Optimize SHA1 calculation during image verification

There is no need to read the entire partition into memory when
calculating the checksum. In the case of e.g. rootfs this may not event
be possible.

Change-Id: I1165024ac8795cedc8ed9904ed35bea626d6601b

diff --git a/ss_engine/SS_UPI.c b/ss_engine/SS_UPI.c
index 71d10a1a7b596433541a773c3b657edfe39dd8bd..87e3054f90bf6d33ce6d5294016389cf3081b96b 100755 (executable)
--- a/ss_engine/SS_UPI.c
+++ b/ss_engine/SS_UPI.c
@@ -2256,10 +2256,10 @@ Cleanup:
 
 int SS_IMGVerfiyPartition(ua_dataSS_t * ua_dataSS)
 {
-       FileInfo source_file;
        int ulResult = S_SS_SUCCESS;
        uint8_t source_sha1[SHA_DIGEST_SIZE];
        uint8_t target_sha1[SHA_DIGEST_SIZE];
+       uint8_t calculated_sha1[SHA_DIGEST_SIZE];
        size_t free_space = 0;
 
        if (!(ua_dataSS && ua_dataSS->update_cfg && ua_dataSS->parti_info && ua_dataSS->parti_info->ua_blk_name)) {
@@ -2289,22 +2289,18 @@ int SS_IMGVerfiyPartition(ua_dataSS_t * ua_dataSS)
                return E_SS_FAILURE;
        }
 
-       source_file.size = ua_dataSS->update_cfg->soure_img_size;
-       source_file.data = NULL;
-       if (SS_LoadPartition(ua_dataSS->parti_info->ua_blk_name, &source_file) == 0) {
-               if (memcmp(source_file.sha1, source_sha1, SHA_DIGEST_SIZE) == 0) {
-                       LOGL(LOG_SSENGINE, "SS_IMGVerfiyPartition - SHA matches with source [%s] \n",
-                                ua_dataSS->parti_info->ua_blk_name);
-               } else {                          // Need not compare with Target sha as once upgraded, it should NOT verify same partition again.
-                       unsigned char actualShaBuffer[41] = { 0, };
-                       hex_digest(source_file.sha1, actualShaBuffer, SHA_DIGEST_SIZE);
-                       LOGE("SS_IMGVerfiyPartition - SHA mismatch with SRC [%s] Expected [%s] Actual [%s]\n",
-                               ua_dataSS->parti_info->ua_blk_name, ua_dataSS->update_cfg->soure_sha1, actualShaBuffer);
-                       SS_SetUpgradeState(E_SS_IMGSRCCURRUPTED);
-                       ulResult = E_SS_FAILURE;
-               }
+       SS_CalculateFileSha(ua_dataSS->parti_info->ua_blk_name, ua_dataSS->update_cfg->soure_img_size, calculated_sha1);
+       if (memcmp(calculated_sha1, source_sha1, SHA_DIGEST_SIZE) == 0) {
+               LOGL(LOG_SSENGINE, "SS_IMGVerfiyPartition - SHA matches with source [%s] \n",
+                        ua_dataSS->parti_info->ua_blk_name);
+       } else {                          // Need not compare with Target sha as once upgraded, it should NOT verify same partition again.
+               unsigned char actualShaBuffer[41] = { 0, };
+               hex_digest(calculated_sha1, actualShaBuffer, SHA_DIGEST_SIZE);
+               LOGE("SS_IMGVerfiyPartition - SHA mismatch with SRC [%s] Expected [%s] Actual [%s]\n",
+                       ua_dataSS->parti_info->ua_blk_name, ua_dataSS->update_cfg->soure_sha1, actualShaBuffer);
+               SS_SetUpgradeState(E_SS_IMGSRCCURRUPTED);
+               ulResult = E_SS_FAILURE;
        }
-       SS_Free(source_file.data);
        if (ulResult == S_SS_SUCCESS) {
                if (ua_dataSS->ui_progress)
                        ua_dataSS->ui_progress(ua_dataSS, 100);