The NSString category for MD5, SHA1, SHA256, SHA512 Hash, and hashes of files with small memory usage

• string.md5String
• string.sha1String
• string.sha256String
• string.sha512String

• [string hmacMD5StringWithKey:key]
• [string hmacSHA1StringWithKey:key]
• [string hmacSHA256StringWithKey:key]
• [string hmacSHA256StringWithKey:key]

• filePath.fileMD5Hash
• filePath.fileSHA1Hash
• filePath.fileSHA256Hash
• filePath.fileSHA512Hash