Elliptic curve's keys converter

Tool that can convert binary private or public key to pem and der formats. Also includes factory for KeyObject from @node/crypto.

Install

npm i @didkovsky/keys-converter

Example

random private key for (secp256k1)

9d8ce6ab12507d729b9d160d352a0be329ec73dbc8afa65d6e5570bb14a8f71f

pem

-----BEGIN EC PRIVATE KEY-----
MHQCAQEEIJ2M5qsSUH1ym50WDTUqC+Mp7HPbyK+mXW5VcLsUqPcfoAcGBSuBBAAK
oUQDQgAE4zjQ9EYcK1uUoF/eCboVjNVlCOFH58VV6RmyZfZzpSrQjltCJQVubOmt
LLD1FWKZv76d4H4UNc/0mN0LkMKGDw==
-----END EC PRIVATE KEY-----

der (hex)

307402010104209d8ce6ab12507d729b9d160d352a0be329ec73dbc8afa65d6e5570bb14a8f71fa00706052b8104000aa14403420004e338d0f4461c2b5b94a05fde09ba158cd56508e147e7c555e919b265f673a52ad08e5b4225056e6ce9ad2cb0f5156299bfbe9de07e1435cff498dd0b90c2860f

Supported curves

Name	Priv length (bytes)	Pub length (bytes)	Priv header	Priv options	Pub header
SM2	32	65	0x30770201010420	0xa00a06082a811ccf5501822da144034200	0x3059301306072a8648ce3d020106082a811ccf5501822d034200
brainpoolP160r1	20	41	0x30540201010414	0xa00b06092b2403030208010101a12c032a00	0x3042301406072a8648ce3d020106092b2403030208010101032a00
brainpoolP160t1	20	41	0x30540201010414	0xa00b06092b2403030208010102a12c032a00	0x3042301406072a8648ce3d020106092b2403030208010102032a00
brainpoolP192r1	24	49	0x30600201010418	0xa00b06092b2403030208010103a134033200	0x304a301406072a8648ce3d020106092b2403030208010103033200
brainpoolP192t1	24	49	0x30600201010418	0xa00b06092b2403030208010104a134033200	0x304a301406072a8648ce3d020106092b2403030208010104033200
brainpoolP224r1	28	57	0x306c020101041c	0xa00b06092b2403030208010105a13c033a00	0x3052301406072a8648ce3d020106092b2403030208010105033a00
brainpoolP224t1	28	57	0x306c020101041c	0xa00b06092b2403030208010106a13c033a00	0x3052301406072a8648ce3d020106092b2403030208010106033a00
brainpoolP256r1	32	65	0x30780201010420	0xa00b06092b2403030208010107a144034200	0x305a301406072a8648ce3d020106092b2403030208010107034200
brainpoolP256t1	32	65	0x30780201010420	0xa00b06092b2403030208010108a144034200	0x305a301406072a8648ce3d020106092b2403030208010108034200
brainpoolP320r1	40	81	0x3081900201010428	0xa00b06092b2403030208010109a154035200	0x306a301406072a8648ce3d020106092b2403030208010109035200
brainpoolP320t1	40	81	0x3081900201010428	0xa00b06092b240303020801010aa154035200	0x306a301406072a8648ce3d020106092b240303020801010a035200
brainpoolP384r1	48	97	0x3081a80201010430	0xa00b06092b240303020801010ba164036200	0x307a301406072a8648ce3d020106092b240303020801010b036200
brainpoolP384t1	48	97	0x3081a80201010430	0xa00b06092b240303020801010ca164036200	0x307a301406072a8648ce3d020106092b240303020801010c036200
