/// <summary>
/// Generates a JWT with RSA512 using a private key loaded from the environment.
/// </summary>
/// <remarks>
/// A JWT is compromised of 3 dot-separated, base64 strings.
/// Jose_Header.JWT_Payload.JWT_Signature
/// </remarks>
/// <param name="payload">The data to be encrypted.</param>
/// <returns>The JWT.</returns>
public string GenerateJWT(Dictionary <string, string> payload)
{
// TODO CHECK PUBLIC KEY AND PRIVATE KEY, CHECK THEIR LENGTHS AND IF THEY INCLUDE ----BEGIN... ---END... ETC
// Make sure we have the proper parameters inside the dictionary
if (!payload.ContainsKey(Constants.UserTypeKey) || !payload.ContainsKey(Constants.IdKey))
{
throw new ArgumentException("UserType or ID was not provided.");
}
// Create the header and convert it to a Base64 string
Dictionary <string, string> joseHeader = new Dictionary <string, string> {
{ Constants.MediaType, Constants.MediaJWT }, // Media type
{ Constants.SigningAlgKey, Constants.SIGNING_ALGORITHM } // Signing algorithm type
};
// If the expiration date wasn't already specified, then create one
if (!payload.ContainsKey(Constants.EXPIRATION_FIELD))
{
// Add a 20 min expiration
payload.Add(Constants.EXPIRATION_FIELD, TimeUtilityService.GetEpochFromNow().ToString());
}
// Base64 encode the header and payload
string encodedHeader = StringUtilityService.DictionaryToString(joseHeader).ToBase64URL();
string encodedPayload = StringUtilityService.DictionaryToString(payload).ToBase64URL();
// The signature will be the hash of the header and payload
string stringToSign = encodedHeader + '.' + encodedPayload;
// Create the signature
string signature = GetPKCSSignature(stringToSign).ToBase64URL();
return(string.Format("{0}.{1}.{2}", encodedHeader, encodedPayload, signature));
}
/// <summary>
/// Hash a string data with HMAC SHA256.
/// </summary>
/// <param name="data"> a string to be hashed </param>
/// <returns> a string of hash code </returns>
public static string HashWithSHA256(string data)
{
using (SHA256CryptoServiceProvider sha256 = new SHA256CryptoServiceProvider())
{
return(StringUtilityService.BytesToHexString(sha256.ComputeHash(Encoding.ASCII.GetBytes(data))));
}
}
/// <summary>
/// Hashes the string with SHA1.
/// </summary>
/// <param name="str">The input to be hashed </param>
/// <returns>Hex string of the hashed input</returns>
public static string HashWithSHA1(string str)
{
using (SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider())
{
// Convert the str to ASCII byte array ->
// Compute the hashcode in byte array with the ASCII byte array ->
// Convert the hashcode byte array to a hex string
return(StringUtilityService.BytesToHexString(sha1.ComputeHash(Encoding.ASCII.GetBytes(str))));
}
}
/// <summary>
/// Hash a password with SHA3-256 KDF.
/// </summary>
/// <param name="password"> password to be hashed</param>
/// <param name="salt"> salt used for hashing </param>
/// <param name="iterations"> number of iterations </param>
/// <param name="hashLength"> the length of the output hashcode </param>
/// <returns> a string of derived key </returns>
public static string HashWithKDF(string password, byte[] salt, int iterations = Constants.DefaultHashIterations,
int hashLength = Constants.DefaultHashByteLength)
{
byte[] passwordBytes = StringUtilityService.HexStringToBytes(password);
Pkcs5S2ParametersGenerator pbkdf = new Pkcs5S2ParametersGenerator(new Sha3Digest());
pbkdf.Init(passwordBytes, salt, iterations);
KeyParameter derivedKey = pbkdf.GenerateDerivedMacParameters(hashLength * Constants.ByteLength) as KeyParameter;
return(StringUtilityService.BytesToHexString(derivedKey.GetKey()));
}
/// <summary>
/// Decrypts a JWT in order to verify it and see the payload.
