Canonicalise input in CMS_verify.
authorDr. Stephen Henson <steve@openssl.org>
Sun, 22 Dec 2013 00:35:29 +0000 (00:35 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Sun, 22 Dec 2013 00:35:29 +0000 (00:35 +0000)
If content is detached and not binary mode translate the input to
CRLF format. Before this change the input was verified verbatim
which lead to a discrepancy between sign and verify.

crypto/cms/cms_smime.c

index 204595b..8f1aa38 100644 (file)
 #include "cms_lcl.h"
 #include "asn1_locl.h"
 
-static int cms_copy_content(BIO *out, BIO *in, unsigned int flags)
+static BIO *cms_get_text_bio(BIO *out, unsigned int flags)
        {
-       unsigned char buf[4096];
-       int r = 0, i;
-       BIO *tmpout = NULL;
-
+       BIO *rbio;
        if (out == NULL)
-               tmpout = BIO_new(BIO_s_null());
+               rbio = BIO_new(BIO_s_null());
        else if (flags & CMS_TEXT)
                {
-               tmpout = BIO_new(BIO_s_mem());
-               BIO_set_mem_eof_return(tmpout, 0);
+               rbio = BIO_new(BIO_s_mem());
+               BIO_set_mem_eof_return(rbio, 0);
                }
        else
-               tmpout = out;
+               rbio = out;
+       return rbio;
+       }
+
+static int cms_copy_content(BIO *out, BIO *in, unsigned int flags)
+       {
+       unsigned char buf[4096];
+       int r = 0, i;
+       BIO *tmpout;
+
+       tmpout = cms_get_text_bio(out, flags);
 
        if(!tmpout)
                {
@@ -142,7 +149,7 @@ static void do_free_upto(BIO *f, BIO *upto)
                        BIO_free(f);
                        f = tbio;
                        }
-               while (f != upto);
+               while (f && f != upto);
                }
        else
                BIO_free_all(f);
@@ -323,7 +330,7 @@ int CMS_verify(CMS_ContentInfo *cms, STACK_OF(X509) *certs,
        STACK_OF(X509_CRL) *crls = NULL;
        X509 *signer;
        int i, scount = 0, ret = 0;
-       BIO *cmsbio = NULL, *tmpin = NULL;
+       BIO *cmsbio = NULL, *tmpin = NULL, *tmpout = NULL;
 
        if (!dcont && !check_content(cms))
                return 0;
@@ -406,15 +413,48 @@ int CMS_verify(CMS_ContentInfo *cms, STACK_OF(X509) *certs,
                }
        else
                tmpin = dcont;
-               
+       /* If not binary mode and detached generate digests by *writing*
+        * through the BIO. That makes it possible to canonicalise the
+        * input.
+        */
+       if (!(flags & SMIME_BINARY) && dcont)
+               {
+               /* Create output BIO so we can either handle text or to
+                * ensure included content doesn't override detached content.
+                */
+               tmpout = cms_get_text_bio(out, flags);
+               if(!tmpout)
+                       {
+                       CMSerr(CMS_F_CMS_VERIFY,ERR_R_MALLOC_FAILURE);
+                       goto err;
+                       }
+               cmsbio = CMS_dataInit(cms, tmpout);
+               if (!cmsbio)
+                       goto err;
+               /* Don't use SMIME_TEXT for verify: it adds headers and
+                * we want to remove them.
+                */
+               SMIME_crlf_copy(dcont, cmsbio, flags & ~SMIME_TEXT);
 
-       cmsbio=CMS_dataInit(cms, tmpin);
-       if (!cmsbio)
-               goto err;
+               if(flags & CMS_TEXT)
+                       {
+                       if (!SMIME_text(tmpout, out))
+                               {
+                               CMSerr(CMS_F_CMS_VERIFY,CMS_R_SMIME_TEXT_ERROR);
+                               goto err;
+                               }
+                       }
+               }
+       else
+               {
+               cmsbio=CMS_dataInit(cms, tmpin);
+               if (!cmsbio)
+                       goto err;
 
-       if (!cms_copy_content(out, cmsbio, flags))
-               goto err;
+               if (!cms_copy_content(out, cmsbio, flags))
+                       goto err;
 
+               }
        if (!(flags & CMS_NO_CONTENT_VERIFY))
                {
                for (i = 0; i < sk_CMS_SignerInfo_num(sinfos); i++)
@@ -432,11 +472,23 @@ int CMS_verify(CMS_ContentInfo *cms, STACK_OF(X509) *certs,
        ret = 1;
 
        err:
-       
-       if (dcont && (tmpin == dcont))
-               do_free_upto(cmsbio, dcont);
+       if (!(flags & SMIME_BINARY) && dcont)
+               {
+               do_free_upto(cmsbio, tmpout);
+               if (tmpin != dcont)
+                       BIO_free(tmpin);
+               }
        else
-               BIO_free_all(cmsbio);
+               {
+
+               if (dcont && (tmpin == dcont))
+                       do_free_upto(cmsbio, dcont);
+               else
+                       BIO_free_all(cmsbio);
+               }
+
+       if (tmpout && out != tmpout)
+               BIO_free_all(tmpout);
 
        if (cms_certs)
                sk_X509_pop_free(cms_certs, X509_free);