brainpoolP512r1	64	129	0x3081da0201010440	0xa00b06092b240303020801010da1818503818200	0x30819b301406072a8648ce3d020106092b240303020801010d03818200
brainpoolP512t1	64	129	0x3081da0201010440	0xa00b06092b240303020801010ea1818503818200	0x30819b301406072a8648ce3d020106092b240303020801010e03818200
c2pnb163v1	21	43	0x30560201010415	0xa00a06082a8648ce3d030001a12e032c00	0x3043301306072a8648ce3d020106082a8648ce3d030001032c00
c2pnb163v2	21	43	0x30560201010415	0xa00a06082a8648ce3d030002a12e032c00	0x3043301306072a8648ce3d020106082a8648ce3d030002032c00
c2pnb163v3	21	43	0x30560201010415	0xa00a06082a8648ce3d030003a12e032c00	0x3043301306072a8648ce3d020106082a8648ce3d030003032c00
c2pnb208w1	24	53	0x3064020101041900	0xa00a06082a8648ce3d03000aa138033600	0x304d301306072a8648ce3d020106082a8648ce3d03000a033600
c2pnb272w1	32	69	0x307c020101042100	0xa00a06082a8648ce3d030010a148034600	0x305d301306072a8648ce3d020106082a8648ce3d030010034600
c2pnb304w1	36	77	0x308188020101042500	0xa00a06082a8648ce3d030011a150034e00	0x3065301306072a8648ce3d020106082a8648ce3d030011034e00
c2pnb368w1	44	93	0x3081a0020101042d00	0xa00a06082a8648ce3d030013a160035e00	0x3075301306072a8648ce3d020106082a8648ce3d030013035e00
c2tnb191v1	24	49	0x305f0201010418	0xa00a06082a8648ce3d030005a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030005033200
c2tnb191v2	24	49	0x305f0201010418	0xa00a06082a8648ce3d030006a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030006033200
c2tnb191v3	24	49	0x305f0201010418	0xa00a06082a8648ce3d030007a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030007033200
c2tnb239v1	30	61	0x3071020101041e	0xa00a06082a8648ce3d03000ba140033e00	0x3055301306072a8648ce3d020106082a8648ce3d03000b033e00
c2tnb239v2	30	61	0x3071020101041e	0xa00a06082a8648ce3d03000ca140033e00	0x3055301306072a8648ce3d020106082a8648ce3d03000c033e00
c2tnb239v3	30	61	0x3071020101041e	0xa00a06082a8648ce3d03000da140033e00	0x3055301306072a8648ce3d020106082a8648ce3d03000d033e00
c2tnb359v1	45	91	0x30819e020101042d	0xa00a06082a8648ce3d030012a15e035c00	0x3073301306072a8648ce3d020106082a8648ce3d030012035c00
c2tnb431r1	53	109	0x3081b80201010435	0xa00a06082a8648ce3d030014a170036e00	0x308185301306072a8648ce3d020106082a8648ce3d030014036e00
prime192v1	24	49	0x305f0201010418	0xa00a06082a8648ce3d030101a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030101033200
prime192v2	24	49	0x305f0201010418	0xa00a06082a8648ce3d030102a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030102033200
prime192v3	24	49	0x305f0201010418	0xa00a06082a8648ce3d030103a134033200	0x3049301306072a8648ce3d020106082a8648ce3d030103033200
prime239v1	30	61	0x3071020101041e	0xa00a06082a8648ce3d030104a140033e00	0x3055301306072a8648ce3d020106082a8648ce3d030104033e00
