Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2431 insertions, 0 deletions

diff --git a/svl/source/crypto/cryptosign.cxx b/svl/source/crypto/cryptosign.cxx
new file mode 100644
index 000000000..573c06ba5
--- /dev/null
+++ b/svl/source/crypto/cryptosign.cxx
@@ -0,0 +1,2431 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <svl/cryptosign.hxx>
+#include <svl/sigstruct.hxx>
+#include <config_features.h>
+
+#include <rtl/character.hxx>
+#include <rtl/strbuf.hxx>
+#include <rtl/string.hxx>
+#include <sal/log.hxx>
+#include <tools/datetime.hxx>
+#include <tools/stream.hxx>
+#include <comphelper/base64.hxx>
+#include <comphelper/hash.hxx>
+#include <comphelper/processfactory.hxx>
+#include <comphelper/random.hxx>
+#include <com/sun/star/security/XCertificate.hpp>
+#include <com/sun/star/uno/Sequence.hxx>
+#include <filter/msfilter/mscodec.hxx>
+#include <o3tl/char16_t2wchar_t.hxx>
+
+#if HAVE_FEATURE_NSS && !defined(_WIN32)
+// NSS headers for PDF signing
+#include <cert.h>
+#include <hasht.h>
+#include <secerr.h>
+#include <sechash.h>
+#include <cms.h>
+#include <cmst.h>
+
+// We use curl for RFC3161 time stamp requests
+#include <curl/curl.h>
+#endif
+
+#ifdef _WIN32
+// WinCrypt headers for PDF signing
+// Note: this uses Windows 7 APIs and requires the relevant data types
+#include <prewin.h>
+#include <wincrypt.h>
+#include <postwin.h>
+#include <comphelper/windowserrorstring.hxx>
+#endif
+
+#if HAVE_FEATURE_NSS
+
+#include <com/sun/star/xml/crypto/XDigestContext.hpp>
+#include <com/sun/star/xml/crypto/DigestID.hpp>
+#include <com/sun/star/xml/crypto/NSSInitializer.hpp>
+#include <mutex>
+
+// Is this length truly the maximum possible, or just a number that
+// seemed large enough when the author tested this (with some type of
+// certificates)? I suspect the latter.
+
+// Used to be 0x4000 = 16384, but a sample signed PDF (produced by
+// some other software) provided by the customer has a signature
+// content that is 30000 bytes. The SampleSignedPDFDocument.pdf from
+// Adobe has one that is 21942 bytes. So let's be careful. Pity this
+// can't be dynamic, at least not without restructuring the code. Also
+// note that the checks in the code for this being too small
+// apparently are broken, if this overflows you end up with an invalid
+// PDF. Need to fix that.
+
+#define MAX_SIGNATURE_CONTENT_LENGTH 50000
+#endif
+
+using namespace com::sun::star;
+
+namespace {
+
+#if HAVE_FEATURE_NSS
+void appendHex( sal_Int8 nInt, OStringBuffer& rBuffer )
+{
+    static const char pHexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7',
+                                           '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+    rBuffer.append( pHexDigits[ (nInt >> 4) & 15 ] );
+    rBuffer.append( pHexDigits[ nInt & 15 ] );
+}
+#endif // HAVE_FEATURE_NSS
+
+#if HAVE_FEATURE_NSS && !defined(_WIN32)
+
+char *PDFSigningPKCS7PasswordCallback(PK11SlotInfo * /*slot*/, PRBool /*retry*/, void *arg)
+{
+    return PL_strdup(static_cast<char *>(arg));
+}
+
+// ASN.1 used in the (much simpler) time stamp request. From RFC3161
+// and other sources.
+
+/*
+AlgorithmIdentifier  ::=  SEQUENCE  {
+     algorithm  OBJECT IDENTIFIER,
+     parameters ANY DEFINED BY algorithm OPTIONAL  }
+                   -- contains a value of the type
+                   -- registered for use with the
+                   -- algorithm object identifier value
+
+MessageImprint ::= SEQUENCE  {
+    hashAlgorithm AlgorithmIdentifier,
+    hashedMessage OCTET STRING  }
+*/
+
+struct MessageImprint {
+    SECAlgorithmID hashAlgorithm;
+    SECItem hashedMessage;
+};
+
+/*
+Extension  ::=  SEQUENCE  {
+    extnID    OBJECT IDENTIFIER,
+    critical  BOOLEAN DEFAULT FALSE,
+    extnValue OCTET STRING  }
+*/
+
+struct Extension {
+    SECItem  extnID;
+    SECItem  critical;
+    SECItem  extnValue;
+};
+
+/*
+Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
+*/
+
+/*
+TSAPolicyId ::= OBJECT IDENTIFIER
+
+TimeStampReq ::= SEQUENCE  {
+    version            INTEGER  { v1(1) },
+    messageImprint     MessageImprint,
+    --a hash algorithm OID and the hash value of the data to be
+    --time-stamped
+    reqPolicy          TSAPolicyId         OPTIONAL,
+    nonce              INTEGER             OPTIONAL,
+    certReq            BOOLEAN             DEFAULT FALSE,
+    extensions     [0] IMPLICIT Extensions OPTIONAL  }
+*/
+
+struct TimeStampReq {
+    SECItem version;
+    MessageImprint messageImprint;
+    SECItem reqPolicy;
+    SECItem nonce;
+    SECItem certReq;
+    Extension *extensions;
+};
+
+/**
+ * General name, defined by RFC 3280.
+ */
+struct GeneralName
+{
+    CERTName name;
+};
+
+/**
+ * List of general names (only one for now), defined by RFC 3280.
+ */
+struct GeneralNames
+{
+    GeneralName names;
+};
+
+/**
+ * Supplies different fields to identify a certificate, defined by RFC 5035.
+ */
+struct IssuerSerial
+{
+    GeneralNames issuer;
+    SECItem serialNumber;
+};
+
+/**
+ * Supplies different fields that are used to identify certificates, defined by
+ * RFC 5035.
+ */
+struct ESSCertIDv2
+{
+    SECAlgorithmID hashAlgorithm;
+    SECItem certHash;
+    IssuerSerial issuerSerial;
+};
+
+/**
+ * This attribute uses the ESSCertIDv2 structure, defined by RFC 5035.
+ */
+struct SigningCertificateV2
+{
+    ESSCertIDv2** certs;
+
+    SigningCertificateV2()
+        : certs(nullptr)
+    {
+    }
+};
+
+/**
+ * GeneralName ::= CHOICE {
+ *      otherName                       [0]     OtherName,
+ *      rfc822Name                      [1]     IA5String,
+ *      dNSName                         [2]     IA5String,
+ *      x400Address                     [3]     ORAddress,
+ *      directoryName                   [4]     Name,
+ *      ediPartyName                    [5]     EDIPartyName,
+ *      uniformResourceIdentifier       [6]     IA5String,
+ *      iPAddress                       [7]     OCTET STRING,
+ *      registeredID                    [8]     OBJECT IDENTIFIER
+ * }
+ */
+const SEC_ASN1Template GeneralNameTemplate[] =
+{
+    {SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(GeneralName)},
+    {SEC_ASN1_INLINE, offsetof(GeneralName, name), CERT_NameTemplate, 0},
+    {0, 0, nullptr, 0}
+};
+
+/**
+ * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
+ */
+const SEC_ASN1Template GeneralNamesTemplate[] =
+{
+    {SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(GeneralNames)},
+    {SEC_ASN1_INLINE | SEC_ASN1_CONTEXT_SPECIFIC | 4, offsetof(GeneralNames, names), GeneralNameTemplate, 0},
+    {0, 0, nullptr, 0}
+};
+
+/**
+ * IssuerSerial ::= SEQUENCE {
+ *     issuer GeneralNames,
+ *     serialNumber CertificateSerialNumber
+ * }
+ */
+const SEC_ASN1Template IssuerSerialTemplate[] =
+{
+    {SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(IssuerSerial)},
+    {SEC_ASN1_INLINE, offsetof(IssuerSerial, issuer), GeneralNamesTemplate, 0},
+    {SEC_ASN1_INTEGER, offsetof(IssuerSerial, serialNumber), nullptr, 0},
+    {0, 0, nullptr, 0}
+};
+
+
+/**
+ * Hash ::= OCTET STRING
+ *
+ * ESSCertIDv2 ::= SEQUENCE {
+ *     hashAlgorithm AlgorithmIdentifier DEFAULT {algorithm id-sha256},
+ *     certHash Hash,
+ *     issuerSerial IssuerSerial OPTIONAL
+ * }
+ */
+
+SEC_ASN1_MKSUB(SECOID_AlgorithmIDTemplate)
+
+const SEC_ASN1Template ESSCertIDv2Template[] =
+{
+    {SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(ESSCertIDv2)},
+    {SEC_ASN1_INLINE | SEC_ASN1_XTRN, offsetof(ESSCertIDv2, hashAlgorithm), SEC_ASN1_SUB(SECOID_AlgorithmIDTemplate), 0},
+    {SEC_ASN1_OCTET_STRING, offsetof(ESSCertIDv2, certHash), nullptr, 0},
+    {SEC_ASN1_INLINE | SEC_ASN1_XTRN, offsetof(ESSCertIDv2, issuerSerial), IssuerSerialTemplate, 0},
+    {0, 0, nullptr, 0}
+};
+
+/**
+ * SigningCertificateV2 ::= SEQUENCE {
+ * }
+ */
+const SEC_ASN1Template SigningCertificateV2Template[] =
+{
+    {SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(SigningCertificateV2)},
+    {SEC_ASN1_SEQUENCE_OF, offsetof(SigningCertificateV2, certs), ESSCertIDv2Template, 0},
+    {0, 0, nullptr, 0}
+};
+
+struct PKIStatusInfo {
+    SECItem status;
+    SECItem statusString;
+    SECItem failInfo;
+};
+
+const SEC_ASN1Template PKIStatusInfo_Template[] =
+{
+    { SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(PKIStatusInfo) },
+    { SEC_ASN1_INTEGER, offsetof(PKIStatusInfo, status), nullptr, 0 },
+    { SEC_ASN1_CONSTRUCTED | SEC_ASN1_SEQUENCE | SEC_ASN1_OPTIONAL, offsetof(PKIStatusInfo, statusString), nullptr, 0 },
+    { SEC_ASN1_BIT_STRING | SEC_ASN1_OPTIONAL, offsetof(PKIStatusInfo, failInfo), nullptr, 0 },
+    { 0, 0, nullptr, 0 }
+};
+
+const SEC_ASN1Template Any_Template[] =
+{
+    { SEC_ASN1_ANY, 0, nullptr, sizeof(SECItem) }
+};
+
+struct TimeStampResp {
+    PKIStatusInfo status;
+    SECItem timeStampToken;
+};
+
+const SEC_ASN1Template TimeStampResp_Template[] =
+{
+    { SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(TimeStampResp) },
+    { SEC_ASN1_INLINE, offsetof(TimeStampResp, status), PKIStatusInfo_Template, 0 },
+    { SEC_ASN1_ANY | SEC_ASN1_OPTIONAL, offsetof(TimeStampResp, timeStampToken), Any_Template, 0 },
+    { 0, 0, nullptr, 0 }
+};
+
+const SEC_ASN1Template MessageImprint_Template[] =
+{
+    { SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(MessageImprint) },
+    { SEC_ASN1_INLINE, offsetof(MessageImprint, hashAlgorithm), SECOID_AlgorithmIDTemplate, 0 },
+    { SEC_ASN1_OCTET_STRING, offsetof(MessageImprint, hashedMessage), nullptr, 0 },
+    { 0, 0, nullptr, 0 }
+};
+
+const SEC_ASN1Template Extension_Template[] =
+{
+    { SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(Extension) },
+    { SEC_ASN1_OBJECT_ID, offsetof(Extension, extnID), nullptr, 0 },
+    { SEC_ASN1_BOOLEAN, offsetof(Extension, critical), nullptr, 0 },
+    { SEC_ASN1_OCTET_STRING, offsetof(Extension, extnValue), nullptr, 0 },
+    { 0, 0, nullptr, 0 }
+};
+
+const SEC_ASN1Template Extensions_Template[] =
+{
+    { SEC_ASN1_SEQUENCE_OF, 0, Extension_Template, 0 }
+};
+
+const SEC_ASN1Template TimeStampReq_Template[] =
+{
+    { SEC_ASN1_SEQUENCE, 0, nullptr, sizeof(TimeStampReq) },
+    { SEC_ASN1_INTEGER, offsetof(TimeStampReq, version), nullptr, 0 },
+    { SEC_ASN1_INLINE, offsetof(TimeStampReq, messageImprint), MessageImprint_Template, 0 },
+    { SEC_ASN1_OBJECT_ID | SEC_ASN1_OPTIONAL, offsetof(TimeStampReq, reqPolicy), nullptr, 0 },
+    { SEC_ASN1_INTEGER | SEC_ASN1_OPTIONAL, offsetof(TimeStampReq, nonce), nullptr, 0 },
+    { SEC_ASN1_BOOLEAN | SEC_ASN1_OPTIONAL, offsetof(TimeStampReq, certReq), nullptr, 0 },
+    { SEC_ASN1_OPTIONAL | SEC_ASN1_CONTEXT_SPECIFIC | 0, offsetof(TimeStampReq, extensions), Extensions_Template, 0 },
+    { 0, 0, nullptr, 0 }
+};
+
+size_t AppendToBuffer(char const *ptr, size_t size, size_t nmemb, void *userdata)
+{
+    OStringBuffer *pBuffer = static_cast<OStringBuffer*>(userdata);
+    pBuffer->append(ptr, size*nmemb);
+
+    return size*nmemb;
+}
+
+OUString PKIStatusToString(int n)
+{
+    switch (n)
+    {
+    case 0: return "granted";
+    case 1: return "grantedWithMods";
+    case 2: return "rejection";
+    case 3: return "waiting";
+    case 4: return "revocationWarning";
+    case 5: return "revocationNotification";
+    default: return "unknown (" + OUString::number(n) + ")";
+    }
+}
+
+OUString PKIStatusInfoToString(const PKIStatusInfo& rStatusInfo)
+{
+    OUString result = "{status=";
+    if (rStatusInfo.status.len == 1)
+        result += PKIStatusToString(rStatusInfo.status.data[0]);
+    else
+        result += "unknown (len=" + OUString::number(rStatusInfo.status.len);
+
+    // FIXME: Perhaps look at rStatusInfo.statusString.data but note
+    // that we of course can't assume it contains proper UTF-8. After
+    // all, it is data from an external source. Also, RFC3161 claims
+    // it should be a SEQUENCE (1..MAX) OF UTF8String, but another
+    // source claimed it would be a single UTF8String, hmm?
