パラメータファイルの生成
$ openssl ecparam -name secp256k1 -out secp256k1.pem
secp256k1.pem
-----BEGIN EC PARAMETERS----- BgUrgQQACg== -----END EC PARAMETERS-----
$ openssl ecparam -in secp256k1.pem -text -noout
EC-Parameters: (256 bit)
ASN1 OID: secp256k1
パラメータの確認
$ openssl ecparam -in secp256k1.pem -text -param_enc explicit -noout
EC-Parameters: (256 bit)
Field Type: prime-field
Prime:
00:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:
ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:fe:ff:
ff:fc:2f
A: 0
B: 7 (0x7)
Generator (uncompressed):
04:79:be:66:7e:f9:dc:bb:ac:55:a0:62:95:ce:87:
0b:07:02:9b:fc:db:2d:ce:28:d9:59:f2:81:5b:16:
f8:17:98:48:3a:da:77:26:a3:c4:65:5d:a4:fb:fc:
0e:11:08:a8:fd:17:b4:48:a6:85:54:19:9c:47:d0:
8f:fb:10:d4:b8
Order:
00:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:
ff:fe:ba:ae:dc:e6:af:48:a0:3b:bf:d2:5e:8c:d0:
36:41:41
Cofactor: 1 (0x1)
秘密鍵を生成
$ openssl ecparam -in secp256k1.pem -genkey -noout -out secp256k1-private.pem
$ cat secp256k1-private.pem
—–BEGIN EC PRIVATE KEY—–
MHQCAQEEIAqV2IN8gUr9qXpsJyhpYA4KQfXioS/oiDMh1dgPcncAoAcGBSuBBAAK
oUQDQgAEeiuKeXTtb0t4F7DzVMbIHOrLIQ5T4JPq3NTU7OC7TWCghk6ALrWLgTGD
zUuuEIWI4GLsYea/829orVMO4Rz/FQ==
—–END EC PRIVATE KEY—–
秘密鍵を16進数表記で出力
$ openssl ec -in secp256k1-private.pem -outform DER | tail -c +8 | head -c 32 | xxd -p -c 32
read EC key
writing EC key
0a95d8837c814afda97a6c272869600e0a41f5e2a12fe8883321d5d80f727700
秘密鍵を変数に格納
$ privKey=0a95d8837c814afda97a6c272869600e0a41f5e2a12fe8883321d5d80f727700
公開鍵を生成
$ openssl ec -in secp256k1-private.pem -pubout -out secp256k1-public.pem; cat secp256k1-public.pem
read EC key
writing EC key
—–BEGIN PUBLIC KEY—–
MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEeiuKeXTtb0t4F7DzVMbIHOrLIQ5T4JPq
3NTU7OC7TWCghk6ALrWLgTGDzUuuEIWI4GLsYea/829orVMO4Rz/FQ==
公開鍵を16進数で出力
$ openssl ec -in secp256k1-private.pem -pubout -outform DER | tail -c 65 | xxd -p -c 65
read EC key
writing EC key
047a2b8a7974ed6f4b7817b0f354c6c81ceacb210e53e093eadcd4d4ece0bb4d60a0864e802eb58b813183cd4bae108588e062ec61e6bff36f68ad530ee11cff15
秘密鍵はスカラーですが、公開鍵は座標x, y
$ pubKey=047a2b8a7974ed6f4b7817b0f354c6c81ceacb210e53e093eadcd4d4ece0bb4d60a0864e802eb58b813183cd4bae108588e062ec61e6bff36f68ad530ee11cff15
$ prefix=`echo $pubKey | cut -c1-2`; echo “prefix= $prefix”
prefix= 04
$ x=`echo $pubKey | cut -c3-66` ; echo “x = $x”
x = 7a2b8a7974ed6f4b7817b0f354c6c81ceacb210e53e093eadcd4d4ece0bb4d60
$ y=`echo $pubKey | cut -c67-130`; echo “y= $y”
y= a0864e802eb58b813183cd4bae108588e062ec61e6bff36f68ad530ee11cff15
