Generate ESP IV from previous packet for GnuTLS too.

Less dramatic speedup here (only 4%) as we were already using
GNUTLS_RND_NONCE but still worth having.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/gnutls-esp.c b/gnutls-esp.c
index a565f1c70be32bf8d520066eb008fb8317defa76..d8a8d7c07edf0c9fb3a453374f032adb430daac7 100644 (file)
--- a/gnutls-esp.c
+++ b/gnutls-esp.c
@@ -128,6 +128,15 @@ int setup_esp_keys(struct openconnect_info *vpninfo, int new_keys)
        if (ret)
                return ret;
 
+       if (gnutls_rnd(GNUTLS_RND_NONCE, vpninfo->esp_out.iv, sizeof(vpninfo->esp_out.iv))) {
+               vpn_progress(vpninfo, PRG_ERR, _("Failed to generate ESP IV\n"));
+               destroy_esp_ciphers(&vpninfo->esp_out);
+               return -EIO;
+       }
+       gnutls_cipher_set_iv(vpninfo->esp_out.cipher, vpninfo->esp_out.iv,
+                            sizeof(vpninfo->esp_out.iv));
+
+
        ret = init_esp_ciphers(vpninfo, esp_in, macalg, encalg);
        if (ret) {
                destroy_esp_ciphers(&vpninfo->esp_out);
@@ -185,13 +194,6 @@ int encrypt_esp_packet(struct openconnect_info *vpninfo, struct pkt *pkt)
        /* This gets much more fun if the IV is variable-length */
        pkt->esp.spi = vpninfo->esp_out.spi;
        pkt->esp.seq = htonl(vpninfo->esp_out.seq++);
-       err = gnutls_rnd(GNUTLS_RND_NONCE, pkt->esp.iv, sizeof(pkt->esp.iv));
-       if (err) {
-               vpn_progress(vpninfo, PRG_ERR,
-                            _("Failed to generate ESP packet IV: %s\n"),
-                            gnutls_strerror(err));
-               return -EIO;
-       }
 
        padlen = blksize - 1 - ((pkt->len + 1) % blksize);
        for (i=0; i<padlen; i++)
@@ -199,7 +201,8 @@ int encrypt_esp_packet(struct openconnect_info *vpninfo, struct pkt *pkt)
        pkt->data[pkt->len + padlen] = padlen;
        pkt->data[pkt->len + padlen + 1] = 0x04; /* Legacy IP */
 
-       gnutls_cipher_set_iv(vpninfo->esp_out.cipher, pkt->esp.iv, sizeof(pkt->esp.iv));
+       memcpy(pkt->esp.iv, vpninfo->esp_out.iv, sizeof(pkt->esp.iv));
+
        err = gnutls_cipher_encrypt(vpninfo->esp_out.cipher, pkt->data, pkt->len + padlen + 2);
        if (err) {
                vpn_progress(vpninfo, PRG_ERR,
@@ -216,5 +219,8 @@ int encrypt_esp_packet(struct openconnect_info *vpninfo, struct pkt *pkt)
                return -EIO;
        }
        gnutls_hmac_output(vpninfo->esp_out.hmac, pkt->data + pkt->len + padlen + 2);
+
+       memcpy(vpninfo->esp_out.iv, pkt->data + pkt->len + padlen + 2, blksize);
+       gnutls_cipher_encrypt(vpninfo->esp_out.cipher, vpninfo->esp_out.iv, blksize);
        return sizeof(pkt->esp) + pkt->len + padlen + 2 + 12;
 }