diff options
| author | David Benjamin <davidben@google.com> | 2016-08-20 13:35:17 -0400 |
|---|---|---|
| committer | Kurt Roeckx <kurt@roeckx.be> | 2016-11-07 21:04:54 +0100 |
| commit | 608a026494c1e7a14f6d6cfcc5e4994fe2728836 (patch) | |
| tree | d519d9b8d3b385df8551e560abf46568c1016a8f /test/evptests.txt | |
| parent | c8e2f98c97ff3327784843946c2d62761572e5d5 (diff) | |
Implement RSASSA-PKCS1-v1_5 as specified.
RFC 3447, section 8.2.2, steps 3 and 4 states that verifiers must encode
the DigestInfo struct and then compare the result against the public key
operation result. This implies that one and only one encoding is legal.
OpenSSL instead parses with crypto/asn1, then checks that the encoding
round-trips, and allows some variations for the parameter. Sufficient
laxness in this area can allow signature forgeries, as described in
https://www.imperialviolet.org/2014/09/26/pkcs1.html
Although there aren't known attacks against OpenSSL's current scheme,
this change makes OpenSSL implement the algorithm as specified. This
avoids the uncertainty and, more importantly, helps grow a healthy
ecosystem. Laxness beyond the spec, particularly in implementations
which enjoy wide use, risks harm to the ecosystem for all. A signature
producer which only tests against OpenSSL may not notice bugs and
accidentally become widely deployed. Thus implementations have a
responsibility to honor the specification as tightly as is practical.
In some cases, the damage is permanent and the spec deviation and
security risk becomes a tax all implementors must forever pay, but not
here. Both BoringSSL and Go successfully implemented and deployed
RSASSA-PKCS1-v1_5 as specified since their respective beginnings, so
this change should be compatible enough to pin down in future OpenSSL
releases.
See also https://tools.ietf.org/html/draft-thomson-postel-was-wrong-00
As a bonus, by not having to deal with sign/verify differences, this
version is also somewhat clearer. It also more consistently enforces
digest lengths in the verify_recover codepath. The NID_md5_sha1 codepath
wasn't quite doing this right.
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>
GH: #1474
Diffstat (limited to 'test/evptests.txt')
| -rw-r--r-- | test/evptests.txt | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/test/evptests.txt b/test/evptests.txt index 147c8a4ea6..775371f274 100644 --- a/test/evptests.txt +++ b/test/evptests.txt @@ -2535,11 +2535,12 @@ Input = "0123456789ABCDEF1233" Output = 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 Result = VERIFY_ERROR -# parameter is not NULL: should verify OK +# parameter is not NULL Verify = RSA-2048 Ctrl = digest:sha1 Input = "0123456789ABCDEF1234" Output = 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 +Result = VERIFY_ERROR # embedded digest too long Verify = RSA-2048 |