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introduce sign tx usecase
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@janmazak
janmazak committed Apr 10, 2021
1 parent 95fd07a commit 7583ed3
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Showing 4 changed files with 227 additions and 98 deletions.
200 changes: 143 additions & 57 deletions src/securityPolicy.c
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Expand Up @@ -36,18 +36,6 @@ static inline bool is_valid_stake_pool_owner_path(const bip44_path_t* pathSpec)
return bip44_isValidStakingKeyPath(pathSpec);
}

// general requirements on witnesses
static inline bool is_valid_witness(const bip44_path_t* pathSpec)
{
if (!bip44_hasValidCardanoPrefix(pathSpec))
return false;

if (bip44_isValidStakingKeyPath(pathSpec))
return true;

return bip44_isValidAddressPath(pathSpec);
}

// account is from a small brute-forcable range
static inline bool has_reasonable_account(const bip44_path_t* pathSpec)
{
Expand All @@ -72,12 +60,26 @@ static inline bool is_too_deep(const bip44_path_t* pathSpec)
}

bool is_tx_network_verifiable(
sign_tx_usecase_t signTxUsecase,
uint16_t numOutputs,
uint16_t numWithdrawals,
bool isSigningPoolRegistrationAsOwner
uint16_t numWithdrawals
)
{
return (numOutputs > 0) || (numWithdrawals > 0) || (isSigningPoolRegistrationAsOwner);
if (numOutputs > 0) return true;
if (numWithdrawals > 0) return true;

switch (signTxUsecase) {

#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
#endif
case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER:
// pool registration certificate contains pool reward account
return true;

default:
return false;
}
}


Expand Down Expand Up @@ -174,18 +176,18 @@ security_policy_t policyForShowDeriveAddress(const addressParams_t* addressParam

// Initiate transaction signing
security_policy_t policyForSignTxInit(
sign_tx_usecase_t signTxUsecase,
uint8_t networkId,
uint32_t protocolMagic,
uint16_t numOutputs,
uint16_t numWithdrawals,
bool isSigningPoolRegistrationAsOwner
uint16_t numWithdrawals
)
{
// Deny shelley mainnet with weird byron protocol magic
DENY_IF(networkId == MAINNET_NETWORK_ID && protocolMagic != MAINNET_PROTOCOL_MAGIC);
// Note: testnets can still use byron mainnet protocol magic so we can't deny the opposite direction

WARN_IF(!is_tx_network_verifiable(numOutputs, numWithdrawals, isSigningPoolRegistrationAsOwner));
WARN_IF(!is_tx_network_verifiable(numOutputs, numWithdrawals, signTxUsecase));

WARN_IF(networkId != MAINNET_NETWORK_ID);
WARN_IF(protocolMagic != MAINNET_PROTOCOL_MAGIC);
Expand All @@ -203,16 +205,12 @@ security_policy_t policyForSignTxInput()

// For each transaction (third-party) address output
security_policy_t policyForSignTxOutputAddressBytes(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const uint8_t* rawAddressBuffer, size_t rawAddressSize,
const uint8_t networkId, const uint32_t protocolMagic
)
{
TRACE("isSigningPoolRegistrationAsOwner = %d", isSigningPoolRegistrationAsOwner);

ALLOW_IF(isSigningPoolRegistrationAsOwner);

// network identification should be consistent across tx
// network identification must be consistent across tx
ASSERT(rawAddressSize >= 1);
address_type_t addressType = getAddressType(rawAddressBuffer[0]);
if (addressType == BYRON) {
Expand All @@ -224,37 +222,69 @@ security_policy_t policyForSignTxOutputAddressBytes(
DENY_IF(addressType == REWARD);
}

// We always show third-party output addresses
SHOW();
switch (signTxUsecase) {
case SIGN_TX_USECASE_ORDINARY_TX:
// We always show third-party output addresses
SHOW();

case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER:
// all the funds are provided by the operator
// and thus outputs are irrelevant to the owner
ALLOW();

