* tpm2d/command.c (cmd_pkdecrypt): Handle unknown algo.  Also slightly
rework error handling.
* tpm2d/tpm2.c (sexp_to_tpm2_public_ecc): Check length before checking
for 0x04.  Rework error handling.
(tpm2_ObjectPublic_GetName): Check the return value of
TSS_GetDigestSize before use.  Erro handling rework.
(tpm2_SensitiveToDuplicate): Ditto.
(tpm2_import_key): Ditto.
* tpm2d/intel-tss.h (TSS_Hash_Generate): Check passed length for
negative values.  Check return value of TSS_GetDigestSize.  Use
dedicated 16 bit length variable.