diff options
Diffstat (limited to 'src/libcharon/encoding')
| -rw-r--r-- | src/libcharon/encoding/message.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/src/libcharon/encoding/message.c b/src/libcharon/encoding/message.c index 43f74238f..4504c5b48 100644 --- a/src/libcharon/encoding/message.c +++ b/src/libcharon/encoding/message.c @@ -1895,6 +1895,13 @@ static void clear_fragments(private_message_t *this) this->fragments = NULL; } +/** + * Reduce the fragment length but ensure it stays > 0 + */ +#define REDUCE_FRAG_LEN(fl, amount) ({ \ + fl = max(1, (ssize_t)fl - (amount)); \ +}) + METHOD(message_t, fragment, status_t, private_message_t *this, keymat_t *keymat, size_t frag_len, enumerator_t **fragments) @@ -1919,13 +1926,13 @@ METHOD(message_t, fragment, status_t, } /* frag_len is the complete IP datagram length, account for overhead (we * assume no IP options/extension headers are used) */ - frag_len -= (src->get_family(src) == AF_INET) ? 20 : 40; + REDUCE_FRAG_LEN(frag_len, (src->get_family(src) == AF_INET) ? 20 : 40); /* 8 (UDP header) */ - frag_len -= 8; + REDUCE_FRAG_LEN(frag_len, 8); if (dst->get_port(dst) != IKEV2_UDP_PORT && src->get_port(src) != IKEV2_UDP_PORT) { /* reduce length due to non-ESP marker */ - frag_len -= 4; + REDUCE_FRAG_LEN(frag_len, 4); } if (is_encoded(this)) @@ -1969,7 +1976,7 @@ METHOD(message_t, fragment, status_t, /* frag_len denoted the maximum IKE message size so far, later on it will * denote the maximum content size of a fragment payload, therefore, * account for IKE header */ - frag_len -= 28; + REDUCE_FRAG_LEN(frag_len, 28); if (this->major_version == IKEV1_MAJOR_VERSION) { @@ -1984,7 +1991,7 @@ METHOD(message_t, fragment, status_t, generator = NULL; } /* overhead for the fragmentation payload header */ - frag_len -= 8; + REDUCE_FRAG_LEN(frag_len, 8); } else { @@ -2008,10 +2015,13 @@ METHOD(message_t, fragment, status_t, } aead = keymat->get_aead(keymat, FALSE); /* overhead for the encrypted fragment payload */ - frag_len -= aead->get_iv_size(aead) + aead->get_icv_size(aead); - frag_len -= 8 /* header */; + REDUCE_FRAG_LEN(frag_len, aead->get_iv_size(aead)); + REDUCE_FRAG_LEN(frag_len, aead->get_icv_size(aead)); + /* header */ + REDUCE_FRAG_LEN(frag_len, 8); /* padding and padding length */ - frag_len = round_down(frag_len, aead->get_block_size(aead)) - 1; + frag_len = round_down(frag_len, aead->get_block_size(aead)); + REDUCE_FRAG_LEN(frag_len, 1); /* TODO-FRAG: if there are unencrypted payloads, should we account for * their length in the first fragment? we still would have to add * an encrypted fragment payload (albeit empty), even so we couldn't |