The input to the comp128 algorithm was relying on QSTRING_TO_BUF returning a pointer to persistant memory. This was not the case as it was returning a pointer to an intermediate object which was being freed once out of scope. It just happened to work most of the time. This change copies ki/rand into a static buffer. --- src/simauth.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/simauth.cpp b/src/simauth.cpp index 24b2d17..93b8826 100644 --- a/src/simauth.cpp +++ b/src/simauth.cpp @@ -42,10 +42,13 @@ SimAuth::~SimAuth() void SimAuth::gsmAuthenticate( QString rand, QString &sres, QString &kc ) { - uint8_t *ki = QSTRING_TO_BUF( _ki ); - uint8_t *_rand = QSTRING_TO_BUF( rand ); - uint8_t _sres[4]; - uint8_t _kc[8]; + uint8_t ki[16]; + uint8_t _rand[16]; + uint8_t _sres[4] = { 0 }; + uint8_t _kc[8] = { 0 }; + + memcpy(ki, QSTRING_TO_BUF( _ki ), 16); + memcpy(_rand, QSTRING_TO_BUF( rand ), 16); comp128( ki, _rand, _sres, _kc ); -- 2.17.1