diff options
| author | Richard Levitte <levitte@openssl.org> | 2023-05-12 10:00:13 +0200 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2023-06-06 10:48:50 +0200 |
| commit | d63b3e7959e79f98d60760a739f7876dc5adc838 (patch) | |
| tree | 987531abfe2b0ed71fc1f1bc6e4a40238e0aab03 /crypto/objects | |
| parent | 3ca28c9e81fae36b0b44dc39beecd2b5a7561975 (diff) | |
Restrict the size of OBJECT IDENTIFIERs that OBJ_obj2txt will translate
OBJ_obj2txt() would translate any size OBJECT IDENTIFIER to canonical
numeric text form. For gigantic sub-identifiers, this would take a very
long time, the time complexity being O(n^2) where n is the size of that
sub-identifier.
To mitigate this, a restriction on the size that OBJ_obj2txt() will
translate to canonical numeric text form is added, based on RFC 2578
(STD 58), which says this:
> 3.5. OBJECT IDENTIFIER values
>
> An OBJECT IDENTIFIER value is an ordered list of non-negative numbers.
> For the SMIv2, each number in the list is referred to as a sub-identifier,
> there are at most 128 sub-identifiers in a value, and each sub-identifier
> has a maximum value of 2^32-1 (4294967295 decimal).
Fixes otc/security#96
Fixes CVE-2023-2650
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Diffstat (limited to 'crypto/objects')
| -rw-r--r-- | crypto/objects/obj_dat.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/crypto/objects/obj_dat.c b/crypto/objects/obj_dat.c index 0ef8330772..116080438b 100644 --- a/crypto/objects/obj_dat.c +++ b/crypto/objects/obj_dat.c @@ -464,6 +464,25 @@ int OBJ_obj2txt(char *buf, int buf_len, const ASN1_OBJECT *a, int no_name) first = 1; bl = NULL; + /* + * RFC 2578 (STD 58) says this about OBJECT IDENTIFIERs: + * + * > 3.5. OBJECT IDENTIFIER values + * > + * > An OBJECT IDENTIFIER value is an ordered list of non-negative + * > numbers. For the SMIv2, each number in the list is referred to as a + * > sub-identifier, there are at most 128 sub-identifiers in a value, + * > and each sub-identifier has a maximum value of 2^32-1 (4294967295 + * > decimal). + * + * So a legitimate OID according to this RFC is at most (32 * 128 / 7), + * i.e. 586 bytes long. + * + * Ref: https://datatracker.ietf.org/doc/html/rfc2578#section-3.5 + */ + if (len > 586) + goto err; + while (len > 0) { l = 0; use_bn = 0; |