Ok, so the options for our specification are: (a) choose a fixed value e.g. support only CFB128 (b) allow the caller to specify the value (c) remove the algorithm from the specification It seems from what you say that it is not the case that everyone supports just one value - so there must be applications for the different values. So, that would suggest we choose (b) if we don't choose (c). ...Mark On Fri, Feb 14, 2014 at 3:16 PM, Ryan Sleevi <sleevi@google.com> wrote: > I haven't heard any implementation movement on CFB. > > If using PKCS#11, only 8-bit, 64-bit, and 128-bit are defined mechanisms. > SP800-38a only provides vectors for 1, 8, 128. > > AFAICT, CNG supports CFB8 and CFB128 with AES. CFB128 isn't until Win8. > > OS X only supports CFB8 from what I can tell (at least, via the > CommonCrypto interface being used to implement in WebKit) > On Feb 14, 2014 3:04 PM, "Mark Watson" <watsonm@netflix.com> wrote: > >> All, >> >> Apologies in advance if this has been discussed before, or has a >> well-known answer. >> >> According to NIST SP800-38A [1] Section 6.3 which we reference for AES >> CFB, the input parameters to the encrypt/decrypt operations consist of an >> IV, the plaintext / ciphertext (respectively) and an additional parameter, >> s, which takes a value between 1 and 128, inclusive. >> >> What values of this shall we support in WebCrypto ? >> >> I assume that if we wish to support more than one value, then we must add >> a property to AesCfbParams for this. >> >> ...Mark >> >> [1] http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf >> >
Received on Saturday, 15 February 2014 01:08:03 UTC