.SerialNumber,
+		SealType:          report.SealType,
+		SignatureMethod:   report.SignatureMethod,
+		SignatureDateTime: report.SignatureDateTime,
+		DigestMethod:      report.DigestMethod,
+		ReferenceCount:    len(report.References),
+		ReferencePassed:   signatureReferencePassed(report.References),
+		DigestOK:          report.DigestOK,
+		DataHashOK:        report.DataHashOK,
+		SignedValueOK:     report.SignedValueOK,
+		SealOK:            report.SealOK,
+		SealMatchOK:       report.SealMatchOK,
+		CertOK:            report.CertOK,
+		Stamps:            signatureStampInfos(positions),
+	}
+}
+
+// signatureSigner 获取签名人名称
+// 入参: report 签名验证报告
+// 返回: string 签名人名称
+func signatureSigner(report ofdgo.SignatureVerifyReport) string {
+	if report.Signer != "" {
+		return report.Signer
+	}
+	if report.SignCert.CommonName != "" {
+		return report.SignCert.CommonName
+	}
+	if report.SignCert.Organization != "" {
+		return report.SignCert.Organization
+	}
+	return report.SignCert.Subject
+}
+
+// signatureReferencePassed 获取已通过保护文件数量
+// 入参: refs 保护文件验证结果
+// 返回: int 已通过保护文件数量
+func signatureReferencePassed(refs []ofdgo.SignatureReferenceVerify) int {
+	count := 0
+	for _, ref := range refs {
+		if ref.OK {
+			count++
+		}
+	}
+	return count
+}
+
+// signatureStampInfos 转换签名外观位置
+// 入参: positions 签名外观位置
+// 返回: []SignatureStampInfo 签名外观信息
+func signatureStampInfos(positions []ofdgo.SignatureStampPosition) []SignatureStampInfo {
+	infos := make([]SignatureStampInfo, 0, len(positions))
+	for _, position := range positions {
+		infos = append(infos, SignatureStampInfo{
+			ID:       position.ID,
+			Page:     position.Page,
+			PageID:   position.PageID,
+			Boundary: position.Boundary,
+			X:        position.Box.X,
+			Y:        position.Box.Y,
+			Width:    position.Box.W,
+			Height:   position.Box.H,
+		})
+	}
+	return infos
+}
+
 // ExportPDF 导出文档为PDF
 // 返回: []byte PDF文件数据, error 错误信息
 func (s *Session) ExportPDF() ([]byte, error) {

ofdgo.go

@@ -43,7 +43,7 @@ func Open(path string) (*Reader, error) {
 	return reader, nil
 }
 
-// NewReader 从流创建一个 OFD 阅读器
+// NewReader 从IO读取器创建OFD阅读器
 // 入参: r IO读取器, size 数据大小
 // 返回: *Reader 阅读器实例, error 错误信息
 func NewReader(r io.ReaderAt, size int64) (*Reader, error) {

ofdgo_sign.go

@@ -22,11 +22,12 @@ import (
 	"strings"
 )
 
+// SignType 签名类型
 type SignType string
 
 const (
-	SignTypeSeal = "Seal"
-	SignTypeSign = "Sign"
+	SignTypeSeal SignType = "Seal"
+	SignTypeSign SignType = "Sign"
 )
 
 // Signatures 签名列表
@@ -47,16 +48,81 @@ type Signature struct {
 type SignatureFile struct {
 	XMLName     xml.Name `xml:"Signature"`
 	SignedValue string   `xml:"SignedValue"`
-	SignedInfo  struct {
-		Seal struct {
+	SignedInfo  SignedInfo
+}
+
+// SignedInfo 签名信息
+type SignedInfo struct {
+	Provider          SignatureProvider   `xml:"Provider"`
+	SignatureMethod   string              `xml:"SignatureMethod"`
+	SignatureDateTime string              `xml:"SignatureDateTime"`
+	Seal              SignatureSeal       `xml:"Seal"`
+	StampAnnot        []SignatureStamp    `xml:"StampAnnot"`
+	References        SignatureReferences `xml:"References"`
+	Raw               []byte              `xml:"-"`
+}
+
+// SignatureProvider 签名提供者信息
+type SignatureProvider struct {
+	ProviderName string `xml:"ProviderName,attr"`
+	Company      string `xml:"Company,attr"`
+	Version      string `xml:"Version,attr"`
+}
+
+// SignatureSeal 签名印章引用
+type SignatureSeal struct {
 	BaseLoc string `xml:"BaseLoc"`
-		} `xml:"Seal"`
-		StampAnnot []struct {
+}
+
+// SignatureStamp 签名印章注释
+type SignatureStamp struct {
 	ID       string `xml:"ID,attr"`
 	PageRef  string `xml:"PageRef,attr"`
 	Boundary string `xml:"Boundary,attr"`
-		} `xml:"StampAnnot"`
-	} `xml:"SignedInfo"`
+}
+
+// SignatureStampPosition 签名外观位置信息
+type SignatureStampPosition struct {
+	ID       string
+	Page     int
+	PageID   string
+	Boundary string
+	Box      Box
+}
+
+// SignatureReferences 签名保护文件列表
+type SignatureReferences struct {
+	CheckMethod string               `xml:"CheckMethod,attr"`
+	Reference   []SignatureReference `xml:"Reference"`
+}
+
+// SignatureReference 签名保护文件引用
+type SignatureReference struct {
+	FileRef    string `xml:"FileRef,attr"`
+	CheckValue string `xml:"CheckValue"`
+}
+
+// SignatureStampPositions 获取签名外观位置信息
+// 入参: stamps 签名外观列表
+// 返回: []SignatureStampPosition 签名外观位置信息, error 错误信息
+func (r *Reader) SignatureStampPositions(stamps []SignatureStamp) ([]SignatureStampPosition, error) {
+	doc, err := r.Doc()
+	if err != nil {
+		return nil, err
+	}
+	pages := signaturePageNumbers(doc)
+	positions := make([]SignatureStampPosition, 0, len(stamps))
+	for _, stamp := range stamps {
+		box, _ := ParseBox(stamp.Boundary)
+		positions = append(positions, SignatureStampPosition{
+			ID:       stamp.ID,
+			Page:     pages[stamp.PageRef],
+			PageID:   stamp.PageRef,
+			Boundary: stamp.Boundary,
+			Box:      box,
+		})
+	}
+	return positions, nil
 }
 
 // parseSignatures 解析签名文件
@@ -99,9 +165,13 @@ func (r *Reader) parseSignatures(doc *Document) error {
 			if len(sealData) == 0 && sigFile.SignedValue != "" {
 				signedValuePath := resolveResourcePath(sigPath, "", sigFile.SignedValue)
 				if data, err := r.ResData(signedValuePath); err == nil {
+					if sig, err := parseSESSignature(data); err == nil {
+						sealType, sealData = sig.Seal.PicType, sig.Seal.PicData
+					} else {
 						sealType, sealData = extractSeal(data)
 					}
 				}
+			}
 			if len(sealData) == 0 {
 				return
 			}
@@ -115,6 +185,19 @@ func (r *Reader) parseSignatures(doc *Document) error {
 	return nil
 }
 
+// signaturePageNumbers 获取签名页面编号索引
+// 入参: doc 文档结构
+// 返回: map[string]int 页面编号索引
+func signaturePageNumbers(doc *Document) map[string]int {
+	pages := make(map[string]int, len(doc.Pages.Page))
+	for index, page := range doc.Pages.Page {
+		if page.ID != "" {
+			pages[page.ID] = index + 1
+		}
+	}
+	return pages
+}
+
 // 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

