tree da467334fa6c17001c5b8f007db1c7160e7461bb
parent f305d92480c81c6eb02934a4e1af58152cba28ea
author Gilles Peskine <Gilles.Peskine@arm.com> 1612048011 +0100
committer Gilles Peskine <Gilles.Peskine@arm.com> 1614018243 +0100

Fix mutex leak in HMAC_DRBG

mbedtls_hmac_drbg_free() left a mutex in the initialized state. This
caused a resource leak on platforms where mbedtls_mutex_init()
allocates resources.

To fix this, mbedtls_hmac_drbg_free() no longer reinitializes the
mutex. To preserve the property that mbedtls_hmac_drbg_free() leaves
the object in an initialized state, which is generally true throughout
the library except regarding mutex objects on some platforms, no
longer initialize the mutex in mbedtls_hmac_drbg_init(). Since the
mutex is only used after seeding, and seeding is only permitted once,
call mbedtls_mutex_init() as part of the seeding process.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>