New answer as of February 23rd 2017 For more than six years, the SHA1 cryptographic hash function underpinning Internet security has been at death’s door. Now it’s officially dead, thanks to the submission of the first known instance of a fatal exploit known as a “collision.” Previous answer (no longer accurate) There is no known … Read more
Use checksumdir python package available for calculating checksum/hash of directory. It’s available at https://pypi.python.org/pypi/checksumdir Usage : import checksumdir hash = checksumdir.dirhash(“c:\\temp”) print hash
Your current equality method is broken – there are more values than possible hash codes. It’s entirely reasonable (and expected) that you will occasionally have values which are unequal but give the same hash. Equals should check the actual values: public override bool Equals(object obj) { Test test = obj as Test; if (obj == … Read more
That’s just because of String#inspect. There are no backslashes. Try: hjs = hash.to_json puts hjs
If you have all of your data at once, just use the SHA1 function: // The data to be hashed char data[] = “Hello, world!”; size_t length = strlen(data); unsigned char hash[SHA_DIGEST_LENGTH]; SHA1(data, length, hash); // hash now contains the 20-byte SHA-1 hash If, on the other hand, you only get your data one piece … Read more
SHA512, SHA256, SHA1, and MD5 are vulnerable to a length extension attack. SHA224 and SHA384 are not since reduced output to internal state, SHA3 is also not vulnerable. Having that in mind, SHA512 is a good cryptographic collision-resistant hash function.
For a quick solution involving no external libraries, you can use hash<std::string> to hash strings. It’s defined by including the header files hash_map or unordered_map (or some others too). #include <string> #include <unordered_map> hash<string> hasher; string s = “heyho”; size_t hash = hasher(s); If you decide you want the added security of SHA, you don’t … Read more
An MD5 value is always 22 (useful) characters long in Base64 notation. Many Base64 algorithms will also append 2 characters of padding when encoding an MD5 hash, bringing the total to 24 characters. The padding adds no useful information and can be discarded. Only the first 22 characters matter. Here’s why: An MD5 hash is … Read more
You can see the implementation of hashCode function in java.util.ArrayList as public int hashCode() { int hashCode = 1; Iterator<E> i = iterator(); while (i.hasNext()) { E obj = i.next(); hashCode = 31*hashCode + (obj==null ? 0 : obj.hashCode()); } return hashCode; } It is one such example and your Eclipse generated code follows a … Read more
First, let’s point out that SHA-256 does not accept all possible binary strings as input. As defined by FIPS 180-3, SHA-256 accepts as input any sequence of bits of length lower than 2^64 bits (i.e. no more than 18446744073709551615 bits). This is very common; all hash functions are somehow limited in formal input length. One … Read more