- From: Pratik Datta <pratik.datta@oracle.com>
- Date: Fri, 22 May 2009 15:15:47 -0700
- To: XMLSec WG Public List <public-xmlsec@w3.org>
Received on Friday, 22 May 2009 22:16:38 UTC
Currently the XML Signature 1.1 spec says: The output of the ECDSA algorithm consists of a pair of integers usually referred by the pair (r, s). The signature value consists of the base64 encoding of the concatenation of two octet-streams that respectively result from the octet-encoding of the values r and s in that order. Integer to octet-stream conversion must be done according to the I2OSP operation defined in the RFC 2437 <http://www.ietf.org/rfc/rfc2437.txt> [ PKCS1 <#ref-PKCS1> ] specification with the |l| parameter equal to the size of the output of the digest function in bytes (e.g. 32 for SHA-256). But shouldn't the length of r and s be dependent on the length of the key, not the length of digest function? E.g. if you are using "ecdsa-sha256", with P521 curve, then the length of r and s should not be 32, but should be 66 (521 ; round up to multiple of 8 and get 528 bits = 66 bytes) Pratik
Received on Friday, 22 May 2009 22:16:38 UTC