prime239v2	30	61	0x3071020101041e	0xa00a06082a8648ce3d030105a140033e00	0x3055301306072a8648ce3d020106082a8648ce3d030105033e00
prime239v3	30	61	0x3071020101041e	0xa00a06082a8648ce3d030106a140033e00	0x3055301306072a8648ce3d020106082a8648ce3d030106033e00
prime256v1	32	65	0x30770201010420	0xa00a06082a8648ce3d030107a144034200	0x3059301306072a8648ce3d020106082a8648ce3d030107034200
secp112r1	14	29	0x303e020101040e	0xa00706052b81040006a120031e00	0x3032301006072a8648ce3d020106052b81040006031e00
secp112r2	14	29	0x303e020101040e	0xa00706052b81040007a120031e00	0x3032301006072a8648ce3d020106052b81040007031e00
secp128r1	16	33	0x30440201010410	0xa00706052b8104001ca124032200	0x3036301006072a8648ce3d020106052b8104001c032200
secp128r2	16	33	0x30440201010410	0xa00706052b8104001da124032200	0x3036301006072a8648ce3d020106052b8104001d032200
secp160k1	20	41	0x3051020101041500	0xa00706052b81040009a12c032a00	0x303e301006072a8648ce3d020106052b81040009032a00
secp160r1	20	41	0x3051020101041500	0xa00706052b81040008a12c032a00	0x303e301006072a8648ce3d020106052b81040008032a00
secp160r2	20	41	0x3051020101041500	0xa00706052b8104001ea12c032a00	0x303e301006072a8648ce3d020106052b8104001e032a00
secp192k1	24	49	0x305c0201010418	0xa00706052b8104001fa134033200	0x3046301006072a8648ce3d020106052b8104001f033200
secp224k1	28	57	0x3069020101041d00	0xa00706052b81040020a13c033a00	0x304e301006072a8648ce3d020106052b81040020033a00
secp224r1	28	57	0x3068020101041c	0xa00706052b81040021a13c033a00	0x304e301006072a8648ce3d020106052b81040021033a00
secp256k1	32	65	0x30740201010420	0xa00706052b8104000aa144034200	0x3056301006072a8648ce3d020106052b8104000a034200
secp384r1	48	97	0x3081a40201010430	0xa00706052b81040022a164036200	0x3076301006072a8648ce3d020106052b81040022036200
secp521r1	66	133	0x3081dc0201010442	0xa00706052b81040023a1818903818600	0x30819b301006072a8648ce3d020106052b8104002303818600
sect113r1	14	31	0x3041020101040f00	0xa00706052b81040004a122032000	0x3034301006072a8648ce3d020106052b81040004032000
sect113r2	14	31	0x3041020101040f00	0xa00706052b81040005a122032000	0x3034301006072a8648ce3d020106052b81040005032000
sect131r1	17	35	0x30470201010411	0xa00706052b81040016a126032400	0x3038301006072a8648ce3d020106052b81040016032400
sect131r2	17	35	0x30470201010411	0xa00706052b81040017a126032400	0x3038301006072a8648ce3d020106052b81040017032400
sect163k1	21	43	0x30530201010415	0xa00706052b81040001a12e032c00	0x3040301006072a8648ce3d020106052b81040001032c00
sect163r1	21	43	0x30530201010415	0xa00706052b81040002a12e032c00	0x3040301006072a8648ce3d020106052b81040002032c00
sect163r2	21	43	0x30530201010415	0xa00706052b8104000fa12e032c00	0x3040301006072a8648ce3d020106052b8104000f032c00
