tree 9a68ab548c1f03afbe640b765917b9f7ee615e9b
parent a1af5c8ea2586c2f4f93908cc84398041ee8c806
author Gilles Peskine <Gilles.Peskine@arm.com> 1538681061 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> 1538682280 +0200

Use branch-free size comparison for the padding size

In mbedtls_rsa_rsaes_pkcs1_v15_decrypt, use size_greater_than (which
is based on bitwise operations) instead of the < operator to compare
sizes when the values being compared must not leak. Some compilers
compile < to a branch at least under some circumstances (observed with
gcc 5.4 for arm-gnueabi -O9 on a toy program).