General:
Forums topic: Privacy & Security
Apple Platform Security support document
Developer > Security
Enabling enhanced security for your app documentation article
Creating enhanced security helper extensions documentation article
Security Audit Thoughts forums post
Cryptography:
Forums tags: Security, Apple CryptoKit
Security framework documentation
Apple CryptoKit framework documentation
Common Crypto man pages — For the full list of pages, run:
% man -k 3cc
For more information about man pages, see Reading UNIX Manual Pages.
On Cryptographic Key Formats forums post
SecItem attributes for keys forums post
CryptoCompatibility sample code
Keychain:
Forums tags: Security
Security > Keychain Items documentation
TN3137 On Mac keychain APIs and implementations
SecItem Fundamentals forums post
SecItem Pitfalls and Best Practices forums post
Investigating hard-to-reproduce keychain problems forums post
App ID Prefix Change and Keychain Access forums post
Smart cards and other secure tokens:
Forums tag: CryptoTokenKit
CryptoTokenKit framework documentation
Mac-specific resources:
Forums tags: Security Foundation, Security Interface
Security Foundation framework documentation
Security Interface framework documentation
BSD Privilege Escalation on macOS
Related:
Networking Resources — This covers high-level network security, including HTTPS and TLS.
Network Extension Resources — This covers low-level network security, including VPN and content filters.
Code Signing Resources
Notarisation Resources
Trusted Execution Resources — This includes Gatekeeper.
App Sandbox Resources
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
General
RSS for tagPrioritize user privacy and data security in your app. Discuss best practices for data handling, user consent, and security measures to protect user information.
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General:
Forums topic: Privacy & Security
Privacy Resources
Security Resources
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
Topic:
Privacy & Security
SubTopic:
General
I'm experiencing a strange issue where ASWebAuthenticationSession works perfectly when running from Xcode (both Debug and Release), but fails on TestFlight builds.
The setup:
iOS app using ASWebAuthenticationSession for OIDC login (Keycloak)
Custom URL scheme callback (myapp://)
prefersEphemeralWebBrowserSession = false
The issue:
When using iOS Keychain autofill (with Face ID/Touch ID or normal iphone pw, that auto-submits the form) -> works perfectly
When manually typing credentials and clicking the login button -> fails with white screen
When it fails, the form POST from Keycloak back to my server (/signin-oidc) never reaches the server at all. The authentication session just shows a white screen.
Reproduced on:
Multiple devices (iPhone 15 Pro, etc.)
iOS 18.x
Xcode 16.x
Multiple TestFlight testers confirmed same behavior
What I've tried:
Clearing Safari cookies/data
prefersEphemeralWebBrowserSession = true and false
Different SameSite cookie policies on server
Verified custom URL scheme is registered and works (testing myapp://test in Safari opens the app)
Why custom URL scheme instead of Universal Links:
We couldn't get Universal Links to trigger from a js redirect (window.location.href) within ASWebAuthenticationSession. Only custom URL schemes seemed to be intercepted. If there's a way to make Universal Links work in this context, without a manual user-interaction we'd be happy to try.
iOS Keychain autofill works
The only working path is iOS Keychain autofill that requires iphone-authentication and auto-submits the form. Any manual form submission fails, but only on TestFlight - not Xcode builds.
Has anyone encountered this or know a workaround?
Hi everyone,
I'm developing an iOS app using the AppsFlyer SDK. I understand that starting with iOS 14.5, if a user denies the App Tracking Transparency (ATT) permission, we are not allowed to access the IDFA or perform cross-app tracking.
However, I’d like to clarify which in-app events are still legally and technically safe to send when the user denies ATT permission.
Specifically, I want to know:
Is it acceptable to send events like onboarding_completed, paywall_viewed, subscription_started, subscribe, subscribe_price, or app_opened if they are not linked to IDFA or any form of user tracking?
Would sending such internal behavioral events (used purely for SKAdNetwork performance tracking or in-app analytics) violate Apple’s privacy policy if no device identifiers are attached?
Additionally, if these events are sent in fully anonymous form (i.e., not associated with IDFA, user ID, email, or any identifiable metadata), does Apple still consider this a privacy concern? In other words, can onboarding_completed, paywall_viewed, subsribe, subscribe_price, etc., be sent in anonymous format without violating ATT policies?
