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TLS: Fix unsigned int underflow in internal TLS 1.0/1.1 implementation

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Taking sizeof(ptr) is incorrect to determine size of passed in hash and
results in hlen getting set to a very large value since MD5_MAC_LEN >
sizeof(ptr). Provide the actual size of the hash buffer from the caller
to fix this.

tls_key_x_server_params_hash() callers src/tls/tlsv1_client_read.c and
src/tls/tlsv1_server_write.c both pass in a large enough hash (hash[64]
or hash[100]) that this does not appear to have an impact, though it is
still wrong.

Signed-off-by: Glenn Strauss <gstrauss@gluelogic.com>
This commit is contained in:
Glenn Strauss 2022-11-08 00:05:54 -05:00 committed by Jouni Malinen
parent 802b67bced
commit 12f16c27ba
4 changed files with 9 additions and 5 deletions
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3
src/tls/tlsv1_client_read.c
View file

@ -771,7 +771,8 @@ static int tlsv1_process_diffie_hellman(struct tlsv1_client *conn,
hlen = tls_key_x_server_params_hash(
conn->rl.tls_version, conn->client_random,
conn->server_random, server_params,
server_params_end - server_params, hash);
server_params_end - server_params, hash,
sizeof(hash));
}
if (hlen < 0)

6
src/tls/tlsv1_common.c
View file

@ -378,7 +378,7 @@ int tlsv12_key_x_server_params_hash(u16 tls_version, u8 hash_alg,
int tls_key_x_server_params_hash(u16 tls_version, const u8 *client_random,
const u8 *server_random,
const u8 *server_params,
size_t server_params_len, u8 *hash)
size_t server_params_len, u8 *hash, size_t hsz)
{
u8 *hpos;
size_t hlen;
@ -393,6 +393,8 @@ int tls_key_x_server_params_hash(u16 tls_version, const u8 *client_random,
crypto_hash_update(ctx, server_random, TLS_RANDOM_LEN);
crypto_hash_update(ctx, server_params, server_params_len);
hlen = MD5_MAC_LEN;
if (hsz < hlen)
return -1;
if (crypto_hash_finish(ctx, hash, &hlen) < 0)
return -1;
hpos += hlen;
@ -403,7 +405,7 @@ int tls_key_x_server_params_hash(u16 tls_version, const u8 *client_random,
crypto_hash_update(ctx, client_random, TLS_RANDOM_LEN);
crypto_hash_update(ctx, server_random, TLS_RANDOM_LEN);
crypto_hash_update(ctx, server_params, server_params_len);
hlen = hash + sizeof(hash) - hpos;
hlen = hsz - hlen;
if (crypto_hash_finish(ctx, hpos, &hlen) < 0)
return -1;
hpos += hlen;

3
src/tls/tlsv1_common.h
View file

@ -267,7 +267,8 @@ int tlsv12_key_x_server_params_hash(u16 tls_version, u8 hash_Alg,
int tls_key_x_server_params_hash(u16 tls_version, const u8 *client_random,
const u8 *server_random,
const u8 *server_params,
size_t server_params_len, u8 *hash);
size_t server_params_len,
u8 *hash, size_t hsz);
int tls_verify_signature(u16 tls_version, struct crypto_public_key *pk,
const u8 *data, size_t data_len,
const u8 *pos, size_t len, u8 *alert);

2
src/tls/tlsv1_server_write.c
View file

@ -620,7 +620,7 @@ static int tls_write_server_key_exchange(struct tlsv1_server *conn,
hlen = tls_key_x_server_params_hash(
conn->rl.tls_version, conn->client_random,
conn->server_random, server_params,
pos - server_params, hash);
pos - server_params, hash, sizeof(hash));
}
if (hlen < 0) {