sgaunet/jwt-cli

package cryptojwt

import (
    "crypto"
    "crypto/x509"
    "encoding/pem"
    "fmt"
    "os"

    "github.com/golang-jwt/jwt/v5"
)

type esjwtEncoderWithPrivateKeyFile struct {
    encoder
    privateKeyFile string
    method         jwt.SigningMethod
}

type esjwtDecoderWithPrivateKeyFile struct {
    decoder
    privateKeyFile string
    method         jwt.SigningMethod
}

type esjwtDecoderWithPublicKeyFile struct {
    decoder
    publicKeyFile string
    method        jwt.SigningMethod
}

func NewES256Encoder(privateKeyFile string) Encoder {
    return &esjwtEncoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES256,
        privateKeyFile: privateKeyFile,
    }
}

func NewES384Encoder(privateKeyFile string) Encoder {
    return &esjwtEncoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES384,
        privateKeyFile: privateKeyFile,
    }
}

func NewES512Encoder(privateKeyFile string) Encoder {
    return &esjwtEncoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES512,
        privateKeyFile: privateKeyFile,
    }
}

func NewES256DecoderWithPrivateKeyFile(privateKeyFile string) Decoder {
    return &esjwtDecoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES256,
        privateKeyFile: privateKeyFile,
    }
}

func NewES384DecoderWithPrivateKeyFile(privateKeyFile string) Decoder {
    return &esjwtDecoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES384,
        privateKeyFile: privateKeyFile,
    }
}

func NewES512DecoderWithPrivateKeyFile(privateKeyFile string) Decoder {
    return &esjwtDecoderWithPrivateKeyFile{
        method:         jwt.SigningMethodES512,
        privateKeyFile: privateKeyFile,
    }
}

func NewES256DecoderWithPublicKeyFile(publicKeyFile string) Decoder {
    return &esjwtDecoderWithPublicKeyFile{
        method:        jwt.SigningMethodES256,
        publicKeyFile: publicKeyFile,
    }
}

func NewES384DecoderWithPublicKeyFile(publicKeyFile string) Decoder {
    return &esjwtDecoderWithPublicKeyFile{
        method:        jwt.SigningMethodES384,
        publicKeyFile: publicKeyFile,
    }
}

func NewES512DecoderWithPublicKeyFile(publicKeyFile string) Decoder {
    return &esjwtDecoderWithPublicKeyFile{
        method:        jwt.SigningMethodES512,
        publicKeyFile: publicKeyFile,
    }
}

func readECDSAPrivateKey(privateKeyFile string) (crypto.PrivateKey, crypto.PublicKey, error) {
    contentKeyFile, err := os.ReadFile(privateKeyFile)
    if err != nil {
        return nil, nil, fmt.Errorf("error reading private key file: %v", err)
    }
    block, _ := pem.Decode(contentKeyFile)
    if block == nil {
        return nil, nil, fmt.Errorf("unable to load key")
    }
    if block.Type != "EC PRIVATE KEY" {
        return nil, nil, fmt.Errorf("wrong type of key - %s", block.Type)
    }
    privateKey, err := x509.ParseECPrivateKey(block.Bytes)
    if err != nil {
        return nil, nil, fmt.Errorf("error parsing EC private key: %v", err)
    }
    publicKey := privateKey.Public()
    return privateKey, publicKey, nil
}

func (j *esjwtEncoderWithPrivateKeyFile) Encode(payload string) (string, error) {
    privateKey, _, err := readECDSAPrivateKey(j.privateKeyFile)
    if err != nil {
        return "", err
    }
    return j.EncodeJWT(privateKey, j.method, payload)
}

func (j *esjwtDecoderWithPrivateKeyFile) Decode(token string) (string, error) {
    _, publicKey, err := readECDSAPrivateKey(j.privateKeyFile)
    if err != nil {
        return "", err
    }
    return j.DecodeJWT(publicKey, token)
}

func (j *esjwtDecoderWithPublicKeyFile) Decode(token string) (string, error) {
    publicKey, err := os.ReadFile(j.publicKeyFile)
    if err != nil {
        return "", fmt.Errorf("error reading public key file: %v", err)
    }
    key, err := jwt.ParseECPublicKeyFromPEM(publicKey)
    if err != nil {
        return "", fmt.Errorf("error parsing RSA public key: %v", err)
    }
    return j.DecodeJWT(key, token)
}