1 files changed, 40 insertions, 17 deletions

diff --git a/src/AccessoryCards/Mtac15Fpga.cpp b/src/AccessoryCards/Mtac15Fpga.cpp
index ef3b7bd..a6ac838 100644
--- a/src/AccessoryCards/Mtac15Fpga.cpp
+++ b/src/AccessoryCards/Mtac15Fpga.cpp
@@ -14,7 +14,7 @@
  * WRITTEN AGREEMENT SIGNED BY MULTI-TECH SYSTEMS, INC. IS PROHIBITED.
  *
  ***********************************************************************/
-
+#include <openssl/evp.h>
 #include "Fpga.h"
 
 /* -------------------------------------------------------------------------- */
@@ -85,24 +85,45 @@ void Mtac15Fpga::sha256_hash_string(unsigned char hash[SHA256_DIGEST_LENGTH],
 }
 
 /* Initialize, update and finalize sha256 */
-void Mtac15Fpga::sha256(char *string, char outputBuffer[65]) {
-    unsigned char hash[SHA256_DIGEST_LENGTH];
-    int len;
-    SHA256_CTX sha256;
-    SHA256_Init(&sha256);
+#define OUTPUTBUFFERSZ 65
+void Mtac15Fpga::sha256(char *string, char outputBuffer[OUTPUTBUFFERSZ]) {
+    unsigned int len;
+    EVP_MD_CTX *mdctx;
+    unsigned char *digest;
+
+    mdctx = EVP_MD_CTX_new();
+    EVP_DigestInit_ex(mdctx, EVP_sha256(), NULL);
+
     len = strlen(string);
-    SHA256_Update(&sha256, string, len);
-    SHA256_Final(hash, &sha256);
-    int i = 0;
-    for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
-        sprintf(outputBuffer + (i * 2), "%02x", (unsigned char)hash[i]);
+    EVP_DigestUpdate(mdctx, string, len);
+
+    digest = (unsigned char *)OPENSSL_malloc(EVP_MD_size(EVP_sha256()));
+
+    EVP_DigestFinal_ex(mdctx, digest, &len);
+
+    int total = 0;
+    for (unsigned int i = 0; i < len; i++) {
+        if(total + 2 <= OUTPUTBUFFERSZ - 1)
+            total += sprintf(outputBuffer + (i * 2), "%02x", (unsigned char)digest[i]);
+        else {
+            printError("%s:%s: overflow of outputBuffer %d/%d\n",
+                       __FILE__,__FUNCTION__,total+2,EVP_MD_size(EVP_sha256()));
+            abort();
+        }
     }
     outputBuffer[64] = 0;
     printInfo("OutputBuffer finalized: %s", outputBuffer);
+    EVP_MD_CTX_free(mdctx);
+    OPENSSL_free(digest);
 }
 
 /* Open input file and verify sha256 with verified list */
 int Mtac15Fpga::sha256_file(const char *path) {
+    unsigned int len;
+    EVP_MD_CTX *mdctx;
+    unsigned char *digest;
+
+
     printInfo("Checking hash on input file: %s", path);
 
     FILE *file = fopen(path, "rb");
@@ -115,9 +136,10 @@ int Mtac15Fpga::sha256_file(const char *path) {
 
     unsigned int i;
     char file_hash[65];
-    unsigned char hash[SHA256_DIGEST_LENGTH];
-    SHA256_CTX sha256;
-    SHA256_Init(&sha256);
+
+    mdctx = EVP_MD_CTX_new();
+    EVP_DigestInit_ex(mdctx, EVP_sha256(), NULL);
+
     const int bufSize = 32768;
     unsigned char *buffer = (unsigned char *)malloc(bufSize);
     int bytesRead = 0;
@@ -125,10 +147,11 @@ int Mtac15Fpga::sha256_file(const char *path) {
     if (!buffer)
         return ENOMEM;
     while ((bytesRead = fread(buffer, 1, bufSize, file))) {
-        SHA256_Update(&sha256, buffer, bytesRead);
+	EVP_DigestUpdate(mdctx, buffer, bytesRead);
     }
-    SHA256_Final(hash, &sha256);
-    sha256_hash_string(hash, file_hash);
+    digest = (unsigned char *)OPENSSL_malloc(EVP_MD_size(EVP_sha256()));
+    EVP_DigestFinal_ex(mdctx, digest, &len);
+    sha256_hash_string(digest, file_hash);
     fclose(file);
     free(buffer);