tree 3f09718ace7bc551fef129c80ddf71a5ffcc4fd3
parent 897a2ca3f184b34278641138c726ef902ab1fab2
author Dan McArdle <dmcardle@google.com> 1626800135 -0400
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1626806240 +0000

Check strtoul return for overflow error in GetUnsigned()

Currently, GetUnsigned() calls strtoul and checks whether the resulting
unsigned long int is greater than UINT_MAX. This implicitly assumes that
UINT_MAX < ULONG_MAX.

Problematically, `unsigned long int` and `unsigned` have the same size
on Windows [0] and on 32-bit architectures.

For correctness, we now check whether strtoul failed because it would
overflow the unsigned long int before checking whether the value fits in
an unsigned type.

[0]: https://docs.microsoft.com/en-us/cpp/cpp/data-type-ranges?view=msvc-160

Change-Id: I49702febf4543bfb7991592717443e0b2adb954f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48545
Commit-Queue: Dan McArdle <dmcardle@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>