title: Unable to load certificate, Xcode builds fails to install certificate (VSTS/Azure DevOps, YAML Pipeline)
body: <p>I'm using the YAML pipelines in Azure DevOps, to build an iOS app.</p>
  
  <p>My YAML looks as follows:</p>
  
  <pre><code># Xcode
  # Build, test, and archive an Xcode workspace on macOS.
  # Add steps that install certificates, test, sign, and distribute the app, save build artifacts, and more:
  # https://docs.microsoft.com/vsts/pipelines/languages/xcode
  
  pool:
    vmImage: 'macOS 10.13'
  
  steps:
  - task: InstallAppleCertificate@2
    displayName: 'Install an Apple certificate'
    inputs:
      certSecureFile: 'FILE_ID'
      certPwd: '$(P12password)'
  
  - task: InstallAppleProvisioningProfile@1
    displayName: 'Install an Apple provisioning profile'
    inputs:
      provProfileSecureFile: 'FILE_ID'
  
  - task: CocoaPods@0
    displayName: 'pod install using the CocoaPods task with defaults'
  
  - task: Xcode@5
    displayName: 'Xcode build'
    inputs:
      xcWorkspacePath: 'MyApp.xcworkspace'
      scheme: 'MyApp'
      xcodeVersion: 'Default'
      signingOption: manual
      signingIdentity: '$(APPLE_CERTIFICATE_SIGNING_IDENTITY)'
      provisioningProfileUuid: '$(APPLE_PROV_PROFILE_UUID)'
  </code></pre>
  
  <p>I'm getting an error in the Install Apple Certificate step:</p>
  
  <pre><code>2018-10-02T20:08:23.4496940Z ##[section]Starting: Install an Apple certificate
  2018-10-02T20:08:23.4786520Z ==============================================================================
  2018-10-02T20:08:23.4786680Z Task         : Install Apple Certificate
  2018-10-02T20:08:23.4786800Z Description  : Install an Apple certificate required to build on a macOS agent
  2018-10-02T20:08:23.4786940Z Version      : 2.137.0
  2018-10-02T20:08:23.4787050Z Author       : Microsoft Corporation
  2018-10-02T20:08:23.4787160Z Help         : [More Information](https://go.microsoft.com/fwlink/?LinkID=862067)
  2018-10-02T20:08:23.4787280Z ==============================================================================
  2018-10-02T20:08:24.9657760Z [command]/usr/local/bin/openssl pkcs12 -in /Users/vsts/agent/2.140.2/work/_temp/PWEKQ6YCZA.p12 -nokeys -passin pass:*** | /usr/local/bin/openssl x509 -noout -fingerprint
  2018-10-02T20:08:25.0196330Z 140735606010824:error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag:tasn_dec.c:1220:
  2018-10-02T20:08:25.0197000Z 140735606010824:error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error:tasn_dec.c:386:Type=PKCS12
  2018-10-02T20:08:25.0332040Z unable to load certificate
  2018-10-02T20:08:25.0332600Z 140735606010824:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:697:Expecting: TRUSTED CERTIFICATE
  2018-10-02T20:08:25.0437120Z ##[error]Error: /usr/local/bin/openssl failed with return code: 1
  2018-10-02T20:08:25.0514080Z ##[section]Finishing: Install an Apple certificate
  </code></pre>
  
  <p>Any idea what could be wrong here?</p>
  
  <p>I also tried setting up a build pipeline in Azure DevOps from the UI, but I get the same result.</p>