Are there any official Apple guidelines or best practices that outline what types of events are considered compliant in the absence of ATT consent?
My goal is to remain 100% compliant with Apple’s policies while still analyzing meaningful user behavior to improve the in-app experience.
Any clarification or pointers to documentation would be greatly appreciated.
Thanks in advance!
In these threads, it was clarified that Credential Provider Extensions must set both Backup Eligible (BE) and Backup State (BS) flags to 1 in authenticator data:
https://developer.apple.com/forums/thread/745605
https://developer.apple.com/forums/thread/787629
However, I'm developing a passkey manager that intentionally stores credentials only on the local device. My implementation uses:
kSecAttrAccessibleWhenUnlockedThisDeviceOnly for keychain items
kSecAttrTokenIDSecureEnclave for private keys
No iCloud sync or backup
These credentials are, by definition, single-device credentials. According to the WebAuthn specification, they should be represented with BE=0, BS=0.
Currently, I'm forced to set BE=1, BS=1 to make the extension work, which misrepresents the actual backup status to relying parties. This is problematic because:
Servers using BE/BS flags for security policies will incorrectly classify these as synced passkeys
Users who specifically want device-bound credentials for higher security cannot get accurate flag representation
Request: Please allow Credential Provider Extensions to return credentials with BE=0, BS=0 for legitimate device-bound passkey implementations.
Environment: macOS 26.2 (25C56), Xcode 26.2 (17C52)
Topic:
Privacy & Security
SubTopic:
General
Tags:
Extensions
macOS
Authentication Services
Passkeys in iCloud Keychain
Can someone please guide me on the entire process of integrating ads in an IOS application using google's admob sdk? Not related to code but things related to Apple's privacy policy. Which options do need to select or specify in my app profile's privacy policy (identifier) section?
Hi Apple Developer Team,
I am encountering an issue with the “Sign in with Apple” feature. While implementing this functionality in my dotnet application, I noticed that the user’s first name and last name are not being returned, even though I have explicitly requested the name scope. However, the email and other requested information are returned successfully.
Here are the details of my implementation: 1. Scope Requested: name, email 2. Response Received: Email and other data are present, but fullName is missing or null. 3. Expected Behavior: I expected to receive the user’s first and last name as per the fullName scope.
I have verified the implementation and ensured that the correct scopes are being passed in the request.
Could you please help clarify the following? 1. Are there specific conditions under which Apple may not return the user’s fullName despite the scope being requested? 2. Is there a recommended approach or fallback mechanism to handle this scenario? 3. Could this behavior be related to a limitation or change in the API, or might it be an issue on my end?
I also came to know that for initial sign in the user details will be displayed in the signin-apple payload as Form data but how do I fetch those form-data from the signin-apple request, please suggest
I would greatly appreciate any guidance or solutions to resolve this issue.
Thank you for your support!
News link: https://developer.apple.com/news/?id=12m75xbj
If your app offers Sign in with Apple, you’ll need to use the Sign in with Apple REST API to revoke user tokens when deleting an account.
I'm not good English. I'm confused about the above sentence
Do I have to use REST API unconditionally or can I just delete to the account data?
Topic:
Privacy & Security
SubTopic:
General
Tags:
App Review
Sign in with Apple REST API
Sign in with Apple
Hey there, I used our team's account to configure sign in with Apple, the mode is pop up, my clientId scope redirectUrl state are both correct. I got Failed to verify your identity. Try again., actually my account is valid because I can login to my mac and every apple website. I have tried many apple accounts and still got this error. That was so weird, I didn't find a solution online. Pls help me thanks.
I can't find any information about why this is happening, nor can I reproduce the 'successful' state on this device. My team needs to understand this behavior, so any insight would be greatly appreciated!
The expected behavior: If I delete both apps and reinstall them, attempting to open the second app from my app should trigger the system confirmation dialog.
The specifics: I'm using the MSAL library. It navigates the user to the Microsoft Authenticator app and then returns to my app. However, even after resetting the phone and reinstalling both apps, the dialog never shows up (it just opens the app directly).