+
+    // FIXME: Worth it to decode failInfo to cleartext, probably not at least as long as this is only for a SAL_INFO
+
+    result += "}";
+
+    return result;
+}
+
+// SEC_StringToOID() and NSS_CMSSignerInfo_AddUnauthAttr() are
+// not exported from libsmime, so copy them here. Sigh.
+
+SECStatus
+my_SEC_StringToOID(SECItem *to, const char *from, PRUint32 len)
+{
+    PRUint32 decimal_numbers = 0;
+    PRUint32 result_bytes = 0;
+    SECStatus rv;
+    PRUint8 result[1024];
+
+    static const PRUint32 max_decimal = 0xffffffff / 10;
+    static const char OIDstring[] = {"OID."};
+
+    if (!from || !to) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return SECFailure;
+    }
+    if (!len) {
+        len = PL_strlen(from);
+    }
+    if (len >= 4 && !PL_strncasecmp(from, OIDstring, 4)) {
+        from += 4; /* skip leading "OID." if present */
+        len  -= 4;
+    }
+    if (!len) {
+bad_data:
+        PORT_SetError(SEC_ERROR_BAD_DATA);
+        return SECFailure;
+    }
+    do {
+        PRUint32 decimal = 0;
+        while (len > 0 && rtl::isAsciiDigit(static_cast<unsigned char>(*from))) {
+            PRUint32 addend = *from++ - '0';
+            --len;
+            if (decimal > max_decimal)  /* overflow */
+                goto bad_data;
+            decimal = (decimal * 10) + addend;
+            if (decimal < addend)   /* overflow */
+                goto bad_data;
+        }
+        if (len != 0 && *from != '.') {
+            goto bad_data;
+        }
+        if (decimal_numbers == 0) {
+            if (decimal > 2)
+                goto bad_data;
+            result[0] = decimal * 40;
+            result_bytes = 1;
+        } else if (decimal_numbers == 1) {
+            if (decimal > 40)
+                goto bad_data;
+            result[0] += decimal;
+        } else {
+            /* encode the decimal number,  */
+            PRUint8 * rp;
+            PRUint32 num_bytes = 0;
+            PRUint32 tmp = decimal;
+            while (tmp) {
+                num_bytes++;
+                tmp >>= 7;
+            }
+            if (!num_bytes )
+                ++num_bytes;  /* use one byte for a zero value */
+            if (num_bytes + result_bytes > sizeof result)
+                goto bad_data;
+            tmp = num_bytes;
+            rp = result + result_bytes - 1;
+            rp[tmp] = static_cast<PRUint8>(decimal & 0x7f);
+            decimal >>= 7;
+            while (--tmp > 0) {
+                rp[tmp] = static_cast<PRUint8>(decimal | 0x80);
+                decimal >>= 7;
+            }
+            result_bytes += num_bytes;
+        }
+        ++decimal_numbers;
+        if (len > 0) { /* skip trailing '.' */
+            ++from;
+            --len;
+        }
+    } while (len > 0);
+    /* now result contains result_bytes of data */
+    if (to->data && to->len >= result_bytes) {
+        to->len = result_bytes;
+        PORT_Memcpy(to->data, result, to->len);
+        rv = SECSuccess;
+    } else {
+        SECItem result_item = {siBuffer, nullptr, 0 };
+        result_item.data = result;
+        result_item.len  = result_bytes;
+        rv = SECITEM_CopyItem(nullptr, to, &result_item);
+    }
+    return rv;
+}
+
+NSSCMSAttribute *
+my_NSS_CMSAttributeArray_FindAttrByOidTag(NSSCMSAttribute **attrs, SECOidTag oidtag, PRBool only)
+{
+    SECOidData *oid;
+    NSSCMSAttribute *attr1, *attr2;
+
+    if (attrs == nullptr)
+        return nullptr;
+
+    oid = SECOID_FindOIDByTag(oidtag);
+    if (oid == nullptr)
+        return nullptr;
+
+    while ((attr1 = *attrs++) != nullptr) {
+    if (attr1->type.len == oid->oid.len && PORT_Memcmp (attr1->type.data,
+                                oid->oid.data,
+                                oid->oid.len) == 0)
+        break;
+    }
+
+    if (attr1 == nullptr)
+        return nullptr;
+
+    if (!only)
+        return attr1;
+
+    while ((attr2 = *attrs++) != nullptr) {
+    if (attr2->type.len == oid->oid.len && PORT_Memcmp (attr2->type.data,
+                                oid->oid.data,
+                                oid->oid.len) == 0)
+        break;
+    }
+
+    if (attr2 != nullptr)
+        return nullptr;
+
+    return attr1;
+}
+
+SECStatus
+my_NSS_CMSArray_Add(PLArenaPool *poolp, void ***array, void *obj)
+{
+    int n = 0;
+    void **dest;
+
+    PORT_Assert(array != NULL);
+    if (array == nullptr)
+        return SECFailure;
+
+    if (*array == nullptr) {
+        dest = static_cast<void **>(PORT_ArenaAlloc(poolp, 2 * sizeof(void *)));
+    } else {
+        void **p = *array;
+        while (*p++)
+            n++;
+        dest = static_cast<void **>(PORT_ArenaGrow (poolp,
+                      *array,
+                      (n + 1) * sizeof(void *),
+                      (n + 2) * sizeof(void *)));
+    }
+
+    if (dest == nullptr)
+        return SECFailure;
+
+    dest[n] = obj;
+    dest[n+1] = nullptr;
+    *array = dest;
+    return SECSuccess;
+}
+
+SECOidTag
+my_NSS_CMSAttribute_GetType(NSSCMSAttribute *attr)
+{
+    SECOidData *typetag;
+
+    typetag = SECOID_FindOID(&(attr->type));
+    if (typetag == nullptr)
+        return SEC_OID_UNKNOWN;
+
+    return typetag->offset;
+}
+
+SECStatus
+my_NSS_CMSAttributeArray_AddAttr(PLArenaPool *poolp, NSSCMSAttribute ***attrs, NSSCMSAttribute *attr)
+{
+    NSSCMSAttribute *oattr;
+    void *mark;
+    SECOidTag type;
+
+    mark = PORT_ArenaMark(poolp);
+
+    /* find oidtag of attr */
+    type = my_NSS_CMSAttribute_GetType(attr);
+
+    /* see if we have one already */
+    oattr = my_NSS_CMSAttributeArray_FindAttrByOidTag(*attrs, type, PR_FALSE);
+    PORT_Assert (oattr == NULL);
+    if (oattr != nullptr)
+        goto loser; /* XXX or would it be better to replace it? */
+
+    /* no, shove it in */
+    if (my_NSS_CMSArray_Add(poolp, reinterpret_cast<void ***>(attrs), static_cast<void *>(attr)) != SECSuccess)
+        goto loser;
+
+    PORT_ArenaUnmark(poolp, mark);
+    return SECSuccess;
+
+loser:
+    PORT_ArenaRelease(poolp, mark);
+    return SECFailure;
+}
+
+SECStatus
+my_NSS_CMSSignerInfo_AddUnauthAttr(NSSCMSSignerInfo *signerinfo, NSSCMSAttribute *attr)
+{
+    return my_NSS_CMSAttributeArray_AddAttr(signerinfo->cmsg->poolp, &(signerinfo->unAuthAttr), attr);
+}
+
+SECStatus
+my_NSS_CMSSignerInfo_AddAuthAttr(NSSCMSSignerInfo *signerinfo, NSSCMSAttribute *attr)
+{
+    return my_NSS_CMSAttributeArray_AddAttr(signerinfo->cmsg->poolp, &(signerinfo->authAttr), attr);
+}
+
+NSSCMSMessage *CreateCMSMessage(const PRTime* time,
+                                NSSCMSSignedData **cms_sd,
+                                NSSCMSSignerInfo **cms_signer,
+                                CERTCertificate *cert,
+                                SECItem *digest)
+{
+    NSSCMSMessage *result = NSS_CMSMessage_Create(nullptr);
+    if (!result)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSMessage_Create failed");
+        return nullptr;
+    }
+
+    *cms_sd = NSS_CMSSignedData_Create(result);
+    if (!*cms_sd)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignedData_Create failed");
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    NSSCMSContentInfo *cms_cinfo = NSS_CMSMessage_GetContentInfo(result);
+    if (NSS_CMSContentInfo_SetContent_SignedData(result, cms_cinfo, *cms_sd) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSContentInfo_SetContent_SignedData failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    cms_cinfo = NSS_CMSSignedData_GetContentInfo(*cms_sd);
+
+    // Attach NULL data as detached data
+    if (NSS_CMSContentInfo_SetContent_Data(result, cms_cinfo, nullptr, PR_TRUE) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSContentInfo_SetContent_Data failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    *cms_signer = NSS_CMSSignerInfo_Create(result, cert, SEC_OID_SHA256);
+    if (!*cms_signer)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignerInfo_Create failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    if (time && NSS_CMSSignerInfo_AddSigningTime(*cms_signer, *time) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignerInfo_AddSigningTime failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    if (NSS_CMSSignerInfo_IncludeCerts(*cms_signer, NSSCMSCM_CertChain, certUsageEmailSigner) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignerInfo_IncludeCerts failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    if (NSS_CMSSignedData_AddCertificate(*cms_sd, cert) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignedData_AddCertificate failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    if (NSS_CMSSignedData_AddSignerInfo(*cms_sd, *cms_signer) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignedData_AddSignerInfo failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    if (NSS_CMSSignedData_SetDigestValue(*cms_sd, SEC_OID_SHA256, digest) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSSignedData_SetDigestValue failed");
+        NSS_CMSSignedData_Destroy(*cms_sd);
+        NSS_CMSMessage_Destroy(result);
+        return nullptr;
+    }
+
+    return result;
+}
+
+#endif // HAVE_FEATURE_NSS && !_WIN32
+
+} // Anonymous namespace
+
+#ifdef _WIN32
+namespace
+{
+
+/// Counts how many bytes are needed to encode a given length.
