From 6fbff7fc8aabeee2254405f254220bbe8c05c67d Mon Sep 17 00:00:00 2001
From: Daiki Ueno <ueno@gnu.org>
Date: Fri, 5 Jun 2020 16:26:33 +0200
Subject: [PATCH] crypto-api: always allocate memory when serializing iovec_t
The AEAD iov interface falls back to serializing the input buffers if
the low-level cipher doesn't support scatter/gather encryption.
However, there was a bug in the functions used for the serialization,
which causes memory leaks under a certain condition (i.e. the number
of input buffers is 1).
This patch makes the logic of the functions simpler, by removing a
micro-optimization that tries to minimize the number of calls to
malloc/free.
The original problem was reported by Marius Steffen in:
https://bugzilla.samba.org/show_bug.cgi?id=14399
and the cause was investigated by Alexander Haase in:
https://gitlab.com/gnutls/gnutls/-/merge_requests/1277
Signed-off-by: Daiki Ueno <ueno@gnu.org>
---
lib/crypto-api.c | 36 +++++++++++-------------------------
tests/aead-cipher-vec.c | 33 ++++++++++++++++++---------------
2 files changed, 29 insertions(+), 40 deletions(-)
diff --git a/lib/crypto-api.c b/lib/crypto-api.c
index 45be64ed1..8524f5ed4 100644
--- a/lib/crypto-api.c
+++ b/lib/crypto-api.c
@@ -891,32 +891,23 @@ gnutls_aead_cipher_encrypt(gnutls_aead_cipher_hd_t handle,
struct iov_store_st {
void *data;
size_t size;
- unsigned allocated;
};
static void iov_store_free(struct iov_store_st *s)
{
- if (s->allocated) {
- gnutls_free(s->data);
- s->allocated = 0;
- }
+ gnutls_free(s->data);
}
static int iov_store_grow(struct iov_store_st *s, size_t length)
{
- if (s->allocated || s->data == NULL) {
- s->size += length;
- s->data = gnutls_realloc(s->data, s->size);
- if (s->data == NULL)
- return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
- s->allocated = 1;
- } else {
- void *data = s->data;
- size_t size = s->size + length;
- s->data = gnutls_malloc(size);
- memcpy(s->data, data, s->size);
- s->size += length;
- }
+ void *data;
+
+ s->size += length;
+ data = gnutls_realloc(s->data, s->size);
+ if (data == NULL)
+ return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+
+ s->data = data;
return 0;
}
@@ -926,11 +917,6 @@ copy_from_iov(struct iov_store_st *dst, const giovec_t *iov, int iovcnt)
memset(dst, 0, sizeof(*dst));
if (iovcnt == 0) {
return 0;
- } else if (iovcnt == 1) {
- dst->data = iov[0].iov_base;
- dst->size = iov[0].iov_len;
- /* implies: dst->allocated = 0; */
- return 0;
} else {
int i;
uint8_t *p;
@@ -944,11 +930,11 @@ copy_from_iov(struct iov_store_st *dst, const giovec_t *iov, int iovcnt)
p = dst->data;
for (i=0;i<iovcnt;i++) {
- memcpy(p, iov[i].iov_base, iov[i].iov_len);
+ if (iov[i].iov_len > 0)
+ memcpy(p, iov[i].iov_base, iov[i].iov_len);
p += iov[i].iov_len;
}
- dst->allocated = 1;
return 0;
}
}
diff --git a/tests/aead-cipher-vec.c b/tests/aead-cipher-vec.c
index fba9010d9..6a30a35f7 100644
--- a/tests/aead-cipher-vec.c
+++ b/tests/aead-cipher-vec.c
@@ -49,6 +49,7 @@ static void start(const char *name, int algo)
giovec_t auth_iov[2];
uint8_t tag[64];
size_t tag_size = 0;
+ size_t i;
key.data = key16;
key.size = gnutls_cipher_get_key_size(algo);
@@ -82,21 +83,23 @@ static void start(const char *name, int algo)
if (ret < 0)
fail("gnutls_cipher_init: %s\n", gnutls_strerror(ret));
- ret = gnutls_aead_cipher_encryptv2(ch,
- iv.data, iv.size,
- auth_iov, 2,
- iov, 3,
- tag, &tag_size);
- if (ret < 0)
- fail("could not encrypt data: %s\n", gnutls_strerror(ret));
-
- ret = gnutls_aead_cipher_decryptv2(ch,
- iv.data, iv.size,
- auth_iov, 2,
- iov, 3,
- tag, tag_size);
- if (ret < 0)
- fail("could not decrypt data: %s\n", gnutls_strerror(ret));
+ for (i = 0; i < 2; i++) {
+ ret = gnutls_aead_cipher_encryptv2(ch,
+ iv.data, iv.size,
+ auth_iov, 2,
+ iov, i + 1,
+ tag, &tag_size);
+ if (ret < 0)
+ fail("could not encrypt data: %s\n", gnutls_strerror(ret));
+
+ ret = gnutls_aead_cipher_decryptv2(ch,
+ iv.data, iv.size,
+ auth_iov, 2,
+ iov, i + 1,
+ tag, tag_size);
+ if (ret < 0)
+ fail("could not decrypt data: %s\n", gnutls_strerror(ret));
+ }
gnutls_aead_cipher_deinit(ch);
}
--
2.25.4