From 58fc3e9505fc044c5a06ad72855f6c9e491e3d70 Mon Sep 17 00:00:00 2001
From: Viktor Tarasov <viktor.tarasov@gmail.com>
Date: Wed, 26 Sep 2018 10:02:07 +0200
Subject: [PATCH] OER: fix encoding of big integers
there was no leading pad byte for the big positive integers with
the MSBit at 1
Fix decoding of big unsigned integers with MSB at '1'
---
core/Integer.cc | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/core/Integer.cc b/core/Integer.cc
index 88509c137..360880bb2 100644
--- a/core/Integer.cc
+++ b/core/Integer.cc
@@ -1836,6 +1836,7 @@ int INTEGER::OER_encode(const TTCN_Typedescriptor_t& p_td, TTCN_Buffer& p_buf) c
unsigned char* bn_as_bin = (unsigned char*) Malloc(num_bytes);
BN_bn2bin(D, bn_as_bin);
+ boolean pad = FALSE;
if (BN_is_negative(D)) {
for(size_t i = 0; i < num_bytes; ++i){
bn_as_bin[i] = ~bn_as_bin[i];
@@ -1854,15 +1855,25 @@ int INTEGER::OER_encode(const TTCN_Typedescriptor_t& p_td, TTCN_Buffer& p_buf) c
}
}
}
+
+ pad = p_td.oer->signed_ && (!(bn_as_bin[0] & 0x80));
+ } else {
+ pad = p_td.oer->signed_ && (bn_as_bin[0] & 0x80);
}
if (p_td.oer->bytes == -1) {
- encode_oer_length(num_bytes, p_buf, FALSE);
+ if (pad) {
+ char pad_ch = BN_is_negative(D) ? 0xFF : 0;
+ encode_oer_length(num_bytes + 1, p_buf, FALSE);
+ p_buf.put_c(pad_ch);
+ } else {
+ encode_oer_length(num_bytes, p_buf, FALSE);
+ }
} else {
int rem_bytes = p_td.oer->bytes - num_bytes;
- char pad = BN_is_negative(D) ? 0xFF : 0;
+ char pad_ch = BN_is_negative(D) ? 0xFF : 0;
for (int i = 0; i < rem_bytes; i++) {
- p_buf.put_c(pad);
+ p_buf.put_c(pad_ch);
}
}
p_buf.put_s(num_bytes, bn_as_bin);
@@ -1884,7 +1895,7 @@ int INTEGER::OER_decode(const TTCN_Typedescriptor_t& p_td, TTCN_Buffer& p_buf, O
}
const unsigned char* const ucstr = p_buf.get_read_data();
if ((num_bytes > sizeof(RInt)) || (num_bytes >= 4 && p_td.oer->signed_ == FALSE)) { // Bignum
- const boolean negative = ucstr[0] & 0x80 && (p_td.oer->signed_ == TRUE || p_td.oer->bytes == -1);
+ const boolean negative = ucstr[0] & 0x80 && p_td.oer->signed_ == TRUE;
BIGNUM *D = BN_new();
if (negative) {
unsigned char* const tmp = (unsigned char*) Malloc(num_bytes);
--
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