swtpm crash via undersized RSA output buffer

Stack corruption in libtpms before 0.7.2 and before 0.8.0 allows local users to crash swtpm during RSA decryption. CryptRsaDecrypt supplies EVP_PKEY_decrypt with the destination buffer while setting the output length to the ciphertext size, so a larger decrypted result overwrites the stack; the correction decrypts into a maximum-key-sized temporary buffer and checks the destination capacity. Local access to a consumer exposing TPM commands is required, and successful exploitation terminates the swtpm process without reported confidentiality or integrity impact.