+size_t GetDERLengthOfLength(size_t nLength)
+{
+    size_t nRet = 1;
+
+    if(nLength > 127)
+    {
+        while (nLength >> (nRet * 8))
+            ++nRet;
+        // Long form means one additional byte: the length of the length and
+        // the length itself.
+        ++nRet;
+    }
+    return nRet;
+}
+
+/// Writes the length part of the header.
+void WriteDERLength(SvStream& rStream, size_t nLength)
+{
+    size_t nLengthOfLength = GetDERLengthOfLength(nLength);
+    if (nLengthOfLength == 1)
+    {
+        // We can use the short form.
+        rStream.WriteUInt8(nLength);
+        return;
+    }
+
+    // 0x80 means that the we use the long form: the first byte is the length
+    // of length with the highest bit set to 1, not the actual length.
+    rStream.WriteUInt8(0x80 | (nLengthOfLength - 1));
+    for (size_t i = 1; i < nLengthOfLength; ++i)
+        rStream.WriteUInt8(nLength >> ((nLengthOfLength - i - 1) * 8));
+}
+
+const unsigned nASN1_INTEGER = 0x02;
+const unsigned nASN1_OCTET_STRING = 0x04;
+const unsigned nASN1_NULL = 0x05;
+const unsigned nASN1_OBJECT_IDENTIFIER = 0x06;
+const unsigned nASN1_SEQUENCE = 0x10;
+/// An explicit tag on a constructed value.
+const unsigned nASN1_TAGGED_CONSTRUCTED = 0xa0;
+const unsigned nASN1_CONSTRUCTED = 0x20;
+
+/// Create payload for the 'signing-certificate' signed attribute.
+bool CreateSigningCertificateAttribute(void const * pDerEncoded, int nDerEncoded, PCCERT_CONTEXT pCertContext, SvStream& rEncodedCertificate)
+{
+    // CryptEncodeObjectEx() does not support encoding arbitrary ASN.1
+    // structures, like SigningCertificateV2 from RFC 5035, so let's build it
+    // manually.
+
+    // Count the certificate hash and put it to aHash.
+    // 2.16.840.1.101.3.4.2.1, i.e. sha256.
+    std::vector<unsigned char> aSHA256{0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01};
+
+    HCRYPTPROV hProv = 0;
+    if (!CryptAcquireContextW(&hProv, nullptr, nullptr, PROV_RSA_AES, CRYPT_VERIFYCONTEXT))
+    {
+        SAL_WARN("svl.crypto", "CryptAcquireContext() failed");
+        return false;
+    }
+
+    HCRYPTHASH hHash = 0;
+    if (!CryptCreateHash(hProv, CALG_SHA_256, 0, 0, &hHash))
+    {
+        SAL_WARN("svl.crypto", "CryptCreateHash() failed");
+        return false;
+    }
+
+    if (!CryptHashData(hHash, static_cast<const BYTE*>(pDerEncoded), nDerEncoded, 0))
+    {
+        SAL_WARN("svl.crypto", "CryptHashData() failed");
+        return false;
+    }
+
+    DWORD nHash = 0;
+    if (!CryptGetHashParam(hHash, HP_HASHVAL, nullptr, &nHash, 0))
+    {
+        SAL_WARN("svl.crypto", "CryptGetHashParam() failed to provide the hash length");
+        return false;
+    }
+
+    std::vector<unsigned char> aHash(nHash);
+    if (!CryptGetHashParam(hHash, HP_HASHVAL, aHash.data(), &nHash, 0))
+    {
+        SAL_WARN("svl.crypto", "CryptGetHashParam() failed to provide the hash");
+        return false;
+    }
+
+    CryptDestroyHash(hHash);
+    CryptReleaseContext(hProv, 0);
+
+    // Collect info for IssuerSerial.
+    BYTE* pIssuer = pCertContext->pCertInfo->Issuer.pbData;
+    DWORD nIssuer = pCertContext->pCertInfo->Issuer.cbData;
+    BYTE* pSerial = pCertContext->pCertInfo->SerialNumber.pbData;
+    DWORD nSerial = pCertContext->pCertInfo->SerialNumber.cbData;
+    // pSerial is LE, aSerial is BE.
+    std::vector<BYTE> aSerial(nSerial);
+    for (size_t i = 0; i < nSerial; ++i)
+        aSerial[i] = *(pSerial + nSerial - i - 1);
+
+    // We now have all the info to count the lengths.
+    // The layout of the payload is:
+    // SEQUENCE: SigningCertificateV2
+    //     SEQUENCE: SEQUENCE OF ESSCertIDv2
+    //         SEQUENCE: ESSCertIDv2
+    //             SEQUENCE: AlgorithmIdentifier
+    //                 OBJECT: algorithm
+    //                 NULL: parameters
+    //             OCTET STRING: certHash
+    //             SEQUENCE: IssuerSerial
+    //                 SEQUENCE: GeneralNames
+    //                     cont [ 4 ]: Name
+    //                         SEQUENCE: Issuer blob
+    //                 INTEGER: CertificateSerialNumber
+
+    size_t nAlgorithm = 1 + GetDERLengthOfLength(aSHA256.size()) + aSHA256.size();
+    size_t nParameters = 1 + GetDERLengthOfLength(1);
+    size_t nAlgorithmIdentifier = 1 + GetDERLengthOfLength(nAlgorithm + nParameters) + nAlgorithm + nParameters;
+    size_t nCertHash = 1 + GetDERLengthOfLength(aHash.size()) + aHash.size();
+    size_t nName = 1 + GetDERLengthOfLength(nIssuer) + nIssuer;
+    size_t nGeneralNames = 1 + GetDERLengthOfLength(nName) + nName;
+    size_t nCertificateSerialNumber = 1 + GetDERLengthOfLength(nSerial) + nSerial;
+    size_t nIssuerSerial = 1 + GetDERLengthOfLength(nGeneralNames + nCertificateSerialNumber) + nGeneralNames + nCertificateSerialNumber;
+    size_t nESSCertIDv2 = 1 + GetDERLengthOfLength(nAlgorithmIdentifier + nCertHash + nIssuerSerial) + nAlgorithmIdentifier + nCertHash + nIssuerSerial;
+    size_t nESSCertIDv2s = 1 + GetDERLengthOfLength(nESSCertIDv2) + nESSCertIDv2;
+
+    // Write SigningCertificateV2.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nESSCertIDv2s);
+    // Write SEQUENCE OF ESSCertIDv2.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nESSCertIDv2);
+    // Write ESSCertIDv2.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nAlgorithmIdentifier + nCertHash + nIssuerSerial);
+    // Write AlgorithmIdentifier.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nAlgorithm + nParameters);
+    // Write algorithm.
+    rEncodedCertificate.WriteUInt8(nASN1_OBJECT_IDENTIFIER);
+    WriteDERLength(rEncodedCertificate, aSHA256.size());
+    rEncodedCertificate.WriteBytes(aSHA256.data(), aSHA256.size());
+    // Write parameters.
+    rEncodedCertificate.WriteUInt8(nASN1_NULL);
+    rEncodedCertificate.WriteUInt8(0);
+    // Write certHash.
+    rEncodedCertificate.WriteUInt8(nASN1_OCTET_STRING);
+    WriteDERLength(rEncodedCertificate, aHash.size());
+    rEncodedCertificate.WriteBytes(aHash.data(), aHash.size());
+    // Write IssuerSerial.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nGeneralNames + nCertificateSerialNumber);
+    // Write GeneralNames.
+    rEncodedCertificate.WriteUInt8(nASN1_SEQUENCE | nASN1_CONSTRUCTED);
+    WriteDERLength(rEncodedCertificate, nName);
+    // Write Name.
+    rEncodedCertificate.WriteUInt8(nASN1_TAGGED_CONSTRUCTED | 4);
+    WriteDERLength(rEncodedCertificate, nIssuer);
+    rEncodedCertificate.WriteBytes(pIssuer, nIssuer);
+    // Write CertificateSerialNumber.
+    rEncodedCertificate.WriteUInt8(nASN1_INTEGER);
+    WriteDERLength(rEncodedCertificate, nSerial);
+    rEncodedCertificate.WriteBytes(aSerial.data(), aSerial.size());
+
+    return true;
+}
+} // anonymous namespace
+#endif //_WIN32
+
+namespace svl::crypto {
+
+static int AsHex(char ch)
+{
+    int nRet = 0;
+    if (rtl::isAsciiDigit(static_cast<unsigned char>(ch)))
+        nRet = ch - '0';
+    else
+    {
+        if (ch >= 'a' && ch <= 'f')
+            nRet = ch - 'a';
+        else if (ch >= 'A' && ch <= 'F')
+            nRet = ch - 'A';
+        else
+            return -1;
+        nRet += 10;
+    }
+    return nRet;
+}
+
+std::vector<unsigned char> DecodeHexString(const OString& rHex)
+{
+    std::vector<unsigned char> aRet;
+    size_t nHexLen = rHex.getLength();
+    {
+        int nByte = 0;
+        int nCount = 2;
+        for (size_t i = 0; i < nHexLen; ++i)
+        {
+            nByte = nByte << 4;
+            sal_Int8 nParsed = AsHex(rHex[i]);
+            if (nParsed == -1)
+            {
+                SAL_WARN("svl.crypto", "DecodeHexString: invalid hex value");
+                return aRet;
+            }
+            nByte += nParsed;
+            --nCount;
+            if (!nCount)
+            {
+                aRet.push_back(nByte);
+                nCount = 2;
+                nByte = 0;
+            }
+        }
+    }
+
+    return aRet;
+}
+
+
+#if defined(SVL_CRYPTO_NSS) || defined(SVL_CRYPTO_MSCRYPTO)
+
+bool Signing::Sign(OStringBuffer& rCMSHexBuffer)
+{
+    // Create the PKCS#7 object.
