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Use larger buffer for TLS encryption to avoid issues with GnuTLS

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It looks like GnuTLS (at least newer versions) is using random padding
on the application data and the previously used 100 byte extra buffer
for tls_connection_encrypt() calls was not enough to handle all cases.
This resulted in semi-random authentication failures with EAP-PEAP and
EAP-TTLS during Phase 2.

Increase the extra space for encryption from 100 to 300 bytes and add an
error message into tls_gnutls.c to make it easier to notice this issue
should it ever show up again even with the larger buffer.
This commit is contained in:
Jouni Malinen 2009-02-09 22:37:55 +02:00
parent 363a9e2434
commit edd757e8a3
2 changed files with 9 additions and 1 deletions
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8
src/crypto/tls_gnutls.c
View file

@ -1060,6 +1060,14 @@ int tls_connection_encrypt(void *ssl_ctx, struct tls_connection *conn,
return -1; return -1;
if (conn->push_buf_len < out_len) if (conn->push_buf_len < out_len)
out_len = conn->push_buf_len; out_len = conn->push_buf_len;
else if (conn->push_buf_len > out_len) {
wpa_printf(MSG_INFO, "GnuTLS: Not enough buffer space for "
"encrypted message (in_len=%lu push_buf_len=%lu "
"out_len=%lu",
(unsigned long) in_len,
(unsigned long) conn->push_buf_len,
(unsigned long) out_len);
}
os_memcpy(out_data, conn->push_buf, out_len); os_memcpy(out_data, conn->push_buf, out_len);
os_free(conn->push_buf); os_free(conn->push_buf);
conn->push_buf = NULL; conn->push_buf = NULL;

2
src/eap_peer/eap_tls_common.c
View file

@ -904,7 +904,7 @@ int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
if (in_data) { if (in_data) {
eap_peer_tls_reset_output(data); eap_peer_tls_reset_output(data);
len = wpabuf_len(in_data) + 100; len = wpabuf_len(in_data) + 300;
data->tls_out = os_malloc(len); data->tls_out = os_malloc(len);
if (data->tls_out == NULL) if (data->tls_out == NULL)
return -1; return -1;