ofdgo_sign_gbt.go

@@ -0,0 +1,477 @@
+// Copyright 2025-2026 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 (
+	"bytes"
+	"encoding/asn1"
+	"fmt"
+	"math/big"
+)
+
+const (
+	signContentData       = "1.2.156.10197.6.1.4.2.1"
+	signContentSignedData = "1.2.156.10197.6.1.4.2.2"
+	signAttrMessageDigest = "1.2.840.113549.1.9.4"
+)
+
+// digitalVerifyResult 数字签名验证结果
+type digitalVerifyResult struct {
+	DataHashOK bool
+	SignedOK   bool
+	CertOK     bool
+	CertInfo   SignatureCertInfo
+}
+
+// gbtSignedData GB/T 35275 SignedData结构
+type gbtSignedData struct {
+	ContentDigest []byte
+	Certs         []gbtCertificate
+	Signers       []gbtSignerInfo
+}
+
+// gbtCertificate SignedData证书索引信息
+type gbtCertificate struct {
+	Raw    []byte
+	Issuer []byte
+	Serial *big.Int
+}
+
+// gbtSignerInfo SignedData签名者信息
+type gbtSignerInfo struct {
+	Issuer       []byte
+	Serial       *big.Int
+	DigestAlg    string
+	SignatureAlg string
+	Signature    []byte
+	AuthAttrs    []byte
+	AttrDigest   []byte
+}
+
+// verifyDigitalSignature 验证OFD数字签名
+// 入参: method 签名算法, signedValue 签名值, signedData 被签名原文, options 验证选项
+// 返回: *digitalVerifyResult 验证结果, error 错误信息
+func verifyDigitalSignature(method string, signedValue, signedData []byte, options *signatureVerifyOptions) (*digitalVerifyResult, error) {
+	if !isSM2SignatureMethod(method) {
+		return nil, fmt.Errorf("unsupported signature method")
+	}
+	if isGBT35275SignedValue(signedValue) {
+		return verifyGBT35275SignedData(signedValue, signedData, options)
+	}
+	return verifyRawDigitalSignature(signedValue, signedData, options)
+}
+
+// verifyRawDigitalSignature 验证裸SM2数字签名
+// 入参: signedValue 签名值, signedData 被签名原文, options 验证选项
+// 返回: *digitalVerifyResult 验证结果, error 错误信息
+func verifyRawDigitalSignature(signedValue, signedData []byte, options *signatureVerifyOptions) (*digitalVerifyResult, error) {
+	if len(options.SignCerts) == 0 {
+		return nil, fmt.Errorf("signature certificate not found")
+	}
+	result := &digitalVerifyResult{DataHashOK: true}
+	for _, cert := range options.SignCerts {
+		pub, err := parseSM2PublicKeyFromCert(cert)
+		if err != nil {
+			continue
+		}
+		result.CertOK = true
+		result.CertInfo = signatureCertInfo(cert)
+		if sm2VerifySignature(pub, nil, signedData, signedValue) {
+			result.SignedOK = true
+			return result, nil
+		}
+	}
+	return result, nil
+}
+
+// verifyGBT35275SignedData 验证GB/T 35275 SignedData签名值
+// 入参: signedValue 签名值, signedData 被签名原文, options 验证选项
+// 返回: *digitalVerifyResult 验证结果, error 错误信息
+func verifyGBT35275SignedData(signedValue, signedData []byte, options *signatureVerifyOptions) (*digitalVerifyResult, error) {
+	sd, err := parseGBT35275SignedData(signedValue)
+	if err != nil {
+		return nil, err
+	}
+	for _, cert := range options.SignCerts {
+		c, err := parseGBTCertificate(cert)
+		if err == nil {
+			sd.Certs = append(sd.Certs, c)
+		}
+	}
+	if len(sd.Signers) == 0 {
+		return nil, fmt.Errorf("invalid signed data signer info")
+	}
+	result := &digitalVerifyResult{}
+	digest := signSM3(signedData)
+	if len(sd.ContentDigest) != 0 && !bytes.Equal(sd.ContentDigest, digest) {
+		return result, nil
+	}
+	result.DataHashOK = true
+	for _, signer := range sd.Signers {
+		if !isSM3DigestMethod(signer.DigestAlg) {
+			return nil, fmt.Errorf("unsupported digest method")
+		}
+		plain := sd.ContentDigest
+		if len(signer.AuthAttrs) != 0 {
+			if !bytes.Equal(signer.AttrDigest, digest) {
+				result.DataHashOK = false
+				return result, nil
+			}
+			plain = signer.AuthAttrs
+		}
+		if len(plain) == 0 {
+			return nil, fmt.Errorf("invalid signed data content")
+		}
+		cert := sd.findCert(signer.Issuer, signer.Serial)
+		if cert == nil {
+			return result, nil
+		}
+		result.CertInfo = signatureCertInfo(cert.Raw)
+		if !isSM2SignatureMethod(signer.SignatureAlg) {
+			return nil, fmt.Errorf("unsupported signature method")
+		}
+		pub, err := parseSM2PublicKeyFromCert(cert.Raw)
+		if err != nil {
+			return result, err
+		}
+		result.CertOK = true
+		if !sm2VerifySignature(pub, nil, plain, signer.Signature) {
+			return result, nil
+		}
+	}
+	result.SignedOK = true
+	return result, nil
+}
+
+// isGBT35275SignedValue 判断签名值是否为GB/T 35275 SignedData
+// 入参: data 签名值数据
+// 返回: bool 是否为SignedData
+func isGBT35275SignedValue(data []byte) bool {
+	var root asn1.RawValue
+	rest, err := asn1.Unmarshal(data, &root)
+	if err != nil || len(rest) != 0 || root.Tag != signASN1Sequence {
+		return false
+	}
+	items, ok := asn1Children(root.Bytes)
+	if !ok || len(items) < 2 {
+		return false
+	}
+	oid, err := asn1OIDString(items[0])
+	return err == nil && oid == signContentSignedData
+}
+
+// parseGBT35275SignedData 解析GB/T 35275 SignedData
+// 入参: data 签名值数据
+// 返回: *gbtSignedData SignedData结构, error 错误信息
+func parseGBT35275SignedData(data []byte) (*gbtSignedData, error) {
+	contentType, content, ok, err := parseGBTContentInfoBytes(data)
+	if err != nil {
+		return nil, err
+	}
+	if !ok || contentType != signContentSignedData {
+		return nil, fmt.Errorf("invalid signed data content type")
+	}
+	items, ok := asn1Children(content.Bytes)
+	if !ok || len(items) < 4 {
+		return nil, fmt.Errorf("invalid signed data")
+	}
+	sd := &gbtSignedData{}
+	contentOID, content, hasContent, err := parseGBTContentInfo(items[2])
+	if err != nil {
+		return nil, err
+	}
+	if hasContent {
+		if contentOID != signContentData {
+			return nil, fmt.Errorf("invalid signed data inner content type")
+		}
+		if content.Tag == asn1.TagOctetString {
+			sd.ContentDigest, err = asn1OctetString(content)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	for i := 3; i < len(items); i++ {
+		item := items[i]
+		if item.Class == asn1.ClassContextSpecific && item.Tag == 0 {
+			certs, err := parseGBTCertificates(item)
+			if err != nil {
+				return nil, err
+			}
+			sd.Certs = certs
+			continue
+		}
+		if item.Class == asn1.ClassContextSpecific && item.Tag == 1 {
+			continue
+		}
+		signers, err := parseGBTSignerInfos(item)
+		if err != nil {
+			return nil, err
+		}
+		sd.Signers = signers
+	}
+	return sd, nil
+}
+
+// parseGBTContentInfoBytes 解析ContentInfo字节
+// 入参: data DER编码数据
+// 返回: string 内容类型, asn1.RawValue 内容, bool 是否存在内容, error 错误信息
+func parseGBTContentInfoBytes(data []byte) (string, asn1.RawValue, bool, error) {
+	var raw asn1.RawValue
+	rest, err := asn1.Unmarshal(data, &raw)
+	if err != nil || len(rest) != 0 {
+		return "", asn1.RawValue{}, false, fmt.Errorf("invalid content info")
+	}
+	return parseGBTContentInfo(raw)
+}
+
+// parseGBTContentInfo 解析ContentInfo结构
+// 入参: raw ASN.1原始值
+// 返回: string 内容类型, asn1.RawValue 内容, bool 是否存在内容, error 错误信息