+    css::uno::Sequence<sal_Int8> aDerEncoded = m_xCertificate->getEncoded();
+    if (!aDerEncoded.hasElements())
+    {
+        SAL_WARN("svl.crypto", "Crypto::Signing: empty certificate");
+        return false;
+    }
+
+#ifndef _WIN32
+
+    CERTCertificate *cert = CERT_DecodeCertFromPackage(reinterpret_cast<char *>(aDerEncoded.getArray()), aDerEncoded.getLength());
+
+    if (!cert)
+    {
+        SAL_WARN("svl.crypto", "CERT_DecodeCertFromPackage failed");
+        return false;
+    }
+
+    std::vector<unsigned char> aHashResult;
+    {
+        comphelper::Hash aHash(comphelper::HashType::SHA256);
+
+        for (const auto& pair : m_dataBlocks)
+            aHash.update(static_cast<const unsigned char*>(pair.first), pair.second);
+
+        aHashResult = aHash.finalize();
+    }
+    SECItem digest;
+    digest.data = aHashResult.data();
+    digest.len = aHashResult.size();
+
+#ifdef DBG_UTIL
+    {
+        FILE *out = fopen("PDFWRITER.hash.data", "wb");
+        fwrite(aHashResult.data(), SHA256_LENGTH, 1, out);
+        fclose(out);
+    }
+#endif
+
+    PRTime now = PR_Now();
+    NSSCMSSignedData *cms_sd;
+    NSSCMSSignerInfo *cms_signer;
+    NSSCMSMessage *cms_msg = CreateCMSMessage(nullptr, &cms_sd, &cms_signer, cert, &digest);
+    if (!cms_msg)
+        return false;
+
+    OString pass(OUStringToOString( m_aSignPassword, RTL_TEXTENCODING_UTF8 ));
+
+    TimeStampReq src;
+    OStringBuffer response_buffer;
+    TimeStampResp response;
+    SECItem response_item;
+    NSSCMSAttribute timestamp;
+    SECItem values[2];
+    SECItem *valuesp[2];
+    valuesp[0] = values;
+    valuesp[1] = nullptr;
+    SECOidData typetag;
+
+    if( !m_aSignTSA.isEmpty() )
+    {
+        // Create another CMS message with the same contents as cms_msg, because it doesn't seem
+        // possible to encode a message twice (once to get something to timestamp, and then after
+        // adding the timestamp attribute).
+
+        NSSCMSSignedData *ts_cms_sd;
+        NSSCMSSignerInfo *ts_cms_signer;
+        NSSCMSMessage *ts_cms_msg = CreateCMSMessage(&now, &ts_cms_sd, &ts_cms_signer, cert, &digest);
+        if (!ts_cms_msg)
+        {
+            return false;
+        }
+
+        SECItem ts_cms_output;
+        ts_cms_output.data = nullptr;
+        ts_cms_output.len = 0;
+        PLArenaPool *ts_arena = PORT_NewArena(10000);
+        NSSCMSEncoderContext *ts_cms_ecx;
+        ts_cms_ecx = NSS_CMSEncoder_Start(ts_cms_msg, nullptr, nullptr, &ts_cms_output, ts_arena, PDFSigningPKCS7PasswordCallback,
+                                          const_cast<char*>(pass.getStr()), nullptr, nullptr, nullptr, nullptr);
+
+        if (NSS_CMSEncoder_Finish(ts_cms_ecx) != SECSuccess)
+        {
+            SAL_WARN("svl.crypto", "NSS_CMSEncoder_Finish failed");
+            return false;
+        }
+
+        // I have compared the ts_cms_output produced here with the cms_output produced below, with
+        // the DONTCALLADDUNAUTHATTR env var set (i.e. without actually calling
+        // my_NSS_CMSSignerInfo_AddUnauthAttr()), and they are identical.
+
+#ifdef DBG_UTIL
+        {
+            FILE *out = fopen("PDFWRITER.ts_cms.data", "wb");
+            fwrite(ts_cms_output.data, ts_cms_output.len, 1, out);
+            fclose(out);
+        }
+#endif
+
+        std::vector<unsigned char> aTsHashResult = comphelper::Hash::calculateHash(ts_cms_signer->encDigest.data, ts_cms_signer->encDigest.len, comphelper::HashType::SHA256);
+        SECItem ts_digest;
+        ts_digest.type = siBuffer;
+        ts_digest.data = aTsHashResult.data();
+        ts_digest.len = aTsHashResult.size();
+
+#ifdef DBG_UTIL
+        {
+            FILE *out = fopen("PDFWRITER.ts_hash.data", "wb");
+            fwrite(aTsHashResult.data(), SHA256_LENGTH, 1, out);
+            fclose(out);
+        }
+#endif
+
+        unsigned char cOne = 1;
+        src.version.type = siUnsignedInteger;
+        src.version.data = &cOne;
+        src.version.len = sizeof(cOne);
+
+        src.messageImprint.hashAlgorithm.algorithm.data = nullptr;
+        src.messageImprint.hashAlgorithm.parameters.data = nullptr;
+        SECOID_SetAlgorithmID(nullptr, &src.messageImprint.hashAlgorithm, SEC_OID_SHA256, nullptr);
+        src.messageImprint.hashedMessage = ts_digest;
+
+        src.reqPolicy.type = siBuffer;
+        src.reqPolicy.data = nullptr;
+        src.reqPolicy.len = 0;
+
+        unsigned int nNonce = comphelper::rng::uniform_uint_distribution(0, SAL_MAX_UINT32);
+        src.nonce.type = siUnsignedInteger;
+        src.nonce.data = reinterpret_cast<unsigned char*>(&nNonce);
+        src.nonce.len = sizeof(nNonce);
+
+        src.certReq.type = siUnsignedInteger;
+        src.certReq.data = &cOne;
+        src.certReq.len = sizeof(cOne);
+
+        src.extensions = nullptr;
+
+        SECItem* timestamp_request = SEC_ASN1EncodeItem(nullptr, nullptr, &src, TimeStampReq_Template);
+        if (timestamp_request == nullptr)
+        {
+            SAL_WARN("svl.crypto", "SEC_ASN1EncodeItem failed");
+            return false;
+        }
+
+        if (timestamp_request->data == nullptr)
+        {
+            SAL_WARN("svl.crypto", "SEC_ASN1EncodeItem succeeded but got NULL data");
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "request length=" << timestamp_request->len);
+
+#ifdef DBG_UTIL
+        {
+            FILE *out = fopen("PDFWRITER.timestampreq.data", "wb");
+            fwrite(timestamp_request->data, timestamp_request->len, 1, out);
+            fclose(out);
+        }
+#endif
+
+        // Send time stamp request to TSA server, receive response
+
+        CURL* curl = curl_easy_init();
+        CURLcode rc;
+        struct curl_slist* slist = nullptr;
+
+        if (!curl)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_init failed");
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "Setting curl to verbose: " << (curl_easy_setopt(curl, CURLOPT_VERBOSE, 1) == CURLE_OK ? "OK" : "FAIL"));
+
+        if ((rc = curl_easy_setopt(curl, CURLOPT_URL, OUStringToOString(m_aSignTSA, RTL_TEXTENCODING_UTF8).getStr())) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_URL) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        slist = curl_slist_append(slist, "Content-Type: application/timestamp-query");
+        slist = curl_slist_append(slist, "Accept: application/timestamp-reply");
+
+        if ((rc = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, slist)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_HTTPHEADER) failed: " << curl_easy_strerror(rc));
+            curl_slist_free_all(slist);
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        if ((rc = curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, static_cast<long>(timestamp_request->len))) != CURLE_OK ||
+            (rc = curl_easy_setopt(curl, CURLOPT_POSTFIELDS, timestamp_request->data)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_POSTFIELDSIZE or CURLOPT_POSTFIELDS) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        if ((rc = curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response_buffer)) != CURLE_OK ||
+            (rc = curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, AppendToBuffer)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_WRITEDATA or CURLOPT_WRITEFUNCTION) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        if ((rc = curl_easy_setopt(curl, CURLOPT_POST, 1)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_POST) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        char error_buffer[CURL_ERROR_SIZE];
+        if ((rc = curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, error_buffer)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_ERRORBUFFER) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        // Use a ten second timeout
+        if ((rc = curl_easy_setopt(curl, CURLOPT_TIMEOUT, 10)) != CURLE_OK ||
+            (rc = curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10)) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_setopt(CURLOPT_TIMEOUT or CURLOPT_CONNECTTIMEOUT) failed: " << curl_easy_strerror(rc));
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        if (curl_easy_perform(curl) != CURLE_OK)
+        {
+            SAL_WARN("svl.crypto", "curl_easy_perform failed: " << error_buffer);
+            curl_easy_cleanup(curl);
+            SECITEM_FreeItem(timestamp_request, PR_TRUE);
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "PDF signing: got response, length=" << response_buffer.getLength());
+
+#ifdef DBG_UTIL
+        {
+            FILE *out = fopen("PDFWRITER.reply.data", "wb");
+            fwrite(response_buffer.getStr(), response_buffer.getLength(), 1, out);
+            fclose(out);
+        }
+#endif
+
+        curl_slist_free_all(slist);
+        curl_easy_cleanup(curl);
+        SECITEM_FreeItem(timestamp_request, PR_TRUE);
+
+        memset(&response, 0, sizeof(response));
+
+        response_item.type = siBuffer;
+        response_item.data = reinterpret_cast<unsigned char*>(const_cast<char*>(response_buffer.getStr()));
+        response_item.len = response_buffer.getLength();
+
+        if (SEC_ASN1DecodeItem(nullptr, &response, TimeStampResp_Template, &response_item) != SECSuccess)
+        {
+            SAL_WARN("svl.crypto", "SEC_ASN1DecodeItem failed");
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "TimeStampResp received and decoded, status=" << PKIStatusInfoToString(response.status));
+
+        if (response.status.status.len != 1 ||
+            (response.status.status.data[0] != 0 && response.status.status.data[0] != 1))
+        {
+            SAL_WARN("svl.crypto", "Timestamp request was not granted");
+            return false;
+        }
+
+        // timestamp.type filled in below
+
+        // Not sure if we actually need two entries in the values array, now when valuesp is an
+        // array too, the pointer to the values array followed by a null pointer. But I don't feel
+        // like experimenting.
+        values[0] = response.timeStampToken;
+        values[1].type = siBuffer;
+        values[1].data = nullptr;
+        values[1].len = 0;
+
+        timestamp.values = valuesp;
+
+        typetag.oid.data = nullptr;
+        // id-aa-timeStampToken OBJECT IDENTIFIER ::= { iso(1)
+        // member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
+        // smime(16) aa(2) 14 }
+        if (my_SEC_StringToOID(&typetag.oid, "1.2.840.113549.1.9.16.2.14", 0) != SECSuccess)
+        {
+            SAL_WARN("svl.crypto", "SEC_StringToOID failed");
+            return false;
+        }
+        typetag.offset = SEC_OID_UNKNOWN; // ???
+        typetag.desc = "id-aa-timeStampToken";
+        typetag.mechanism = CKM_SHA_1; // ???
+        typetag.supportedExtension = UNSUPPORTED_CERT_EXTENSION; // ???
+        timestamp.typeTag = &typetag;
+
+        timestamp.type = typetag.oid; // ???
+
+        timestamp.encoded = PR_TRUE; // ???
+
+#ifdef DBG_UTIL
+        if (getenv("DONTCALLADDUNAUTHATTR"))
+            ;
+        else
+#endif
+        if (my_NSS_CMSSignerInfo_AddUnauthAttr(cms_signer, &timestamp) != SECSuccess)
+        {
+            SAL_WARN("svl.crypto", "NSS_CMSSignerInfo_AddUnauthAttr failed");
+            return false;
+        }
+    }
+
+    // Add the signing certificate as a signed attribute.
+    ESSCertIDv2* aCertIDs[2];
+    ESSCertIDv2 aCertID;
+    // Write ESSCertIDv2.hashAlgorithm.
+    aCertID.hashAlgorithm.algorithm.data = nullptr;
+    aCertID.hashAlgorithm.parameters.data = nullptr;
+    SECOID_SetAlgorithmID(nullptr, &aCertID.hashAlgorithm, SEC_OID_SHA256, nullptr);
+    // Write ESSCertIDv2.certHash.