#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
SHOW();
#endif

default:
ASSERT(false);
}

DENY(); // should not be reached
}

// For each output given by derivation path
security_policy_t policyForSignTxOutputAddressParams(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const addressParams_t* params,
const uint8_t networkId, const uint32_t protocolMagic
)
{
// we forbid these to avoid leaking information
// (since the outputs are not shown, the user is unaware of what addresses are being derived)
// it also makes the tx signing faster if all outputs are given as addresses
DENY_IF(isSigningPoolRegistrationAsOwner);

DENY_UNLESS(isValidAddressParams(params));

DENY_IF(is_too_deep(&params->spendingKeyPath));

// network identification should be consistent across tx
if (params->type == BYRON) {
DENY_IF(params->protocolMagic != protocolMagic);
} else { // shelley
DENY_IF(params->networkId != networkId);
}

SHOW_UNLESS(has_reasonable_account_and_address(&params->spendingKeyPath));
SHOW_UNLESS(is_standard_base_address(params));
switch (signTxUsecase) {

ALLOW();
#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
#endif
case SIGN_TX_USECASE_ORDINARY_TX: {
DENY_IF(is_too_deep(&params->spendingKeyPath));

SHOW_UNLESS(has_reasonable_account_and_address(&params->spendingKeyPath));
SHOW_UNLESS(is_standard_base_address(params));

ALLOW();
}
case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER: {
// we forbid these to avoid leaking information
// (since the outputs are not shown, the user is unaware of what addresses are being derived)
// it also makes the tx signing faster if all outputs are given as addresses
DENY();
}
default: {
ASSERT(false);
}
}

DENY(); // should not be reached
}

security_policy_t policyForSignTxOutputConfirm(
Expand All @@ -280,12 +310,29 @@ security_policy_t policyForSignTxOutputConfirm(
}

// For transaction fee
security_policy_t policyForSignTxFee(bool isSigningPoolRegistrationAsOwner, uint64_t fee MARK_UNUSED)
security_policy_t policyForSignTxFee(
sign_tx_usecase_t signTxUsecase,
uint64_t fee MARK_UNUSED
)
{
ALLOW_IF(isSigningPoolRegistrationAsOwner);
switch (signTxUsecase) {

// always show the fee in ordinary transactions
SHOW();
#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
#endif
case SIGN_TX_USECASE_ORDINARY_TX:
// always show the fee in ordinary transactions
SHOW();

case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER:
// fees are paid by the operator and are thus irrelevant for owners
ALLOW();

default:
ASSERT(false);
}

DENY(); // should not be reached
}

// For transaction TTL
Expand All @@ -302,21 +349,29 @@ security_policy_t policyForSignTxTtl(uint32_t ttl)
}

// a generic policy for all certificates
// does not evaluate all aspects for specific certificates
// does not evaluate aspects of specific certificates
security_policy_t policyForSignTxCertificate(
const bool includeStakePoolRegistrationCertificate,
sign_tx_usecase_t signTxUsecase,
const certificate_type_t certificateType
)
{
if (includeStakePoolRegistrationCertificate) {
DENY_UNLESS(certificateType == CERTIFICATE_TYPE_STAKE_POOL_REGISTRATION);

ALLOW();
} else {
switch (signTxUsecase) {
case SIGN_TX_USECASE_ORDINARY_TX:
DENY_IF(certificateType == CERTIFICATE_TYPE_STAKE_POOL_REGISTRATION);
ALLOW();

#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
#endif
case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER:
DENY_UNLESS(certificateType == CERTIFICATE_TYPE_STAKE_POOL_REGISTRATION);
ALLOW();

default:
ASSERT(false);
}

DENY(); // should not be reached
}

// for certificates concerning staking keys and stake delegation
Expand Down Expand Up @@ -385,26 +440,57 @@ security_policy_t policyForSignTxWithdrawal()
SHOW();
}

static inline bool is_valid_input_witness(const bip44_path_t* pathSpec)
{
return bip44_isValidAddressPath(pathSpec);
}

static inline bool is_valid_withdrawal_witness(const bip44_path_t* pathSpec)
{
return bip44_isValidStakingKeyPath(pathSpec);
}

