Description:
------------
When message.eml contains row longer than 76 characters, it generates error.

message.eml example:
Content-Type: application/x-pkcs7-mime; name=smime.p7m; smime-type=signed-data
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7m"
Content-Description: S/MIME Cryptographic Signed Data

MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAaCAJIAEggPoQ29u
...
AJLxjYfEXR/ltNihtpCr9LQLxH02OBbE8YuhZuOpOeZ6mf+yqgD2AnFuEV0pdX8GTHY+KTe56yzU
2DnMC/2+kWQxs0wz+z/EEluGH+MEIplh1UFiLc/zn6DHbzBORTZNWd94aJzHFyQw50RK3hAw3uLjAAAA
AAAA

If the last row is fixed:
2DnMC/2+kWQxs0wz+z/EEluGH+MEIplh1UFiLc/zn6DHbzBORTZNWd94aJzHFyQw50RK3hAw3uLj
AAAA
AAAA

everything is ok.

Maybe not an error because message is against RFC 2045 which specifies base64 76 character row. 
But messages like this exists and at least good to mention it in documentation.


Reproduce code:
---------------
openssl_pkcs7_verify(
  'message.eml'
  PKCS7_NOVERIFY,
  'certificate.pem',
  array('some_ca_certficates')
  'some_ca_certficate',
  'content.eml'
);

Actual result:
--------------
openssl_error_string()
returns:

error:0D06B08E:asn1 encoding routines:ASN1_D2I_READ_BIO:not enough data
error:21078082:PKCS7 routines:B64_READ_PKCS7:decode error 
error:2107A08B:PKCS7 routines:SMIME_read_PKCS7:pkcs7 parse error