+    SECItem aCertHashItem;
+    auto pDerEncoded = reinterpret_cast<const unsigned char *>(aDerEncoded.getArray());
+    std::vector<unsigned char> aCertHashResult = comphelper::Hash::calculateHash(pDerEncoded, aDerEncoded.getLength(), comphelper::HashType::SHA256);
+    aCertHashItem.type = siBuffer;
+    aCertHashItem.data = aCertHashResult.data();
+    aCertHashItem.len = aCertHashResult.size();
+    aCertID.certHash = aCertHashItem;
+    // Write ESSCertIDv2.issuerSerial.
+    IssuerSerial aSerial;
+    GeneralName aName;
+    aName.name = cert->issuer;
+    aSerial.issuer.names = aName;
+    aSerial.serialNumber = cert->serialNumber;
+    aCertID.issuerSerial = aSerial;
+    // Write SigningCertificateV2.certs.
+    aCertIDs[0] = &aCertID;
+    aCertIDs[1] = nullptr;
+    SigningCertificateV2 aCertificate;
+    aCertificate.certs = &aCertIDs[0];
+    SECItem* pEncodedCertificate = SEC_ASN1EncodeItem(nullptr, nullptr, &aCertificate, SigningCertificateV2Template);
+    if (!pEncodedCertificate)
+    {
+        SAL_WARN("svl.crypto", "SEC_ASN1EncodeItem() failed");
+        return false;
+    }
+
+    NSSCMSAttribute aAttribute;
+    SECItem aAttributeValues[2];
+    SECItem* pAttributeValues[2];
+    pAttributeValues[0] = aAttributeValues;
+    pAttributeValues[1] = nullptr;
+    aAttributeValues[0] = *pEncodedCertificate;
+    aAttributeValues[1].type = siBuffer;
+    aAttributeValues[1].data = nullptr;
+    aAttributeValues[1].len = 0;
+    aAttribute.values = pAttributeValues;
+
+    SECOidData aOidData;
+    aOidData.oid.data = nullptr;
+    /*
+     * id-aa-signingCertificateV2 OBJECT IDENTIFIER ::=
+     * { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
+     *   smime(16) id-aa(2) 47 }
+     */
+    if (my_SEC_StringToOID(&aOidData.oid, "1.2.840.113549.1.9.16.2.47", 0) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "my_SEC_StringToOID() failed");
+        return false;
+    }
+    aOidData.offset = SEC_OID_UNKNOWN;
+    aOidData.desc = "id-aa-signingCertificateV2";
+    aOidData.mechanism = CKM_SHA_1;
+    aOidData.supportedExtension = UNSUPPORTED_CERT_EXTENSION;
+    aAttribute.typeTag = &aOidData;
+    aAttribute.type = aOidData.oid;
+    aAttribute.encoded = PR_TRUE;
+
+    if (my_NSS_CMSSignerInfo_AddAuthAttr(cms_signer, &aAttribute) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "my_NSS_CMSSignerInfo_AddAuthAttr() failed");
+        return false;
+    }
+
+    SECItem cms_output;
+    cms_output.data = nullptr;
+    cms_output.len = 0;
+    PLArenaPool *arena = PORT_NewArena(10000);
+    NSSCMSEncoderContext *cms_ecx;
+
+    // Possibly it would work to even just pass NULL for the password callback function and its
+    // argument here. After all, at least with the hardware token and associated software I tested
+    // with, the software itself pops up a dialog asking for the PIN (password). But I am not going
+    // to test it and risk locking up my token...
+
+    cms_ecx = NSS_CMSEncoder_Start(cms_msg, nullptr, nullptr, &cms_output, arena, PDFSigningPKCS7PasswordCallback,
+                                   const_cast<char*>(pass.getStr()), nullptr, nullptr, nullptr, nullptr);
+
+    if (!cms_ecx)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSEncoder_Start failed");
+        return false;
+    }
+
+    if (NSS_CMSEncoder_Finish(cms_ecx) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "NSS_CMSEncoder_Finish failed");
+        return false;
+    }
+
+#ifdef DBG_UTIL
+    {
+        FILE *out = fopen("PDFWRITER.cms.data", "wb");
+        fwrite(cms_output.data, cms_output.len, 1, out);
+        fclose(out);
+    }
+#endif
+
+    if (cms_output.len*2 > MAX_SIGNATURE_CONTENT_LENGTH)
+    {
+        SAL_WARN("svl.crypto", "Signature requires more space (" << cms_output.len*2 << ") than we reserved (" << MAX_SIGNATURE_CONTENT_LENGTH << ")");
+        NSS_CMSMessage_Destroy(cms_msg);
+        return false;
+    }
+
+    for (unsigned int i = 0; i < cms_output.len ; i++)
+        appendHex(cms_output.data[i], rCMSHexBuffer);
+
+    SECITEM_FreeItem(pEncodedCertificate, PR_TRUE);
+    NSS_CMSMessage_Destroy(cms_msg);
+
+    return true;
+
+#else // _WIN32
+    PCCERT_CONTEXT pCertContext = CertCreateCertificateContext(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, reinterpret_cast<const BYTE*>(aDerEncoded.getArray()), aDerEncoded.getLength());
+    if (pCertContext == nullptr)
+    {
+        SAL_WARN("svl.crypto", "CertCreateCertificateContext failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    CRYPT_SIGN_MESSAGE_PARA aPara = {};
+    aPara.cbSize = sizeof(aPara);
+    aPara.dwMsgEncodingType = PKCS_7_ASN_ENCODING | X509_ASN_ENCODING;
+    aPara.pSigningCert = pCertContext;
+    aPara.HashAlgorithm.pszObjId = const_cast<LPSTR>(szOID_NIST_sha256);
+    aPara.HashAlgorithm.Parameters.cbData = 0;
+    aPara.cMsgCert = 1;
+    aPara.rgpMsgCert = &pCertContext;
+
+    NCRYPT_KEY_HANDLE hCryptKey = 0;
+    DWORD dwFlags = CRYPT_ACQUIRE_CACHE_FLAG | CRYPT_ACQUIRE_ONLY_NCRYPT_KEY_FLAG;
+    HCRYPTPROV_OR_NCRYPT_KEY_HANDLE* phCryptProvOrNCryptKey = &hCryptKey;
+    DWORD nKeySpec;
+    BOOL bFreeNeeded;
+
+    if (!CryptAcquireCertificatePrivateKey(pCertContext,
+                                           dwFlags,
+                                           nullptr,
+                                           phCryptProvOrNCryptKey,
+                                           &nKeySpec,
+                                           &bFreeNeeded))
+    {
+        SAL_WARN("svl.crypto", "CryptAcquireCertificatePrivateKey failed: " << WindowsErrorString(GetLastError()));
+        CertFreeCertificateContext(pCertContext);
+        return false;
+    }
+    assert(!bFreeNeeded);
+
+    CMSG_SIGNER_ENCODE_INFO aSignerInfo = {};
+    aSignerInfo.cbSize = sizeof(aSignerInfo);
+    aSignerInfo.pCertInfo = pCertContext->pCertInfo;
+    aSignerInfo.hNCryptKey = hCryptKey;
+    aSignerInfo.dwKeySpec = nKeySpec;
+    aSignerInfo.HashAlgorithm.pszObjId = const_cast<LPSTR>(szOID_NIST_sha256);
+    aSignerInfo.HashAlgorithm.Parameters.cbData = 0;
+
+    // Add the signing certificate as a signed attribute.
+    CRYPT_INTEGER_BLOB aCertificateBlob;
+    SvMemoryStream aEncodedCertificate;
+    if (!CreateSigningCertificateAttribute(aDerEncoded.getArray(), aDerEncoded.getLength(), pCertContext, aEncodedCertificate))
+    {
+        SAL_WARN("svl.crypto", "CreateSigningCertificateAttribute() failed");
+        return false;
+    }
+    aCertificateBlob.pbData = const_cast<BYTE*>(static_cast<const BYTE*>(aEncodedCertificate.GetData()));
+    aCertificateBlob.cbData = aEncodedCertificate.GetSize();
+    CRYPT_ATTRIBUTE aCertificateAttribute;
+    /*
+     * id-aa-signingCertificateV2 OBJECT IDENTIFIER ::=
+     * { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
+     *   smime(16) id-aa(2) 47 }
+     */
+    aCertificateAttribute.pszObjId = const_cast<LPSTR>("1.2.840.113549.1.9.16.2.47");
+    aCertificateAttribute.cValue = 1;
+    aCertificateAttribute.rgValue = &aCertificateBlob;
+    aSignerInfo.cAuthAttr = 1;
+    aSignerInfo.rgAuthAttr = &aCertificateAttribute;
+
+    CMSG_SIGNED_ENCODE_INFO aSignedInfo = {};
+    aSignedInfo.cbSize = sizeof(aSignedInfo);
+    aSignedInfo.cSigners = 1;
+    aSignedInfo.rgSigners = &aSignerInfo;
+
+    CERT_BLOB aCertBlob;
+
+    aCertBlob.cbData = pCertContext->cbCertEncoded;
+    aCertBlob.pbData = pCertContext->pbCertEncoded;
+
+    aSignedInfo.cCertEncoded = 1;
+    aSignedInfo.rgCertEncoded = &aCertBlob;
+
+    HCRYPTMSG hMsg = CryptMsgOpenToEncode(PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                          CMSG_DETACHED_FLAG,
+                                          CMSG_SIGNED,
+                                          &aSignedInfo,
+                                          nullptr,
+                                          nullptr);
+    if (!hMsg)
+    {
+        SAL_WARN("svl.crypto", "CryptMsgOpenToEncode failed: " << WindowsErrorString(GetLastError()));
+        CertFreeCertificateContext(pCertContext);
+        return false;
+    }
+
+    for (size_t i = 0; i < m_dataBlocks.size(); ++i)
+    {
+        const bool last = (i == m_dataBlocks.size() - 1);
+        if (!CryptMsgUpdate(hMsg, static_cast<const BYTE *>(m_dataBlocks[i].first), m_dataBlocks[i].second, last))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgUpdate failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+    }
+
+    PCRYPT_TIMESTAMP_CONTEXT pTsContext = nullptr;
+
+    if( !m_aSignTSA.isEmpty() )
+    {
+        HCRYPTMSG hDecodedMsg = CryptMsgOpenToDecode(PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                                     CMSG_DETACHED_FLAG,
+                                                     CMSG_SIGNED,
+                                                     NULL,
+                                                     nullptr,
+                                                     nullptr);
+        if (!hDecodedMsg)
+        {
+            SAL_WARN("svl.crypto", "CryptMsgOpenToDecode failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        DWORD nTsSigLen = 0;
+
+        if (!CryptMsgGetParam(hMsg, CMSG_BARE_CONTENT_PARAM, 0, nullptr, &nTsSigLen))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_BARE_CONTENT_PARAM) failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "nTsSigLen=" << nTsSigLen);
+
+        std::unique_ptr<BYTE[]> pTsSig(new BYTE[nTsSigLen]);
+
+        if (!CryptMsgGetParam(hMsg, CMSG_BARE_CONTENT_PARAM, 0, pTsSig.get(), &nTsSigLen))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_BARE_CONTENT_PARAM) failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        if (!CryptMsgUpdate(hDecodedMsg, pTsSig.get(), nTsSigLen, TRUE))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgUpdate failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        DWORD nDecodedSignerInfoLen = 0;
+        if (!CryptMsgGetParam(hDecodedMsg, CMSG_SIGNER_INFO_PARAM, 0, nullptr, &nDecodedSignerInfoLen))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_SIGNER_INFO_PARAM) failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        std::unique_ptr<BYTE[]> pDecodedSignerInfoBuf(new BYTE[nDecodedSignerInfoLen]);
+
+        if (!CryptMsgGetParam(hDecodedMsg, CMSG_SIGNER_INFO_PARAM, 0, pDecodedSignerInfoBuf.get(), &nDecodedSignerInfoLen))
+        {
+            SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_SIGNER_INFO_PARAM) failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        CMSG_SIGNER_INFO *pDecodedSignerInfo = reinterpret_cast<CMSG_SIGNER_INFO *>(pDecodedSignerInfoBuf.get());
+
+        CRYPT_TIMESTAMP_PARA aTsPara;
+        unsigned int nNonce = comphelper::rng::uniform_uint_distribution(0, SAL_MAX_UINT32);
+
+        aTsPara.pszTSAPolicyId = nullptr;
+        aTsPara.fRequestCerts = TRUE;
+        aTsPara.Nonce.cbData = sizeof(nNonce);
+        aTsPara.Nonce.pbData = reinterpret_cast<BYTE *>(&nNonce);
+        aTsPara.cExtension = 0;
+        aTsPara.rgExtension = nullptr;
+
+        if (!CryptRetrieveTimeStamp(o3tl::toW(m_aSignTSA.getStr()),
+                     0,
+                     10000,
+                     szOID_NIST_sha256,
+                     &aTsPara,
+                     pDecodedSignerInfo->EncryptedHash.pbData,
+                     pDecodedSignerInfo->EncryptedHash.cbData,
+                     &pTsContext,
+                     nullptr,
+                     nullptr))
+        {
+            SAL_WARN("svl.crypto", "CryptRetrieveTimeStamp failed: " << WindowsErrorString(GetLastError()));
+            CryptMsgClose(hDecodedMsg);
+            CryptMsgClose(hMsg);
+            CertFreeCertificateContext(pCertContext);
+            return false;
+        }
+
+        SAL_INFO("svl.crypto", "Time stamp size is " << pTsContext->cbEncoded << " bytes");
+
+#ifdef DBG_UTIL
+        {
+            FILE *out = fopen("PDFWRITER.tstoken.data", "wb");
+            fwrite(pTsContext->pbEncoded, pTsContext->cbEncoded, 1, out);
+            fclose(out);
+        }
+#endif
+
+        // I tried to use CryptMsgControl() with CMSG_CTRL_ADD_SIGNER_UNAUTH_ATTR to add the
+        // timestamp, but that failed with "The parameter is incorrect". Probably it is too late to
+        // modify the message once its data has already been encoded as part of the
+        // CryptMsgGetParam() with CMSG_BARE_CONTENT_PARAM above. So close the message and re-do its
+        // creation steps, but now with an amended aSignerInfo.
