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
Add -DBIO_DEBUG to --strict-warnings.
Remove comments about outdated debugging ifdef guards.
Remove md_rand ifdef guarding an assert; it doesn't seem used.
Remove the conf guards in conf_api since we use OPENSSL_assert, not assert.
For pkcs12 stuff put OPENSSL_ in front of the macro name.
Merge TLS_DEBUG into SSL_DEBUG.
Various things just turned on/off asserts, mainly for checking non-NULL
arguments, which is now removed: camellia, bn_ctx, crypto/modes.
Remove some old debug code, that basically just printed things to stderr:
DEBUG_PRINT_UNKNOWN_CIPHERSUITES, DEBUG_ZLIB, OPENSSL_RI_DEBUG,
RL_DEBUG, RSA_DEBUG, SCRYPT_DEBUG.
Remove OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL.
Reviewed-by: Richard Levitte <levitte@openssl.org>
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Remove RSA_FLAG_SIGN_VER: this was origininally used to retain binary
compatibility after RSA_METHOD was extended to include rsa_sign and
rsa_verify fields. It is no longer needed.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The function int_rsa_verify is an internal function used for verifying an
RSA signature. It takes an argument |dtype| which indicates the digest type
that was used. Dependant on that digest type the processing of the
signature data will vary. In particular if |dtype == NID_mdc2| and the
signature data is a bare OCTETSTRING then it is treated differently to the
default case where the signature data is treated as a DigestInfo (X509_SIG).
Due to a missing "else" keyword the logic actually correctly processes the
OCTETSTRING format signature first, and then attempts to continue and
process it as DigestInfo. This will invariably fail because we already know
that it is a bare OCTETSTRING.
This failure doesn't actualy make a real difference because it ends up at
the |err| label regardless and still returns a "success" result. This patch
just cleans things up to make it look a bit more sane.
RT#4076
Reviewed-by: Richard Levitte <levitte@openssl.org>
There are header files in crypto/ that are used by a number of crypto/
submodules. Move those to crypto/include/internal and adapt the
affected source code and Makefiles.
The header files that got moved are:
crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: Rich Salz <rsalz@openssl.org>
Add OPENSSL_clear_free which merges cleanse and free.
(Names was picked to be similar to BN_clear_free, etc.)
Removed OPENSSL_freeFunc macro.
Fixed the small simple ones that are left:
CRYPTO_free CRYPTO_free_locked OPENSSL_free_locked
Reviewed-by: Richard Levitte <levitte@openssl.org>
Don't check for NULL before calling a free routine. This gets X509_.*free:
x509_name_ex_free X509_policy_tree_free X509_VERIFY_PARAM_free
X509_STORE_free X509_STORE_CTX_free X509_PKEY_free
X509_OBJECT_free_contents X509_LOOKUP_free X509_INFO_free
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reencode DigestInto in DER and check against the original: this
will reject any improperly encoded DigestInfo structures.
Note: this is a precautionary measure, there is no known attack
which can exploit this.
Thanks to Brian Smith for reporting this issue.
Reviewed-by: Tim Hudson <tjh@openssl.org>
signatures and MDC2 using EVP or RSA_sign. This has become more apparent
when the dgst utility in OpenSSL 1.0.0 and later switched to using the
EVP_DigestSign functions which call RSA_sign.
This means that the signature format OpenSSL 1.0.0 and later used with
dgst -sign and MDC2 is incompatible with previous versions.
Add detection in RSA_verify so either format works.
Note: MDC2 is disabled by default in OpenSSL and very rarely used in practice.
functions and macros.
This change has associated tags: LEVITTE_before_const and
LEVITTE_after_const. Those will be removed when this change has been
properly reviewed.
called downstream that need it to be non-const. The fact that the RSA_METHOD
functions take the RSA* as a const doesn't matter, it just expresses that
*they* won't touch it.
PR: 602
sure they are available in opensslconf.h, by giving them names starting
with "OPENSSL_" to avoid conflicts with other packages and by making
sure e_os2.h will cover all platform-specific cases together with
opensslconf.h.
I've checked fairly well that nothing breaks with this (apart from
external software that will adapt if they have used something like
NO_KRB5), but I can't guarantee it completely, so a review of this
change would be a good thing.
like Malloc, Realloc and especially Free conflict with already existing names
on some operating systems or other packages. That is reason enough to change
the names of the OpenSSL memory allocation macros to something that has a
better chance of being unique, like prepending them with OPENSSL_.
This change includes all the name changes needed throughout all C files.
