Validate ASiC-S manifest containers

IB-8180, IB-8330

Signed-off-by: Raul Metsma <[email protected]>

Author: metsma

src/ASiC_S.cpp

@@ -19,7 +19,6 @@
 
 #include "ASiC_S.h"
 
-#include "Conf.h"
 #include "SignatureTST.h"
 #include "SignatureXAdES_LTA.h"
 #include "crypto/Signer.h"
@@ -33,18 +32,6 @@ using namespace digidoc;
 using namespace digidoc::util;
 using namespace std;
 
-struct ASiC_S::Data {
-    std::string name, mime, data;
-
-    Digest digest(Digest digest = {}) const
-    {
-        digest.update((const unsigned char*)data.data(), data.size());
-        return digest;
-    }
-};
-
-
-
 /**
  * Initialize ASiCS container.
  */
@@ -59,17 +46,19 @@ ASiC_S::ASiC_S(const string &path)
     : ASiContainer(MIMETYPE_ASIC_S)
 {
     auto z = load(path, false, {mediaType()});
+    bool foundTimestamp = false;
     for(const string &file: z.list())
     {
         if(file == "mimetype")
             continue;
         if(file == "META-INF/timestamp.tst")
+            foundTimestamp = true;
+        if(file == "META-INF/ASiCArchiveManifest.xml")
         {
             if(!signatures().empty())
                 THROW("Can not add signature to ASiC-S container which already contains a signature.");
-            string tst = z.extract<stringstream>(file).str();
-            addSignature(make_unique<SignatureTST>(tst, this));
-            metadata.push_back({file, "application/vnd.etsi.timestamp-token", std::move(tst)});
+            addSignature(make_unique<SignatureTST>(true, z, this));
+            foundTimestamp = false; // Manifest contains timestamp
         }
         else if(file == "META-INF/signatures.xml")
         {
@@ -80,28 +69,6 @@ ASiC_S::ASiC_S(const string &path)
             for(auto s = signatures->signature(); s; s++)
                 addSignature(make_unique<SignatureXAdES_LTA>(signatures, s, this));
         }
-        else if(file == "META-INF/ASiCArchiveManifest.xml")
-        {
-            function<void(const string &, string_view)> add = [this, &add, &z](const string &file, string_view mime) {
-                auto xml = z.extract<stringstream>(file);
-                XMLDocument doc = XMLDocument::openStream(xml, {"ASiCManifest", ASIC_NS});
-                doc.validateSchema(util::File::path(Conf::instance()->xsdPath(), "en_31916201v010101.xsd"));
-
-                for(auto ref = doc/"DataObjectReference"; ref; ref++)
-                {
-                    if(ref["Rootfile"] == "true")
-                        add(util::File::fromUriPath(ref["URI"]), ref["MimeType"]);
-                }
-
-                auto ref = doc/"SigReference";
-                string uri = util::File::fromUriPath(ref["URI"]);
-                string tst = z.extract<stringstream>(uri).str();
-                addSignature(make_unique<SignatureTST>(file, ::move(doc), tst, this));
-                metadata.push_back({file, string(mime), xml.str()});
-                metadata.push_back({uri, string(ref["MimeType"]), std::move(tst)});
-            };
-            add(file, "text/xml");
-        }
         else if(starts_with(file, "META-INF/"))
             continue;
         else if(const auto directory = File::directory(file);
@@ -112,6 +79,12 @@ ASiC_S::ASiC_S(const string &path)
         else
             addDataFile(dataStream(file, z), file, "application/octet-stream");
     }
+    if(foundTimestamp)
+    {
+        if(!signatures().empty())
+            THROW("Can not add signature to ASiC-S container which already contains a signature.");
+        addSignature(make_unique<SignatureTST>(false, z, this));
+    }
 
     if(dataFiles().empty())
         THROW("ASiC-S container does not contain any data objects.");
@@ -147,20 +120,20 @@ void ASiC_S::canSave()
         THROW("ASiC-S container supports only saving TimeStampToken signatures.");
 }
 
