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)