[REGRESSION]: Install an Apple certificate task does not work when using macOS-26 image

[fredfoc]

New issue checklist

• I searched for existing GitHub issues
• I read pipeline troubleshooting guide
• I checked how to collect logs

Task name

Install an Apple certificate

Breaking task version

2

Last working task version

2

Regression Description

"Install an Apple certificate" task does not work when using macOS-26 image. Used to work on macOS-15

Environment type (Please select at least one enviroment where you face this issue)

• Self-Hosted
• Microsoft Hosted
• VMSS Pool
• Container

Azure DevOps Server type

dev.azure.com (formerly visualstudio.com)

Azure DevOps Server Version (if applicable)

No response

Operation system

macOS

Relevant log output

/usr/local/bin/openssl pkcs12 -in /Users/runner/work/_temp/Certif_GIE_2028-07-16.p12 -nokeys -passin pass:*** | /usr/local/bin/openssl x509 -sha1 -noout -fingerprint -subject -dates -nameopt utf8,sep_semi_plus_space
Error outputting keys and certificates
007CCC50F87F0000:error:0308010C:digital envelope routines:inner_evp_generic_fetch:unsupported:crypto/evp/evp_fetch.c:376:Global default library context, Algorithm (RC2-40-CBC : 0), Properties ()
##[debug]success of first tool:false
Could not find certificate from <stdin>
##[debug]rc:1
##[debug]success:false
##[warning]Error parsing certificate. This might be caused by an unsupported algorithm. If you're using old certificate with a new OpenSSL version try to set -legacy flag in opensslPkcsArgs input.
##[debug]Processed: ##vso[task.issue type=warning;source=TaskInternal;correlationId=ef57bd9d-2a20-422d-ba9f-04abe1e840fe;]Error parsing certificate. This might be caused by an unsupported algorithm. If you're using old certificate with a new OpenSSL version try to set -legacy flag in opensslPkcsArgs input.
##[debug]task result: Failed
##[error]Error: /usr/local/bin/openssl failed with return code: 1

Full task logs with system.debug enabled

UNSUCCESSFUL RUN

 [REPLACE THIS WITH YOUR INFORMATION] 

SUCCESSFUL RUN

 [REPLACE THIS WITH YOUR INFORMATION] 

Repro steps

#Your build pipeline references an undefined variable named ‘P12password’. Create or edit the build pipeline for this YAML file, define the variable on the Variables tab. See https://go.microsoft.com/fwlink/?linkid=865972

steps:
- task: InstallAppleCertificate@2
  displayName: 'Install an Apple certificate'
  inputs:
    certSecureFile: 'Certif_GIE_2028-07-16.p12'
    certPwd: '$(P12password)'
    signingIdentity: 'iOS Development'
    setUpPartitionIdACLForPrivateKey: false

[dassayantan24]

Hi @fredfoc ,
Could you please try passing another argument as input:
opensslPkcsArgs: "-legacy"

steps:
- task: InstallAppleCertificate@2
  displayName: 'Install an Apple certificate'
  inputs:
    certSecureFile: 'Certif_GIE_2028-07-16.p12'
    certPwd: '$(P12password)'
    signingIdentity: 'iOS Development'
    setUpPartitionIdACLForPrivateKey: false
    opensslPkcsArgs: "-legacy"