private string BuildCapsVersion(DiscoInfo di)
{
/*
1. Initialize an empty string S.
2. Sort the service discovery identities by category and then by type (if it exists), formatted as 'category' '/' 'type'.
3. For each identity, append the 'category/type' to S, followed by the '<' character.
4. Sort the supported features.
5. For each feature, append the feature to S, followed by the '<' character.
6. Compute ver by hashing S using the SHA-1 algorithm as specified in RFC 3174 [17] (with binary output) and
encoding the hash using Base64 as specified in Section 4 of RFC 4648 [18]
(note: the Base64 output MUST NOT include whitespace and MUST set padding bits to zero). [19]
*/
ArrayList features = new ArrayList();
ArrayList identities = new ArrayList();
foreach (DiscoIdentity did in di.GetIdentities())
identities.Add(did.Type == null ? did.Category : did.Category + "/" + did.Type);
foreach (DiscoFeature df in di.GetFeatures())
features.Add(df.Var);
identities.Sort();
features.Sort();
StringBuilder S = new StringBuilder();
foreach (string s in identities)
S.Append(s + "<");
foreach (string s in features)
S.Append(s + "<");
byte[] sha1 = util.Hash.Sha1HashBytes(S.ToString());
#if CF
return Convert.ToBase64String(sha1, 0, sha1.Length);
#else
return Convert.ToBase64String(sha1);
#endif
}
/// <summary>
/// Builds and sets the caps ver attribute from a DiscoInfo object
/// </summary>
/// <param name="di"></param>
public void SetVersion(DiscoInfo di)
{
Version = BuildCapsVersion(di);
}