+
+        CRYPT_INTEGER_BLOB aTimestampBlob;
+        aTimestampBlob.cbData = pTsContext->cbEncoded;
+        aTimestampBlob.pbData = pTsContext->pbEncoded;
+
+        CRYPT_ATTRIBUTE aTimestampAttribute;
+        aTimestampAttribute.pszObjId = const_cast<LPSTR>(
+            "1.2.840.113549.1.9.16.2.14");
+        aTimestampAttribute.cValue = 1;
+        aTimestampAttribute.rgValue = &aTimestampBlob;
+
+        aSignerInfo.cUnauthAttr = 1;
+        aSignerInfo.rgUnauthAttr = &aTimestampAttribute;
+
+        CryptMsgClose(hMsg);
+
+        hMsg = CryptMsgOpenToEncode(PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                    CMSG_DETACHED_FLAG,
+                                    CMSG_SIGNED,
+                                    &aSignedInfo,
+                                    nullptr,
+                                    nullptr);
+
+        for (size_t i = 0; i < m_dataBlocks.size(); ++i)
+        {
+            const bool last = (i == m_dataBlocks.size() - 1);
+            if (!hMsg ||
+                !CryptMsgUpdate(hMsg, static_cast<const BYTE *>(m_dataBlocks[i].first), m_dataBlocks[i].second, last))
+            {
+                SAL_WARN("svl.crypto", "Re-creating the message failed: " << WindowsErrorString(GetLastError()));
+                CryptMemFree(pTsContext);
+                CryptMsgClose(hDecodedMsg);
+                CryptMsgClose(hMsg);
+                CertFreeCertificateContext(pCertContext);
+                return false;
+            }
+        }
+
+        CryptMsgClose(hDecodedMsg);
+    }
+
+    DWORD nSigLen = 0;
+
+    if (!CryptMsgGetParam(hMsg, CMSG_CONTENT_PARAM, 0, nullptr, &nSigLen))
+    {
+        SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_CONTENT_PARAM) failed: " << WindowsErrorString(GetLastError()));
+        if (pTsContext)
+            CryptMemFree(pTsContext);
+        CryptMsgClose(hMsg);
+        CertFreeCertificateContext(pCertContext);
+        return false;
+    }
+
+    if (nSigLen*2 > MAX_SIGNATURE_CONTENT_LENGTH)
+    {
+        SAL_WARN("svl.crypto", "Signature requires more space (" << nSigLen*2 << ") than we reserved (" << MAX_SIGNATURE_CONTENT_LENGTH << ")");
+        if (pTsContext)
+            CryptMemFree(pTsContext);
+        CryptMsgClose(hMsg);
+        CertFreeCertificateContext(pCertContext);
+        return false;
+    }
+
+    SAL_INFO("svl.crypto", "Signature size is " << nSigLen << " bytes");
+    std::unique_ptr<BYTE[]> pSig(new BYTE[nSigLen]);
+
+    if (!CryptMsgGetParam(hMsg, CMSG_CONTENT_PARAM, 0, pSig.get(), &nSigLen))
+    {
+        SAL_WARN("svl.crypto", "CryptMsgGetParam(CMSG_CONTENT_PARAM) failed: " << WindowsErrorString(GetLastError()));
+        if (pTsContext)
+            CryptMemFree(pTsContext);
+        CryptMsgClose(hMsg);
+        CertFreeCertificateContext(pCertContext);
+        return false;
+    }
+
+#ifdef DBG_UTIL
+    {
+        FILE *out = fopen("PDFWRITER.signature.data", "wb");
+        fwrite(pSig.get(), nSigLen, 1, out);
+        fclose(out);
+    }
+#endif
+
+    // Release resources
+    if (pTsContext)
+        CryptMemFree(pTsContext);
+    CryptMsgClose(hMsg);
+    CertFreeCertificateContext(pCertContext);
+
+    for (unsigned int i = 0; i < nSigLen ; i++)
+        appendHex(pSig[i], rCMSHexBuffer);
+
+    return true;
+#endif
+}
+#else
+bool Signing::Sign(OStringBuffer&)
+{
+    return false;
+}
+#endif //!SVL_CRYPTO_NSS && !SVL_CRYPTO_MSCRYPTO
+
+
+namespace
+{
+#ifdef SVL_CRYPTO_NSS
+/// Similar to NSS_CMSAttributeArray_FindAttrByOidTag(), but works directly with a SECOidData.
+NSSCMSAttribute* CMSAttributeArray_FindAttrByOidData(NSSCMSAttribute** attrs, SECOidData const * oid, PRBool only)
+{
+    NSSCMSAttribute* attr1, *attr2;
+
+    if (attrs == nullptr)
+        return nullptr;
+
+    if (oid == nullptr)
+        return nullptr;
+
+    while ((attr1 = *attrs++) != nullptr)
+    {
+        if (attr1->type.len == oid->oid.len && PORT_Memcmp(attr1->type.data,
+                oid->oid.data,
+                oid->oid.len) == 0)
+            break;
+    }
+
+    if (attr1 == nullptr)
+        return nullptr;
+
+    if (!only)
+        return attr1;
+
+    while ((attr2 = *attrs++) != nullptr)
+    {
+        if (attr2->type.len == oid->oid.len && PORT_Memcmp(attr2->type.data,
+                oid->oid.data,
+                oid->oid.len) == 0)
+            break;
+    }
+
+    if (attr2 != nullptr)
+        return nullptr;
+
+    return attr1;
+}
+
+/// Same as SEC_StringToOID(), which is private to us.
+SECStatus StringToOID(SECItem* to, const char* from, PRUint32 len)
+{
+    PRUint32 decimal_numbers = 0;
+    PRUint32 result_bytes = 0;
+    SECStatus rv;
+    PRUint8 result[1024];
+
+    static const PRUint32 max_decimal = 0xffffffff / 10;
+    static const char OIDstring[] = {"OID."};
+
+    if (!from || !to)
+    {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return SECFailure;
+    }
+    if (!len)
+    {
+        len = PL_strlen(from);
+    }
+    if (len >= 4 && !PL_strncasecmp(from, OIDstring, 4))
+    {
+        from += 4; /* skip leading "OID." if present */
+        len  -= 4;
+    }
+    if (!len)
+    {
+bad_data:
+        PORT_SetError(SEC_ERROR_BAD_DATA);
+        return SECFailure;
+    }
+    do
+    {
+        PRUint32 decimal = 0;
+        while (len > 0 && rtl::isAsciiDigit(static_cast<unsigned char>(*from)))
+        {
+            PRUint32 addend = *from++ - '0';
+            --len;
+            if (decimal > max_decimal)  /* overflow */
+                goto bad_data;
+            decimal = (decimal * 10) + addend;
+            if (decimal < addend)   /* overflow */
+                goto bad_data;
+        }
+        if (len != 0 && *from != '.')
+        {
+            goto bad_data;
+        }
+        if (decimal_numbers == 0)
+        {
+            if (decimal > 2)
+                goto bad_data;
+            result[0] = decimal * 40;
+            result_bytes = 1;
+        }
+        else if (decimal_numbers == 1)
+        {
+            if (decimal > 40)
+                goto bad_data;
+            result[0] += decimal;
+        }
+        else
+        {
+            /* encode the decimal number,  */
+            PRUint8* rp;
+            PRUint32 num_bytes = 0;
+            PRUint32 tmp = decimal;
+            while (tmp)
+            {
+                num_bytes++;
+                tmp >>= 7;
+            }
+            if (!num_bytes)
+                ++num_bytes;  /* use one byte for a zero value */
+            if (static_cast<size_t>(num_bytes) + result_bytes > sizeof result)
+                goto bad_data;
+            tmp = num_bytes;
+            rp = result + result_bytes - 1;
+            rp[tmp] = static_cast<PRUint8>(decimal & 0x7f);
+            decimal >>= 7;
+            while (--tmp > 0)
+            {
+                rp[tmp] = static_cast<PRUint8>(decimal | 0x80);
+                decimal >>= 7;
+            }
+            result_bytes += num_bytes;
+        }
+        ++decimal_numbers;
+        if (len > 0)   /* skip trailing '.' */
+        {
+            ++from;
+            --len;
+        }
+    }
+    while (len > 0);
+    /* now result contains result_bytes of data */
+    if (to->data && to->len >= result_bytes)
+    {
+        to->len = result_bytes;
+        PORT_Memcpy(to->data, result, to->len);
+        rv = SECSuccess;
+    }
+    else
+    {
+        SECItem result_item = {siBuffer, nullptr, 0 };
+        result_item.data = result;
+        result_item.len  = result_bytes;
+        rv = SECITEM_CopyItem(nullptr, to, &result_item);
+    }
+    return rv;
+}
+#elif defined SVL_CRYPTO_MSCRYPTO
+/// Verifies a non-detached signature using CryptoAPI.
