SAML IdP overview

Casdoor can act as a SAML 2.0 IdP. This page covers SP configuration, Casdoor IdP settings, and SAML attributes.

Configuration in the SP (service provider)

The SP typically needs Single Sign-On URL, Issuer, and Public Certificate. Most SPs can fill these from the Casdoor XML Metadata URL or by uploading the metadata file.

Casdoor metadata URL format: <casdoor-endpoint>/api/saml/metadata?application=admin/<application-name>

Example: if Casdoor is at https://door.casdoor.com and the application is app-built-in:

https://door.casdoor.com/api/saml/metadata?application=admin/app-built-in

The metadata URL is also on the application edit page; copy it and open in a browser to download the XML.

metadados

Configuração no Casdoor IdP

Casdoor suporta tanto GET quanto POST SAMLResponse. Configure the application in Casdoor to match the SAMLResponse binding (GET or POST) that your SP supports.

When integrating Casdoor as a SAML IdP with external identity providers (like Azure AD), the /api/acs endpoint receives SAML responses. This endpoint is configured to accept cross-origin POST requests, allowing IdPs from different domains to send authentication data.

informação

Se você preencher a URL de Resposta, o Casdoor enviará o SAMLResponse por Solicitação POST. Se a URL de Resposta estiver vazia, o Casdoor usará a solicitação GET. Você pode se perguntar como o Casdoor sabe a URL de Resposta do SP se a URL de Resposta estiver vazia. Na verdade, o Casdoor pode obter a URL chamada AssertionConsumerServiceURL analisando o SAMLRequest e enviar a solicitação com SAMLResponse para AssertionConsumerServiceURL. A URL de Resposta substituirá a AssertionConsumerServiceURL no SAMLRequest.

URL de Resposta: Digite a URL do ACS que verifica a resposta SAML.
URL de Redirecionamento: Digite um nome único. Isto pode ser chamado de Audience ou Entity ID no seu SP. Certifique-se de preencher a mesma URL de Redirecionamento aqui como no seu SP.

SAML attributes

If the SP requires extra attributes in the SAML response, add them in the SAML attributes table and map user fields as needed.

If the service provider only needs NameID and not extra user attributes (Email, Name, DisplayName, Roles), enable Disable SAML attributes in the application settings. When enabled, Casdoor will omit these attributes from the SAML response, which can help avoid XML namespace issues with certain SPs that have strict validation requirements.

Assertion signature control

SAML responses from Casdoor are always signed to ensure authenticity. However, some service providers may not support or require signed assertions within the response itself. Starting from version 2.81.0, Casdoor added assertion signatures following SAML 2.0 best practices, but this caused compatibility issues with certain SPs like Sentry.

If a service provider does not handle signed assertions correctly, disable assertion signing while keeping the response envelope signed. Toggle the Enable SAML assertion signature option in your application settings to control this behavior. When disabled, Casdoor will sign only the SAML response envelope, which maintains security while ensuring compatibility with a wider range of service providers.

For example

Nome	Name format	Value
`https://www.aliyun.com/SAML-Role/Attributes/RoleSessionName`	Unspecified	`$user.name`
`https://www.aliyun.com/SAML-Role/Attributes/Role`	Unspecified	`acs:ram::1879818006829152:role/$user.roles,acs:ram::1879818006829152:saml-provider/testa`

will generate response with external saml:Attribute

<saml:Attribute Name="https://www.aliyun.com/SAML-Role/Attributes/RoleSessionName" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
    <saml:AttributeValue xsi:type="xs:string">admi122n@outlook.com</saml:AttributeValue>
</saml:Attribute>
<saml:Attribute Name="https://www.aliyun.com/SAML-Role/Attributes/Role" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
    <saml:AttributeValue xsi:type="xs:string"> acs:ram::1879818006829152:role/role1,acs:ram::1879818006829152:saml-provider/testa</saml:AttributeValue>
    <saml:AttributeValue xsi:type="xs:string"> acs:ram::1879818006829152:role/role2,acs:ram::1879818006829152:saml-provider/testa</saml:AttributeValue>
</saml:Attribute>

informação

We only support insert $user.owner,$user.name,$user.email,$user.id,$user.phone,$user.roles,$user.permissions,$user.groups

Perfil do usuário

Após o login bem-sucedido, o perfil do usuário na SAMLResponse retornada do Casdoor tem três campos. Os atributos no XML e os atributos do usuário no Casdoor são mapeados da seguinte forma:

Nome do Atributo XML	Campo do usuário
Email	email
DisplayName	displayName
Name	name

See https://en.wikipedia.org/wiki/SAML_2.0 for more information about SAML and its different versions.

Um exemplo

gosaml2 é uma implementação do SAML 2.0 para Provedores de Serviço baseada em etree e goxmldsig, uma implementação pura em Go de assinaturas digitais XML. Usamos esta biblioteca para testar o SAML 2.0 no Casdoor como mostrado abaixo.

