[git commit] tls: do not leak RSA key

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=a6192f347fb87289c9cfdc4d57b126d704eba0de
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
tls_handshake                                       1957    2059    +102

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 networking/tls.c     |  1 +
 networking/tls_rsa.h | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/networking/tls.c b/networking/tls.c
index 9b4298de7..9833a0adb 100644
--- a/networking/tls.c
+++ b/networking/tls.c
@@ -2168,6 +2168,7 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni)
 	/* application data can be sent/received */
 
 	/* free handshake data */
+	psRsaKey_clear(&tls->hsd->server_rsa_pub_key);
 //	if (PARANOIA)
 //		memset(tls->hsd, 0, tls->hsd->hsd_size);
 	free(tls->hsd);
diff --git a/networking/tls_rsa.h b/networking/tls_rsa.h
index f42923ff5..82bea2a67 100644
--- a/networking/tls_rsa.h
+++ b/networking/tls_rsa.h
@@ -13,6 +13,18 @@ typedef struct {
 //bbox	psPool_t *pool;
 } psRsaKey_t;
 
+static ALWAYS_INLINE void psRsaKey_clear(psRsaKey_t *key)
+{
+	pstm_clear(&key->N);
+	pstm_clear(&key->e);
+	pstm_clear(&key->d);
+	pstm_clear(&key->p);
+	pstm_clear(&key->q);
+	pstm_clear(&key->dP);
+	pstm_clear(&key->dQ);
+	pstm_clear(&key->qP);
+}
+
 #define psRsaEncryptPub(pool, key, in, inlen, out, outlen, data) \
         psRsaEncryptPub(      key, in, inlen, out, outlen)
 int32 psRsaEncryptPub(psPool_t *pool, psRsaKey_t *key,