diff options
| author | Daiki Ueno <ueno@gnu.org> | 2020-08-13 18:17:08 +0200 |
|---|---|---|
| committer | Daiki Ueno <ueno@gnu.org> | 2020-08-17 10:45:16 +0200 |
| commit | 206124659008728cb01eeab710322c7611a28676 (patch) | |
| tree | 150555234fc577da7d32cbf0f7d7258f2355a1aa /lib | |
| parent | 606b77a2422c7e4124d80904bd191184323205fc (diff) | |
| download | gnutls-tmp-cipher-check-length.tar.gz | |
gnutls_aead_cipher_decrypt: check output buffer size before writingtmp-cipher-check-length
While the documentation of gnutls_aead_cipher_decrypt indicates that
the inout argument ptext_len initially holds the size that
sufficiently fits the expected output size, there was no runtime check
on that. This makes the interface robuster against misuses.
Signed-off-by: Daiki Ueno <ueno@gnu.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/nettle/cipher.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/nettle/cipher.c b/lib/nettle/cipher.c index ec0c1ab043..a82386b100 100644 --- a/lib/nettle/cipher.c +++ b/lib/nettle/cipher.c @@ -1288,6 +1288,10 @@ wrap_nettle_cipher_aead_decrypt(void *_ctx, ctx->cipher->auth(ctx->ctx_ptr, auth_size, auth); encr_size -= tag_size; + + if (unlikely(plain_size < encr_size)) + return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER); + ctx->cipher->decrypt(ctx, encr_size, plain, encr); ctx->cipher->tag(ctx->ctx_ptr, tag_size, tag); @@ -1297,6 +1301,10 @@ wrap_nettle_cipher_aead_decrypt(void *_ctx, } else { /* CCM-style cipher */ encr_size -= tag_size; + + if (unlikely(plain_size < encr_size)) + return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER); + ret = ctx->cipher->aead_decrypt(ctx, nonce_size, nonce, auth_size, auth, |