Apple Pay Signature Validation Fails

I'm currently integrating Apple Pay with my payment provider, and I'm encountering a signature validation error during the payment flow.

Here's the setup:

  • I’ve verified that my Merchant Certificate is valid, and I'm able to initialize the Apple Pay session without any issues. Also this curl works fine

  • The Payment Processing Certificate was created by my PSP.
  • PSP claims that the payment token signature is invalid during the transaction phase, which prevents payment completion.

The parsed signature starts like this

    0:d=0  hl=2 l=inf  cons: SEQUENCE          
    2:d=1  hl=2 l=   9 prim: OBJECT            :pkcs7-signedData
   13:d=1  hl=2 l=inf  cons: cont [ 0 ]        
   15:d=2  hl=2 l=inf  cons: SEQUENCE          
   17:d=3  hl=2 l=   1 prim: INTEGER           :01
   20:d=3  hl=2 l=  13 cons: SET               
   22:d=4  hl=2 l=  11 cons: SEQUENCE          
   24:d=5  hl=2 l=   9 prim: OBJECT            :sha256
   35:d=3  hl=2 l=inf  cons: SEQUENCE          
   37:d=4  hl=2 l=   9 prim: OBJECT            :pkcs7-data
   48:d=4  hl=2 l=   0 prim: EOC               
   50:d=3  hl=2 l=inf  cons: cont [ 0 ]        
   52:d=4  hl=4 l= 995 cons: SEQUENCE          
   56:d=5  hl=4 l= 904 cons: SEQUENCE          
   60:d=6  hl=2 l=   3 cons: cont [ 0 ]        
   62:d=7  hl=2 l=   1 prim: INTEGER           :02
   65:d=6  hl=2 l=   8 prim: INTEGER           :16634C8B0E305717
   75:d=6  hl=2 l=  10 cons: SEQUENCE          
   77:d=7  hl=2 l=   8 prim: OBJECT            :ecdsa-with-SHA256
   87:d=6  hl=2 l= 122 cons: SEQUENCE          
   89:d=7  hl=2 l=  46 cons: SET               
   91:d=8  hl=2 l=  44 cons: SEQUENCE          
   93:d=9  hl=2 l=   3 prim: OBJECT            :commonName
   98:d=9  hl=2 l=  37 prim: UTF8STRING        :Apple Application Integration CA - G3

I'm looking for guidance on what could be causing this signature failure. Does anyone know what else I can check regarding the merchant or payment processing certificates, private keys, or key usage that might cause Apple Pay signature validation to fail, even if the session initializes successfully? Domains are also verified.

Any help or suggestions would be greatly appreciated.

Apple Pay Signature Validation Fails
 
 
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