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C++: Add openssl low-level API

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This commit is contained in:
Robert Marsh
2022-02-14 14:47:55 -05:00
parent dbe4770c7d
commit 0e50c4b186
1 changed files with 22 additions and 16 deletions
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38
cpp/ql/src/Security/CWE/CWE-326/InsufficientKeySize.ql
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@@ -14,37 +14,43 @@ import cpp
import semmle.code.cpp.ir.dataflow.DataFlow
import semmle.code.cpp.ir.IR
int getMinimumKeyStrength(string func) {
func = "EVP_PKEY_CTX_set_dsa_paramgen_bits" and result = 2048
or
func = "EVP_PKEY_CTX_set_dh_paramgen_prime_len" and result = 2048
or
func = "EVP_PKEY_CTX_set_rsa_keygen_bits" and result = 2048
// Holds if `func` is the name of an encryption function that accepts a key size as parameter `paramIndex`
int getMinimumKeyStrength(string func, int paramIndex) {
func =
[
"EVP_PKEY_CTX_set_dsa_paramgen_bits", "DSA_generate_parameters_ex",
"EVP_PKEY_CTX_set_rsa_keygen_bits", "RSA_generate_key_ex", "RSA_generate_key_fips",
"EVP_PKEY_CTX_set_dh_paramgen_prime_len", "DH_generate_parameters_ex"
] and
paramIndex = 1 and
result = 2048
}
class KeyStrengthFlow extends DataFlow::Configuration {
KeyStrengthFlow() {
this = "KeyStrengthFlow"
}
KeyStrengthFlow() { this = "KeyStrengthFlow" }
override predicate isSource(DataFlow::Node node) {
node.asInstruction() instanceof IntegerConstantInstruction
}
override predicate isSink(DataFlow::Node node) {
exists(FunctionCall fc, string name|
node.asExpr() = fc.getArgument(1) and
exists(FunctionCall fc, string name, int param |
node.asExpr() = fc.getArgument(param) and
fc.getTarget().hasGlobalName(name) and
exists(getMinimumKeyStrength(name))
exists(getMinimumKeyStrength(name, param))
)
}
}
from DataFlow::PathNode source, DataFlow::PathNode sink, KeyStrengthFlow conf, FunctionCall fc, string name, int bits
from
DataFlow::PathNode source, DataFlow::PathNode sink, KeyStrengthFlow conf, FunctionCall fc,
string name, int bits
where
conf.hasFlowPath(source, sink) and
sink.getNode().asExpr() = fc.getArgument(1) and
fc.getTarget().hasGlobalName(name) and
bits = getMinimumKeyStrength(name) and
source.getNode().asInstruction().(ConstantValueInstruction).getValue().toInt() < bits
select fc, source, sink, "The key size $@ is insufficient for security", source, source.toString()
bits = getMinimumKeyStrength(name, _) and
source.getNode().asInstruction().(ConstantValueInstruction).getValue().toInt() < bits
select fc, source, sink,
"The key size $@ is less than the recommended key size of " + bits.toString() + " bits.", source,
source.toString()