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bn_ucmp

API Overview​

BN_ucmp is an API in openssl. This rule belongs to the return value check type. This rule is generated using AURC.

Rule Description​

tip

BN_cmp() returns -1 if I<a> E<lt> I<b>, 0 if I<a> == I<b> and 1 if I<a> E<gt> I<b>. BN_ucmp() is the same using the absolute values of I<a> and I<b>.

info
  • Tags: return value check
  • Parameter Index: N/A
  • CWE Type: CWE-253

Rule Code​

import cpp

class OpenSSLFunctionCall extends FunctionCall {
  OpenSSLFunctionCall() {
    this.getTarget().hasName("BN_ucmp")
  }
}

from OpenSSLFunctionCall call, UnaryOperation uop
where
  uop.getOperator() = "!" and
  uop.getOperand() = call.getAnAccess()
select uop, "This negation checks the return value of BN_ucmp."