Does anyone know the logic behind how iOS handles these prompts or why it might be persistent even after a reset?
Thanks in advance!
Topic:
Privacy & Security
SubTopic:
General
Hello,
I am working on a script to update an application which bundle ID changed. Only the bundle ID was modified; all other aspects remain unchanged.
This application requires access to "Screen & System Audio Recording" permissions, which are currently granted to the old bundle ID.
The script performs the following steps:
launchctl bootout gui/$(id -u) /Library/LaunchAgents/com.my_agent_1.plist
pkgutil --forget com.my_agent_1
tccutil reset All com.my_agent_1
rm /Library/LaunchAgents/com.my_agent_1.plist
rm -rf </path/to/com_my_agent_1>
installer -dumplog -allowUntrusted -pkg </path/to/com_my_agent_2.pkg> -target /
...
When running steps #1-6 without a restart between steps #5 and #6, the old bundle ID (com.my_agent_1) remains visible in TCC.db (verified via SQL queries).
Looks like this is the reason why "com.my_agent_2" is not automatically added to the permission list (requiring manual add).
Moreover, "tccutil reset All com.my_agent_1" does not work anymore, the error:
tccutil: No such bundle identifier "com.my_agent_1": The operation couldn’t be completed. (OSStatus error -10814.)
Is there any way to completely clear the "Privacy & Security" permissions without requiring a system restart?
Thank you a lot for your help in advance!
Hello,
We are working on integrating app integrity verification into our service application, following Apple's App Attest and DeviceCheck guide.
Our server issues a challenge to the client, which then sends the challenge, attestation, and keyId in CBOR format to Apple's App Attest server for verification. However, we are unable to reach both https://attest.apple.com and https://attest.development.apple.com due to network issues.
These attempts have been made from both our internal corporate network and mobile hotspot environments. Despite adjusting DNS settings and other configurations, the issue persists.
Are there alternative methods or solutions to address this problem? Any recommended network configurations or guidelines to successfully connect to Apple's App Attest servers would be greatly appreciated.
Thank you.
we develop extension "Autofill Credential Provider" function for passkey.
1.first step registe passkey
2.second step authenticate with passkey
step 1 & step 2 has finished and run success with provideCredentialWithoutUserInteraction.
But we want to prepare our interface for use to input password and select passkey what the want. however the func prepareInterfaceToProvideCredential in ASCredentialProviderViewController does call? what i missed? how can i do it?
General:
Forums topic: Privacy & Security
Forums tag: Privacy
Developer > Security — This also covers privacy topics.
App privacy details on the App Store
UIKit > Protecting the User’s Privacy documentation
Bundle Resources > Privacy manifest files documentation
TN3181 Debugging an invalid privacy manifest technote
TN3182 Adding privacy tracking keys to your privacy manifest technote
TN3183 Adding required reason API entries to your privacy manifest technote
TN3184 Adding data collection details to your privacy manifest technote
TN3179 Understanding local network privacy technote
Handling ITMS-91061: Missing privacy manifest forums post
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
General:
Forums subtopic: Privacy & Security > General
Forums tag: App Sandbox
App Sandbox documentation
App Sandbox Design Guide documentation — This is no longer available from Apple. There’s still some info in there that isn’t covered by the current docs but, with the latest updates, it’s pretty minimal (r. 110052019). Still, if you’re curious, you can consult an old copy [1].
App Sandbox Temporary Exception Entitlements archived documentation — To better understand the role of temporary exception entitlements, see this post.
Embedding a command-line tool in a sandboxed app documentation
Discovering and diagnosing App Sandbox violations (replaces the Viewing Sandbox Violation Reports forums post)
Resolving App Sandbox Inheritance Problems forums post
The Case for Sandboxing a Directly Distributed App forums post
Implementing Script Attachment in a Sandboxed App forums post
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
[1] For example, this one archived by the Wayback Machine.
When presenting a cookie banner for GDPR purposes, should ATT precede the cookie banner?
It seems that showing a Cookie Banner and then showing the ATT permission prompt afterwards (if a user elects to allow cookies/tracking) would be more appropriate.
Related question: Should the “Allow Tracking” toggle for an app in system settings serve as a master switch for any granular tracking that might be managed by a 3rd party Consent Management Platform?
