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Fix signature hash on NSS backend

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When using the NSS backend, the SignedAttributes were added after the hash
computation for the timestamp request, altering the final signature and
rendering the timestamp unverifiable.
This patch changes the order in which the attributes are added and uses a copy
of the signer for the hash computation in order to generate a correct hash.

Change-Id: I14cecf1819e80d7a2e470e0f1dee2d09bcbe852c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/171384
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>
This commit is contained in:
Eloi Montañés
2024-09-04 10:46:25 +02:00
committed by Michael Stahl
parent 87bfd87ecf
commit 16a9df3638
1 changed files with 78 additions and 75 deletions
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svl/source/crypto/cryptosign.cxx
+78 -75
View File
@@ -988,6 +988,81 @@ bool Signing::Sign(OStringBuffer& rCMSHexBuffer)
OString pass(OUStringToOString( m_aSignPassword, RTL_TEXTENCODING_UTF8 ));
// 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);
comphelper::ScopeGuard aAlgoGuard(
[&aCertID] () { SECOID_DestroyAlgorithmID(&aCertID.hashAlgorithm, false); } );
// 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;
}
comphelper::ScopeGuard aGuard(
[&aOidData] () { SECITEM_FreeItem(&aOidData.oid, 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;
}
TimeStampReq src;
OStringBuffer response_buffer;
TimeStampResp response;
@@ -999,6 +1074,7 @@ bool Signing::Sign(OStringBuffer& rCMSHexBuffer)
valuesp[1] = nullptr;
SECOidData typetag;
//NOTE: All signed/authenticated attributes are to be added before the following hash computation
if( !m_aSignTSA.isEmpty() )
{
// Create another CMS message with the same contents as cms_msg, because it doesn't seem
@@ -1013,6 +1089,8 @@ bool Signing::Sign(OStringBuffer& rCMSHexBuffer)
return false;
}
PORT_Memcpy(ts_cms_signer, cms_signer, sizeof(NSSCMSSignerInfo));
SECItem ts_cms_output;
ts_cms_output.data = nullptr;
ts_cms_output.len = 0;
@@ -1233,81 +1311,6 @@ bool Signing::Sign(OStringBuffer& rCMSHexBuffer)
}
}
// 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);
comphelper::ScopeGuard aAlgoGuard(
[&aCertID] () { SECOID_DestroyAlgorithmID(&aCertID.hashAlgorithm, false); } );
// 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;
}
comphelper::ScopeGuard aGuard(
[&aOidData] () { SECITEM_FreeItem(&aOidData.oid, 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;