From 65e605a10d059807e2d0c0de4e7467daf72aa155 Mon Sep 17 00:00:00 2001
From: linsc <linsc@wangus.com>
Date: Tue, 15 Nov 2022 16:54:53 +0800
Subject: [PATCH] drop some redundant checking.

---
 src/liblsquic/lsquic_enc_sess_ietf.c | 8 ++------
 src/liblsquic/lsquic_handshake.c     | 8 ++------
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/src/liblsquic/lsquic_enc_sess_ietf.c b/src/liblsquic/lsquic_enc_sess_ietf.c
index 772f045..0288bb3 100644
--- a/src/liblsquic/lsquic_enc_sess_ietf.c
+++ b/src/liblsquic/lsquic_enc_sess_ietf.c
@@ -2240,6 +2240,7 @@ iquic_esf_decrypt_packet (enc_session_t *enc_session_p,
     enum enc_level enc_level;
     enum packnum_space pns;
     lsquic_packno_t packno;
+    size_t out_sz;
     enum dec_packin dec_packin;
     int s;
     /* 16Bytes: AEAD authentication tag
@@ -2251,17 +2252,12 @@ iquic_esf_decrypt_packet (enc_session_t *enc_session_p,
      *  These cipher suites have a 16-byte authentication tag and
      *  produce an output 16 bytes larger than their input.
      */
-    size_t out_sz, dst_sz;
+    const size_t dst_sz = packet_in->pi_data_sz - IQUIC_TAG_LEN;
     unsigned char new_secret[EVP_MAX_KEY_LENGTH];
     struct crypto_ctx crypto_ctx_buf;
     char secret_str[EVP_MAX_KEY_LENGTH * 2 + 1];
     char errbuf[ERR_ERROR_STRING_BUF_LEN];
 
-    if (packet_in->pi_data_sz <= 16) {
-        dec_packin = DECPI_TOO_SHORT;
-        goto err;
-    }
-    dst_sz = packet_in->pi_data_sz - 16;
     dst = lsquic_mm_get_packet_in_buf(&enpub->enp_mm, dst_sz);
     if (!dst)
     {
diff --git a/src/liblsquic/lsquic_handshake.c b/src/liblsquic/lsquic_handshake.c
index 2cfb2d9..964e48a 100644
--- a/src/liblsquic/lsquic_handshake.c
+++ b/src/liblsquic/lsquic_handshake.c
@@ -4177,15 +4177,11 @@ gquic2_esf_decrypt_packet (enc_session_t *enc_session_p,
     unsigned sample_off, packno_len, divers_nonce_len;
     enum gel gel;
     lsquic_packno_t packno;
-    size_t out_sz, dst_sz;
+    size_t out_sz;
     enum dec_packin dec_packin;
+    const size_t dst_sz = packet_in->pi_data_sz - IQUIC_TAG_LEN;
     char errbuf[ERR_ERROR_STRING_BUF_LEN];
 
-    dst_sz = packet_in->pi_data_sz - 16;
-    if (dst_sz <= 16) {
-        dec_packin = DECPI_TOO_SHORT;
-        goto err;
-    }
     dst = lsquic_mm_get_packet_in_buf(&enpub->enp_mm, dst_sz);
     if (!dst)
     {