Example: Casdoor at http://localhost:7001/, application app-built-in in org built-in. Add http://localhost:6900/acs/example and http://localhost:6900/saml/acs/example to Redirect URLs in app-built-in.

import (
    "crypto/x509"
    "fmt"
    "net/http"

    "io/ioutil"

    "encoding/base64"
    "encoding/xml"

    saml2 "github.com/russellhaering/gosaml2"
    "github.com/russellhaering/gosaml2/types"
    dsig "github.com/russellhaering/goxmldsig"
)

func main() {
    res, err := http.Get("http://localhost:7001/api/saml/metadata?application=admin/app-built-in")
    if err != nil {
        panic(err)
    }

    rawMetadata, err := ioutil.ReadAll(res.Body)
    if err != nil {
        panic(err)
    }

    metadata := &types.EntityDescriptor{}
    err = xml.Unmarshal(rawMetadata, metadata)
    if err != nil {
        panic(err)
    }

    certStore := dsig.MemoryX509CertificateStore{
        Roots: []*x509.Certificate{},
    }

    for _, kd := range metadata.IDPSSODescriptor.KeyDescriptors {
        for idx, xcert := range kd.KeyInfo.X509Data.X509Certificates {
            if xcert.Data == "" {
                panic(fmt.Errorf("metadata certificate(%d) must not be empty", idx))
            }
            certData, err := base64.StdEncoding.DecodeString(xcert.Data)
            if err != nil {
                panic(err)
            }

            idpCert, err := x509.ParseCertificate(certData)
            if err != nil {
                panic(err)
            }

            certStore.Roots = append(certStore.Roots, idpCert)
        }
    }

    randomKeyStore := dsig.RandomKeyStoreForTest()

    sp := &saml2.SAMLServiceProvider{
        IdentityProviderSSOURL:      metadata.IDPSSODescriptor.SingleSignOnServices[0].Location,
        IdentityProviderIssuer:      metadata.EntityID,
        ServiceProviderIssuer:       "http://localhost:6900/acs/example",
        AssertionConsumerServiceURL: "http://localhost:6900/v1/_saml_callback",
        SignAuthnRequests:           true,
        AudienceURI:                 "http://localhost:6900/saml/acs/example",
        IDPCertificateStore:         &certStore,
        SPKeyStore:                  randomKeyStore,
    }

    http.HandleFunc("/v1/_saml_callback", func(rw http.ResponseWriter, req *http.Request) {
        err := req.ParseForm()
        if err != nil {
            rw.WriteHeader(http.StatusBadRequest)
            return
        }
        samlReponse := req.URL.Query().Get("SAMLResponse")
        assertionInfo, err := sp.RetrieveAssertionInfo(samlReponse)
        if err != nil {
            fmt.Println(err)
            rw.WriteHeader(http.StatusForbidden)
            return
        }
        fmt.Println(assertionInfo)
        if assertionInfo.WarningInfo.InvalidTime {
            fmt.Println("here12:", assertionInfo.WarningInfo.InvalidTime)
            rw.WriteHeader(http.StatusForbidden)
            return
        }

        if assertionInfo.WarningInfo.NotInAudience {
            fmt.Println(assertionInfo)
            fmt.Println("here13:", assertionInfo.WarningInfo.NotInAudience)
            rw.WriteHeader(http.StatusForbidden)
            return
        }

        fmt.Fprintf(rw, "NameID: %s\n", assertionInfo.NameID)

        fmt.Fprintf(rw, "Assertions:\n")

        for key, val := range assertionInfo.Values {
            fmt.Fprintf(rw, "  %s: %+v\n", key, val)
        }
        fmt.Println(assertionInfo.Values.Get("FirstName"))
        fmt.Fprintf(rw, "\n")

        fmt.Fprintf(rw, "Warnings:\n")
        fmt.Fprintf(rw, "%+v\n", assertionInfo.WarningInfo)
    })

    println("Visit this URL To Authenticate:")
    authURL, err := sp.BuildAuthURL("")
    if err != nil {
        panic(err)
    }

    println(authURL)

    println("Supply:")
    fmt.Printf("  SP ACS URL      : %s\n", sp.AssertionConsumerServiceURL)

    err = http.ListenAndServe(":6900", nil)
    if err != nil {
        panic(err)
    }
}

Execute o código acima, e o console exibirá a seguinte mensagem.

Visit this URL To Authenticate:
http://localhost:7001/login/saml/authorize/admin/app-built-in?SAMLRequest=lFVbk6K8Fv0rFvNo2QR...
Supply:
  SP ACS URL      : http://localhost:6900/v1/_saml_callback

Clique na URL para autenticar, e a página de login do Casdoor será exibida.

After authentication, the response looks like the examples below.

resposta

Configuration in the SP (service provider)​

Configuração no Casdoor IdP​

SAML attributes​

Assertion signature control​

Perfil do usuário​

Um exemplo​