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nervosnetwork / ckb-auth

A consolidated library featuring numerous blockchains authentication techniques on CKB-VM
MIT License
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Missing docs about secp256r1 in auth.md #28

Closed doitian closed 8 months ago

doitian commented 8 months ago

secp256r1.md refers to auth.md for more details, but auth.md has nothing about secp256r1

contrun commented 8 months ago

secp256r1 is not different from other algorithms other than the thing mentioned in https://github.com/nervosnetwork/ckb-auth/pull/29 .

doitian commented 8 months ago

@contrun the openssl command in secp256r1.md generate a signature in DER format, do you know a tool to get the 64 bytes signature from the file?

contrun commented 8 months ago

In my local machine, the signature is saved in a file called signature, whose hex contents are

xxd signature 
00000000: 3044 0220 63bf dc57 257a 6cf6 7393 e4bf  0D. c..W%zl.s...
00000010: 2aa0 af38 f25f a04d ec3d 1428 b83f 9f8c  *..8._.M.=.(.?..
00000020: f4d8 050f 0220 2744 17cb 0d9d 625a b0ba  ..... 'D....bZ..
00000030: b1c6 11e0 c445 081a 31f6 8266 8c0a bfa0  .....E..1..f....
00000040: 1341 e977 08af

Running the following command will output the R and S value of the signature

openssl asn1parse -dump -inform DER -in signature
    0:d=0  hl=2 l=  68 cons: SEQUENCE          
    2:d=1  hl=2 l=  32 prim: INTEGER           :63BFDC57257A6CF67393E4BF2AA0AF38F25FA04DEC3D1428B83F9F8CF4D8050F
   36:d=1  hl=2 l=  32 prim: INTEGER           :274417CB0D9D625AB0BAB1C611E0C445081A31F682668C0ABFA01341E97708AF

All that we need to do to convert the signature to the 64-bytes form is to concatenate the R and S value in the last two lines. Running the following command suffices

openssl asn1parse -dump -inform DER -in signature | awk -F: '/33 prim: INTEGER/ {print $NF}' |  xxd -r -p > signature.raw

I added the this instructions in the PR https://github.com/nervosnetwork/ckb-auth/pull/30

doitian commented 8 months ago

Thanks again.