-Digest ASiC_S::fileDigest(const string &file, string_view method) const
-{
-    if(auto i = find_if(metadata.cbegin(), metadata.cend(), [&file](const auto &d) { return d.name == file; });
-        i != metadata.cend())
-        return i->digest(method);
-    THROW("File not found %s.", file.c_str());
-}
-
 unique_ptr<Container> ASiC_S::openInternal(const string &path, ContainerOpenCB * /*cb*/)
 {
-    if (!isContainerSimpleFormat(path))
-        return {};
     DEBUG("ASiC_S::openInternal(%s)", path.c_str());
-    return unique_ptr<Container>(new ASiC_S(path));
+    try
+    {
+        if(util::File::fileExtension(path, {"asice", "sce", "bdoc"}))
+            return {};
+        return unique_ptr<Container>(new ASiC_S(path));
+    }
+    catch(const Exception &)
+    {
+        // Ignore the exception: not ASiC/zip document
+    }
+    return {};
 }
 
 Signature* ASiC_S::prepareSignature(Signer * /*signer*/)
@@ -170,10 +143,11 @@ Signature* ASiC_S::prepareSignature(Signer * /*signer*/)
 
 void ASiC_S::save(const ZipSerialize &s)
 {
-    if(zproperty("META-INF/manifest.xml").size && !createManifest().save(s.addFile("META-INF/manifest.xml", zproperty("META-INF/manifest.xml")), true))
+    if(const auto &prop = zproperty("META-INF/manifest.xml");
+        prop.size && !createManifest().save(s.addFile("META-INF/manifest.xml", prop), true))
         THROW("Failed to create manifest XML");
-    for(const auto &[name, mime, data]: metadata)
-        s.addFile(name, zproperty(name))(data);
+    for(Signature *sig: signatures())
+        static_cast<SignatureTST*>(sig)->save(s);
 }
 
 Signature *ASiC_S::sign(Signer *signer)
@@ -184,31 +158,3 @@ Signature *ASiC_S::sign(Signer *signer)
         THROW("ASiC-S container supports only one TimeStampToken signature.");
     return addSignature(make_unique<SignatureTST>(this, signer));
 }
-
-/**
- * Detect ASiC format based on file extentions, mimetype or zip contents.<br/>
- * Container format is simple (ASiC-S) or extended (ASiC-E).
- *
- * @param path Path of the container.
- * @throws Exception
- */
-bool ASiC_S::isContainerSimpleFormat(const string &path)
-{
-    DEBUG("isContainerSimpleFormat(path = '%s')", path.c_str());
-    if(util::File::fileExtension(path, {"asice", "sce", "bdoc"}))
-        return false;
-    if(util::File::fileExtension(path, {"asics", "scs"}))
-        return true;
-    DEBUG("Check if ASiC/zip containter");
-    try
-    {
-        ZipSerialize z(path, false);
-        vector<string> list = z.list();
-        return list.front() == "mimetype" && readMimetype(z) == MIMETYPE_ASIC_S;
-    }
-    catch(const Exception &)
-    {
-        // Ignore the exception: not ASiC/zip document
-    }
-    return false;
-}

src/ASiC_S.h

@@ -23,8 +23,6 @@
 
 namespace digidoc
 {
-    class Digest;
-
     /**
     * Implements the ASiC-S specification of the timestamped digital document container.
     * Container contains a single datafile object and one time assertion file.
@@ -39,8 +37,6 @@ namespace digidoc
         Signature* prepareSignature(Signer *signer) override;
         Signature* sign(Signer* signer) override;
 
-        Digest fileDigest(const std::string &file, std::string_view method = {}) const;
-
         static std::unique_ptr<Container> createInternal(const std::string &path);
         static std::unique_ptr<Container> openInternal(const std::string &path, ContainerOpenCB *cb);
 
@@ -53,9 +49,6 @@ namespace digidoc
         void canSave() final;
         void save(const ZipSerialize &s) final;
 
