Missing resource release of function SSL_CTX_new()

[lc3412]

Hi,

I find that several error handling sites forget to free the resource, which is allocated by function SSL_CTX_new(). See the following code, at line 128, function SSL_CTX_new() allocates the resource. However, several followed up error handling sites forget to free the resource that allocated by SSL_CTX_new(), including the handling actions of function SSL_new() (line 170 - line 172), SSL_set_fd() (line 181 - line 183), SSL_connect() (line 189 - line 191), SSL_get_peer_certificate(line 197 - line 199). For example, function SSL_new() does the handling actions: print the log message, then propogate the error code, therefore, miss the resource release action related to SSL_CTX_new(). This causes a missing resource release bug about function SSL_CTX_new().

function SSL_CTX_new() call site:

dma/crypto.c

Line 128 in 14ea7d7

ctx = SSL_CTX_new(meth);

followed up handling actions:

dma/crypto.c

Lines 168 to 173 in 14ea7d7

	config.ssl = SSL_new(ctx);
	if (config.ssl == NULL) {
	syslog(LOG_NOTICE, "remote delivery deferred: SSL struct creation failed: %s",
	ssl_errstr());
	return (1);
	}

dma/crypto.c

Lines 179 to 184 in 14ea7d7

	error = SSL_set_fd(config.ssl, fd);
	if (error == 0) {
	syslog(LOG_NOTICE, "remote delivery deferred: SSL set fd failed: %s",
	ssl_errstr());
	return (1);
	}

dma/crypto.c

Lines 187 to 192 in 14ea7d7

	error = SSL_connect(config.ssl);
	if (error != 1) {
	syslog(LOG_ERR, "remote delivery deferred: SSL handshake failed fatally: %s",
	ssl_errstr());
	return (1);
	}

dma/crypto.c

Lines 195 to 200 in 14ea7d7

	cert = SSL_get_peer_certificate(config.ssl);
	if (cert == NULL) {
	syslog(LOG_WARNING, "remote delivery deferred: Peer did not provide certificate: %s",
	ssl_errstr());
	return (1);
	}

======================================================================

Furthermore, I check the usages of SSL_CTX_new() from other projects, for instance, in the OpenSSL project at apps/ciphers.c. See the following code, in the end, the resource allocated by SSL_CTX_new() is freed by the action SSL_CTX_free(ctx) (line 280) :

line 195:    ctx = SSL_CTX_new(meth);
...
line 223:    ssl = SSL_new(ctx);
line 224:    if (ssl == NULL)
line 225:        goto err;
...
line 275: err:
line 276:    ERR_print_errors(bio_err);
line 277: end:
line 278:    if (use_supported)
line 279:        sk_SSL_CIPHER_free(sk);
line 280:    SSL_CTX_free(ctx);
line 281:    SSL_free(ssl);
line 282:    return ret;

Ref: https://github.com/openssl/openssl/blob/master/apps/ciphers.c