If ATT is intended to serve as a master switch for tracking consent, if the ATT prompt is presented before a cookie banner, should the banner even appear if a user declines tracking consent?
I’m not finding any good resources that describe this flow in detail and I’m seeing implementations all over the place on this.
Help!
Thanks!!!
Hey everyone, I'm hitting a really frustrating issue with App Attest. My app was working perfectly with DCAppAttestService on October 12th, but starting October 13th it started failing with DCError Code 2 "Failed to fetch App UUID" at DCAppAttestController.m:153. The weird part is I didn't change any code - same implementation, same device, same everything.
I've tried switching between development and production entitlement modes, re-registered my device in the Developer Portal, created fresh provisioning profiles with App Attest capability, and verified that my App ID has App Attest enabled. DCAppAttestService.isSupported returns true, so the device supports it. Has anyone else run into this? This is blocking my production launch and I'm not sure if it's something on my end or an Apple infrastructure issue.
My app has been rejected by App Store review because the sign in with Apple functionality is not working properly. I'm able to reproduce the issue on my end but I don't understand why it's happening.
I have two other apps that implement the same OAuth flow in an identical manner, and those apps have no issues signing in with Apple.
I've copied my OAuth flow to a fresh project to see if that would make a difference, and it gives me the exact same error. In the simulator I get "invalid_request, invalid web redirect URL", and on-device the FaceID authentication fails with a very non-specific "Sign Up Not Completed" error.
I'm completely out of ideas here, so any guidance would be appreciated. Thanks!
We're experiencing crashes in our production iOS app related to Apple's DeviceCheck framework. The crash occurs in DCAnalytics internal performance tracking, affecting some specific versions of iOS 18 (18.4.1, 18.5.0).
Crash Signature
CoreFoundation: -[__NSDictionaryM setObject:forKeyedSubscript:] + 460
DeviceCheck: -[DCAnalytics sendPerformanceForCategory:eventType:] + 236
Observed Patterns
Scenario 1 - Token Generation:
Crashed: com.appQueue
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000010
DeviceCheck: -[DCDevice generateTokenWithCompletionHandler:]
Thread: Background dispatch queue
Scenario 2 - Support Check:
Crashed: com.apple.main-thread
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000008
DeviceCheck: -[DCDevice _isSupportedReturningError:]
DeviceCheck: -[DCDevice isSupported]
Thread: Main thread
Root Cause Analysis
The DCAnalytics component within DeviceCheck attempts to insert a nil value into an NSMutableDictionary when recording performance metrics, indicating missing nil validation before dictionary operations.
Reproduction Context
Crashes occur during standard DeviceCheck API usage:
Calling DCDevice.isSupported property
Calling DCDevice.generateToken(completionHandler:) (triggered by Firebase App Check SDK)
Both operations invoke internal analytics that fail with nil insertion attempts.
Concurrency Considerations
We've implemented sequential access guards around DeviceCheck token generation to prevent race conditions, yet crashes persist. This suggests the issue likely originates within the DeviceCheck framework's internal implementation rather than concurrent access from our application code.
Note: Scenario 2 occurs through Firebase SDK's App Check integration, which internally uses DeviceCheck for attestation.
Request
Can Apple engineering confirm if this is a known issue with DeviceCheck's analytics subsystem? Is there a recommended workaround to disable DCAnalytics or ensure thread-safe DeviceCheck API usage?
Any guidance on preventing these crashes would be appreciated.
Feedback report id: FB16605524
I'm trying to send emails to private relay service addresses using AWS SES and emails are not received. My emails are sent from dev@mydomain.fr and I've set a custom FROM domain of mail.mydomain.fr. I've added both domains and the dev@mydomain.fr adress to the "Certificates, Identifies & Profiles" section. I've set up DKIM and SPF for both.
Attached a redacted version of email headers.
email_headers_redacted.txt
Estou compartilhando algumas observações técnicas sobre Crash Detection / Emergency SOS no ecossistema Apple, com base em eventos amplamente observados em 2022 e 2024, quando houve chamadas automáticas em massa para serviços de emergência.
