/
claims.go
70 lines (52 loc) · 1.61 KB
/
claims.go
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package rfc8693
import (
"context"
"crypto/sha256"
"encoding/hex"
"github.com/ory/fosite/token/jwt"
"go.infratographer.com/identity-api/internal/celutils"
"go.infratographer.com/identity-api/internal/types"
)
// ClaimMappingStrategy represents a mapping from external identity claims to identity-api claims.
type ClaimMappingStrategy struct {
issuerSvc types.IssuerService
}
// NewClaimMappingStrategy creates a ClaimMappingStrategy given an issuer service.
func NewClaimMappingStrategy(issuerSvc types.IssuerService) ClaimMappingStrategy {
out := ClaimMappingStrategy{
issuerSvc: issuerSvc,
}
return out
}
// MapClaims consumes a set of JWT claims and produces a new set of mapped claims.
func (m ClaimMappingStrategy) MapClaims(ctx context.Context, claims *jwt.JWTClaims) (jwt.JWTClaimsContainer, error) {
if claims.Subject == "" {
return nil, ErrorMissingSub
}
if claims.Issuer == "" {
return nil, ErrorMissingIss
}
iss := claims.Issuer
issuer, err := m.issuerSvc.GetIssuerByURI(ctx, iss)
if err != nil {
return nil, err
}
inputMap := claims.ToMapClaims()
outputMap := make(map[string]any, len(issuer.ClaimMappings))
subSHA256Bytes := sha256.Sum256([]byte(claims.Subject))
subSHA256 := hex.EncodeToString(subSHA256Bytes[0:])
inputEnv := map[string]any{
celutils.CELVariableClaims: inputMap,
celutils.CELVariableSubSHA256: subSHA256,
}
for k, v := range issuer.ClaimMappings {
out, err := celutils.Eval(v, inputEnv)
if err != nil {
return nil, err
}
outputMap[k] = out.Value()
}
var outputClaims jwt.JWTClaims
outputClaims.FromMap(outputMap)
return &outputClaims, nil
}