84 lines
2.3 KiB
Plaintext
84 lines
2.3 KiB
Plaintext
== Why is this an issue?
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include::../description.adoc[]
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=== Noncompliant code example
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[source,java]
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----
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float twoThirds = 2/3; // Noncompliant; int division. Yields 0.0
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long millisInYear = 1_000*3_600*24*365; // Noncompliant; int multiplication. Yields 1471228928
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long bigNum = Integer.MAX_VALUE + 2; // Noncompliant. Yields -2147483647
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long bigNegNum = Integer.MIN_VALUE-1; //Noncompliant, gives a positive result instead of a negative one.
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Date myDate = new Date(seconds * 1_000); //Noncompliant, won't produce the expected result if seconds > 2_147_483
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...
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public long compute(int factor){
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return factor * 10_000; //Noncompliant, won't produce the expected result if factor > 214_748
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}
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public float compute2(long factor){
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return factor / 123; //Noncompliant, will be rounded to closest long integer
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}
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----
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=== Compliant solution
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[source,java]
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----
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float twoThirds = 2f/3; // 2 promoted to float. Yields 0.6666667
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long millisInYear = 1_000L*3_600*24*365; // 1000 promoted to long. Yields 31_536_000_000
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long bigNum = Integer.MAX_VALUE + 2L; // 2 promoted to long. Yields 2_147_483_649
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long bigNegNum = Integer.MIN_VALUE-1L; // Yields -2_147_483_649
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Date myDate = new Date(seconds * 1_000L);
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...
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public long compute(int factor){
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return factor * 10_000L;
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}
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public float compute2(long factor){
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return factor / 123f;
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}
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----
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or
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[source,java]
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----
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float twoThirds = (float)2/3; // 2 cast to float
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long millisInYear = (long)1_000*3_600*24*365; // 1_000 cast to long
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long bigNum = (long)Integer.MAX_VALUE + 2;
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long bigNegNum = (long)Integer.MIN_VALUE-1;
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Date myDate = new Date((long)seconds * 1_000);
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...
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public long compute(long factor){
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return factor * 10_000;
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}
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public float compute2(float factor){
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return factor / 123;
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}
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----
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== Resources
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* CWE - https://cwe.mitre.org/data/definitions/190[CWE-190 - Integer Overflow or Wraparound]
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* https://wiki.sei.cmu.edu/confluence/x/AjdGBQ[CERT, NUM50-J.] - Convert integers to floating point for floating-point operations
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* https://wiki.sei.cmu.edu/confluence/x/I9cxBQ[CERT, INT18-C.] - Evaluate integer expressions in a larger size before comparing or assigning to that size
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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include::../message.adoc[]
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'''
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== Comments And Links
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(visible only on this page)
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include::../comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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