A ideia aqui não é discutir UX superficial ou “edge cases isolados”, mas sim comportamento sistêmico em escala, algo que acredito ser relevante para qualquer time que trabalhe com sistemas críticos orientados a eventos físicos.
Contexto resumido
A partir do iPhone 14, a Detecção de Acidente passou a correlacionar múltiplos sensores (acelerômetros de alta faixa, giroscópio, GPS, microfones) para inferir eventos de impacto severo e acionar automaticamente chamadas de emergência. Em 2022, isso resultou em um volume significativo de falsos positivos, especialmente em atividades com alta aceleração (esqui, snowboard, parques de diversão). Em 2024, apesar de ajustes, houve recorrência localizada do mesmo padrão.
Ponto técnico central
O problema não parece ser hardware, nem um “bug pontual”, mas sim o estado intermediário de decisão:
Aceleração ≠ acidente
Ruído ≠ impacto real
Movimento extremo ≠ incapacidade humana
Quando o classificador entra em estado ambíguo, o sistema depende de uma janela curta de confirmação humana (toque/voz). Em ambientes ruidosos, com o usuário em movimento ou fisicamente ativo, essa confirmação frequentemente falha. O sistema então assume incapacidade e executa a ação fail-safe: chamada automática.
Do ponto de vista de engenharia de segurança, isso é compreensível. Do ponto de vista de escala, é explosivo.
Papel da Siri
A Siri não “decide” o acidente, mas é um elo sensível na cadeia humano–máquina. Falhas de compreensão por ruído, idioma, respiração ofegante ou ausência de resposta acabam sendo interpretadas como sinal de emergência real. Isso é funcionalmente equivalente ao que vemos em sistemas automotivos como o eCall europeu, quando a confirmação humana é inexistente ou degradada.
O dilema estrutural
Há um trade-off claro e inevitável:
Reduzir falsos negativos (não perder um acidente real)
Aumentar falsos positivos (chamadas indevidas)
Para o usuário individual, errar “para mais” faz sentido. Para serviços públicos de emergência, milhões de dispositivos errando “para mais” criam ruído operacional real.
Por que isso importa para developers
A Apple hoje opera, na prática, um dos maiores sistemas privados de segurança pessoal automatizada do mundo, interagindo diretamente com infraestrutura pública crítica. Isso coloca Crash Detection / SOS na mesma categoria de sistemas safety-critical, onde:
UX é parte da segurança
Algoritmos precisam ser auditáveis
“Human-in-the-loop” não pode ser apenas nominal
Reflexões abertas
Alguns pontos que, como developer, acho que merecem discussão:
Janelas de confirmação humana adaptativas ao contexto (atividade física, ruído).
Cancelamento visual mais agressivo em cenários de alto movimento.
Perfis de sensibilidade por tipo de atividade, claramente comunicados.
Critérios adicionais antes da chamada automática quando o risco de falso positivo é estatisticamente alto.
Não é um problema simples, nem exclusivo da Apple. É um problema de software crítico em contato direto com o mundo físico, operando em escala planetária. Justamente por isso, acho que vale uma discussão técnica aberta, sem ruído emocional.
Curioso para ouvir perspectivas de quem trabalha com sistemas similares (automotivo, wearables, safety-critical, ML embarcado).
— Rafa
Topic:
Privacy & Security
SubTopic:
General
Tags:
Siri Event Suggestions Markup
Core ML
App Intents
Communication Safety
This post is an extension to Importing Cryptographic Keys that covers one specific common case: importing a PEM-based RSA private key and its certificate to form a digital identity.
If you have questions or comments, start a new thread in Privacy & Security > General. Tag your thread with Security so that I see it.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
Importing a PEM-based RSA Private Key and its Certificate
I regularly see folks struggle to import an RSA private key and its corresponding certificate. Importing Cryptographic Keys outlines various options for importing keys, but in this post I want to cover one specific case, namely, a PEM-based RSA private key and its corresponding certificate. Together these form a digital identity, represented as a SecIdentity object.
IMPORTANT If you can repackage your digital identity as a PKCS#12, please do. It’s easy to import that using SecPKCS12Import. If you can switch to an elliptic curve (EC) private key, please do. It’s generally better and Apple CryptoKit has direct support for importing an EC PEM.