+func parseGBTContentInfo(raw asn1.RawValue) (string, asn1.RawValue, bool, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) == 0 {
+		return "", asn1.RawValue{}, false, fmt.Errorf("invalid content info")
+	}
+	oid, err := asn1OIDString(items[0])
+	if err != nil {
+		return "", asn1.RawValue{}, false, err
+	}
+	if len(items) == 1 {
+		return oid, asn1.RawValue{}, false, nil
+	}
+	content, err := asn1Explicit(items[1])
+	if err != nil {
+		return "", asn1.RawValue{}, false, err
+	}
+	return oid, content, true, nil
+}
+
+// parseGBTCertificates 解析SignedData证书集合
+// 入参: raw ASN.1原始值
+// 返回: []gbtCertificate 证书列表, error 错误信息
+func parseGBTCertificates(raw asn1.RawValue) ([]gbtCertificate, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("invalid signed data certificates")
+	}
+	certs := make([]gbtCertificate, 0, len(items))
+	for _, item := range items {
+		cert, err := parseGBTCertificate(item.FullBytes)
+		if err != nil {
+			return nil, err
+		}
+		certs = append(certs, cert)
+	}
+	return certs, nil
+}
+
+// parseGBTCertificate 解析X.509证书索引字段
+// 入参: data DER编码证书
+// 返回: gbtCertificate 证书索引信息, error 错误信息
+func parseGBTCertificate(data []byte) (gbtCertificate, error) {
+	var cert struct {
+		TBSCertificate     asn1.RawValue
+		SignatureAlgorithm asn1.RawValue
+		SignatureValue     asn1.BitString
+	}
+	rest, err := asn1.Unmarshal(data, &cert)
+	if err != nil || len(rest) != 0 {
+		return gbtCertificate{}, fmt.Errorf("invalid certificate")
+	}
+	items, ok := asn1Children(cert.TBSCertificate.Bytes)
+	if !ok {
+		return gbtCertificate{}, fmt.Errorf("invalid tbs certificate")
+	}
+	idx := 0
+	if len(items) > 0 && items[0].Class == asn1.ClassContextSpecific && items[0].Tag == 0 {
+		idx++
+	}
+	if len(items) <= idx+2 {
+		return gbtCertificate{}, fmt.Errorf("invalid certificate issuer")
+	}
+	serial, err := asn1IntegerBig(items[idx])
+	if err != nil {
+		return gbtCertificate{}, err
+	}
+	return gbtCertificate{
+		Raw:    append([]byte(nil), data...),
+		Issuer: append([]byte(nil), items[idx+2].FullBytes...),
+		Serial: serial,
+	}, nil
+}
+
+// parseGBTSignerInfos 解析签名者信息集合
+// 入参: raw ASN.1原始值
+// 返回: []gbtSignerInfo 签名者列表, error 错误信息
+func parseGBTSignerInfos(raw asn1.RawValue) ([]gbtSignerInfo, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("invalid signer infos")
+	}
+	signers := make([]gbtSignerInfo, 0, len(items))
+	for _, item := range items {
+		signer, err := parseGBTSignerInfo(item)
+		if err != nil {
+			return nil, err
+		}
+		signers = append(signers, signer)
+	}
+	return signers, nil
+}
+
+// parseGBTSignerInfo 解析签名者信息
+// 入参: raw ASN.1原始值
+// 返回: gbtSignerInfo 签名者信息, error 错误信息
+func parseGBTSignerInfo(raw asn1.RawValue) (gbtSignerInfo, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) < 5 {
+		return gbtSignerInfo{}, fmt.Errorf("invalid signer info")
+	}
+	issuer, serial, err := parseGBTIssuerAndSerial(items[1])
+	if err != nil {
+		return gbtSignerInfo{}, err
+	}
+	digestAlg, err := parseGBTAlgorithm(items[2])
+	if err != nil {
+		return gbtSignerInfo{}, err
+	}
+	idx := 3
+	var authAttrs []byte
+	var attrDigest []byte
+	if items[idx].Class == asn1.ClassContextSpecific && items[idx].Tag == 0 {
+		authAttrs = asn1SetBytes(items[idx].Bytes)
+		attrDigest, err = parseGBTMessageDigestAttr(items[idx])
+		if err != nil {
+			return gbtSignerInfo{}, err
+		}
+		idx++
+	}
+	if len(items) <= idx+1 {
+		return gbtSignerInfo{}, fmt.Errorf("invalid signer info")
+	}
+	signatureAlg, err := parseGBTAlgorithm(items[idx])
+	if err != nil {
+		return gbtSignerInfo{}, err
+	}
+	signature, err := asn1OctetString(items[idx+1])
+	if err != nil {
+		return gbtSignerInfo{}, err
+	}
+	return gbtSignerInfo{
+		Issuer:       issuer,
+		Serial:       serial,
+		DigestAlg:    digestAlg,
+		SignatureAlg: signatureAlg,
+		Signature:    signature,
+		AuthAttrs:    authAttrs,
+		AttrDigest:   attrDigest,
+	}, nil
+}
+
+// parseGBTIssuerAndSerial 解析证书颁发者和序列号
+// 入参: raw ASN.1原始值
+// 返回: []byte 颁发者DN, *big.Int 序列号, error 错误信息
+func parseGBTIssuerAndSerial(raw asn1.RawValue) ([]byte, *big.Int, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) < 2 {
+		return nil, nil, fmt.Errorf("invalid issuer and serial")
+	}
+	serial, err := asn1IntegerBig(items[1])
+	if err != nil {
+		return nil, nil, err
+	}
+	return append([]byte(nil), items[0].FullBytes...), serial, nil
+}
+
+// parseGBTAlgorithm 解析算法标识
+// 入参: raw ASN.1原始值
+// 返回: string 算法OID, error 错误信息
+func parseGBTAlgorithm(raw asn1.RawValue) (string, error) {
+	if raw.Tag == asn1.TagOID {
+		return asn1OIDString(raw)
+	}
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) == 0 {
+		return "", fmt.Errorf("invalid algorithm identifier")
+	}
+	return asn1OIDString(items[0])
+}
+
+// parseGBTMessageDigestAttr 解析认证属性中的message-digest
+// 入参: raw ASN.1原始值
+// 返回: []byte 摘要值, error 错误信息
+func parseGBTMessageDigestAttr(raw asn1.RawValue) ([]byte, error) {
+	attrs, ok := asn1Children(raw.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("invalid authenticated attributes")
+	}
+	for _, attr := range attrs {
+		items, ok := asn1Children(attr.Bytes)
+		if !ok || len(items) < 2 {
+			continue
+		}
+		oid, err := asn1OIDString(items[0])
+		if err != nil || oid != signAttrMessageDigest {
+			continue
+		}
+		values, ok := asn1Children(items[1].Bytes)
+		if !ok || len(values) == 0 {
+			return nil, fmt.Errorf("invalid message digest attribute")
+		}
+		return asn1OctetString(values[0])
+	}
+	return nil, fmt.Errorf("message digest attribute not found")
+}
+
+// findCert 查找签名者证书
+// 入参: issuer 颁发者DN, serial 证书序列号
+// 返回: *gbtCertificate 证书信息
+func (sd *gbtSignedData) findCert(issuer []byte, serial *big.Int) *gbtCertificate {
+	for i := range sd.Certs {
+		cert := &sd.Certs[i]
+		if bytes.Equal(cert.Issuer, issuer) && cert.Serial.Cmp(serial) == 0 {
+			return cert
+		}
+	}
+	return nil
+}
+
+// asn1Explicit 解析显式标签内容
+// 入参: raw ASN.1原始值
+// 返回: asn1.RawValue 标签内容, error 错误信息
+func asn1Explicit(raw asn1.RawValue) (asn1.RawValue, error) {
+	if raw.Class != asn1.ClassContextSpecific || raw.Tag != 0 || !raw.IsCompound {
+		return asn1.RawValue{}, fmt.Errorf("invalid explicit content")
+	}
+	var out asn1.RawValue
+	rest, err := asn1.Unmarshal(raw.Bytes, &out)
+	if err != nil || len(rest) != 0 {
+		return asn1.RawValue{}, fmt.Errorf("invalid explicit content")
+	}
+	return out, nil
+}
+
+// asn1IntegerBig 解析ASN.1整数
+// 入参: raw ASN.1原始值
+// 返回: *big.Int 整数值, error 错误信息
+func asn1IntegerBig(raw asn1.RawValue) (*big.Int, error) {
+	var out *big.Int
+	rest, err := asn1.Unmarshal(raw.FullBytes, &out)
+	if err != nil || len(rest) != 0 || out == nil {
+		return nil, fmt.Errorf("invalid integer")
+	}
+	return out, nil
+}