+bool VerifyNonDetachedSignature(const std::vector<unsigned char>& aData, const std::vector<BYTE>& rExpectedHash)
+{
+    HCRYPTPROV hProv = 0;
+    if (!CryptAcquireContextW(&hProv, nullptr, nullptr, PROV_RSA_AES, CRYPT_VERIFYCONTEXT))
+    {
+        SAL_WARN("svl.crypto", "CryptAcquireContext() failed");
+        return false;
+    }
+
+    HCRYPTHASH hHash = 0;
+    if (!CryptCreateHash(hProv, CALG_SHA1, 0, 0, &hHash))
+    {
+        SAL_WARN("svl.crypto", "CryptCreateHash() failed");
+        return false;
+    }
+
+    if (!CryptHashData(hHash, aData.data(), aData.size(), 0))
+    {
+        SAL_WARN("svl.crypto", "CryptHashData() failed");
+        return false;
+    }
+
+    DWORD nActualHash = 0;
+    if (!CryptGetHashParam(hHash, HP_HASHVAL, nullptr, &nActualHash, 0))
+    {
+        SAL_WARN("svl.crypto", "CryptGetHashParam() failed to provide the hash length");
+        return false;
+    }
+
+    std::vector<unsigned char> aActualHash(nActualHash);
+    if (!CryptGetHashParam(hHash, HP_HASHVAL, aActualHash.data(), &nActualHash, 0))
+    {
+        SAL_WARN("svl.crypto", "CryptGetHashParam() failed to provide the hash");
+        return false;
+    }
+
+    CryptDestroyHash(hHash);
+    CryptReleaseContext(hProv, 0);
+
+    return aActualHash.size() == rExpectedHash.size() &&
+           !std::memcmp(aActualHash.data(), rExpectedHash.data(), aActualHash.size());
+}
+
+OUString GetSubjectName(PCCERT_CONTEXT pCertContext)
+{
+    OUString subjectName;
+
+    // Get Subject name size.
+    DWORD dwData = CertGetNameStringW(pCertContext,
+                                      CERT_NAME_SIMPLE_DISPLAY_TYPE,
+                                      0,
+                                      nullptr,
+                                      nullptr,
+                                      0);
+    if (!dwData)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CertGetNameString failed");
+        return subjectName;
+    }
+
+    // Allocate memory for subject name.
+    LPWSTR szName = static_cast<LPWSTR>(
+        LocalAlloc(LPTR, dwData * sizeof(WCHAR)));
+    if (!szName)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: Unable to allocate memory for subject name");
+        return subjectName;
+    }
+
+    // Get subject name.
+    if (!CertGetNameStringW(pCertContext,
+                            CERT_NAME_SIMPLE_DISPLAY_TYPE,
+                            0,
+                            nullptr,
+                            szName,
+                            dwData))
+    {
+        LocalFree(szName);
+        SAL_WARN("svl.crypto", "ValidateSignature: CertGetNameString failed");
+        return subjectName;
+    }
+
+    subjectName = o3tl::toU(szName);
+    LocalFree(szName);
+
+    return subjectName;
+}
+
+#endif
+}
+
+#ifdef SVL_CRYPTO_NSS
+namespace
+{
+    void ensureNssInit()
+    {
+        // e.g. tdf#122599 ensure NSS library is initialized for NSS_CMSMessage_CreateFromDER
+        css::uno::Reference<css::xml::crypto::XNSSInitializer>
+            xNSSInitializer = css::xml::crypto::NSSInitializer::create(comphelper::getProcessComponentContext());
+
+        // this calls NSS_Init
+        xNSSInitializer->getDigestContext(css::xml::crypto::DigestID::SHA256,
+                                          uno::Sequence<beans::NamedValue>());
+    }
+}
+#endif
+
+bool Signing::Verify(const std::vector<unsigned char>& aData,
+                     const bool bNonDetached,
+                     const std::vector<unsigned char>& aSignature,
+                     SignatureInformation& rInformation)
+{
+#ifdef SVL_CRYPTO_NSS
+    // ensure NSS_Init() is called before using NSS_CMSMessage_CreateFromDER
+    static std::once_flag aInitOnce;
+    std::call_once(aInitOnce, ensureNssInit);
+
+    // Validate the signature.
+    SECItem aSignatureItem;
+    aSignatureItem.data = const_cast<unsigned char*>(aSignature.data());
+    aSignatureItem.len = aSignature.size();
+    NSSCMSMessage* pCMSMessage = NSS_CMSMessage_CreateFromDER(&aSignatureItem,
+                                 /*cb=*/nullptr,
+                                 /*cb_arg=*/nullptr,
+                                 /*pwfn=*/nullptr,
+                                 /*pwfn_arg=*/nullptr,
+                                 /*decrypt_key_cb=*/nullptr,
+                                 /*decrypt_key_cb_arg=*/nullptr);
+    if (!NSS_CMSMessage_IsSigned(pCMSMessage))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: message is not signed");
+        return false;
+    }
+
+    NSSCMSContentInfo* pCMSContentInfo = NSS_CMSMessage_ContentLevel(pCMSMessage, 0);
+    if (!pCMSContentInfo)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: NSS_CMSMessage_ContentLevel() failed");
+        return false;
+    }
+
+    auto pCMSSignedData = static_cast<NSSCMSSignedData*>(NSS_CMSContentInfo_GetContent(pCMSContentInfo));
+    if (!pCMSSignedData)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: NSS_CMSContentInfo_GetContent() failed");
+        return false;
+    }
+
+    // Import certificates from the signed data temporarily, so it'll be
+    // possible to verify the signature, even if we didn't have the certificate
+    // previously.
+    std::vector<CERTCertificate*> aDocumentCertificates;
+    for (size_t i = 0; pCMSSignedData->rawCerts[i]; ++i)
+        aDocumentCertificates.push_back(CERT_NewTempCertificate(CERT_GetDefaultCertDB(), pCMSSignedData->rawCerts[i], nullptr, 0, 0));
+
+    NSSCMSSignerInfo* pCMSSignerInfo = NSS_CMSSignedData_GetSignerInfo(pCMSSignedData, 0);
+    if (!pCMSSignerInfo)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: NSS_CMSSignedData_GetSignerInfo() failed");
+        return false;
+    }
+
+    SECItem aAlgorithm = NSS_CMSSignedData_GetDigestAlgs(pCMSSignedData)[0]->algorithm;
+    SECOidTag eOidTag = SECOID_FindOIDTag(&aAlgorithm);
+
+    // Map a sign algorithm to a digest algorithm.
+    // See NSS_CMSUtil_MapSignAlgs(), which is private to us.
+    switch (eOidTag)
+    {
+    case SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION:
+        eOidTag = SEC_OID_SHA1;
+        break;
+    case SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION:
+        eOidTag = SEC_OID_SHA256;
+        break;
+    case SEC_OID_PKCS1_SHA512_WITH_RSA_ENCRYPTION:
+        eOidTag = SEC_OID_SHA512;
+        break;
+    default:
+        break;
+    }
+
+    HASH_HashType eHashType = HASH_GetHashTypeByOidTag(eOidTag);
+    HASHContext* pHASHContext = HASH_Create(eHashType);
+    if (!pHASHContext)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: HASH_Create() failed");
+        return false;
+    }
+
+    // We have a hash, update it with the byte ranges.
+    HASH_Update(pHASHContext, aData.data(), aData.size());
+
+    // Find out what is the expected length of the hash.
+    unsigned int nMaxResultLen = 0;
+    switch (eOidTag)
+    {
+    case SEC_OID_SHA1:
+        nMaxResultLen = msfilter::SHA1_HASH_LENGTH;
+        rInformation.nDigestID = xml::crypto::DigestID::SHA1;
+        break;
+    case SEC_OID_SHA256:
+        nMaxResultLen = msfilter::SHA256_HASH_LENGTH;
+        rInformation.nDigestID = xml::crypto::DigestID::SHA256;
+        break;
+    case SEC_OID_SHA512:
+        nMaxResultLen = msfilter::SHA512_HASH_LENGTH;
+        rInformation.nDigestID = xml::crypto::DigestID::SHA512;
+        break;
+    default:
+        SAL_WARN("svl.crypto", "ValidateSignature: unrecognized algorithm");
+        return false;
+    }
+
+    auto pActualResultBuffer = static_cast<unsigned char*>(PORT_Alloc(nMaxResultLen));
+    unsigned int nActualResultLen;
+    HASH_End(pHASHContext, pActualResultBuffer, &nActualResultLen, nMaxResultLen);
+
+    CERTCertificate* pCertificate = NSS_CMSSignerInfo_GetSigningCertificate(pCMSSignerInfo, CERT_GetDefaultCertDB());
+    if (!pCertificate)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: NSS_CMSSignerInfo_GetSigningCertificate() failed");
+        return false;
+    }
+    else
+    {
+        uno::Sequence<sal_Int8> aDerCert(pCertificate->derCert.len);
+        for (size_t i = 0; i < pCertificate->derCert.len; ++i)
+            aDerCert[i] = pCertificate->derCert.data[i];
+        OUStringBuffer aBuffer;
+        comphelper::Base64::encode(aBuffer, aDerCert);
+        rInformation.ouX509Certificate = aBuffer.makeStringAndClear();
+        rInformation.ouSubject = OUString(pCertificate->subjectName, PL_strlen(pCertificate->subjectName), RTL_TEXTENCODING_UTF8);
+    }
+
+    PRTime nSigningTime;
+    // This may fail, in which case the date should be taken from the PDF's dictionary's "M" key,
+    // so not critical for PDF at least.
+    if (NSS_CMSSignerInfo_GetSigningTime(pCMSSignerInfo, &nSigningTime) == SECSuccess)
+    {
+        // First convert the UTC UNIX timestamp to a tools::DateTime.
+        // nSigningTime is in microseconds.
+        DateTime aDateTime = DateTime::CreateFromUnixTime(static_cast<double>(nSigningTime) / 1000000);
+
+        // Then convert to a local UNO DateTime.
+        aDateTime.ConvertToLocalTime();
+        rInformation.stDateTime = aDateTime.GetUNODateTime();
+        if (rInformation.ouDateTime.isEmpty())
+        {
+            OUStringBuffer rBuffer;
+            rBuffer.append(static_cast<sal_Int32>(aDateTime.GetYear()));
+            rBuffer.append('-');
+            if (aDateTime.GetMonth() < 10)
+                rBuffer.append('0');
+            rBuffer.append(static_cast<sal_Int32>(aDateTime.GetMonth()));
+            rBuffer.append('-');
+            if (aDateTime.GetDay() < 10)
+                rBuffer.append('0');
+            rBuffer.append(static_cast<sal_Int32>(aDateTime.GetDay()));
+            rInformation.ouDateTime = rBuffer.makeStringAndClear();
+        }
+    }
+
+    // Check if we have a signing certificate attribute.
+    SECOidData aOidData;
+    aOidData.oid.data = nullptr;
+    /*
+     * id-aa-signingCertificateV2 OBJECT IDENTIFIER ::=
+     * { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
+     *   smime(16) id-aa(2) 47 }
+     */
+    if (StringToOID(&aOidData.oid, "1.2.840.113549.1.9.16.2.47", 0) != SECSuccess)
+    {
+        SAL_WARN("svl.crypto", "StringToOID() failed");
+        return false;
+    }
+    aOidData.offset = SEC_OID_UNKNOWN;
+    aOidData.desc = "id-aa-signingCertificateV2";
+    aOidData.mechanism = CKM_SHA_1;
+    aOidData.supportedExtension = UNSUPPORTED_CERT_EXTENSION;
+    NSSCMSAttribute* pAttribute = CMSAttributeArray_FindAttrByOidData(pCMSSignerInfo->authAttr, &aOidData, PR_TRUE);
+    if (pAttribute)
+        rInformation.bHasSigningCertificate = true;
+
+    SECItem* pContentInfoContentData = pCMSSignedData->contentInfo.content.data;
+    if (bNonDetached && pContentInfoContentData && pContentInfoContentData->data)
+    {
+        // Not a detached signature.
+        if (!std::memcmp(pActualResultBuffer, pContentInfoContentData->data, nMaxResultLen) && nActualResultLen == pContentInfoContentData->len)
+            rInformation.nStatus = xml::crypto::SecurityOperationStatus_OPERATION_SUCCEEDED;
+    }
+    else
+    {
+        // Detached, the usual case.
