From 963314f4f449e136195232bdada3109af65d0881 Mon Sep 17 00:00:00 2001
From: Julien Rische <jrische@redhat.com>
Date: Thu, 28 Jul 2022 15:20:12 +0200
Subject: [PATCH] Update error checking for OpenSSL CMS_verify

The code for CMS data verification was initially written for OpenSSL's
PKCS7_verify() function.  It now uses CMS_verify(), but error handling
is still done using PKCS7_verify() error identifiers.  Update the
recognized error codes so that the KDC generates
KDC_ERR_DIGEST_IN_SIGNED_DATA_NOT_ACCEPTED errors when appropriate.
Use ERR_peek_last_error() to observe the error generated closest to
the API surface.

[ghudson@mit.edu: edited commit message]

ticket: 9069 (new)
tags: pullup
target_version: 1.20-next
---
 src/plugins/preauth/pkinit/pkinit_crypto_openssl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
index 1c2aa02827..16edf15cb2 100644
--- a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
+++ b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
@@ -2102,12 +2102,15 @@ cms_signeddata_verify(krb5_context context,
             goto cleanup;
         out = BIO_new(BIO_s_mem());
         if (CMS_verify(cms, NULL, store, NULL, out, flags) == 0) {
-            unsigned long err = ERR_peek_error();
+            unsigned long err = ERR_peek_last_error();
             switch(ERR_GET_REASON(err)) {
-            case PKCS7_R_DIGEST_FAILURE:
+            case RSA_R_DIGEST_NOT_ALLOWED:
+            case CMS_R_UNKNOWN_DIGEST_ALGORITHM:
+            case CMS_R_NO_MATCHING_DIGEST:
+            case CMS_R_NO_MATCHING_SIGNATURE:
                 retval = KRB5KDC_ERR_DIGEST_IN_SIGNED_DATA_NOT_ACCEPTED;
                 break;
-            case PKCS7_R_SIGNATURE_FAILURE:
+            case CMS_R_VERIFICATION_FAILURE:
             default:
                 retval = KRB5KDC_ERR_INVALID_SIG;
             }
-- 
2.38.1