sect193r1	24	51	0x305f020101041900	0xa00706052b81040018a136033400	0x3048301006072a8648ce3d020106052b81040018033400
sect193r2	24	51	0x305f020101041900	0xa00706052b81040019a136033400	0x3048301006072a8648ce3d020106052b81040019033400
sect233k1	29	61	0x306d020101041d	0xa00706052b8104001aa140033e00	0x3052301006072a8648ce3d020106052b8104001a033e00
sect233r1	29	61	0x306e020101041e00	0xa00706052b8104001ba140033e00	0x3052301006072a8648ce3d020106052b8104001b033e00
sect239k1	30	61	0x306e020101041e	0xa00706052b81040003a140033e00	0x3052301006072a8648ce3d020106052b81040003033e00
sect283k1	36	73	0x3081800201010424	0xa00706052b81040010a14c034a00	0x305e301006072a8648ce3d020106052b81040010034a00
sect283r1	36	73	0x3081800201010424	0xa00706052b81040011a14c034a00	0x305e301006072a8648ce3d020106052b81040011034a00
sect409k1	51	105	0x3081af0201010433	0xa00706052b81040024a16c036a00	0x307e301006072a8648ce3d020106052b81040024036a00
sect409r1	51	105	0x3081b0020101043400	0xa00706052b81040025a16c036a00	0x307e301006072a8648ce3d020106052b81040025036a00
sect571k1	72	145	0x3081ee0201010448	0xa00706052b81040026a1819503819200	0x3081a7301006072a8648ce3d020106052b8104002603819200
sect571r1	72	145	0x3081ee0201010448	0xa00706052b81040027a1819503819200	0x3081a7301006072a8648ce3d020106052b8104002703819200
wap-wsg-idm-ecid-wtls1	14	31	0x3040020101040e	0xa0070605672b010401a122032000	0x3034301006072a8648ce3d02010605672b010401032000
wap-wsg-idm-ecid-wtls10	29	61	0x306d020101041d	0xa0070605672b01040aa140033e00	0x3052301006072a8648ce3d02010605672b01040a033e00
wap-wsg-idm-ecid-wtls11	29	61	0x306e020101041e00	0xa0070605672b01040ba140033e00	0x3052301006072a8648ce3d02010605672b01040b033e00
wap-wsg-idm-ecid-wtls12	28	57	0x3068020101041c	0xa0070605672b01040ca13c033a00	0x304e301006072a8648ce3d02010605672b01040c033a00
wap-wsg-idm-ecid-wtls3	21	43	0x30530201010415	0xa0070605672b010403a12e032c00	0x3040301006072a8648ce3d02010605672b010403032c00
wap-wsg-idm-ecid-wtls4	14	31	0x3041020101040f00	0xa0070605672b010404a122032000	0x3034301006072a8648ce3d02010605672b010404032000
wap-wsg-idm-ecid-wtls5	21	43	0x30530201010415	0xa0070605672b010405a12e032c00	0x3040301006072a8648ce3d02010605672b010405032c00
wap-wsg-idm-ecid-wtls6	14	29	0x303e020101040e	0xa0070605672b010406a120031e00	0x3032301006072a8648ce3d02010605672b010406031e00
wap-wsg-idm-ecid-wtls7	20	41	0x3051020101041500	0xa0070605672b010407a12c032a00	0x303e301006072a8648ce3d02010605672b010407032a00
wap-wsg-idm-ecid-wtls8	14	29	0x303f020101040f00	0xa0070605672b010408a120031e00	0x3032301006072a8648ce3d02010605672b010408031e00
wap-wsg-idm-ecid-wtls9	20	41	0x3051020101041500	0xa0070605672b010409a12c032a00	0x303e301006072a8648ce3d02010605672b010409032a00

