In message <1037725127.635.56.camel@fearless> on 19 Nov 2002 11:58:47 -0500, Tobias
DiPasquale <[EMAIL PROTECTED]> said:
toby> I am writing some code that has to do some crypto, and I have come
toby> across a memory leak in OpenSSL resulting from the (possible mis-)use of
toby> the following code:
toby>
toby> <snippet>
toby> char *cert_string;
toby> RSA *rsa;
toby> X509 *cert;
toby> EVP_PKEY *ekey;
toby> [...]
toby> /*
toby> * cert_string contains the text of the certificate
toby> */
toby> if (!(mem = BIO_new_mem_buf( cert_string, -1)))
toby> return -1;
toby> if (!(cert = PEM_read_bio_X509( mem, NULL, NULL, NULL)))
toby> {
toby> BIO_free( mem);
toby> return -1;
toby> }
toby> ekey = X509_get_pubkey( cert);
toby> rsa = ekey->pkey.rsa;
toby> if (!rsa)
toby> {
toby> BIO_free( mem);
toby> X509_free( cert);
toby> return -1;
toby> }
toby> [...]
toby> BIO_free( mem);
toby> RSA_free( rsa);
toby> X509_free( cert);
toby> </snippet>
toby>
toby> I have tracked the leak down with gdb to be coming from the call to
toby> X509_get_pubkey(). The cert->cert_info->key->pkey member is NULL until I
toby> call that function, but then after the call, the pkey member and my ekey
toby> variable both point to the same place, a valid memory address.
Well, an EVP_PKEY is one of those structures that contains a reference
counter. Since it has two references to it (one through
cert->cert_info->key->pkey and one through your ekey variable), the
counter is 2. When you do X509_free(cert), that counter gets
decreased to 1, and the key is kept around, basically because ekey is
still pointing at it. You need to add the following call:
EVP_PKEY_free(ekey);
--
Richard Levitte \ Spannvägen 38, II \ [EMAIL PROTECTED]
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