ofdgo_sign_ses.go

@@ -0,0 +1,643 @@
+// Copyright 2025-2026 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 (
+	"bytes"
+	"encoding/asn1"
+	"fmt"
+	"math/big"
+	"strings"
+)
+
+const (
+	signDigestSM3      = "1.2.156.10197.1.401"
+	signDigestSM3NoKey = "1.2.156.10197.1.401.1"
+	signDigestSM3Key   = "1.2.156.10197.1.401.2"
+	signMethodSM2SM3   = "1.2.156.10197.1.501"
+	signMethodSM2SM3B  = "1.2.156.10197.501"
+	signMethodSM2Sign  = "1.2.156.10197.1.301.1"
+	signCurveSM2P256   = "1.2.156.10197.1.301"
+	signECPublicKey    = "1.2.840.10045.2.1"
+	signASN1Sequence   = 16
+	signPublicKeySize  = 65
+)
+
+// sesSignature SES签章值
+type sesSignature struct {
+	ToSign    []byte
+	Cert      []byte
+	SignAlg   string
+	Signature []byte
+	DataHash  []byte
+	Seal      *sesSeal
+}
+
+// sesSeal SES电子印章
+type sesSeal struct {
+	Raw       []byte
+	SignData  []byte
+	Cert      []byte
+	SignAlg   string
+	Signature []byte
+	PicType   string
+	PicData   []byte
+	CertList  sesCertList
+}
+
+// sesCertList SES印章证书列表
+type sesCertList struct {
+	Certs   [][]byte
+	Digests [][]byte
+}
+
+// sesVerifyResult SES签章验证结果
+type sesVerifyResult struct {
+	DataHashOK bool
+	SignedOK   bool
+	SealOK     bool
+	CertOK     bool
+	SignCert   SignatureCertInfo
+	SealCert   SignatureCertInfo
+	SealType   string
+}
+
+// parseSESSignature 解析SES签章值
+// 入参: data 签章值数据
+// 返回: *sesSignature SES签章值, error 错误信息
+func parseSESSignature(data []byte) (*sesSignature, error) {
+	var root asn1.RawValue
+	rest, err := asn1.Unmarshal(data, &root)
+	if err != nil {
+		return nil, err
+	}
+	if len(rest) != 0 || root.Tag != signASN1Sequence || !root.IsCompound {
+		return nil, fmt.Errorf("invalid ses signature")
+	}
+	items, ok := asn1Children(root.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("invalid ses signature items")
+	}
+	if len(items) == 2 {
+		return parseSESSignatureV1(items)
+	}
+	if len(items) < 4 || len(items) > 5 {
+		return nil, fmt.Errorf("invalid ses signature items")
+	}
+	cert, err := asn1OctetString(items[1])
+	if err != nil {
+		return nil, err
+	}
+	alg, err := asn1OIDString(items[2])
+	if err != nil {
+		return nil, err
+	}
+	signature, err := asn1BitStringBytes(items[3])
+	if err != nil {
+		return nil, err
+	}
+	tbsItems, ok := asn1Children(items[0].Bytes)
+	if !ok || len(tbsItems) < 5 {
+		return nil, fmt.Errorf("invalid ses toSign")
+	}
+	seal, err := parseSESSeal(tbsItems[1])
+	if err != nil {
+		return nil, err
+	}
+	dataHash, err := asn1BitOrOctetBytes(tbsItems[3])
+	if err != nil {
+		return nil, err
+	}
+	return &sesSignature{
+		ToSign:    append([]byte(nil), items[0].FullBytes...),
+		Cert:      cert,
+		SignAlg:   alg,
+		Signature: signature,
+		DataHash:  dataHash,
+		Seal:      seal,
+	}, nil
+}
+
+// parseSESSignatureV1 解析SES V1签章值
+// 入参: items ASN.1子元素
+// 返回: *sesSignature SES签章值, error 错误信息
+func parseSESSignatureV1(items []asn1.RawValue) (*sesSignature, error) {
+	signature, err := asn1BitStringBytes(items[1])
+	if err != nil {
+		return nil, err
+	}
+	tbsItems, ok := asn1Children(items[0].Bytes)
+	if !ok || len(tbsItems) != 7 {
+		return nil, fmt.Errorf("invalid ses v1 toSign")
+	}
+	seal, err := parseSESSeal(tbsItems[1])
+	if err != nil {
+		return nil, err
+	}
+	dataHash, err := asn1BitOrOctetBytes(tbsItems[3])
+	if err != nil {
+		return nil, err
+	}
+	cert, err := asn1OctetString(tbsItems[5])
+	if err != nil {
+		return nil, err
+	}
+	alg, err := asn1OIDString(tbsItems[6])
+	if err != nil {
+		return nil, err
+	}
+	return &sesSignature{
+		ToSign:    append([]byte(nil), items[0].FullBytes...),
+		Cert:      cert,
+		SignAlg:   alg,
+		Signature: signature,
+		DataHash:  dataHash,
+		Seal:      seal,
+	}, nil
+}
+
+// verifySESSignature 验证SES签章值
+// 入参: data 签章值数据, signedData 被签名数据原文
+// 返回: *sesVerifyResult 验证结果, error 错误信息
+func verifySESSignature(data, signedData []byte) (*sesVerifyResult, error) {
+	sig, err := parseSESSignature(data)
+	if err != nil {
+		return nil, err
+	}
+	if !isSM2SignatureMethod(sig.SignAlg) || !isSM2SignatureMethod(sig.Seal.SignAlg) {
+		return nil, fmt.Errorf("unsupported signature method")
+	}
+	result := &sesVerifyResult{}
+	result.SignCert = signatureCertInfo(sig.Cert)
+	result.SealCert = signatureCertInfo(sig.Seal.Cert)
+	result.SealType = sig.Seal.PicType
+	result.DataHashOK = bytes.Equal(sig.DataHash, signSM3(signedData))
+	signPub, err := parseSM2PublicKeyFromCert(sig.Cert)
+	if err != nil {
+		return result, err
+	}
+	sealPub, err := parseSM2PublicKeyFromCert(sig.Seal.Cert)
+	if err != nil {
+		return result, err
+	}
+	result.SignedOK = sm2VerifySignature(signPub, nil, sig.ToSign, sig.Signature)
+	result.SealOK = sm2VerifySignature(sealPub, nil, sig.Seal.SignData, sig.Seal.Signature)
+	result.CertOK = sesCertInList(sig.Cert, sig.Seal.CertList)
+	return result, nil
+}
+
+// parseSESSeal 解析SES电子印章
+// 入参: raw ASN.1原始值
+// 返回: *sesSeal SES电子印章, error 错误信息
+func parseSESSeal(raw asn1.RawValue) (*sesSeal, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("invalid ses seal")
+	}
+	if len(items) == 2 {
+		return parseSESSealV1(raw, items)
+	}
+	if len(items) < 4 || len(items) > 5 {
+		return nil, fmt.Errorf("invalid ses seal")
+	}
+	cert, err := asn1OctetString(items[1])
+	if err != nil {
+		return nil, err
+	}
+	alg, err := asn1OIDString(items[2])
+	if err != nil {
+		return nil, err
+	}
+	signature, err := asn1BitStringBytes(items[3])
+	if err != nil {
+		return nil, err
+	}
+	infoItems, ok := asn1Children(items[0].Bytes)
+	if !ok || len(infoItems) < 4 || len(infoItems) > 5 {
+		return nil, fmt.Errorf("invalid ses seal info")
+	}
+	version, err := parseSESHeaderVersion(infoItems[0])
+	if err != nil {
+		return nil, err
+	}
+	certList, err := parseSESCertList(infoItems[2], version)
+	if err != nil {
+		return nil, err
+	}
+	picType, picData, err := parseSESPicture(infoItems[3])
+	if err != nil {
+		return nil, err
+	}
+	return &sesSeal{
+		Raw:       append([]byte(nil), raw.FullBytes...),
+		SignData:  append([]byte(nil), items[0].FullBytes...),
+		Cert:      cert,
+		SignAlg:   alg,
+		Signature: signature,
+		PicType:   picType,
+		PicData:   picData,
+		CertList:  certList,
+	}, nil
+}
+
+// parseSESSealV1 解析SES V1电子印章
+// 入参: raw ASN.1原始值, items ASN.1子元素
+// 返回: *sesSeal SES电子印章, error 错误信息
+func parseSESSealV1(raw asn1.RawValue, items []asn1.RawValue) (*sesSeal, error) {
+	infoItems, ok := asn1Children(items[0].Bytes)
+	if !ok || len(infoItems) < 4 || len(infoItems) > 5 {
+		return nil, fmt.Errorf("invalid ses v1 seal info")
+	}
+	signItems, ok := asn1Children(items[1].Bytes)
+	if !ok || len(signItems) != 3 {
+		return nil, fmt.Errorf("invalid ses v1 sign info")
+	}
+	cert, err := asn1OctetString(signItems[0])
+	if err != nil {
+		return nil, err
+	}
+	alg, err := asn1OIDString(signItems[1])
+	if err != nil {
+		return nil, err
+	}
+	signature, err := asn1BitStringBytes(signItems[2])
+	if err != nil {
+		return nil, err
+	}
+	certList, err := parseSESCertListV1(infoItems[2])
+	if err != nil {
+		return nil, err
+	}
+	picType, picData, err := parseSESPicture(infoItems[3])
+	if err != nil {
+		return nil, err
+	}
+	signData := asn1SequenceBytes(items[0].FullBytes, signItems[0].FullBytes, signItems[1].FullBytes)
+	return &sesSeal{
+		Raw:       append([]byte(nil), raw.FullBytes...),
+		SignData:  signData,
+		Cert:      cert,
+		SignAlg:   alg,
+		Signature: signature,
+		PicType:   picType,
+		PicData:   picData,
+		CertList:  certList,
+	}, nil
+}
+
+// parseSESHeaderVersion 解析印章头版本
+// 入参: raw 印章头信息
+// 返回: int 版本号, error 错误信息
+func parseSESHeaderVersion(raw asn1.RawValue) (int, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) < 2 {
+		return 0, fmt.Errorf("invalid ses header")
+	}
+	return asn1Integer(items[1])
+}
+
+// parseSESCertList 解析印章证书列表
+// 入参: raw 印章属性信息
+// 返回: sesCertList 证书列表, error 错误信息
+func parseSESCertList(raw asn1.RawValue, version int) (sesCertList, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) < 3 {
+		return sesCertList{}, fmt.Errorf("invalid ses property")
+	}
+	if version < 4 {
+		return parseSESCertInfoList(items[2])
+	}
+	if len(items) < 4 {
+		return sesCertList{}, fmt.Errorf("invalid ses cert list")
+	}
+	listType, err := asn1Integer(items[2])
+	if err != nil {
+		return sesCertList{}, err
+	}
+	switch listType {
+	case 1:
+		return parseSESCertInfoList(items[3])
+	case 2:
+		return parseSESCertDigestList(items[3])
+	default:
+		return sesCertList{}, fmt.Errorf("unsupported ses cert list type")
+	}
+}
+