Assuming that’s not the case, let’s explore how to import a PEM-base RSA private key and its corresponding certificate to form a digital identity.
Note The code below was built with Xcode 16.2 and tested on the iOS 18.2 simulator. It uses the helper routines from Calling Security Framework from Swift.
This code assumes the data protection keychain. If you’re targeting macOS, add kSecUseDataProtectionKeychain to all the keychain calls. See TN3137 On Mac keychain APIs and implementations for more background to that.
Unwrap the PEM
To start, you need to get the data out of the PEM:
/// Extracts the data from a PEM.
///
/// As PEM files can contain a large range of data types, you must supply the
/// expected prefix and suffix strings. For example, for a certificate these
/// are `"-----BEGIN CERTIFICATE-----` and `-----END CERTIFICATE-----`.
///
/// - important: This assumes the simplest possible PEM format. It does not
/// handle metadata at the top of the PEM or PEMs with multiple items in them.
func dataFromPEM(_ pem: String, _ expectedPrefix: String, _ expectedSuffix: String) -> Data? {
let lines = pem.split(separator: "\n")
guard
let first = lines.first,
first == expectedPrefix,
let last = lines.last,
last == expectedSuffix
else { return nil }
let base64 = lines.dropFirst().dropLast().joined()
guard let data = Data(base64Encoded: base64) else { return nil }
return data
}
IMPORTANT Read the doc comment to learn about some important limitations with this code.
Import a Certificate
When adding a digital identity to the keychain, it’s best to import the certificate and the key separately and then add them to the keychain. That makes it easier to track down problems you encounter.
To import a PEM-based certificate, extract the data from the PEM and call SecCertificateCreateWithData:
/// Import a certificate in PEM format.
///
/// - important: See ``dataFromPEM(_:_:_:)`` for some important limitations.
func importCertificatePEM(_ pem: String) throws -> SecCertificate {
guard
let data = dataFromPEM(pem, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----"),
let cert = SecCertificateCreateWithData(nil, data as NSData)
else { throw NSError(domain: NSOSStatusErrorDomain, code: Int(errSecParam), userInfo: nil) }
return cert
}
Here’s an example that shows this in action:
let benjyCertificatePEM = """
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
"""
print(try? importCertificatePEM(benjyCertificatePEM))
If you run this it prints:
Optional(<cert(0x11e304c10) s: Benjy i: MouseCA>)
Import a Private Key
To import a PEM-base RSA private key, extract the data from the PEM and call SecKeyCreateWithData:
/// Import an 2048-bit RSA private key in PEM format.
///
/// Don’t use this code if:
///
/// * If you can switch to an EC key. EC keys are generally better and, for
/// this specific case, there’s support for importing them in Apple CryptoKit.
///
/// * You can switch to using a PKCS#12. In that case, use the system’s
/// `SecPKCS12Import` routine instead.
///
/// - important: See ``dataFromPEM(_:_:_:)`` for some important limitations.
func importRSA2048PrivateKeyPEM(_ pem: String) throws -> SecKey {
// Most private key PEMs are in PKCS#8 format. There’s no way to import
// that directly. Instead you need to strip the header to get to the
// `RSAPrivateKey` data structure encapsulated within the PKCS#8. Doing that
// in the general case is hard. In the specific case of an 2048-bit RSA
// key, the following hack works.
let rsaPrefix: [UInt8] = [
0x30, 0x82, 0x04, 0xBE, 0x02, 0x01, 0x00, 0x30,
0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7,
0x0D, 0x01, 0x01, 0x01, 0x05, 0x00, 0x04, 0x82,
0x04, 0xA8,
]
guard
let pkcs8 = dataFromPEM(pem, "-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----"),
pkcs8.starts(with: rsaPrefix)
else { throw NSError(domain: NSOSStatusErrorDomain, code: Int(errSecParam), userInfo: nil) }
let rsaPrivateKey = pkcs8.dropFirst(rsaPrefix.count)
return try secCall { SecKeyCreateWithData(rsaPrivateKey as NSData, [
kSecAttrKeyType: kSecAttrKeyTypeRSA,
kSecAttrKeyClass: kSecAttrKeyClassPrivate,
] as NSDictionary, $0) }
}
IMPORTANT This code only works with 2048-bit RSA private keys. The comments explain more about that limitation.
