remove unused EncodeBase64Secure

Also the hanging declaration of DecodeBase64Secure

src/utilstrencodings.cpp

@@ -193,33 +193,6 @@ std::string DecodeBase64(const std::string& str)
     return (vchRet.size() == 0) ? std::string() : std::string((const char*)&vchRet[0], vchRet.size());
 }
 
-// Base64 encoding with secure memory allocation
-SecureString EncodeBase64Secure(const SecureString& input)
-{
-    // Init openssl BIO with base64 filter and memory output
-    BIO *b64, *mem;
-    b64 = BIO_new(BIO_f_base64());
-    BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL); // No newlines in output
-    mem = BIO_new(BIO_s_mem());
-    BIO_push(b64, mem);
-
-    // Decode the string
-    BIO_write(b64, &input[0], input.size());
-    (void)BIO_flush(b64);
-
-    // Create output variable from buffer mem ptr
-    BUF_MEM* bptr;
-    BIO_get_mem_ptr(b64, &bptr);
-    SecureString output(bptr->data, bptr->length);
-
-    // Cleanse secure data buffer from memory
-    memory_cleanse((void*)bptr->data, bptr->length);
-
-    // Free memory
-    BIO_free_all(b64);
-    return output;
-}
-
 std::string EncodeBase32(const unsigned char* pch, size_t len)
 {
     static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";

src/utilstrencodings.h

@@ -56,8 +56,6 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = NULL);
 std::string DecodeBase64(const std::string& str);
 std::string EncodeBase64(const unsigned char* pch, size_t len);
 std::string EncodeBase64(const std::string& str);
-SecureString DecodeBase64Secure(const SecureString& input);
-SecureString EncodeBase64Secure(const SecureString& input);
 std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = NULL);
 std::string DecodeBase32(const std::string& str);
 std::string EncodeBase32(const unsigned char* pch, size_t len);