+// parseSESCertListV1 解析SES V1证书列表
+// 入参: raw 证书列表ASN.1值
+// 返回: sesCertList 证书列表, error 错误信息
+func parseSESCertListV1(raw asn1.RawValue) (sesCertList, error) {
+	certs, ok := asn1Children(raw.Bytes)
+	if !ok || len(certs) == 0 {
+		return sesCertList{}, fmt.Errorf("invalid ses cert list")
+	}
+	list := sesCertList{Certs: make([][]byte, 0, len(certs))}
+	for _, item := range certs {
+		list.Certs = append(list.Certs, append([]byte(nil), item.FullBytes...))
+	}
+	return list, nil
+}
+
+// parseSESCertInfoList 解析SES证书信息列表
+// 入参: raw 证书信息列表ASN.1值
+// 返回: sesCertList 证书列表, error 错误信息
+func parseSESCertInfoList(raw asn1.RawValue) (sesCertList, error) {
+	certs, ok := asn1Children(raw.Bytes)
+	if !ok || len(certs) == 0 {
+		return sesCertList{}, fmt.Errorf("invalid ses cert list")
+	}
+	list := sesCertList{Certs: make([][]byte, 0, len(certs))}
+	for _, item := range certs {
+		cert, err := asn1OctetString(item)
+		if err != nil {
+			return sesCertList{}, err
+		}
+		list.Certs = append(list.Certs, cert)
+	}
+	return list, nil
+}
+
+// parseSESCertDigestList 解析SES证书摘要列表
+// 入参: raw 证书摘要列表ASN.1值
+// 返回: sesCertList 证书列表, error 错误信息
+func parseSESCertDigestList(raw asn1.RawValue) (sesCertList, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) == 0 {
+		return sesCertList{}, fmt.Errorf("invalid ses cert digest list")
+	}
+	list := sesCertList{Digests: make([][]byte, 0, len(items))}
+	for _, item := range items {
+		fields, ok := asn1Children(item.Bytes)
+		if !ok || len(fields) < 2 {
+			return sesCertList{}, fmt.Errorf("invalid ses cert digest")
+		}
+		digest, err := asn1OctetString(fields[1])
+		if err != nil {
+			return sesCertList{}, err
+		}
+		list.Digests = append(list.Digests, digest)
+	}
+	return list, nil
+}
+
+// parseSESPicture 解析印章图片
+// 入参: raw 印章图片信息
+// 返回: string 图片类型, []byte 图片数据, error 错误信息
+func parseSESPicture(raw asn1.RawValue) (string, []byte, error) {
+	items, ok := asn1Children(raw.Bytes)
+	if !ok || len(items) < 4 {
+		return "", nil, fmt.Errorf("invalid ses picture")
+	}
+	picType := normalizeSealType(strings.ToLower(strings.TrimSpace(asn1String(items[0]))))
+	picData, err := asn1OctetString(items[1])
+	if err != nil {
+		return "", nil, err
+	}
+	if picType == "ofd" {
+		if data := trimOFDPackage(picData); len(data) > 0 {
+			picData = data
+		}
+	}
+	return picType, picData, nil
+}
+
+// parseSM2PublicKeyFromCert 从证书解析SM2公钥
+// 入参: data DER编码证书
+// 返回: sm2PublicKey SM2公钥, error 错误信息
+func parseSM2PublicKeyFromCert(data []byte) (sm2PublicKey, error) {
+	var cert struct {
+		TBSCertificate     asn1.RawValue
+		SignatureAlgorithm asn1.RawValue
+		SignatureValue     asn1.BitString
+	}
+	rest, err := asn1.Unmarshal(data, &cert)
+	if err != nil {
+		return sm2PublicKey{}, err
+	}
+	if len(rest) != 0 {
+		return sm2PublicKey{}, fmt.Errorf("invalid certificate")
+	}
+	items, ok := asn1Children(cert.TBSCertificate.Bytes)
+	if !ok {
+		return sm2PublicKey{}, fmt.Errorf("invalid tbs certificate")
+	}
+	idx := 0
+	if len(items) > 0 && items[0].Class == asn1.ClassContextSpecific && items[0].Tag == 0 {
+		idx++
+	}
+	if len(items) <= idx+5 {
+		return sm2PublicKey{}, fmt.Errorf("invalid public key info")
+	}
+	return parseSM2PublicKeyInfo(items[idx+5])
+}
+
+// parseSM2PublicKeyInfo 解析SM2公钥信息
+// 入参: raw SubjectPublicKeyInfo原始值
+// 返回: sm2PublicKey SM2公钥, error 错误信息
+func parseSM2PublicKeyInfo(raw asn1.RawValue) (sm2PublicKey, error) {
+	var spki struct {
+		Algorithm        asn1.RawValue
+		SubjectPublicKey asn1.BitString
+	}
+	rest, err := asn1.Unmarshal(raw.FullBytes, &spki)
+	if err != nil {
+		return sm2PublicKey{}, err
+	}
+	if len(rest) != 0 {
+		return sm2PublicKey{}, fmt.Errorf("invalid subject public key info")
+	}
+	algItems, ok := asn1Children(spki.Algorithm.Bytes)
+	if !ok || len(algItems) < 2 {
+		return sm2PublicKey{}, fmt.Errorf("invalid public key algorithm")
+	}
+	alg, err := asn1OIDString(algItems[0])
+	if err != nil {
+		return sm2PublicKey{}, err
+	}
+	curve, err := asn1OIDString(algItems[1])
+	if err != nil {
+		return sm2PublicKey{}, err
+	}
+	if alg != signECPublicKey || curve != signCurveSM2P256 {
+		return sm2PublicKey{}, fmt.Errorf("unsupported public key algorithm")
+	}
+	key := spki.SubjectPublicKey.Bytes
+	if len(key) != signPublicKeySize || key[0] != 4 {
+		return sm2PublicKey{}, fmt.Errorf("invalid sm2 public key")
+	}
+	return sm2PublicKey{
+		X: new(big.Int).SetBytes(key[1:33]),
+		Y: new(big.Int).SetBytes(key[33:65]),
+	}, nil
+}
+
+// signSM3 计算SM3摘要
+// 入参: data 原文数据
+// 返回: []byte 摘要值
+func signSM3(data []byte) []byte {
+	h := newSM3()
+	h.Write(data)
+	return h.Sum(nil)
+}
+
+// isSM2SignatureMethod 判断是否为SM2签名算法
+// 入参: method 算法标识
+// 返回: bool 是否为SM2签名算法
+func isSM2SignatureMethod(method string) bool {
+	method = strings.TrimSpace(method)
+	return method == signMethodSM2SM3 || method == signMethodSM2SM3B || method == signMethodSM2Sign
+}
+
+// isSM3DigestMethod 判断是否为SM3摘要算法
+// 入参: method 算法标识
+// 返回: bool 是否为SM3摘要算法
+func isSM3DigestMethod(method string) bool {
+	method = strings.TrimSpace(method)
+	return method == signDigestSM3 || method == signDigestSM3NoKey || method == signDigestSM3Key || method == "SM3"
+}
+
+// sesCertInList 判断证书是否在印章证书列表中
+// 入参: cert DER编码证书, list 证书列表
+// 返回: bool 是否存在
+func sesCertInList(cert []byte, list sesCertList) bool {
+	for _, item := range list.Certs {
+		if bytes.Equal(cert, item) {
+			return true
+		}
+	}
+	digest := signSM3(cert)
+	for _, item := range list.Digests {
+		if bytes.Equal(digest, item) {
+			return true
+		}
+	}
+	return false
+}
+
+// asn1OctetString 解析ASN.1八位字符串
+// 入参: raw ASN.1原始值
+// 返回: []byte 字节数据, error 错误信息
+func asn1OctetString(raw asn1.RawValue) ([]byte, error) {
+	var out []byte
+	rest, err := asn1.Unmarshal(raw.FullBytes, &out)
+	if err != nil || len(rest) != 0 {
+		return nil, fmt.Errorf("invalid octet string")
+	}
+	return append([]byte(nil), out...), nil
+}
+
+// asn1BitStringBytes 解析ASN.1位字符串
+// 入参: raw ASN.1原始值
+// 返回: []byte 字节数据, error 错误信息
+func asn1BitStringBytes(raw asn1.RawValue) ([]byte, error) {
+	var bits asn1.BitString
+	rest, err := asn1.Unmarshal(raw.FullBytes, &bits)
+	if err != nil || len(rest) != 0 || bits.BitLength%8 != 0 {
+		return nil, fmt.Errorf("invalid bit string")
+	}
+	return append([]byte(nil), bits.Bytes...), nil
+}
+
+// asn1BitOrOctetBytes 解析ASN.1位字符串或八位字符串
+// 入参: raw ASN.1原始值
+// 返回: []byte 字节数据, error 错误信息
+func asn1BitOrOctetBytes(raw asn1.RawValue) ([]byte, error) {
+	if raw.Tag == asn1.TagOctetString {
+		return asn1OctetString(raw)
+	}
+	return asn1BitStringBytes(raw)
+}
+
+// asn1OIDString 解析ASN.1对象标识符
+// 入参: raw ASN.1原始值
+// 返回: string OID字符串, error 错误信息
+func asn1OIDString(raw asn1.RawValue) (string, error) {
+	var oid asn1.ObjectIdentifier
+	rest, err := asn1.Unmarshal(raw.FullBytes, &oid)
+	if err != nil || len(rest) != 0 {
+		return "", fmt.Errorf("invalid oid")
+	}
+	return oid.String(), nil
+}
+
+// asn1Integer 解析ASN.1整数
+// 入参: raw ASN.1原始值
+// 返回: int 整数值, error 错误信息
+func asn1Integer(raw asn1.RawValue) (int, error) {
+	var out int
+	rest, err := asn1.Unmarshal(raw.FullBytes, &out)
+	if err != nil || len(rest) != 0 {
+		return 0, fmt.Errorf("invalid integer")
+	}
+	return out, nil
+}
+
+// asn1String 解析ASN.1字符串
+// 入参: raw ASN.1原始值
+// 返回: string 字符串
+func asn1String(raw asn1.RawValue) string {
+	var s string
+	if _, err := asn1.Unmarshal(raw.FullBytes, &s); err != nil {
+		return strings.TrimSpace(string(raw.Bytes))
+	}
+	return s
+}
+
+// asn1SequenceBytes 编码ASN.1序列
+// 入参: parts 序列元素DER数据
+// 返回: []byte ASN.1序列DER数据
+func asn1SequenceBytes(parts ...[]byte) []byte {
+	var content []byte
+	for _, part := range parts {
+		content = append(content, part...)
+	}
+	return asn1Wrap(0x30, content)
+}
+
+// asn1SetBytes 编码ASN.1集合
+// 入参: content 集合内容DER数据
+// 返回: []byte ASN.1集合DER数据
+func asn1SetBytes(content []byte) []byte {
+	return asn1Wrap(0x31, content)
+}
+
+// asn1Wrap 包装ASN.1标签
+// 入参: tag ASN.1标签, content 内容DER数据
+// 返回: []byte ASN.1 DER数据
+func asn1Wrap(tag byte, content []byte) []byte {
+	out := []byte{tag}
+	out = append(out, asn1LengthBytes(len(content))...)
+	out = append(out, content...)
+	return out
+}
+
+// asn1LengthBytes 编码ASN.1长度
+// 入参: n 内容长度
+// 返回: []byte ASN.1长度编码
+func asn1LengthBytes(n int) []byte {
+	if n < 128 {
+		return []byte{byte(n)}
+	}
+	var buf [8]byte
+	i := len(buf)
+	for n > 0 {
+		i--
+		buf[i] = byte(n)
+		n >>= 8
+	}
+	out := []byte{0x80 | byte(len(buf)-i)}
+	return append(out, buf[i:]...)
+}

