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ANSI X9.63 key derivation functions for CKM_ECDH1_DERIVE #599

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ANSI X9.63 key derivation functions for CKM_ECDH1_DERIVE #599

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5c8d939
Implement key derivation functions for CKM_ECDH1_DERIVE
Aearsis Jan 27, 2021
6207282
Add tests for ECDH with KDFs
Aearsis Jan 27, 2021
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198 changes: 166 additions & 32 deletions src/lib/SoftHSM.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -10607,29 +10607,52 @@ CK_RV SoftHSM::deriveECDH
CK_BBOOL isPrivate)
{
*phKey = CK_INVALID_HANDLE;
HashAlgorithm* kdfAlgorithm = NULL;

if ((pMechanism->pParameter == NULL_PTR) ||
(pMechanism->ulParameterLen != sizeof(CK_ECDH1_DERIVE_PARAMS)))
{
DEBUG_MSG("pParameter must be of type CK_ECDH1_DERIVE_PARAMS");
return CKR_MECHANISM_PARAM_INVALID;
}
if (CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->kdf != CKD_NULL)
{
DEBUG_MSG("kdf must be CKD_NULL");
return CKR_MECHANISM_PARAM_INVALID;
}
if ((CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulSharedDataLen != 0) ||
(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pSharedData != NULL_PTR))

CK_ECDH1_DERIVE_PARAMS_PTR ecdhParams = CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter);

if ((ecdhParams->ulPublicDataLen == 0) ||
(ecdhParams->pPublicData == NULL_PTR))
{
DEBUG_MSG("there must be no shared data");
DEBUG_MSG("there must be a public data");
return CKR_MECHANISM_PARAM_INVALID;
}
if ((CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen == 0) ||
(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pPublicData == NULL_PTR))

switch (ecdhParams->kdf)
{
DEBUG_MSG("there must be a public data");
return CKR_MECHANISM_PARAM_INVALID;
case CKD_NULL:
if ((ecdhParams->ulSharedDataLen != 0) ||
(ecdhParams->pSharedData != NULL_PTR))
{
DEBUG_MSG("there must be no shared data when KDF is CKD_NULL");
return CKR_MECHANISM_PARAM_INVALID;
}
break;
case CKD_SHA1_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA1);
break;
case CKD_SHA224_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA224);
break;
case CKD_SHA256_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA256);
break;
case CKD_SHA384_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA384);
break;
case CKD_SHA512_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA512);
break;
default:
DEBUG_MSG("Unknown KDF");
return CKR_MECHANISM_PARAM_INVALID;
}

// Get the session
Expand Down Expand Up @@ -10678,6 +10701,14 @@ CK_RV SoftHSM::deriveECDH
switch (keyType)
{
case CKK_GENERIC_SECRET:
if (kdfAlgorithm != NULL) {
const size_t maxLen = kdfAlgorithm->getHashSize() * (1UL << 32);
if (byteLen > maxLen)
{
INFO_MSG("CKA_VALUE_LEN must be at most %zu", maxLen);
return CKR_ATTRIBUTE_VALUE_INVALID;
}
}
break;
#ifndef WITH_FIPS
case CKK_DES:
Expand Down Expand Up @@ -10741,10 +10772,8 @@ CK_RV SoftHSM::deriveECDH
}

ByteString publicData;
publicData.resize(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen);
memcpy(&publicData[0],
CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pPublicData,
CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen);
publicData.resize(ecdhParams->ulPublicDataLen);
memcpy(&publicData[0], ecdhParams->pPublicData, ecdhParams->ulPublicDataLen);
PublicKey* publicKey = ecdh->newPublicKey();
if (publicKey == NULL)
{
Expand All @@ -10768,6 +10797,44 @@ CK_RV SoftHSM::deriveECDH
ecdh->recyclePrivateKey(privateKey);
ecdh->recyclePublicKey(publicKey);

// Apply key derivation function (ANSI X9.63)
if (rv == CKR_OK && kdfAlgorithm != NULL) {
const ByteString& secretBits = secret->getKeyBits();
const size_t counterOffset = secretBits.size();
unsigned long counter = 1;

ByteString hashInput;
hashInput.resize(secretBits.size() + 4 + ecdhParams->ulSharedDataLen);

// Prepare hash input content - derived secret, 4 bytes for counter, shared data
memcpy(&hashInput[0], secretBits.const_byte_str(), secretBits.size());
memcpy(&hashInput[secretBits.size() + 4], ecdhParams->pSharedData, ecdhParams->ulSharedDataLen);

ByteString hashOutput;
ByteString derivedOutput;

while (derivedOutput.size() < byteLen) {
hashInput[counterOffset + 0] = (counter >> 48) & 0xFF;
hashInput[counterOffset + 1] = (counter >> 32) & 0xFF;
hashInput[counterOffset + 2] = (counter >> 16) & 0xFF;
hashInput[counterOffset + 3] = (counter >> 0) & 0xFF;

kdfAlgorithm->hashInit();
kdfAlgorithm->hashUpdate(hashInput);
kdfAlgorithm->hashFinal(hashOutput);

derivedOutput += hashOutput;
counter++;
}

// Trim to desired length
derivedOutput.resize(byteLen);

secret->setBitLen(byteLen * 8);
if (!secret->setKeyBits(derivedOutput))
rv = CKR_FUNCTION_FAILED;
}

