lkml.org 
[lkml]   [2018]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.15 14/64] PKCS#7: fix certificate blacklisting
    Date
    4.15-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Eric Biggers <ebiggers@google.com>

    commit 29f4a67c17e19314b7d74b8569be935e6c7edf50 upstream.

    If there is a blacklisted certificate in a SignerInfo's certificate
    chain, then pkcs7_verify_sig_chain() sets sinfo->blacklisted and returns
    0. But, pkcs7_verify() fails to handle this case appropriately, as it
    actually continues on to the line 'actual_ret = 0;', indicating that the
    SignerInfo has passed verification. Consequently, PKCS#7 signature
    verification ignores the certificate blacklist.

    Fix this by not considering blacklisted SignerInfos to have passed
    verification.

    Also fix the function comment with regards to when 0 is returned.

    Fixes: 03bb79315ddc ("PKCS#7: Handle blacklisted certificates")
    Cc: <stable@vger.kernel.org> # v4.12+
    Signed-off-by: Eric Biggers <ebiggers@google.com>
    Signed-off-by: David Howells <dhowells@redhat.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    crypto/asymmetric_keys/pkcs7_verify.c | 10 ++++++----
    1 file changed, 6 insertions(+), 4 deletions(-)

    --- a/crypto/asymmetric_keys/pkcs7_verify.c
    +++ b/crypto/asymmetric_keys/pkcs7_verify.c
    @@ -366,8 +366,7 @@ static int pkcs7_verify_one(struct pkcs7
    *
    * (*) -EBADMSG if some part of the message was invalid, or:
    *
    - * (*) 0 if no signature chains were found to be blacklisted or to contain
    - * unsupported crypto, or:
    + * (*) 0 if a signature chain passed verification, or:
    *
    * (*) -EKEYREJECTED if a blacklisted key was encountered, or:
    *
    @@ -423,8 +422,11 @@ int pkcs7_verify(struct pkcs7_message *p

    for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
    ret = pkcs7_verify_one(pkcs7, sinfo);
    - if (sinfo->blacklisted && actual_ret == -ENOPKG)
    - actual_ret = -EKEYREJECTED;
    + if (sinfo->blacklisted) {
    + if (actual_ret == -ENOPKG)
    + actual_ret = -EKEYREJECTED;
    + continue;
    + }
    if (ret < 0) {
    if (ret == -ENOPKG) {
    sinfo->unsupported_crypto = true;

    \
     
     \ /
      Last update: 2018-02-26 21:45    [W:4.112 / U:0.244 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site