ofdgo_sign_sm2.go

@@ -0,0 +1,163 @@
+// Copyright 2025-2026 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 (
+	"crypto/elliptic"
+	"encoding/asn1"
+	"encoding/binary"
+	"math/big"
+)
+
+const sm2DefaultUserID = "1234567812345678"
+
+var sm2P256 = newSM2P256()
+
+// sm2PublicKey SM2公钥
+type sm2PublicKey struct {
+	X *big.Int
+	Y *big.Int
+}
+
+// newSM2P256 创建SM2椭圆曲线
+// 返回: elliptic.Curve SM2椭圆曲线
+func newSM2P256() elliptic.Curve {
+	c := &elliptic.CurveParams{Name: "SM2-P-256"}
+	c.P = sm2Big("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF")
+	c.N = sm2Big("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123")
+	c.B = sm2Big("28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93")
+	c.Gx = sm2Big("32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7")
+	c.Gy = sm2Big("BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0")
+	c.BitSize = 256
+	return c
+}
+
+// sm2Big 解析SM2大整数常量
+// 入参: s 十六进制字符串
+// 返回: *big.Int 大整数
+func sm2Big(s string) *big.Int {
+	n, _ := new(big.Int).SetString(s, 16)
+	return n
+}
+
+// sm2VerifySignature 验证SM2签名值
+// 入参: pub 公钥, userID 用户标识, msg 原文, sig 签名值
+// 返回: bool 是否验证通过
+func sm2VerifySignature(pub sm2PublicKey, userID, msg, sig []byte) bool {
+	r, s, ok := parseSM2Signature(sig)
+	if !ok {
+		return false
+	}
+	return sm2Verify(pub, userID, msg, r, s)
+}
+
+// parseSM2Signature 解析SM2签名值
+// 入参: sig 签名值
+// 返回: *big.Int R值, *big.Int S值, bool 是否解析成功
+func parseSM2Signature(sig []byte) (*big.Int, *big.Int, bool) {
+	if len(sig) == 64 {
+		return new(big.Int).SetBytes(sig[:32]), new(big.Int).SetBytes(sig[32:]), true
+	}
+	var rs struct {
+		R *big.Int
+		S *big.Int
+	}
+	rest, err := asn1.Unmarshal(sig, &rs)
+	if err != nil || len(rest) != 0 || rs.R == nil || rs.S == nil {
+		return nil, nil, false
+	}
+	return rs.R, rs.S, true
+}
+
+// sm2Verify 验证SM2签名
+// 入参: pub 公钥, userID 用户标识, msg 原文, r R值, s S值
+// 返回: bool 是否验证通过
+func sm2Verify(pub sm2PublicKey, userID, msg []byte, r, s *big.Int) bool {
+	n := sm2P256.Params().N
+	if r.Sign() <= 0 || s.Sign() <= 0 || r.Cmp(n) >= 0 || s.Cmp(n) >= 0 {
+		return false
+	}
+	if pub.X == nil || pub.Y == nil || !sm2P256.IsOnCurve(pub.X, pub.Y) {
+		return false
+	}
+	e := new(big.Int).SetBytes(sm2MessageDigest(pub, userID, msg))
+	t := new(big.Int).Add(r, s)
+	t.Mod(t, n)
+	if t.Sign() == 0 {
+		return false
+	}
+	x1, y1 := sm2P256.ScalarBaseMult(s.Bytes())
+	x2, y2 := sm2P256.ScalarMult(pub.X, pub.Y, t.Bytes())
+	x, _ := sm2P256.Add(x1, y1, x2, y2)
+	if x == nil {
+		return false
+	}
+	v := new(big.Int).Add(e, x)
+	v.Mod(v, n)
+	return v.Cmp(r) == 0
+}
+
+// sm2MessageDigest 计算SM2签名摘要
+// 入参: pub 公钥, userID 用户标识, msg 原文
+// 返回: []byte 摘要值
+func sm2MessageDigest(pub sm2PublicKey, userID, msg []byte) []byte {
+	h := newSM3()
+	h.Write(sm2ZA(pub, userID))
+	h.Write(msg)
+	return h.Sum(nil)
+}
+
+// sm2ZA 计算SM2用户标识杂凑值
+// 入参: pub 公钥, userID 用户标识
+// 返回: []byte ZA值
+func sm2ZA(pub sm2PublicKey, userID []byte) []byte {
+	if len(userID) == 0 {
+		userID = []byte(sm2DefaultUserID)
+	}
+	h := newSM3()
+	var entl [2]byte
+	binary.BigEndian.PutUint16(entl[:], uint16(len(userID)*8))
+	h.Write(entl[:])
+	h.Write(userID)
+	h.Write(sm2Fixed(sm2A()))
+	h.Write(sm2Fixed(sm2P256.Params().B))
+	h.Write(sm2Fixed(sm2P256.Params().Gx))
+	h.Write(sm2Fixed(sm2P256.Params().Gy))
+	h.Write(sm2Fixed(pub.X))
+	h.Write(sm2Fixed(pub.Y))
+	return h.Sum(nil)
+}
+
+// sm2A 获取SM2曲线A参数
+// 返回: *big.Int 曲线A参数
+func sm2A() *big.Int {
+	return new(big.Int).Sub(sm2P256.Params().P, big.NewInt(3))
+}
+
+// sm2Fixed 转换为SM2固定长度字节
+// 入参: n 大整数
+// 返回: []byte 固定长度字节
+func sm2Fixed(n *big.Int) []byte {
+	out := make([]byte, 32)
+	if n == nil {
+		return out
+	}
+	b := n.Bytes()
+	if len(b) > len(out) {
+		b = b[len(b)-len(out):]
+	}
+	copy(out[len(out)-len(b):], b)
+	return out
+}

ofdgo_sign_sm3.go

@@ -0,0 +1,211 @@
+// Copyright 2025-2026 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/binary"
+	"hash"
+	"math/bits"
+)
+
+const (
+	sm3Size      = 32
+	sm3BlockSize = 64
+)
+
+var sm3Init = [8]uint32{
+	0x7380166f,
+	0x4914b2b9,
+	0x172442d7,
+	0xda8a0600,
+	0xa96f30bc,
+	0x163138aa,
+	0xe38dee4d,
+	0xb0fb0e4e,
+}
+
+// sm3Digest SM3杂凑值计算器
+type sm3Digest struct {
+	h   [8]uint32
+	x   [sm3BlockSize]byte
+	nx  int
+	len uint64
+}
+
+// newSM3 创建SM3杂凑值计算器
+// 返回: hash.Hash SM3杂凑值计算器
+func newSM3() hash.Hash {
+	d := new(sm3Digest)
+	d.Reset()
+	return d
+}
+
+// Reset 重置SM3状态
+func (d *sm3Digest) Reset() {
+	d.h = sm3Init
+	d.nx = 0
+	d.len = 0
+}
+
+// Size 获取SM3杂凑值长度
+// 返回: int 杂凑值长度
+func (d *sm3Digest) Size() int {
+	return sm3Size
+}
+
+// BlockSize 获取SM3分组长度
+// 返回: int 分组长度
+func (d *sm3Digest) BlockSize() int {
+	return sm3BlockSize
+}
+
+// Write 写入待计算数据
+// 入参: p 待计算数据
+// 返回: int 写入长度, error 错误信息
+func (d *sm3Digest) Write(p []byte) (int, error) {
+	nn := len(p)
+	d.len += uint64(nn)
+	if d.nx > 0 {
+		n := copy(d.x[d.nx:], p)
+		d.nx += n
+		if d.nx == sm3BlockSize {
+			sm3Block(d, d.x[:])
+			d.nx = 0
+		}
+		p = p[n:]
+	}
+	if len(p) >= sm3BlockSize {
+		n := len(p) &^ (sm3BlockSize - 1)
+		sm3Block(d, p[:n])
+		p = p[n:]
+	}
+	if len(p) > 0 {
+		d.nx = copy(d.x[:], p)
+	}
+	return nn, nil
+}
+
+// Sum 返回SM3杂凑值
+// 入参: in 前缀数据
+// 返回: []byte 杂凑值
+func (d *sm3Digest) Sum(in []byte) []byte {
+	dd := *d
+	hash := dd.checkSum()
+	return append(in, hash[:]...)
+}
+
+// checkSum 计算SM3最终杂凑值
+// 返回: [sm3Size]byte 杂凑值
+func (d *sm3Digest) checkSum() [sm3Size]byte {
+	lenBits := d.len << 3
+	var tmp [64]byte
+	tmp[0] = 0x80
+	if d.nx < 56 {
+		d.Write(tmp[:56-d.nx])
+	} else {
+		d.Write(tmp[:64+56-d.nx])
+	}
+	binary.BigEndian.PutUint64(tmp[:8], lenBits)
+	d.Write(tmp[:8])
+	var digest [sm3Size]byte
+	for i, v := range d.h {
+		binary.BigEndian.PutUint32(digest[i*4:], v)
+	}
+	return digest
+}
+
+// sm3Block 处理SM3消息分组
+// 入参: d SM3杂凑值计算器, p 消息分组数据
+func sm3Block(d *sm3Digest, p []byte) {
+	var w [68]uint32
+	var w1 [64]uint32
+	for len(p) >= sm3BlockSize {
+		for i := 0; i < 16; i++ {
+			w[i] = binary.BigEndian.Uint32(p[i*4:])
+		}
+		for i := 16; i < 68; i++ {
+			x := w[i-16] ^ w[i-9] ^ bits.RotateLeft32(w[i-3], 15)
+			w[i] = sm3P1(x) ^ bits.RotateLeft32(w[i-13], 7) ^ w[i-6]
+		}
+		for i := 0; i < 64; i++ {
+			w1[i] = w[i] ^ w[i+4]
+		}
+		a, b, c, e := d.h[0], d.h[1], d.h[2], d.h[4]
+		dd, f, g, hh := d.h[3], d.h[5], d.h[6], d.h[7]
+		for i := 0; i < 64; i++ {
+			t := uint32(0x7a879d8a)
+			if i < 16 {
+				t = 0x79cc4519
+			}
+			ss1 := bits.RotateLeft32(bits.RotateLeft32(a, 12)+e+bits.RotateLeft32(t, i), 7)
+			ss2 := ss1 ^ bits.RotateLeft32(a, 12)
+			tt1 := sm3FF(i, a, b, c) + dd + ss2 + w1[i]
+			tt2 := sm3GG(i, e, f, g) + hh + ss1 + w[i]
+			dd = c
+			c = bits.RotateLeft32(b, 9)
+			b = a
+			a = tt1
+			hh = g
+			g = bits.RotateLeft32(f, 19)
+			f = e
+			e = sm3P0(tt2)
+		}
+		d.h[0] ^= a
+		d.h[1] ^= b
+		d.h[2] ^= c
+		d.h[3] ^= dd
+		d.h[4] ^= e
+		d.h[5] ^= f
+		d.h[6] ^= g
+		d.h[7] ^= hh
+		p = p[sm3BlockSize:]
+	}
+}
+
+// sm3P0 计算SM3置换函数P0
+// 入参: x 输入值
+// 返回: uint32 置换结果
+func sm3P0(x uint32) uint32 {
+	return x ^ bits.RotateLeft32(x, 9) ^ bits.RotateLeft32(x, 17)
+}
+
+// sm3P1 计算SM3置换函数P1
+// 入参: x 输入值
+// 返回: uint32 置换结果
+func sm3P1(x uint32) uint32 {
+	return x ^ bits.RotateLeft32(x, 15) ^ bits.RotateLeft32(x, 23)
+}
+
+// sm3FF 计算SM3布尔函数FF
+// 入参: i 轮数, x 输入值, y 输入值, z 输入值
+// 返回: uint32 计算结果
+func sm3FF(i int, x, y, z uint32) uint32 {
+	if i < 16 {
+		return x ^ y ^ z
+	}
+	return (x & y) | (x & z) | (y & z)
+}
+
+// sm3GG 计算SM3布尔函数GG
+// 入参: i 轮数, x 输入值, y 输入值, z 输入值
+// 返回: uint32 计算结果
+func sm3GG(i int, x, y, z uint32) uint32 {
+	if i < 16 {
+		return x ^ y ^ z
+	}
+	return (x & y) | (^x & z)
+}
+
+var _ hash.Hash = (*sm3Digest)(nil)