+        SECItem aActualResultItem;
+        aActualResultItem.data = pActualResultBuffer;
+        aActualResultItem.len = nActualResultLen;
+        if (NSS_CMSSignerInfo_Verify(pCMSSignerInfo, &aActualResultItem, nullptr) == SECSuccess)
+            rInformation.nStatus = xml::crypto::SecurityOperationStatus_OPERATION_SUCCEEDED;
+    }
+
+    // Everything went fine
+    PORT_Free(pActualResultBuffer);
+    HASH_Destroy(pHASHContext);
+    NSS_CMSSignerInfo_Destroy(pCMSSignerInfo);
+    for (auto pDocumentCertificate : aDocumentCertificates)
+        CERT_DestroyCertificate(pDocumentCertificate);
+
+    return true;
+
+#elif defined SVL_CRYPTO_MSCRYPTO
+    // Open a message for decoding.
+    HCRYPTMSG hMsg = CryptMsgOpenToDecode(PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                          CMSG_DETACHED_FLAG,
+                                          0,
+                                          NULL,
+                                          nullptr,
+                                          nullptr);
+    if (!hMsg)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgOpenToDecode() failed");
+        return false;
+    }
+
+    // Update the message with the encoded header blob.
+    if (!CryptMsgUpdate(hMsg, aSignature.data(), aSignature.size(), TRUE))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature, CryptMsgUpdate() for the header failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    // Update the message with the content blob.
+    if (!CryptMsgUpdate(hMsg, aData.data(), aData.size(), FALSE))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature, CryptMsgUpdate() for the content failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    if (!CryptMsgUpdate(hMsg, nullptr, 0, TRUE))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature, CryptMsgUpdate() for the last content failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+
+    // Get the CRYPT_ALGORITHM_IDENTIFIER from the message.
+    DWORD nDigestID = 0;
+    if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_HASH_ALGORITHM_PARAM, 0, nullptr, &nDigestID))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+    std::unique_ptr<BYTE[]> pDigestBytes(new BYTE[nDigestID]);
+    if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_HASH_ALGORITHM_PARAM, 0, pDigestBytes.get(), &nDigestID))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed: " << WindowsErrorString(GetLastError()));
+        return false;
+    }
+    auto pDigestID = reinterpret_cast<CRYPT_ALGORITHM_IDENTIFIER*>(pDigestBytes.get());
+    if (OString(szOID_NIST_sha256) == pDigestID->pszObjId)
+        rInformation.nDigestID = xml::crypto::DigestID::SHA256;
+    else if (OString(szOID_RSA_SHA1RSA) == pDigestID->pszObjId || OString(szOID_OIWSEC_sha1) == pDigestID->pszObjId)
+        rInformation.nDigestID = xml::crypto::DigestID::SHA1;
+    else
+        // Don't error out here, we can still verify the message digest correctly, just the digest ID won't be set.
+        SAL_WARN("svl.crypto", "ValidateSignature: unhandled algorithm identifier '"<<pDigestID->pszObjId<<"'");
+
+    // Get the signer CERT_INFO from the message.
+    DWORD nSignerCertInfo = 0;
+    if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_CERT_INFO_PARAM, 0, nullptr, &nSignerCertInfo))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed");
+        return false;
+    }
+    std::unique_ptr<BYTE[]> pSignerCertInfoBuf(new BYTE[nSignerCertInfo]);
+    if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_CERT_INFO_PARAM, 0, pSignerCertInfoBuf.get(), &nSignerCertInfo))
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed");
+        return false;
+    }
+    PCERT_INFO pSignerCertInfo = reinterpret_cast<PCERT_INFO>(pSignerCertInfoBuf.get());
+
+    // Open a certificate store in memory using CERT_STORE_PROV_MSG, which
+    // initializes it with the certificates from the message.
+    HCERTSTORE hStoreHandle = CertOpenStore(CERT_STORE_PROV_MSG,
+                                            PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                            NULL,
+                                            0,
+                                            hMsg);
+    if (!hStoreHandle)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CertOpenStore() failed");
+        return false;
+    }
+
+    // Find the signer's certificate in the store.
+    PCCERT_CONTEXT pSignerCertContext = CertGetSubjectCertificateFromStore(hStoreHandle,
+                                        PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+                                        pSignerCertInfo);
+    if (!pSignerCertContext)
+    {
+        SAL_WARN("svl.crypto", "ValidateSignature: CertGetSubjectCertificateFromStore() failed");
+        return false;
+    }
+    else
+    {
+        // Write rInformation.ouX509Certificate.
+        uno::Sequence<sal_Int8> aDerCert(pSignerCertContext->cbCertEncoded);
+        for (size_t i = 0; i < pSignerCertContext->cbCertEncoded; ++i)
+            aDerCert[i] = pSignerCertContext->pbCertEncoded[i];
+        OUStringBuffer aBuffer;
+        comphelper::Base64::encode(aBuffer, aDerCert);
+        rInformation.ouX509Certificate = aBuffer.makeStringAndClear();
+        rInformation.ouSubject = GetSubjectName(pSignerCertContext);
+    }
+
+    if (bNonDetached)
+    {
+        // Not a detached signature.
+        DWORD nContentParam = 0;
+        if (!CryptMsgGetParam(hMsg, CMSG_CONTENT_PARAM, 0, nullptr, &nContentParam))
+        {
+            SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed");
+            return false;
+        }
+
+        std::vector<BYTE> aContentParam(nContentParam);
+        if (!CryptMsgGetParam(hMsg, CMSG_CONTENT_PARAM, 0, aContentParam.data(), &nContentParam))
+        {
+            SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() failed");
+            return false;
+        }
+
+        if (VerifyNonDetachedSignature(aData, aContentParam))
+            rInformation.nStatus = xml::crypto::SecurityOperationStatus_OPERATION_SUCCEEDED;
+    }
+    else
+    {
+        // Detached, the usual case.
+        // Use the CERT_INFO from the signer certificate to verify the signature.
+        if (CryptMsgControl(hMsg, 0, CMSG_CTRL_VERIFY_SIGNATURE, pSignerCertContext->pCertInfo))
+            rInformation.nStatus = xml::crypto::SecurityOperationStatus_OPERATION_SUCCEEDED;
+    }
+
+    // Check if we have a signing certificate attribute.
+    DWORD nSignedAttributes = 0;
+    if (CryptMsgGetParam(hMsg, CMSG_SIGNER_AUTH_ATTR_PARAM, 0, nullptr, &nSignedAttributes))
+    {
+        std::unique_ptr<BYTE[]> pSignedAttributesBuf(new BYTE[nSignedAttributes]);
+        if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_AUTH_ATTR_PARAM, 0, pSignedAttributesBuf.get(), &nSignedAttributes))
+        {
+            SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() authenticated failed");
+            return false;
+        }
+        auto pSignedAttributes = reinterpret_cast<PCRYPT_ATTRIBUTES>(pSignedAttributesBuf.get());
+        for (size_t nAttr = 0; nAttr < pSignedAttributes->cAttr; ++nAttr)
+        {
+            CRYPT_ATTRIBUTE& rAttr = pSignedAttributes->rgAttr[nAttr];
+            /*
+             * id-aa-signingCertificateV2 OBJECT IDENTIFIER ::=
+             * { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
+             *   smime(16) id-aa(2) 47 }
+             */
+            if (OString("1.2.840.113549.1.9.16.2.47") == rAttr.pszObjId)
+            {
+                rInformation.bHasSigningCertificate = true;
+                break;
+            }
+        }
+    }
+
+    // Get the unauthorized attributes.
+    nSignedAttributes = 0;
+    if (CryptMsgGetParam(hMsg, CMSG_SIGNER_UNAUTH_ATTR_PARAM, 0, nullptr, &nSignedAttributes))
+    {
+        std::unique_ptr<BYTE[]> pSignedAttributesBuf(new BYTE[nSignedAttributes]);
+        if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_UNAUTH_ATTR_PARAM, 0, pSignedAttributesBuf.get(), &nSignedAttributes))
+        {
+            SAL_WARN("svl.crypto", "ValidateSignature: CryptMsgGetParam() unauthenticated failed");
+            return false;
+        }
+        auto pSignedAttributes = reinterpret_cast<PCRYPT_ATTRIBUTES>(pSignedAttributesBuf.get());
+        for (size_t nAttr = 0; nAttr < pSignedAttributes->cAttr; ++nAttr)
+        {
+            CRYPT_ATTRIBUTE& rAttr = pSignedAttributes->rgAttr[nAttr];
+            // Timestamp blob
+            if (OString("1.2.840.113549.1.9.16.2.14") == rAttr.pszObjId)
+            {
+                PCRYPT_TIMESTAMP_CONTEXT pTsContext;
+                if (!CryptVerifyTimeStampSignature(rAttr.rgValue->pbData, rAttr.rgValue->cbData, nullptr, 0, nullptr, &pTsContext, nullptr, nullptr))
+                {
+                    SAL_WARN("svl.crypto", "CryptMsgUpdate failed: " << WindowsErrorString(GetLastError()));
+                    break;
+                }
+
+                DateTime aDateTime = DateTime::CreateFromWin32FileDateTime(pTsContext->pTimeStamp->ftTime.dwLowDateTime, pTsContext->pTimeStamp->ftTime.dwHighDateTime);
+
+                // Then convert to a local UNO DateTime.
+                aDateTime.ConvertToLocalTime();
+                rInformation.stDateTime = aDateTime.GetUNODateTime();
+                if (rInformation.ouDateTime.isEmpty())
+                {
+                    OUStringBuffer rBuffer;
+                    rBuffer.append(static_cast<sal_Int32>(aDateTime.GetYear()));
+                    rBuffer.append('-');
+                    if (aDateTime.GetMonth() < 10)
+                        rBuffer.append('0');
+                    rBuffer.append(static_cast<sal_Int32>(aDateTime.GetMonth()));
+                    rBuffer.append('-');
+                    if (aDateTime.GetDay() < 10)
+                        rBuffer.append('0');
+                    rBuffer.append(static_cast<sal_Int32>(aDateTime.GetDay()));
+                    rInformation.ouDateTime = rBuffer.makeStringAndClear();
+                }
+                break;
+            }
+        }
+    }
+
+    CertCloseStore(hStoreHandle, CERT_CLOSE_STORE_FORCE_FLAG);
+    CryptMsgClose(hMsg);
+    return true;
+#else
+    // Not implemented.
+    (void)aData;
+    (void)bNonDetached;
+    (void)aSignature;
+    (void)rInformation;
+    return false;
+#endif
+}
+
+bool Signing::Verify(SvStream& rStream,
+                     const std::vector<std::pair<size_t, size_t>>& aByteRanges,
+                     const bool bNonDetached,
+                     const std::vector<unsigned char>& aSignature,
+                     SignatureInformation& rInformation)
+{
+#if defined(SVL_CRYPTO_NSS) || defined(SVL_CRYPTO_MSCRYPTO)
+
+    std::vector<unsigned char> buffer;
+
+    // Copy the byte ranges into a single buffer.
+    for (const auto& rByteRange : aByteRanges)
+    {
+        rStream.Seek(rByteRange.first);
+        const size_t size = buffer.size();
+        buffer.resize(size + rByteRange.second);
+        rStream.ReadBytes(buffer.data() + size, rByteRange.second);
+    }
+
+    return Verify(buffer, bNonDetached, aSignature, rInformation);
+
+#else
+    // Not implemented.
+    (void)rStream;
+    (void)aByteRanges;
+    (void)bNonDetached;
+    (void)aSignature;
+    (void)rInformation;
+    return false;
+#endif
+}
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */