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In implement of signature, no return check and no use nonce. #1516

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In implement of signature, no return check and no use nonce. #1516

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6 changes: 3 additions & 3 deletions slither/core/solidity_types/elementary_type.py
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Original file line number Diff line number Diff line change
Expand Up @@ -43,8 +43,8 @@
"int256",
]

Max_Int = {k: 2 ** (8 * i - 1) - 1 if i > 0 else 2**255 - 1 for i, k in enumerate(Int)}
Min_Int = {k: -(2 ** (8 * i - 1)) if i > 0 else -(2**255) for i, k in enumerate(Int)}
Max_Int = {k: 2 ** (8 * i - 1) - 1 if i > 0 else 2 ** 255 - 1 for i, k in enumerate(Int)}
Min_Int = {k: -(2 ** (8 * i - 1)) if i > 0 else -(2 ** 255) for i, k in enumerate(Int)}

Uint = [
"uint",
Expand Down Expand Up @@ -82,7 +82,7 @@
"uint256",
]

Max_Uint = {k: 2 ** (8 * i) - 1 if i > 0 else 2**256 - 1 for i, k in enumerate(Uint)}
Max_Uint = {k: 2 ** (8 * i) - 1 if i > 0 else 2 ** 256 - 1 for i, k in enumerate(Uint)}
Min_Uint = {k: 0 for k in Uint}


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1 change: 1 addition & 0 deletions slither/detectors/all_detectors.py
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Original file line number Diff line number Diff line change
Expand Up @@ -85,3 +85,4 @@
from .statements.delegatecall_in_loop import DelegatecallInLoop
from .functions.protected_variable import ProtectedVariables
from .functions.permit_domain_signature_collision import DomainSeparatorCollision
from .statements.ecrecover import Ecrecover
12 changes: 8 additions & 4 deletions slither/detectors/naming_convention/naming_convention.py
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Expand Up @@ -89,10 +89,14 @@ def _detect(self): # pylint: disable=too-many-branches,too-many-statements
if func.is_constructor:
continue
if not self.is_mixed_case(func.name):
if func.visibility in [
"internal",
"private",
] and self.is_mixed_case_with_underscore(func.name):
if (
func.visibility
in [
"internal",
"private",
]
and self.is_mixed_case_with_underscore(func.name)
):
continue
if func.name.startswith(("echidna_", "crytic_")):
continue
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104 changes: 104 additions & 0 deletions slither/detectors/statements/ecrecover.py
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Original file line number Diff line number Diff line change
@@ -0,0 +1,104 @@
"""
Module detecting improper use of ecrecover.

"""

from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification
from slither.slithir.operations import Binary, BinaryType
from slither.slithir.operations.solidity_call import SolidityCall


class Ecrecover(AbstractDetector):
"""
Detect improper use of ecrecover
"""

ARGUMENT = "ecrecover"
HELP = "Return value of ecrecover is not checked. And Signature does not contain a nonce."
IMPACT = DetectorClassification.MEDIUM
CONFIDENCE = DetectorClassification.LOW

WIKI = "https://github.com/crytic/slither/wiki/Detector-Documentation#ecrecover"
WIKI_TITLE = "ECRECOVER"
WIKI_DESCRIPTION = "ECRECOVER"
WIKI_EXPLOIT_SCENARIO = """
```solidity
contract A {
struct Info {
uint tokenId;
address owner;
// uint nonce
}
uint maxBreed = 5;
mapping (uint => mapping(uint => address)) list;
mapping (uint => uint) count;
function mint(uint tokenId, address addr) internal {
require(count[tokenId] < maxBreed, "");
list[tokenId][count[tokenId]] = addr;
count[tokenId]++;
}
function verify(Info calldata info, uint8 v, bytes32 r, bytes32 s) external {
bytes32 hash = keccak256(abi.encode(info));
bytes32 data =
keccak256(
abi.encodePacked("\x19Ethereum Signed Message:\n32", hash)
);
address receiver = ecrecover(data, v, r, s);
// require(signer != address(0), "ECDSA: invalid signature");
mint(info.tokenId, receiver);
}
}
```
First, signature does not contain nonce.
Second, there is no verification of ecrecover's return value.
"""
WIKI_RECOMMENDATION = "Check return value of ecrecover and signature contains a nonce"

def _detect(self):

results = []

for contract in self.compilation_unit.contracts:
for function in contract.functions:
for call in function.solidity_calls:
if call.name == "ecrecover(bytes32,uint8,bytes32,bytes32)":
flag = 0
for vari in function._variables:
if "nonce" in vari.lower():
flag = 1
if flag == 0:
info = [
"No nonce check found in ",
function,
"\n",
]
res = self.generate_result(info)
results.append(res)
flag = 0

find_erecovery = 0
for node in function.nodes:

for ir in node.irs:
if find_erecovery == 1:
if isinstance(ir, Binary):
if (ir.type == BinaryType.NOT_EQUAL) or (
ir.type == BinaryType.EQUAL
):
flag = 1
else:
if (
isinstance(ir, SolidityCall)
and ir.function.name
== "ecrecover(bytes32,uint8,bytes32,bytes32)"
):
find_erecovery = 1
if flag == 0:
info = [
"No return check found in ",
function,
"\n",
]
res = self.generate_result(info)
results.append(res)
return results
2 changes: 1 addition & 1 deletion slither/detectors/statements/type_based_tautology.py
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@
def typeRange(t):
bits = int(t.split("int")[1])
if t in Uint:
return 0, (2**bits) - 1
return 0, (2 ** bits) - 1
if t in Int:
v = (2 ** (bits - 1)) - 1
return -v, v
Expand Down
4 changes: 2 additions & 2 deletions slither/slithir/convert.py
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Original file line number Diff line number Diff line change
Expand Up @@ -171,10 +171,10 @@ def _fits_under_integer(val: int, can_be_int: bool, can_be_uint) -> List[str]:
assert can_be_int | can_be_uint
while n <= 256:
if can_be_uint:
if val <= 2**n - 1:
if val <= 2 ** n - 1:
ret.append(f"uint{n}")
if can_be_int:
if val <= (2**n) / 2 - 1:
if val <= (2 ** n) / 2 - 1:
ret.append(f"int{n}")
n = n + 8
return ret
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2 changes: 1 addition & 1 deletion slither/utils/integer_conversion.py
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Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,7 @@ def convert_string_to_fraction(val: Union[str, int]) -> Fraction:
f"{base}e{expo} is too large to fit in any Solidity integer size"
)
return 0
return Fraction(base) * Fraction(10**expo)
return Fraction(base) * Fraction(10 ** expo)

return Fraction(val)

