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authorymlbright <yml_bright@163.com>2018-08-22 11:22:11 +0800
committerPauli <paul.dale@oracle.com>2018-08-29 13:47:14 +1000
commit307a494e5b01ff9f334a8242d31b8254c7c54baa (patch)
tree8a841594478f976170e6439857ce4f4ee1085dde /crypto/sm2
parent7d38ca3f8bca58bf7b69e78c1f1ab69e5f429dff (diff)
downloadopenssl-new-307a494e5b01ff9f334a8242d31b8254c7c54baa.tar.gz
fix out-of-bounds write in sm2_crypt.c
asn1_encode has two form length octets: short form(1 byte), long form(1+n byte). CLA: Trivial Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com> Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/7027)
Diffstat (limited to 'crypto/sm2')
-rw-r--r--crypto/sm2/sm2_crypt.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/crypto/sm2/sm2_crypt.c b/crypto/sm2/sm2_crypt.c
index 9e7887320c..9c69a45054 100644
--- a/crypto/sm2/sm2_crypt.c
+++ b/crypto/sm2/sm2_crypt.c
@@ -91,11 +91,18 @@ int sm2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
{
const size_t field_size = ec_field_size(EC_KEY_get0_group(key));
const int md_size = EVP_MD_size(digest);
+ size_t sz;
if (field_size == 0 || md_size < 0)
return 0;
- *ct_size = 12 + 2 * field_size + (size_t)md_size + msg_len;
+ /* Integer and string are simple type; set constructed = 0, means primitive and definite length encoding. */
+ sz = 2 * ASN1_object_size(0, field_size + 1, V_ASN1_INTEGER)
+ + ASN1_object_size(0, md_size, V_ASN1_OCTET_STRING)
+ + ASN1_object_size(0, msg_len, V_ASN1_OCTET_STRING);
+ /* Sequence is structured type; set constructed = 1, means constructed and definite length encoding. */
+ *ct_size = ASN1_object_size(1, sz, V_ASN1_SEQUENCE);
+
return 1;
}