- From: Frederick Hirsch <Frederick.Hirsch@nokia.com>
- Date: Wed, 14 Jan 2009 00:57:57 -0500
- To: XMLSec WG Public List <public-xmlsec@w3.org>
- Cc: Frederick Hirsch <Frederick.Hirsch@nokia.com>
- Message-Id: <F18C275C-283D-43FE-AC61-2772DCF39B70@nokia.com>
I have received the following comment on the XML Encryption 1.1 draft (before today's F2F updates), mostly editorial (e.g. spell checking pass needed) regards, Frederick Nokia ---- 3.1 The EncryptedType Element > Implementations SHOULD create these XML structures > (EncryptedType elements and their descendents/content) descendants > in Normalization Form C [NFC, NFC-Corrigendum]. 3.5.1 The EncryptedKey Element > The Type attribute inheritted from EncryptedType can be used to further inherited > specify the type of the encrypted key if the EncryptionMethod Algorithm > does not define a unambiguous encoding/representation. (Note, all the > algorithms in this specification have an unambigous representation for unambiguous > their associated key structures.) 4.1 Encryption > 2. Obtain and (optionally) represent the key. > 1. If the key is to be identified (via naming, URI, or included in > a child element), construct the ds:KeyInfo as approriate (e.g., ds:KeyName, appropriate > ds:KeyValue, ds:RetrievalMethod, etc.) > The definition of this type as bound to an identifier specifies > how to obtain and interpret the plaintext octets after decryption. For > example, the idenifier could indicate that the data is an instance of identifier > another application (e.g., some XML compression application) that must be > further processed. 4.2 Decryption > 5. Process decrypted data if Type is unspecified or is not 'element' or > element 'content'. > MimeType and Encoding are advisory. The Type value is normative as it may > contain information necessary for the processing or interpration of the interpretation > data by the application. 5. Algorithms > Levels of requirement specified, such as "REQUIRED" or "OPTIONAL", > refere to implementation, not use. refer Table of Algorithms 5.6.3 AES KeyWrap > "|" represents concatentation so x|y, where x and y and 64-bit quantities, concatenation > is the 128-bit quantity with x in the most significant bits and y in the > least significant bits. AES(K)enc(x) is the operation of AES encrypting > the 128-bit quantity x under the key K. AES(K)dec(x) is the corresponding > decryption opteration. operation > 2. Initialize variables: > * Set A to 0xA6A6A6A6A6A6A6A6 > * Fori=1 to N, space please > R(i)=P(i) > 3. Calculate intermediate values: > * Forj=0 to 5, space please > o For i=1 to N, > t= i + j*N > B=AES(K)enc(A|R(i)) > A=XOR(t,MSB(B)) > R(i)=LSB(B) > 4. Output the results: > * Set C(0)=A > * For i=1 to N, > C(i)=R(i) 6.3 Nonce and IV (Initialization Value or Vector) > Different algorithms and modes have further requirements on the > characteristic of this information (e.g., randomness and secrecy) that > affect the features (e.g., confidentiality and integrity) and their > resistence to attack. resistance Example > enc-example.xml (not cryptographically valid but excercises much of exercises > the schema) 10 References NFC > TR15, Unicode Normalization Forms. M. Davis and M. D?rst. Revision 18: > November 1999. the letter here should be reencoded.
Received on Wednesday, 14 January 2009 05:58:46 UTC