[EC][ASN1] Detect missing OID when serializing EC parameters and keys

The following built-in curves do not have an assigned OID:

- Oakley-EC2N-3
- Oakley-EC2N-4

In general we shouldn't assume that an OID is always available.

This commit detects such cases, raises an error and returns appropriate
return values so that the condition can be detected and correctly
handled by the callers, when serializing EC parameters or EC keys with
the default `ec_param_enc:named_curve`.

Fixes #12306

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/12313)

1 files changed, 1 insertions, 1 deletions

diff --git a/crypto/pem/pem_lib.c b/crypto/pem/pem_lib.c
index c170f60bcd..bd20bbb783 100644
--- a/crypto/pem/pem_lib.c
+++ b/crypto/pem/pem_lib.c
@@ -334,7 +334,7 @@ int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
         }
     }
 
-    if ((dsize = i2d(x, NULL)) < 0) {
+    if ((dsize = i2d(x, NULL)) <= 0) {
         PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_ASN1_LIB);
         dsize = 0;
         goto err;