Have query about certificates on-disk size on encoded szie of x509 certificate mismatch.

[baban devkate]

  Hello,

Have query about certificates on-disk size on encoded szie of x509
certificate mismatch.


code snippet:-


  Status = ReadCertKeyFile (  ); //populates X509Data & X509DataSize by
reading ca-int.crt of 0x3C9 bytes on-disk size

FYI-ca-int.crt is chained from ca.crt

  BIOX509 = BIO_new_mem_buf((UINT8*)X509Data, (int)X509DataSize);
if (BIOX509 == NULL)
return EFI_INVALID_PARAMETER;

x509 = PEM_read_bio_X509(BIOX509, NULL, NULL, NULL);// cert is in PEM form

  if (x509 == NULL) {// If x509 is not NULL then it is assumed that it
contains a valid X509
return EFI_INVALID_PARAMETER;
  }


 PkCertLen = i2d_X509(x509, NULL);
        Print(L" 3 X509DataSize 0x%x \n", X509DataSize);//----->0x3C9
        Print(L" 3 PkCertLen 0x%x \n", PkCertLen);//-------->  0x2A2


Query-
why on-disk size of certificate is 0x3C9 bytes and 'PkCertLen ' is   0x2A2??
Is this size difference is due to encoding?


~Baban