OSV-2018-195 Heap-buffer-overflow in gmp_emsa_pkcs1_signature_data

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=10671 Crash type: Heap-buffer-overflow WRITE 1 Crash state: gmpemsapkcs1signaturedata verifyemsapkcs1signature verify...