// For each transaction witness
// Note: witnesses reveal public key of an address
// and Ledger *does not* check whether they correspond to previously declared UTxOs
security_policy_t policyForSignTxWitness(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const bip44_path_t* pathSpec
)
{
DENY_UNLESS(is_valid_witness(pathSpec));
switch (signTxUsecase) {

case SIGN_TX_USECASE_ORDINARY_TX:
if (is_valid_input_witness(pathSpec)) {
DENY_IF(is_too_deep(pathSpec));
WARN_UNLESS(has_reasonable_account_and_address(pathSpec));
ALLOW();

} else if (is_valid_withdrawal_witness(pathSpec)) {
WARN_UNLESS(has_reasonable_account(pathSpec));
ALLOW();

} else {
DENY();
}

if (isSigningPoolRegistrationAsOwner) {
case SIGN_TX_USECASE_POOL_REGISTRATION_OWNER:
DENY_UNLESS(is_valid_stake_pool_owner_path(pathSpec));
} else {
// witness for input or withdrawal
DENY_IF(is_too_deep(pathSpec));
}
WARN_UNLESS(has_reasonable_account(pathSpec));
ALLOW();
break;

WARN_UNLESS(has_reasonable_account_and_address(pathSpec));
#ifdef POOL_OPERATOR_APP
case SIGN_TX_USECASE_POOL_REGISTRATION_OPERATOR:
// TODO there could be two witnesses, one for pool key, one for pool owner
break;
#endif

ALLOW();
default:
ASSERT(false);
}

DENY(); // should not be reached
}

security_policy_t policyForSignTxMetadata()
Expand Down
18 changes: 9 additions & 9 deletions src/securityPolicy.h
View file
Expand Up @@ -24,22 +24,22 @@ security_policy_t policyForReturnDeriveAddress(const addressParams_t* addressPar


security_policy_t policyForSignTxInit(
sign_tx_usecase_t signTxUsecase,
uint8_t networkId,
uint32_t protocolMagic,
uint16_t numOutputs,
uint16_t numWithdrawals,
bool isSigningPoolRegistrationAsOwner
uint16_t numWithdrawals
);

security_policy_t policyForSignTxInput();

security_policy_t policyForSignTxOutputAddressBytes(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const uint8_t* rawAddressBuffer, size_t rawAddressSize,
const uint8_t networkId, const uint32_t protocolMagic
);
security_policy_t policyForSignTxOutputAddressParams(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const addressParams_t* params,
const uint8_t networkId, const uint32_t protocolMagic
);
Expand All @@ -48,12 +48,12 @@ security_policy_t policyForSignTxOutputConfirm(
uint64_t numAssetGroups
);

security_policy_t policyForSignTxFee(bool isSigningPoolRegistrationAsOwner, uint64_t fee);
security_policy_t policyForSignTxFee(sign_tx_usecase_t signTxUsecase, uint64_t fee);

security_policy_t policyForSignTxTtl(uint32_t ttl);

security_policy_t policyForSignTxCertificate(
const bool includeStakePoolRegistrationCertificate,
sign_tx_usecase_t signTxUsecase,
const certificate_type_t certificateType
);
security_policy_t policyForSignTxCertificateStaking(
Expand All @@ -74,16 +74,16 @@ security_policy_t policyForSignTxMetadata();
security_policy_t policyForSignTxValidityIntervalStart();

security_policy_t policyForSignTxWitness(
bool isSigningPoolRegistrationAsOwner,
sign_tx_usecase_t signTxUsecase,
const bip44_path_t* pathSpec
);

security_policy_t policyForSignTxConfirm();

bool is_tx_network_verifiable(
sign_tx_usecase_t signTxUsecase,
uint16_t numOutputs,
uint16_t numWithdrawals,
bool isSigningPoolRegistrationAsOwner
uint16_t numWithdrawals
);


Expand Down

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