libmedtls: mpi_miller_rabin: increase count limit

Increase the count limit when generating the witness in the Rabin-Miller
primality test. The previous number 30 was too low to reliably detect
000000022770A7DC599BC90B2FF981CCB5CF05703344C8F350418AAD as a prime
number.

Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
[jf: rebased onto mbedtls-2.22.0]
[jf: rebased onto mbedtls-2.27.0]
Signed-off-by: Jerome Forissier <jerome@forissier.org>
[jw: rebased onto mbedtls-3.4.0]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
[tve: rebased onto mbedtls-3.6.0]
Signed-off-by: Tom Van Eyck <tom.vaneyck@kuleuven.be>
[sby: rebased onto mbedtls-3.6.2]
Signed-off-by: Sungbae Yoo <sungbaey@nvidia.com>
diff --git a/lib/libmbedtls/mbedtls/library/bignum.c b/lib/libmbedtls/mbedtls/library/bignum.c
index e3b9452..8a4f121 100644
--- a/lib/libmbedtls/mbedtls/library/bignum.c
+++ b/lib/libmbedtls/mbedtls/library/bignum.c
@@ -2203,7 +2203,7 @@
                 A.p[A.n - 1] &= ((mbedtls_mpi_uint) 1 << (k - (A.n - 1) * biL - 1)) - 1;
             }
 
-            if (count++ > 30) {
+            if (count++ > 300) {
                 ret = MBEDTLS_ERR_MPI_NOT_ACCEPTABLE;
                 goto cleanup;
             }