Here’s an example that shows this in action:
let benjyPrivateKeyPEM = """
-----BEGIN PRIVATE KEY-----
MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDkHuWouvBUIU1S
IKbAyvlDjyK4Cs6iXFvsMC5yUaehlVfRJonyau8I613qpj9V4HDbbu3FYQ8fvzjS
pf/IbHGpOeB00K4MBOpiutvEU4ZXfQZmaDo2llgpKFOWx+2SGIKyhdbQDubkwJlS
Qfb+w0ELyhEcI0NdGWxTlur/I9oAy3rGUGxSAu3/74g1y7D6vHVGbssm/QV66RCa
V6RQ4v8MwldwtcJrTlK1Nu8c+IAc4t6PTulOEJmhfdccWk5NDrfv0SyO9Jke02Gv
ruqu1FvyivatfvC3k1bNcduFQOXLMRwgEH/sbzKCpaHJlMQgwWJExZJrcoZhkTed
l7nB4LtJAgMBAAECggEBAKOPF6ED776SZgrliEog/dmXrhABB6jXybytyw+CRkuP
dXhrRmr+isZ9Y0gTzMN4+dILVgW4EozzoP0/sgZ04oWwDqQS30eU2qzRRzMbo+3k
oYsZXeu3nhxcYppwXIDsfAEd/ygMFzaadRPKYhrFykR2rA/dpLYCvW2tfm5SuULp
RxnKykFlVi8yVT64AovVm0XGOy/QTO5BBbUdftvZY9QCjGn/IEL8QFEz0rxZsb2L
s0HgVMUcB1My38RksZQRKLMWCtqLqWnez3oCnPka+dxFQj5RU//vNtRoVh1ExbmW
txHz48v00AKQvaudC4ujIspZlY8+UPdYQT0TNjhsfoUCgYEA+7yEvyCgRtYwUNm6
jHTg67LoSldHwENOry63qGZp3rCkWBkPXle7ulgRtuw+e11g4MoMMAgkIGyIGB/Z
6YvnQGmJCTMw+HHIyw3k/OvL1iz4DM+QlxDuD79Zu2j2UIL4maDG0ZDskiJujVAf
sFOy4r36TvYedmd7qgh9pgpsFl8CgYEA5/v8PZDs2I1wSDGllGfTr6aeQcxvw98I
p8l/8EV/lYpdKQMFndeFZI+dnJCcTeBbeXMmPNTAdL5gOTwDReXamIAdr93k7/x6
iKMHzBrpQZUMEhepSd8zdR1+vLvyszvUU6lvNXcfjwbu7gJQkwbA6kSoXRN+C1Cv
i5/w66t0f1cCgYBt02FWwTUrsmaB33uzq4o1SmhthoaXKsY5R3h4z7WAojAQ/13l
GwGb2rBfzdG0oJiTeZK3odWhD7iQTdUUPyU0xNY0XVEQExQ3AmjUr0rOte/CJww9
2/UAicrsKG7N0VYEMFCNPVz4pGz22e35T4rLwXZi3J2NqrgZBntK5WEioQKBgEyx
L4ii+sn0qGQVlankUUVGjhcuoNxeRZxCrzsdnrovTfEbAKZX88908yQpYqMUQul5
ufBuXVm6/lCtmF9pR8UWxbm4X9E+5Lt7Oj6tvuNhhOYOUHcNhRN4tsdqUygR5XXr
E8rXIOXF4wNoXH7ewrQwEoECyq6u8/ny3FDtE8xtAoGBALNFxRGikbQMXhUXj7FA
lLwWlNydCxCc7/YwlHfmekDaJRv59+z7SWAR15azhbjqS9oXWJUQ9uvpKF75opE7
MT0GzblkKAYu/3uhTENCjQg+9RFfu5w37E5RTWHD2hANV0YqXUlmH3d+f5uO0xN7
7bpqwYuYzSv1hBfU/yprDco6
-----END PRIVATE KEY-----
"""
print(try? importRSA2048PrivateKeyPEM(benjyPrivateKeyPEM))
If you run this it prints:
Optional(<SecKeyRef algorithm id: 1, key type: RSAPrivateKey, version: 4, 2048 bits (block size: 256), addr: 0x600000c5ce50>)
Form a Digital Identity
There are two common ways to form a digital identity:
SecPKCSImport
SecItemCopyMatching
SecPKCSImport is the most flexible because it gives you an in-memory digital identity. You can then choose to add it to the keychain or not. However, it requires a PKCS#12 as input. If you’re starting out with separate private key and certificate PEMs, you have to use SecItemCopyMatching.
