The ECDSA signature that is generated and output by the Sign
command or
input to the Verify
command is always 64 bytes in length. The
signature is divided into R and S components. Both components are 32 bytes in length and
R always appears before S on the bus. Each portion of the signature appears MSB first on
the bus, meaning the MSB of the signature is in the lowest memory location.
Any command that returns a signature (Sign
) or accepts a signature
as a parameter (Verify
) will format the signature as the R and S
big-endian unsigned integers concatenated together for a total of 64 bytes.
For example:
R: 7337887F8C39DF79FD8BF88DDFBFB9DB15D7B1AD68196AE3FB0CE5BFA2842DF3
S: 72868A43A42831E950E1DA9F73B29F5C0ED8A96B2889E3CBBE8E61EA6C67F673