-        static bool isContainerSimpleFormat(const std::string &path);
-
-        struct Data;
-        std::vector<Data> metadata;
+        friend class SignatureTST;
     };
 }

src/ASiContainer.h

@@ -45,6 +45,7 @@ namespace digidoc
           //https://signa.mitsoft.lt/static/signa-web/webResources/docs/ADOC_specification_approved20090907_EN.pdf
           static constexpr std::string_view MIMETYPE_ADOC = "application/vnd.lt.archyvai.adoc-2008";
           static constexpr std::string_view MANIFEST_NS = "urn:oasis:names:tc:opendocument:xmlns:manifest:1.0";
+          static constexpr std::string_view ASIC_NS = "http://uri.etsi.org/02918/v1.2.1#";
 
           ~ASiContainer() override;
           std::string mediaType() const override;

src/SignatureTST.cpp

@@ -20,32 +20,62 @@
 #include "SignatureTST.h"
 
 #include "ASiC_S.h"
+#include "Conf.h"
 #include "DataFile_p.h"
+#include "XMLDocument.h"
 #include "crypto/Digest.h"
 #include "crypto/Signer.h"
 #include "crypto/TS.h"
 #include "crypto/X509Cert.h"
+#include "util/algorithm.h"
 #include "util/DateTime.h"
 #include "util/File.h"
 #include "util/log.h"
 
+#include <functional>
+#include <sstream>
+
 using namespace digidoc;
 using namespace std;
 
-constexpr std::string_view DSIG_NS {"http://www.w3.org/2000/09/xmldsig#"};
-constexpr XMLName DigestMethod {"DigestMethod", DSIG_NS};
-constexpr XMLName DigestValue {"DigestValue", DSIG_NS};
+struct SignatureTST::Data {
+    std::string name, mime, data;
+    bool root = false;
 
-SignatureTST::SignatureTST(const string &data, ASiC_S *asicSDoc)
-    : asicSDoc(asicSDoc)
-    , timestampToken(make_unique<TS>((const unsigned char*)data.data(), data.size()))
-{}
+    Digest digest(Digest digest = {}) const
+    {
+        digest.update((const unsigned char*)data.data(), data.size());
+        return digest;
+    }
+};
 
-SignatureTST::SignatureTST(string current, XMLDocument &&xml, const string &data, ASiC_S *asicSDoc)
-    : SignatureTST(data, asicSDoc)
+SignatureTST::SignatureTST(bool manifest, const ZipSerialize &z, ASiC_S *asicSDoc)
+    : asicSDoc(asicSDoc)
 {
-    file = std::move(current);
-    doc = std::move(xml);
+    auto data = z.extract<stringstream>("META-INF/timestamp.tst").str();
+    timestampToken = make_unique<TS>((const unsigned char*)data.data(), data.size());
+    metadata.push_back({"META-INF/timestamp.tst", "application/vnd.etsi.timestamp-token", std::move(data)});
+    if(!manifest)
+        return;
+    XMLSchema schema(util::File::path(Conf::instance()->xsdPath(), "en_31916201v010101.xsd"));
+    function<void(const string &, string_view)> add = [this, &schema, &add, &z](const string &file, string_view mime) {
+        auto xml = z.extract<stringstream>(file);
+        XMLDocument doc = XMLDocument::openStream(xml, {"ASiCManifest", ASiContainer::ASIC_NS});
+        schema.validate(doc);
+
+        for(auto ref = doc/"DataObjectReference"; ref; ref++)
+        {
+            if(ref["Rootfile"] == "true")
+                add(util::File::fromUriPath(ref["URI"]), ref["MimeType"]);
+        }
+
+        auto ref = doc/"SigReference";
+        string uri = util::File::fromUriPath(ref["URI"]);
+        string tst = z.extract<stringstream>(uri).str();
+        metadata.push_back({file, string(mime), xml.str()});
+        metadata.push_back({uri, string(ref["MimeType"]), std::move(tst)});
+    };
+    add("META-INF/ASiCArchiveManifest.xml", "text/xml");
 }
 