// Create the secret object using C_CreateObject
const CK_ULONG maxAttribs = 32;
CK_OBJECT_CLASS objClass = CKO_SECRET_KEY;
Expand Down Expand Up @@ -10961,29 +11028,52 @@ CK_RV SoftHSM::deriveEDDSA
CK_BBOOL isPrivate)
{
*phKey = CK_INVALID_HANDLE;
HashAlgorithm* kdfAlgorithm = NULL;

if ((pMechanism->pParameter == NULL_PTR) ||
(pMechanism->ulParameterLen != sizeof(CK_ECDH1_DERIVE_PARAMS)))
{
DEBUG_MSG("pParameter must be of type CK_ECDH1_DERIVE_PARAMS");
return CKR_MECHANISM_PARAM_INVALID;
}
if (CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->kdf != CKD_NULL)
{
DEBUG_MSG("kdf must be CKD_NULL");
return CKR_MECHANISM_PARAM_INVALID;
}
if ((CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulSharedDataLen != 0) ||
(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pSharedData != NULL_PTR))

CK_ECDH1_DERIVE_PARAMS_PTR ecdhParams = CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter);

if ((ecdhParams->ulPublicDataLen == 0) ||
(ecdhParams->pPublicData == NULL_PTR))
{
DEBUG_MSG("there must be no shared data");
DEBUG_MSG("there must be a public data");
return CKR_MECHANISM_PARAM_INVALID;
}
if ((CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen == 0) ||
(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pPublicData == NULL_PTR))

switch (ecdhParams->kdf)
{
DEBUG_MSG("there must be a public data");
return CKR_MECHANISM_PARAM_INVALID;
case CKD_NULL:
if ((ecdhParams->ulSharedDataLen != 0) ||
(ecdhParams->pSharedData != NULL_PTR))
{
DEBUG_MSG("there must be no shared data when KDF is CKD_NULL");
return CKR_MECHANISM_PARAM_INVALID;
}
break;
case CKD_SHA1_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA1);
break;
case CKD_SHA224_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA224);
break;
case CKD_SHA256_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA256);
break;
case CKD_SHA384_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA384);
break;
case CKD_SHA512_KDF:
kdfAlgorithm = CryptoFactory::i()->getHashAlgorithm(HashAlgo::SHA512);
break;
default:
DEBUG_MSG("Unknown KDF");
return CKR_MECHANISM_PARAM_INVALID;
}

// Get the session
Expand Down Expand Up @@ -11032,6 +11122,14 @@ CK_RV SoftHSM::deriveEDDSA
switch (keyType)
{
case CKK_GENERIC_SECRET:
if (kdfAlgorithm != NULL) {
const size_t maxLen = kdfAlgorithm->getHashSize() * (1UL << 32);
if (byteLen > maxLen)
{
INFO_MSG("CKA_VALUE_LEN must be at most %zu", maxLen);
return CKR_ATTRIBUTE_VALUE_INVALID;
}
}
break;
#ifndef WITH_FIPS
case CKK_DES:
Expand Down Expand Up @@ -11095,10 +11193,8 @@ CK_RV SoftHSM::deriveEDDSA
}

ByteString publicData;
publicData.resize(CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen);
memcpy(&publicData[0],
CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->pPublicData,
CK_ECDH1_DERIVE_PARAMS_PTR(pMechanism->pParameter)->ulPublicDataLen);
publicData.resize(ecdhParams->ulPublicDataLen);
memcpy(&publicData[0], ecdhParams->pPublicData, ecdhParams->ulPublicDataLen);
PublicKey* publicKey = eddsa->newPublicKey();
if (publicKey == NULL)
{
Expand All @@ -11122,6 +11218,44 @@ CK_RV SoftHSM::deriveEDDSA
eddsa->recyclePrivateKey(privateKey);
eddsa->recyclePublicKey(publicKey);

// Apply key derivation function (ANSI X9.63)
if (rv == CKR_OK && kdfAlgorithm != NULL) {
const ByteString& secretBits = secret->getKeyBits();
const size_t counterOffset = secretBits.size();
unsigned long counter = 1;

ByteString hashInput;
hashInput.resize(secretBits.size() + 4 + ecdhParams->ulSharedDataLen);

// Prepare hash input content - derived secret, 4 bytes for counter, shared data
memcpy(&hashInput[0], secretBits.const_byte_str(), secretBits.size());
memcpy(&hashInput[secretBits.size() + 4], ecdhParams->pSharedData, ecdhParams->ulSharedDataLen);

ByteString hashOutput;
ByteString derivedOutput;

while (derivedOutput.size() < byteLen) {
hashInput[counterOffset + 0] = (counter >> 48) & 0xFF;
hashInput[counterOffset + 1] = (counter >> 32) & 0xFF;
hashInput[counterOffset + 2] = (counter >> 16) & 0xFF;
hashInput[counterOffset + 3] = (counter >> 0) & 0xFF;

kdfAlgorithm->hashInit();
kdfAlgorithm->hashUpdate(hashInput);
kdfAlgorithm->hashFinal(hashOutput);

derivedOutput += hashOutput;
counter++;
}

// Trim to desired length
derivedOutput.resize(byteLen);

secret->setBitLen(byteLen * 8);
if (!secret->setKeyBits(derivedOutput))
rv = CKR_FUNCTION_FAILED;
}

// Create the secret object using C_CreateObject
const CK_ULONG maxAttribs = 32;
CK_OBJECT_CLASS objClass = CKO_SECRET_KEY;
Expand Down
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