Use internal SHA256 helpers in hash header

src/hash.h

@@ -23,7 +23,6 @@
 #include "crypto/sha512.h"
 
 #include <iomanip>
-#include <openssl/sha.h>
 #include <sstream>
 #include <vector>
 
@@ -151,13 +150,10 @@ public:
 /** Compute the 256-bit hash of a std::string */
 inline std::string Hash(std::string input)
 {
-    unsigned char hash[SHA256_DIGEST_LENGTH];
-    SHA256_CTX sha256;
-    SHA256_Init(&sha256);
-    SHA256_Update(&sha256, input.c_str(), input.size());
-    SHA256_Final(hash, &sha256);
+    unsigned char hash[CSHA256::OUTPUT_SIZE];
+    CSHA256().Write((const unsigned char*)input.data(), input.size()).Finalize(hash);
     stringstream ss;
-    for (int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
+    for (int i = 0; i < CSHA256::OUTPUT_SIZE; i++) {
         ss << hex << setw(2) << setfill('0') << (int)hash[i];
     }
     return ss.str();
@@ -166,10 +162,7 @@ inline std::string Hash(std::string input)
 /** Compute the 256-bit hash of a void pointer */
 inline void Hash(void* in, unsigned int len, unsigned char* out)
 {
-    SHA256_CTX sha256;
-    SHA256_Init(&sha256);
-    SHA256_Update(&sha256, in, len);
-    SHA256_Final(out, &sha256);
+    CSHA256().Write((const unsigned char*)in, len).Finalize(out);
 }
 
 /** Compute the 512-bit hash of an object. */