Usage

See /examples folder.

convert private key

const { PrivConverter, getCurves } = require('@didkovsky/keys-converter')

/**
 * Get list of supported curves
 */
const curves = getCurves()

/**
 * Create converter for specified curve.
 */
const converter = PrivConverter.for(curves.secp256k1)

/**
 * Some private key.
 */
const priv = Buffer.alloc(32, 0x1)

/**
 * GetPem string.
 */
const pem = converter.toPem(priv)

/*
-----BEGIN EC PRIVATE KEY-----
MHQCAQEEIAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBoAcGBSuBBAAK
oUQDQgAEG4TFVnsSZECZXT7VqroFZdceGDRgSBn/nBf16dXdB49wvq+PWItUFQf+
1qZCxatC39+BIKf2Od5RItR6aajo0Q==
-----END EC PRIVATE KEY-----
*/
console.log(pem)

/**
 * Get der Buffer.
 */
const der = converter.toDer(priv)

// Buffer(118) [Uint8Array] [ ... ]
console.dir(der)

/**
 * Get KeyObject from @node/crypto
 */
const keyObj = converter.toKeyObject(priv)

// PrivateKeyObject { [Symbol(kKeyType)]: 'private' }
console.dir(keyObj)

convert public key

const { PubConverter, getCurves } = require('@didkovsky/keys-converter')
const { createECDH } = require('crypto')

/**
 * Get list of supported curves
 */
const curves = getCurves()

/**
 * Create converter for specified curve.
 */
const converter = PubConverter.for(curves.secp256k1)

/**
 * Create keypair
 */
const priv = Buffer.alloc(32, 0x1)
const ecdh = createECDH('secp256k1')
ecdh.setPrivateKey(priv)
const pub = ecdh.getPublicKey()

// BBuExVZ7EmRAmV0+1aq6BWXXHhg0YEgZ/5wX9enV3QePcL6vj1iLVBUH/tamQsWrQt/fgSCn9jneUSLUemmo6NE=
console.log(pub.toString('base64'))

/**
 * GetPem string.
 */
const pem = converter.toPem(pub)

/*
-----BEGIN PUBLIC KEY-----
MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEG4TFVnsSZECZXT7VqroFZdceGDRgSBn/
nBf16dXdB49wvq+PWItUFQf+1qZCxatC39+BIKf2Od5RItR6aajo0Q==
-----END PUBLIC KEY-----
*/
console.log(pem)

/**
 * Get der Buffer.
 */
const der = converter.toDer(pub)

// Buffer(88) [Uint8Array] [ ... ]
console.dir(der)

/**
 * Get KeyObject from @node/crypto
 */
const keyObj = converter.toKeyObject(pub)

// PublicKeyObject { [Symbol(kKeyType)]: 'public' }
console.dir(keyObj)

sign

With createSign from @node/crypto

const { createSign } = require('crypto')
const { PrivConverter, getCurves } = require('@didkovsky/keys-converter')

/**
 * Get list of supported curves
 */
const curves = getCurves()

/**
 * Create converter for specified curve.
 */
const converter = PrivConverter.for(curves.secp256k1)
 
/**
 * Some private key.
 */
const priv = Buffer.alloc(32, 0x1)

/**
 * Get keyObject from @node/crypto
 */
const privObj = converter.toKeyObject(priv)

/**
 * Signing some message.
 */
const message = 'Hello world!'
const signer = createSign('sha256')
signer.update(message).end()
const signature = signer.sign(privObj)

// MEUCIDHplD47Iy3PaSspcMmAScvE8Acdwc+4nrlPJwq64oynAiEA5+kGFrOqaihg7OQekCae5eKNprwweT02cKNQ5MPBrAE=
console.log(signature.toString('base64'))

verify

With createVerify from @node/crypto

const { createVerify } = require('crypto')
const { PubConverter, getCurves } = require('@didkovsky/keys-converter')

/**
 * Get list of supported curves
 */
const curves = getCurves()

/**
 * Create converter for specified curve.
 */
const converter = PubConverter.for(curves.secp256k1)

/**
 * Raw public key in base64 (65 bytes)
 */
const pub = 'BBuExVZ7EmRAmV0+1aq6BWXXHhg0YEgZ/5wX9enV3QePcL6vj1iLVBUH/tamQsWrQt/fgSCn9jneUSLUemmo6NE='

/**
 * Get keyObject from @node/crypto
 */
const pubObj = converter.toKeyObject(Buffer.from(pub, 'base64'))

/**
 * Our test signature and message
 */
const message = 'Hello world!'
const signature = 'MEUCIDHplD47Iy3PaSspcMmAScvE8Acdwc+4nrlPJwq64oynAiEA5+kGFrOqaihg7OQekCae5eKNprwweT02cKNQ5MPBrAE='

/**
 * Verifiyng signature
 */
const verifier = createVerify('sha256')
verifier.update(message).end()
const result = verifier.verify(pubObj, Buffer.from(signature, 'base64'))

// true
console.log(result)