/// </summary>
/// <param name="jwt">The token to decrypt.</param>
/// <returns>The contents inside the token.</returns>
public Dictionary <string, string> DecryptJWT(string jwt)
{
string[] segments = jwt.Split('.');
// Make sure we have the proper JWT format of 3 tokens delimited by periods
if (segments.Length != 3)
{
throw new InvalidTokenException("JWT must have 3 segments separated by periods.");
}
string encodedHeader = segments[0];
string encodedPayload = segments[1];
// Convert header back to dictionary format
string decodedHeader = segments[0].FromBase64URL();
Dictionary <string, string> headerJSON = StringUtilityService.StringToDictionary(decodedHeader);
// Convert payload back to dictionary format
string decodedPayload = segments[1].FromBase64URL();
Dictionary <string, string> payloadJSON = StringUtilityService.StringToDictionary(decodedPayload);
// Make sure that we are using the correct encryption algorithm in the header
if (headerJSON[Constants.SigningAlgKey] != Constants.SIGNING_ALGORITHM)
{
throw new InvalidTokenException("Incorrect encryption algorithm.");
}
string strToVerify = encodedHeader + '.' + encodedPayload;
// Make sure the signature is correct
if (VerifyPKCSSignature(strToVerify))
{
return(payloadJSON);
}
else
{
throw new InvalidTokenException("JWT could not be verified!");
}
}
public VerifyUploadResult VerifyUpload(UploadDTO dto, int maxPhotoChars, int minPhotoChars, double minimumImageSizeMB, double maximumImageSizeMB, List <string> validExtensions,
int ingredientNameMaxChars, int ingredientNameMinChars, double maxIngredientPrice, int descriptionMaxChars,
int descriptionMinChars, List <string> validCategories, List <string> validPriceUnits, int validTimeBufferMinutes,
int maxRating, int minRating)
{
var validPhotoPath = StringUtilityService.CheckLength(dto.ImagePath, maxPhotoChars, minPhotoChars);
if (!validPhotoPath)
{
return(new VerifyUploadResult(Constants.ImagePathInvalidMessage, false));
}
var sizeMB = dto.ImageSize * Constants.ToMBConversionFactor;
var validSize = sizeMB >= minimumImageSizeMB && sizeMB <= maximumImageSizeMB;
if (!validSize)
{
return(new VerifyUploadResult(Constants.ImageNotWithinSizeMessage, false));
}
var fileExtension = "." + dto.ImagePath.Split('.').Last();
var validExt = false;
foreach (var ext in validExtensions)
{
validExt = validExt || (fileExtension.ToLower().Equals(ext.ToLower()));
}
if (!validExt)
{
return(new VerifyUploadResult(Constants.ExtensionNotValidMessage, false));
}
var validCat = false;
foreach (var cat in validCategories)
{
validCat = validCat || (dto.Category.ToLower().Equals(cat.ToLower()));
}
if (!validCat)
{
return(new VerifyUploadResult(Constants.CategoryNotValidMessage, false));
}
if (!dto.Name.Equals(Constants.NoValueString))
{
var validNameLength = StringUtilityService.CheckLength(dto.Name, ingredientNameMaxChars, ingredientNameMinChars);
if (!validNameLength)
{
return(new VerifyUploadResult(Constants.IngredientNameLengthInvalidMessage, false));
}
}
if (!dto.Price.Equals(Constants.NoValueDouble))
{
var validPrice = dto.Price > Constants.NoValueDouble && dto.Price <= maxIngredientPrice;
if (!validPrice)
{
return(new VerifyUploadResult(Constants.PriceInvalidMessage, false));
}
}
if (!dto.Description.Equals(Constants.NoValueString))
{
var validDescriptionLength = StringUtilityService.CheckLength(dto.Description, descriptionMaxChars, descriptionMinChars);
if (!validDescriptionLength)
{
return(new VerifyUploadResult(Constants.DescriptionLengthInvalidMessage, false));
}
}
if (!dto.PriceUnit.Equals(Constants.NoValueString))
{
var validUnit = false;
foreach (var unit in validPriceUnits)
{
validUnit = validUnit || (dto.PriceUnit.ToLower().Equals(unit.ToLower()));
}
if (!validUnit)
{
return(new VerifyUploadResult(Constants.PriceUnitNotValidMessage, false));
}
}
if (!dto.Time.Equals(Constants.NoValueDatetime))
{
var validTime = (DateTime.Now - dto.Time).TotalMinutes <= validTimeBufferMinutes;
if (!validTime)
{
return(new VerifyUploadResult(Constants.TimeNotValidMessage, false));
}
}
if (!dto.Rating.Equals(Constants.NoValueInt))
{
var validRating = dto.Rating >= minRating && dto.Rating <= maxRating;
if (!validRating)
{
return(new VerifyUploadResult(Constants.InvalidRatingMessage, false));
}
}
return(new VerifyUploadResult(Constants.NoValueString, true));
}