Note macOS also has SecIdentityCreateWithCertificate, but it has some seriously limitations. First, it’s only available on macOS. Second, it requires the key to be in the keychain. If you’re going to add the key to the keychain anyway, you might as well use SecItemCopyMatching.
To form a digital identity from a separate private key and certificate:
Add the certificate to the keychain.
Add the private key to the keychain.
Call SecItemCopyMatching to get back a digital identity.
Here’s an example of that in action:
/// Imports a digital identity composed of separate certificate and private key PEMs.
///
/// - important: See ``dataFromPEM(_:_:_:)`` for some important limitations.
/// See ``importRSA2048PrivateKeyPEM(_:)`` for alternative strategies that are
/// much easier to deploy.
func addRSA2048DigitalIdentityPEMToKeychain(certificate: String, privateKey: String) throws -> SecIdentity {
// First import the certificate and private key. This has the advantage in
// that it triggers an early failure if the data is in the wrong format.
let certificate = try importCertificatePEM(certificate)
let privateKey = try importRSA2048PrivateKeyPEM(privateKey)
// Check that the private key matches the public key in the certificate. If
// not, someone has given you bogus credentials.
let certificatePublicKey = try secCall { SecCertificateCopyKey(certificate) }
let publicKey = try secCall { SecKeyCopyPublicKey(privateKey) }
guard CFEqual(certificatePublicKey, publicKey) else {
throw NSError(domain: NSOSStatusErrorDomain, code: Int(errSecPublicKeyInconsistent))
}
// Add the certificate first. If that fails — and the most likely error is
// `errSecDuplicateItem` — we want to stop immediately.
try secCall { SecItemAdd([
kSecValueRef: certificate,
] as NSDictionary, nil) }
// The add the private key.
do {
try secCall { SecItemAdd([
kSecValueRef: privateKey,
] as NSDictionary, nil) }
} catch let error as NSError {
// We ignore a `errSecDuplicateItem` error when adding the key. It’s
// possible to have multiple digital identities that share the same key,
// so if you try to add the key and it’s already in the keychain then
// that’s fine.
guard error.domain == NSOSStatusErrorDomain, error.code == errSecDuplicateItem else {
throw error
}
}
// Finally, search for the resulting identity.
//
// I originally tried querying for the identity based on the certificate’s
// attributes — the ones that contribute to uniqueness, namely
// `kSecAttrCertificateType`, `kSecAttrIssuer`, and `kSecAttrSerialNumber` —
// but that failed for reasons I don't fully understand (r. 144152660). So
// now I get all digital identities and find the one with our certificate.
let identities = try secCall { SecItemCopyMatching([
kSecClass: kSecClassIdentity,
kSecMatchLimit: kSecMatchLimitAll,
kSecReturnRef: true,
] as NSDictionary, $0) } as! [SecIdentity]
let identityQ = try identities.first { i in
try secCall { SecIdentityCopyCertificate(i, $0) } == certificate
}
return try secCall(Int(errSecItemNotFound)) { identityQ }
}
IMPORTANT This code is quite subtle. Read the comments for an explanation as to why it works the way it does.
Further reading
For more information about the APIs and techniques used above, see:
Importing Cryptographic Keys
On Cryptographic Keys Formats
SecItem: Fundamentals
SecItem: Pitfalls and Best Practices
Calling Security Framework from Swift
TN3137 On Mac keychain APIs and implementations
Finally, for links to documentation and other resources, see Security Resources.
Revision History
2025-02-13 Added code to check for mismatched private key and certificate.
2025-02-04 First posted.