From 3f241f92d455ad9381b3e7ba13cf61def28d0634 Mon Sep 17 00:00:00 2001 From: bjk Date: Mon, 16 Dec 2013 02:25:28 +0000 Subject: [PATCH] MFC r259286,259424,259425: Apply patch from upstream Heimdal for encoding fix RFC 4402 specifies the implementation of the gss_pseudo_random() function for the krb5 mechanism (and the C bindings therein). The implementation uses a PRF+ function that concatenates the output of individual krb5 pseudo-random operations produced with a counter and seed. The original implementation of this function in Heimdal incorrectly encoded the counter as a little-endian integer, but the RFC specifies the counter encoding as big-endian. The implementation initializes the counter to zero, so the first block of output (16 octets, for the modern AES enctypes 17 and 18) is unchanged. (RFC 4402 specifies that the counter should begin at 1, but both existing implementations begin with zero and it looks like the standard will be re-issued, with test vectors, to begin at zero.) This is upstream's commit f85652af868e64811f2b32b815d4198e7f9017f6, from 13 October, 2013: % Fix krb5's gss_pseudo_random() (n is big-endian) % % The first enctype RFC3961 prf output length's bytes are correct because % the little- and big-endian representations of unsigned zero are the % same. The second block of output was wrong because the counter was not % being encoded as big-endian. % % This change could break applications. But those applications would not % have been interoperating with other implementations anyways (in % particular: MIT's). Bump __FreeBSD_version accordingly and add a note in UPDATING. Approved by: hrs (mentor, src committer) git-svn-id: svn://svn.freebsd.org/base/stable/9@259448 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- UPDATING | 11 +++++++++++ crypto/heimdal/lib/gssapi/krb5/prf.c | 4 ++-- sys/sys/param.h | 2 +- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/UPDATING b/UPDATING index 27487500d..065926013 100644 --- a/UPDATING +++ b/UPDATING @@ -11,6 +11,17 @@ handbook: Items affecting the ports and packages system can be found in /usr/ports/UPDATING. Please read that file before running portupgrade. +20131216: + The behavior of gss_pseudo_random() for the krb5 mechanism + has changed, for applications requesting a longer random string + than produced by the underlying enctype's pseudo-random() function. + In particular, the random string produced from a session key of + enctype aes256-cts-hmac-sha1-96 or aes256-cts-hmac-sha1-96 will + be different at the 17th octet and later, after this change. + The counter used in the PRF+ construction is now encoded as a + big-endian integer in accordance with RFC 4402. + __FreeBSD_version is bumped to 902505. + 20130930: 9.2-RELEASE. diff --git a/crypto/heimdal/lib/gssapi/krb5/prf.c b/crypto/heimdal/lib/gssapi/krb5/prf.c index f79c9374a..eaa9a14c2 100644 --- a/crypto/heimdal/lib/gssapi/krb5/prf.c +++ b/crypto/heimdal/lib/gssapi/krb5/prf.c @@ -117,7 +117,7 @@ _gsskrb5_pseudo_random(OM_uint32 *minor_status, num = 0; p = prf_out->value; while(desired_output_len > 0) { - _gsskrb5_encode_om_uint32(num, input.data); + _gsskrb5_encode_be_om_uint32(num, input.data); ret = krb5_crypto_prf(context, crypto, &input, &output); if (ret) { OM_uint32 junk; @@ -129,7 +129,7 @@ _gsskrb5_pseudo_random(OM_uint32 *minor_status, return GSS_S_FAILURE; } memcpy(p, output.data, min(desired_output_len, output.length)); - p += output.length; + p += tsize; desired_output_len -= output.length; krb5_data_free(&output); num++; diff --git a/sys/sys/param.h b/sys/sys/param.h index 9459dbed3..ed0587907 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -58,7 +58,7 @@ * in the range 5 to 9. */ #undef __FreeBSD_version -#define __FreeBSD_version 902504 /* Master, propagated to newvers */ +#define __FreeBSD_version 902505 /* Master, propagated to newvers */ /* * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, -- 2.45.0