 SignatureTST::SignatureTST(ASiC_S *asicSDoc, Signer *signer)
@@ -55,6 +85,8 @@ SignatureTST::SignatureTST(ASiC_S *asicSDoc, Signer *signer)
     Digest digest;
     dataFile->digest(digest);
     timestampToken = make_unique<TS>(digest, signer->userAgent());
+    vector<unsigned char> der = *timestampToken;
+    metadata.push_back({"META-INF/timestamp.tst", "application/vnd.etsi.timestamp-token", {der.cbegin(), der.cend()}});
 }
 
 SignatureTST::~SignatureTST() = default;
@@ -106,28 +138,48 @@ void SignatureTST::validate() const
     }
     try
     {
-        timestampToken->verify(dataToSign());
-        if(auto digestMethod = signatureMethod();
-            !Exception::hasWarningIgnore(Exception::ReferenceDigestWeak) &&
+        auto digestMethod = signatureMethod();
+        DataFile *file = asicSDoc->dataFiles().front();
+        timestampToken->verify(file->calcDigest(digestMethod));
+        if(!Exception::hasWarningIgnore(Exception::ReferenceDigestWeak) &&
             Digest::isWeakDigest(digestMethod))
         {
             Exception e(EXCEPTION_PARAMS("TimeStamp '%s' digest weak", digestMethod.c_str()));
             e.setCode(Exception::ReferenceDigestWeak);
             exception.addCause(e);
         }
-        if(doc)
+        vector<string> list {file->fileName()};
+        for(const auto &manifest: metadata)
         {
-            DataFile *file = asicSDoc->dataFiles().front();
+            if(manifest.mime != "text/xml")
+                continue;
+            istringstream is(manifest.data);
+            XMLDocument doc = XMLDocument::openStream(is, {"ASiCManifest", ASiContainer::ASIC_NS});
+            vector<string> add;
             for(auto ref = doc/"DataObjectReference"; ref; ref++)
             {
                 string_view method = (ref/DigestMethod)["Algorithm"];
-                auto uri = util::File::fromUriPath(ref["URI"]);
-                vector<unsigned char> digest = file->fileName() == uri ?
-                    dynamic_cast<const DataFilePrivate*>(file)->calcDigest(string(method)) :
-                    asicSDoc->fileDigest(uri, method).result();
+                const auto &uri = add.emplace_back(util::File::fromUriPath(ref["URI"]));
+                vector<unsigned char> digest;
+                if(file->fileName() == uri)
+                    digest = file->calcDigest(string(method));
+                else
+                {
+                    auto i = find_if(metadata.cbegin(), metadata.cend(), [&uri](const auto &d) { return d.name == uri; });
+                    if(i == metadata.cend())
+                        THROW("File not found '%s'.", uri.c_str());
+                    digest = i->digest(method).result();
+                }
                 if(vector<unsigned char> digestValue = ref/DigestValue; digest != digestValue)
-                    THROW("Reference %s digest does not match", uri.c_str());
+                    THROW("Reference '%s' digest does not match", uri.c_str());
+            }
+            // Check if all files in previous scope are present
+            for(const string &uri: list)
+            {
+                if(!contains(add, uri))
+                    THROW("Reference '%s' not found in manifest", uri.c_str());
             }
+            list = std::move(add);
         }
     }
     catch (const Exception& e)
@@ -141,8 +193,6 @@ void SignatureTST::validate() const
 
 std::vector<unsigned char> SignatureTST::dataToSign() const
 {
-    if(!file.empty())
-        return asicSDoc->fileDigest(file, signatureMethod()).result();
     return asicSDoc->dataFiles().front()->calcDigest(signatureMethod());
 }
 
@@ -162,7 +212,8 @@ string SignatureTST::profile() const
     return string(ASiC_S::ASIC_TST_PROFILE);
 }
 
-std::vector<unsigned char> SignatureTST::save() const
+void SignatureTST::save(const ZipSerialize &z) const
 {
-    return *timestampToken;
+    for(const auto &[name, mime, data, root]: metadata)
+        z.addFile(name, asicSDoc->zproperty(name))(data);
 }