ofdgo_sign_verify.go

@@ -0,0 +1,528 @@
+// Copyright 2025-2026 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 (
+	"bytes"
+	"crypto/subtle"
+	"encoding/asn1"
+	"encoding/base64"
+	"encoding/pem"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"path"
+	"strings"
+)
+
+// SignatureVerifyReport 签名验证报告
+type SignatureVerifyReport struct {
+	ID                string
+	BaseLoc           string
+	Type              SignType
+	Provider          SignatureProvider
+	Signer            string
+	SignCert          SignatureCertInfo
+	SealCert          SignatureCertInfo
+	SealType          string
+	SignatureMethod   string
+	SignatureDateTime string
+	DigestMethod      string
+	References        []SignatureReferenceVerify
+	Stamps            []SignatureStamp
+	DigestOK          bool
+	DataHashOK        bool
+	SignedValueOK     bool
+	SealOK            bool
+	SealMatchOK       bool
+	CertOK            bool
+	Valid             bool
+	Error             string
+}
+
+// SignatureCertInfo 签名证书信息
+type SignatureCertInfo struct {
+	Subject      string
+	CommonName   string
+	Organization string
+	Issuer       string
+	SerialNumber string
+}
+
+// SignatureReferenceVerify 签名保护文件验证结果
+type SignatureReferenceVerify struct {
+	FileRef    string
+	Path       string
+	CheckValue []byte
+	Actual     []byte
+	OK         bool
+	Error      string
+}
+
+// signatureVerifyOptions 签名验证选项
+type signatureVerifyOptions struct {
+	SignCerts [][]byte
+}
+
+// SignatureVerifyOption 签名验证选项函数
+type SignatureVerifyOption func(*signatureVerifyOptions)
+
+// WithSignatureCert 添加数字签名验证证书
+// 入参: cert DER或PEM编码证书
+// 返回: SignatureVerifyOption 签名验证选项
+func WithSignatureCert(cert []byte) SignatureVerifyOption {
+	return func(o *signatureVerifyOptions) {
+		o.SignCerts = append(o.SignCerts, parseSignatureCerts(cert)...)
+	}
+}
+
+// WithSignatureCerts 添加多张数字签名验证证书
+// 入参: certs DER或PEM编码证书列表
+// 返回: SignatureVerifyOption 签名验证选项
+func WithSignatureCerts(certs ...[]byte) SignatureVerifyOption {
+	return func(o *signatureVerifyOptions) {
+		for _, cert := range certs {
+			o.SignCerts = append(o.SignCerts, parseSignatureCerts(cert)...)
+		}
+	}
+}
+
+// VerifySignaturesBytes 验证OFD字节数据签名
+// 入参: data OFD字节数据, opts 签名验证选项
+// 返回: []SignatureVerifyReport 签名验证报告, error 错误信息
+func VerifySignaturesBytes(data []byte, opts ...SignatureVerifyOption) ([]SignatureVerifyReport, error) {
+	return VerifySignaturesReader(bytes.NewReader(data), int64(len(data)), opts...)
+}
+
+// VerifySignaturesStream 验证OFD顺序流签名
+// 入参: r IO顺序读取器, opts 签名验证选项
+// 返回: []SignatureVerifyReport 签名验证报告, error 错误信息
+func VerifySignaturesStream(r io.Reader, opts ...SignatureVerifyOption) ([]SignatureVerifyReport, error) {
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	return VerifySignaturesBytes(data, opts...)
+}
+
+// VerifySignaturesReader 验证OFD读取器签名
+// 入参: r IO读取器, size 数据大小, opts 签名验证选项
+// 返回: []SignatureVerifyReport 签名验证报告, error 错误信息
+func VerifySignaturesReader(r io.ReaderAt, size int64, opts ...SignatureVerifyOption) ([]SignatureVerifyReport, error) {
+	reader, err := NewReader(r, size)
+	if err != nil {
+		return nil, err
+	}
+	return reader.VerifySignatures(opts...)
+}
+
+// VerifySignatures 验证文档签名
+// 入参: opts 签名验证选项
+// 返回: []SignatureVerifyReport 签名验证报告, error 错误信息
+func (r *Reader) VerifySignatures(opts ...SignatureVerifyOption) ([]SignatureVerifyReport, error) {
+	options := signatureVerifyOptions{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	doc, err := r.Doc()
+	if err != nil {
+		return nil, err
+	}
+	if doc.Signatures == "" {
+		return nil, nil
+	}
+	sigListPath := r.ResPath(doc.Signatures)
+	data, err := r.readFileExact(sigListPath)
+	if err != nil {
+		return nil, err
+	}
+	var signatures Signatures
+	if err := xml.Unmarshal(data, &signatures); err != nil {
+		return nil, err
+	}
+	reports := make([]SignatureVerifyReport, 0, len(signatures.List))
+	for _, sigRef := range signatures.List {
+		reports = append(reports, r.verifySignature(sigListPath, sigRef, &options))
+	}
+	return reports, nil
+}
+
+// verifySignature 验证单个签名
+// 入参: sigListPath 签名列表路径, sigRef 签名引用, options 验证选项
+// 返回: SignatureVerifyReport 签名验证报告
+func (r *Reader) verifySignature(sigListPath string, sigRef Signature, options *signatureVerifyOptions) SignatureVerifyReport {
+	sigPath := signatureRefPath(sigListPath, sigRef.BaseLoc)
+	report := SignatureVerifyReport{
+		ID:          sigRef.ID,
+		BaseLoc:     sigRef.BaseLoc,
+		Type:        sigRef.Type,
+		SealMatchOK: true,
+	}
+	sigData, err := r.readFileExact(sigPath)
+	if err != nil {
+		report.Error = err.Error()
+		return report
+	}
+	sigFile, err := parseSignatureFile(sigData)
+	if err != nil {
+		report.Error = err.Error()
+		return report
+	}
+	report.Provider = sigFile.SignedInfo.Provider
+	report.SignatureMethod = sigFile.SignedInfo.SignatureMethod
+	report.SignatureDateTime = sigFile.SignedInfo.SignatureDateTime
+	report.DigestMethod = sigFile.SignedInfo.References.CheckMethod
+	report.References = r.verifySignatureReferences(sigPath, sigFile.SignedInfo.References)
+	report.Stamps = append(report.Stamps, sigFile.SignedInfo.StampAnnot...)
+	report.DigestOK = referencesOK(report.References)
+	signedValuePath := signatureRefPath(sigPath, sigFile.SignedValue)
+	signedValue, err := r.readFileExact(signedValuePath)
+	if err != nil {
+		report.Error = err.Error()
+		return report
+	}
+	switch sigRef.Type {
+	case SignTypeSign:
+		result, err := verifyDigitalSignature(report.SignatureMethod, signedValue, sigData, options)
+		if err != nil {
+			report.Error = err.Error()
+			return report
+		}
+		report.DataHashOK = result.DataHashOK
+		report.SignedValueOK = result.SignedOK
+		report.SealOK = true
+		report.CertOK = result.CertOK
+		report.SignCert = result.CertInfo
+		report.Signer = result.CertInfo.CommonName
+		report.Valid = report.DigestOK && report.DataHashOK && report.SignedValueOK && report.CertOK
+		return report
+	case "", SignTypeSeal:
+	default:
+		report.Error = fmt.Sprintf("unsupported signature type: %s", sigRef.Type)
+		return report
+	}
+	sesResult, err := verifySESSignature(signedValue, sigData)
+	if sesResult != nil {
+		report.SignCert = sesResult.SignCert
+		report.SealCert = sesResult.SealCert
+		report.SealType = sesResult.SealType
+		report.Signer = sesResult.SignCert.CommonName
+	}
+	if err != nil {
+		report.Error = err.Error()
+		return report
+	}
+	report.DataHashOK = sesResult.DataHashOK
+	report.SignedValueOK = sesResult.SignedOK
+	report.SealOK = sesResult.SealOK
+	report.CertOK = sesResult.CertOK
+	if sigFile.SignedInfo.Seal.BaseLoc != "" {
+		sealPath := signatureRefPath(sigPath, sigFile.SignedInfo.Seal.BaseLoc)
+		sealData, err := r.readFileExact(sealPath)
+		if err != nil {
+			report.Error = err.Error()
+			return report
+		}
+		sig, err := parseSESSignature(signedValue)
+		if err != nil {
+			report.Error = err.Error()
+			return report
+		}
+		report.SealMatchOK = bytes.Equal(sealData, sig.Seal.Raw)
+	}
+	report.Valid = report.DigestOK && report.DataHashOK && report.SignedValueOK && report.SealOK && report.SealMatchOK && report.CertOK
+	return report
+}
+
+// verifySignatureReferences 验证签名保护文件列表