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2 changes: 1 addition & 1 deletion slither/visitors/expression/constants_folding.py
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Original file line number Diff line number Diff line change
Expand Up @@ -43,7 +43,7 @@ def _post_binary_operation(self, expression):
left = get_val(expression.expression_left)
right = get_val(expression.expression_right)
if expression.type == BinaryOperationType.POWER:
set_val(expression, left**right)
set_val(expression, left ** right)
elif expression.type == BinaryOperationType.MULTIPLICATION:
set_val(expression, left * right)
elif expression.type == BinaryOperationType.DIVISION:
Expand Down
25 changes: 25 additions & 0 deletions tests/detectors/ecrecover/0.8.0/ecrecover.sol
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
contract A {
struct Info {
uint tokenId;
address owner;
// uint nonce
}
uint maxBreed = 5;
mapping (uint => mapping(uint => address)) list;
mapping (uint => uint) count;
function mint(uint tokenId, address addr) internal {
require(count[tokenId] < maxBreed, "");
list[tokenId][count[tokenId]] = addr;
count[tokenId]++;
}
function verify(Info calldata info, uint8 v, bytes32 r, bytes32 s) external {
bytes32 hash = keccak256(abi.encode(info));
bytes32 data =
keccak256(
abi.encodePacked("\x19Ethereum Signed Message:\n32", hash)
);
address receiver = ecrecover(data, v, r, s);
// require(signer != address(0), "ECDSA: invalid signature");
mint(info.tokenId, receiver);
}
}
168 changes: 168 additions & 0 deletions tests/detectors/ecrecover/0.8.0/ecrecover.sol.0.8.0.Ecrecover.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,168 @@
[
[
{
"elements": [
{
"type": "function",
"name": "verify",
"source_mapping": {
"start": 401,
"length": 432,
"filename_relative": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"filename_absolute": "/GENERIC_PATH",
"filename_short": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"is_dependency": false,
"lines": [
15,
16,
17,
18,
19,
20,
21,
22,
23,
24
],
"starting_column": 5,
"ending_column": 6
},
"type_specific_fields": {
"parent": {
"type": "contract",
"name": "A",
"source_mapping": {
"start": 0,
"length": 835,
"filename_relative": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"filename_absolute": "/GENERIC_PATH",
"filename_short": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"is_dependency": false,
"lines": [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25,
26
],
"starting_column": 1,
"ending_column": 0
}
},
"signature": "verify(A.Info,uint8,bytes32,bytes32)"
}
}
],
"description": "No nonce check found in A.verify(A.Info,uint8,bytes32,bytes32) (tests/detectors/ecrecover/0.8.0/ecrecover.sol#15-24)\n",
"markdown": "No nonce check found in [A.verify(A.Info,uint8,bytes32,bytes32)](tests/detectors/ecrecover/0.8.0/ecrecover.sol#L15-L24)\n",
"first_markdown_element": "tests/detectors/ecrecover/0.8.0/ecrecover.sol#L15-L24",
"id": "27569155b0bbd34ebee696a624ae9cc839594b156c87544fdb59975326105b18",
"check": "ecrecover",
"impact": "Medium",
"confidence": "Low"
},
{
"elements": [
{
"type": "function",
"name": "verify",
"source_mapping": {
"start": 401,
"length": 432,
"filename_relative": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"filename_absolute": "/GENERIC_PATH",
"filename_short": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"is_dependency": false,
"lines": [
15,
16,
17,
18,
19,
20,
21,
22,
23,
24
],
"starting_column": 5,
"ending_column": 6
},
"type_specific_fields": {
"parent": {
"type": "contract",
"name": "A",
"source_mapping": {
"start": 0,
"length": 835,
"filename_relative": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"filename_absolute": "/GENERIC_PATH",
"filename_short": "tests/detectors/ecrecover/0.8.0/ecrecover.sol",
"is_dependency": false,
"lines": [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25,
26
],
"starting_column": 1,
"ending_column": 0
}
},
"signature": "verify(A.Info,uint8,bytes32,bytes32)"
}
}
],
"description": "No return check found in A.verify(A.Info,uint8,bytes32,bytes32) (tests/detectors/ecrecover/0.8.0/ecrecover.sol#15-24)\n",
"markdown": "No return check found in [A.verify(A.Info,uint8,bytes32,bytes32)](tests/detectors/ecrecover/0.8.0/ecrecover.sol#L15-L24)\n",
"first_markdown_element": "tests/detectors/ecrecover/0.8.0/ecrecover.sol#L15-L24",
"id": "de38bde3cbf7427267ce079a656d9e99c3b2126bdc6b576b05e94df2357dd5d4",
"check": "ecrecover",
"impact": "Medium",
"confidence": "Low"
}
]
]
5 changes: 5 additions & 0 deletions tests/test_detectors.py
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Expand Up @@ -1557,6 +1557,11 @@ def id_test(test_item: Test):
"permit_domain_state_var_collision.sol",
"0.8.0",
),
Test(
all_detectors.Ecrecover,
"ecrecover.sol",
"0.8.0",
),
]


Expand Down