Return an error if no recipient type matches.

If the key type does not match any CMS recipient type return
an error instead of using a random key (MMA mitigation). This
does not leak any useful information to an attacker.

PR#3348

diff --git a/crypto/cms/cms_smime.c b/crypto/cms/cms_smime.c
index e907b279eaac9dd93a906d2646dc2a5e6d155ee8..7ad827697e082f619b6e9065f6b5624d54e6d1b6 100644 (file)
--- a/crypto/cms/cms_smime.c
+++ b/crypto/cms/cms_smime.c
@@ -697,7 +697,7 @@ int CMS_decrypt_set1_pkey(CMS_ContentInfo *cms, EVP_PKEY *pk, X509 *cert)
        STACK_OF(CMS_RecipientInfo) *ris;
        CMS_RecipientInfo *ri;
        int i, r, ri_type;
-       int debug = 0;
+       int debug = 0, match_ri = 0;
        ris = CMS_get0_RecipientInfos(cms);
        if (ris)
                debug = cms->d.envelopedData->encryptedContentInfo->debug;
@@ -714,6 +714,7 @@ int CMS_decrypt_set1_pkey(CMS_ContentInfo *cms, EVP_PKEY *pk, X509 *cert)
                ri = sk_CMS_RecipientInfo_value(ris, i);
                if (CMS_RecipientInfo_type(ri) != ri_type)
                                continue;
+               match_ri = 1;
                if (ri_type == CMS_RECIPINFO_AGREE)
                        {
                        r = cms_kari_set1_pkey(cms, ri, pk, cert);
@@ -757,7 +758,7 @@ int CMS_decrypt_set1_pkey(CMS_ContentInfo *cms, EVP_PKEY *pk, X509 *cert)
                        }
                }
        /* If no cert and not debugging always return success */
-       if (!cert && !debug)
+       if (match_ri && !cert && !debug)
                {
                ERR_clear_error();
                return 1;