+// 入参: sigPath 签名文件路径, refs 签名保护文件列表
+// 返回: []SignatureReferenceVerify 保护文件验证结果
+func (r *Reader) verifySignatureReferences(sigPath string, refs SignatureReferences) []SignatureReferenceVerify {
+	results := make([]SignatureReferenceVerify, 0, len(refs.Reference))
+	for _, ref := range refs.Reference {
+		results = append(results, r.verifySignatureReference(sigPath, refs.CheckMethod, ref))
+	}
+	return results
+}
+
+// verifySignatureReference 验证签名保护文件
+// 入参: sigPath 签名文件路径, method 摘要算法, ref 保护文件引用
+// 返回: SignatureReferenceVerify 保护文件验证结果
+func (r *Reader) verifySignatureReference(sigPath, method string, ref SignatureReference) SignatureReferenceVerify {
+	refPath := signatureRefPath(sigPath, ref.FileRef)
+	result := SignatureReferenceVerify{
+		FileRef: ref.FileRef,
+		Path:    refPath,
+	}
+	checkValue, err := base64.StdEncoding.DecodeString(strings.TrimSpace(ref.CheckValue))
+	if err != nil {
+		result.Error = err.Error()
+		return result
+	}
+	data, err := r.readFileExact(refPath)
+	if err != nil {
+		result.Error = err.Error()
+		return result
+	}
+	actual, err := signatureDigest(method, data)
+	if err != nil {
+		result.Error = err.Error()
+		return result
+	}
+	result.CheckValue = checkValue
+	result.Actual = actual
+	result.OK = subtle.ConstantTimeCompare(checkValue, actual) == 1
+	return result
+}
+
+// parseSignatureFile 解析签名文件
+// 入参: data 签名文件XML数据
+// 返回: *SignatureFile 签名文件结构, error 错误信息
+func parseSignatureFile(data []byte) (*SignatureFile, error) {
+	var sigFile SignatureFile
+	if err := xml.Unmarshal(data, &sigFile); err != nil {
+		return nil, err
+	}
+	raw, err := xmlElementRaw(data, "SignedInfo")
+	if err != nil {
+		return nil, err
+	}
+	sigFile.SignedInfo.Raw = raw
+	return &sigFile, nil
+}
+
+// readFileExact 读取OFD包内文件
+// 入参: name 包内文件路径
+// 返回: []byte 文件数据, error 错误信息
+func (r *Reader) readFileExact(name string) ([]byte, error) {
+	name = cleanPackagePath(name)
+	if f, ok := r.fileIndex[name]; ok {
+		return readZipFile(f)
+	}
+	return nil, fmt.Errorf("file not found: %s", name)
+}
+
+// signatureDigest 计算签名摘要
+// 入参: method 摘要算法, data 原文数据
+// 返回: []byte 摘要值, error 错误信息
+func signatureDigest(method string, data []byte) ([]byte, error) {
+	if isSM3DigestMethod(method) {
+		return signSM3(data), nil
+	}
+	return nil, fmt.Errorf("unsupported digest method: %s", method)
+}
+
+// signatureRefPath 解析签名文件引用路径
+// 入参: basePath 基准路径, refPath 引用路径
+// 返回: string 包内文件路径
+func signatureRefPath(basePath, refPath string) string {
+	p := strings.TrimSpace(refPath)
+	p = strings.ReplaceAll(p, "\\", "/")
+	if strings.HasPrefix(p, "/") {
+		return cleanPackagePath(p)
+	}
+	return path.Clean(resolveResourcePath(basePath, "", p))
+}
+
+// referencesOK 判断保护文件摘要是否全部通过
+// 入参: refs 保护文件验证结果
+// 返回: bool 是否全部通过
+func referencesOK(refs []SignatureReferenceVerify) bool {
+	if len(refs) == 0 {
+		return false
+	}
+	for _, ref := range refs {
+		if !ref.OK {
+			return false
+		}
+	}
+	return true
+}
+
+// xmlElementRaw 提取XML元素原始字节
+// 入参: data XML数据, localName 元素名称
+// 返回: []byte 元素原始字节, error 错误信息
+func xmlElementRaw(data []byte, localName string) ([]byte, error) {
+	dec := xml.NewDecoder(bytes.NewReader(data))
+	for {
+		tok, err := dec.Token()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		start, ok := tok.(xml.StartElement)
+		if !ok || start.Name.Local != localName {
+			continue
+		}
+		end := int(dec.InputOffset())
+		begin := bytes.LastIndex(data[:end], []byte("<"))
+		if begin < 0 {
+			return nil, fmt.Errorf("xml element not found: %s", localName)
+		}
+		depth := 1
+		for depth > 0 {
+			tok, err = dec.Token()
+			if err != nil {
+				return nil, err
+			}
+			switch tok.(type) {
+			case xml.StartElement:
+				depth++
+			case xml.EndElement:
+				depth--
+			}
+		}
+		return append([]byte(nil), data[begin:int(dec.InputOffset())]...), nil
+	}
+	return nil, fmt.Errorf("xml element not found: %s", localName)
+}
+
+// signatureCertInfo 解析签名证书信息
+// 入参: data DER编码证书
+// 返回: SignatureCertInfo 签名证书信息
+func signatureCertInfo(data []byte) SignatureCertInfo {
+	var cert struct {
+		TBSCertificate     asn1.RawValue
+		SignatureAlgorithm asn1.RawValue
+		SignatureValue     asn1.BitString
+	}
+	rest, err := asn1.Unmarshal(data, &cert)
+	if err != nil || len(rest) != 0 {
+		return SignatureCertInfo{}
+	}
+	items, ok := asn1Children(cert.TBSCertificate.Bytes)
+	if !ok {
+		return SignatureCertInfo{}
+	}
+	idx := 0
+	if len(items) > 0 && items[0].Class == asn1.ClassContextSpecific && items[0].Tag == 0 {
+		idx++
+	}
+	if len(items) <= idx+4 {
+		return SignatureCertInfo{}
+	}
+	serial, _ := asn1IntegerBig(items[idx])
+	subject := certificateNameValues(items[idx+4])
+	issuer := certificateNameValues(items[idx+2])
+	info := SignatureCertInfo{
+		Subject:      certificateNameString(subject),
+		CommonName:   certificateNameFirst(subject, "2.5.4.3"),
+		Organization: certificateNameFirst(subject, "2.5.4.10"),
+		Issuer:       certificateNameString(issuer),
+	}
+	if serial != nil {
+		info.SerialNumber = serial.String()
+	}
+	return info
+}
+
+// certificateNameValues 解析证书名称字段
+// 入参: raw 名称原始值
+// 返回: map[string][]string OID字段列表
+func certificateNameValues(raw asn1.RawValue) map[string][]string {
+	out := make(map[string][]string)
+	sets, ok := asn1Children(raw.Bytes)
+	if !ok {
+		return out
+	}
+	for _, set := range sets {
+		attrs, ok := asn1Children(set.Bytes)
+		if !ok {
+			continue
+		}
+		for _, attr := range attrs {
+			items, ok := asn1Children(attr.Bytes)
+			if !ok || len(items) < 2 {
+				continue
+			}
+			oid, err := asn1OIDString(items[0])
+			if err != nil {
+				continue
+			}
+			if value := strings.TrimSpace(asn1String(items[1])); value != "" {
+				out[oid] = append(out[oid], value)
+			}
+		}
+	}
+	return out
+}
+
+// certificateNameFirst 获取证书名称字段首值
+// 入参: values OID字段列表, oid 字段OID
+// 返回: string 字段值
+func certificateNameFirst(values map[string][]string, oid string) string {
+	if items := values[oid]; len(items) > 0 {
+		return items[0]
+	}
+	return ""
+}
+
+// certificateNameString 格式化证书名称
+// 入参: values OID字段列表
+// 返回: string 证书名称
+func certificateNameString(values map[string][]string) string {
+	var parts []string
+	for _, item := range []struct {
+		OID   string
+		Label string
+	}{
+		{"2.5.4.3", "CN"},
+		{"2.5.4.10", "O"},
+		{"2.5.4.11", "OU"},
+		{"2.5.4.6", "C"},
+		{"2.5.4.8", "ST"},
+		{"2.5.4.7", "L"},
+		{"2.5.4.5", "SN"},
+		{"1.2.840.113549.1.9.1", "E"},
+	} {
+		for _, value := range values[item.OID] {
+			parts = append(parts, item.Label+"="+value)
+		}
+	}
+	return strings.Join(parts, ", ")
+}
+
+// parseSignatureCerts 解析签名验证证书
+// 入参: data DER或PEM编码证书
+// 返回: [][]byte DER编码证书列表
+func parseSignatureCerts(data []byte) [][]byte {
+	data = bytes.TrimSpace(data)
+	if len(data) == 0 {
+		return nil
+	}
+	var certs [][]byte
+	rest := data
+	hasPEM := false
+	for {
+		block, next := pem.Decode(rest)
+		if block == nil {
+			break
+		}
+		hasPEM = true
+		if block.Type == "CERTIFICATE" {
+			certs = append(certs, append([]byte(nil), block.Bytes...))
+		}
+		rest = next
+	}
+	if len(certs) != 0 {
+		return certs
+	}
+	if hasPEM {
+		return nil
+	}
+	return [][]byte{append([]byte(nil), data...)}
+}