Handle valid case for hash_size==0

If hash size is 0 then MD algorithm must not be NONE, in this
case hash_size is extracted from expected length for MD algorithm.
If MD algorithm is not NONE, then hash_size is validated against
the algorithm's expected input length.

Change-Id: Ib95d8138ce6a21c364a5d7f88910fde15e32a026
Signed-off-by: Jaroslaw Pelczar <j.pelczar@samsung.com>

diff --git a/dcm-client/dcmclient.cpp b/dcm-client/dcmclient.cpp
index 22f9bb9..8f82f03 100644 (file)
--- a/dcm-client/dcmclient.cpp
+++ b/dcm-client/dcmclient.cpp
@@ -297,25 +297,49 @@ int dcm_client_connection_impl::sign_data(mbedtls_md_type_t digestType, const vo
                return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
        }
 
-       const mbedtls_md_info_t * md_info = mbedtls_md_info_from_type(digestType);
+       /*
+        * If hash_size == 0 then hash type must be known
+        */
+       if(hash_size == 0) {
+               if(digestType == MBEDTLS_MD_NONE) {
+#ifdef USE_DLOG_LOGGING
+                       LOGD("%s: Digest type is NONE and hash size is 0", __FUNCTION__);
+#endif
+                       return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+               }
 
-       if(!md_info) {
+               const mbedtls_md_info_t * md_info = mbedtls_md_info_from_type(digestType);
+
+               if(!md_info) {
 #ifdef USE_DLOG_LOGGING
-               LOGD("%s: Can't find hash data for digest type %d", __FUNCTION__, digestType);
+                       LOGD("%s: Can't find hash data for digest type %d", __FUNCTION__, digestType);
 #endif
-               return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
-       }
+                       return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+               }
 
-       if(hash_size == 0) {
 #ifdef USE_DLOG_LOGGING
                LOGD("%s: Overriding hash size to %zd bytes", __FUNCTION__, hash_size);
 #endif
                hash_size = mbedtls_md_get_size(md_info);
-       } else if(hash_size != mbedtls_md_get_size(md_info)) {
+       } else if(hash_size != 0 && digestType != MBEDTLS_MD_NONE) {
+               /*
+                * If hash_size != 0 then hash type can be specified
+                */
+               const mbedtls_md_info_t * md_info = mbedtls_md_info_from_type(digestType);
+
+               if(!md_info) {
 #ifdef USE_DLOG_LOGGING
-               LOGE("%s: Hash size mismatch. Expected %zd but got %zd", __FUNCTION__, hash_size, (size_t)mbedtls_md_get_size(md_info));
+                       LOGD("%s: Can't find hash data for digest type %d", __FUNCTION__, digestType);
 #endif
-               return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+                       return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+               }
+
+               if(hash_size != mbedtls_md_get_size(md_info)) {
+#ifdef USE_DLOG_LOGGING
+                       LOGE("%s: Hash size mismatch. Expected %zd but got %zd", __FUNCTION__, hash_size, (size_t)mbedtls_md_get_size(md_info));
+#endif
+                       return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+               }
        }
 
        try {

diff --git a/dcm-daemon/dcmsession.cpp b/dcm-daemon/dcmsession.cpp
index 615e762..9bdd07d 100644 (file)
--- a/dcm-daemon/dcmsession.cpp
+++ b/dcm-daemon/dcmsession.cpp
@@ -402,25 +402,33 @@ void dcm_session::handle_sign_request(const SignRequest& message)
                return;
        }
 
-       const mbedtls_md_info_t * md_info = mbedtls_md_info_from_type(
-                       static_cast<mbedtls_md_type_t>(
-                               message.digest_type()));
-
-       if(!md_info) {
-               BOOST_LOG_SEV(dcm_logger::get(), log_severity::error) << "Can't find crypto algorithm specified by caller";
+       if(message.data_to_sign().size() == 0) {
+               BOOST_LOG_SEV(dcm_logger::get(), log_severity::error) << "Data to sign is empty and hash type is NONE";
                signingResponse->set_result(MBEDTLS_ERR_PK_BAD_INPUT_DATA);
-               reply(msg);
                return;
        }
 
-       if(message.data_to_sign().size() != mbedtls_md_get_size(md_info)) {
-               BOOST_LOG_SEV(dcm_logger::get(), log_severity::error) <<
-                               "Input hash length mismatch. It is " <<
-                               message.data_to_sign().size() << " but should be " <<
-                               mbedtls_md_get_size(md_info);
-               signingResponse->set_result(MBEDTLS_ERR_PK_BAD_INPUT_DATA);
-               reply(msg);
-               return;
+       mbedtls_md_type_t mdType = static_cast<mbedtls_md_type_t>(message.digest_type());
+
+       if(mdType != MBEDTLS_MD_NONE) {
+               const mbedtls_md_info_t * md_info = mbedtls_md_info_from_type(mdType);
+
+               if(!md_info) {
+                       BOOST_LOG_SEV(dcm_logger::get(), log_severity::error) << "Can't find MD algorithm specified by caller";
+                       signingResponse->set_result(MBEDTLS_ERR_PK_BAD_INPUT_DATA);
+                       reply(msg);
+                       return;
+               }
+
+               if(message.data_to_sign().size() != mbedtls_md_get_size(md_info)) {
+                       BOOST_LOG_SEV(dcm_logger::get(), log_severity::error) <<
+                                       "Input hash length mismatch. It is " <<
+                                       message.data_to_sign().size() << " but should be " <<
+                                       mbedtls_md_get_size(md_info);
+                       signingResponse->set_result(MBEDTLS_ERR_PK_BAD_INPUT_DATA);
+                       reply(msg);
+                       return;
+               }
        }
 
        signingResponse->set_result(