Typedef structure pkcs7_st
{
/* If the following content contains ASN 1 code, it is not empty.
* This structure */
Unsigned char * ASN1;
Long length;
#define PKCS7_S_HEADER 0
#define PKCS7_S_BODY 1
# define PKCS7_S_TAIL 2
Int status; /* Use during processing */
Int separation;
ASN 1 _ OBJECT * type；
/* Content defined by type */
/* All encryption/message digests are applied to the Content.
* Omit the "Type" field. */
labour union
char * ptr
/* NID _ pkcs 7 _ data */
ASN 1 _ OCTET _ STRING * data；
/* NID _ pkcs 7 _ Signed */
PKCS7 _ SIGNED * sign
/* NID _ pkcs 7 _ envelope */
PKCS7 _ ENVELOPE * envelope;
/* NID _ pkcs 7 _ Signed and Encapsulated */
pkcs 7 _ SIGN _ ENVELOPE * signed _ and _ enveloped；
/* NID _ pkcs 7 _ Summary */
PKCS7 _ DIGEST * digest
/* NID _ pkcs 7 _ Encryption */
PKCS7 _ ENCRYPT * encryption;
/* What else */
ASN 1 _ TYPE * other;
} d；
} PKCS7
Data:
Clear text packaging
The types are NID _ pkcs 7 _ data and ASN 1 _ octet _ string, which is a simple ASN 1 _ string data type.
Signature data (signature):
Encapsulate data and signature value, including signer certificate, CRL, etc. In order to determine the identity of the sender.
Type is NID _ pkcs 7 _ signed. For data of type PKCS7_SIGNED, PKCS7_SIGNED is defined as follows:
Typedef structure pkcs7_signed_st
{
ASN 1 _ INTEGER * version; /* version1*/version
STACK _ OF(X509 _ ALGOR)* MD _ algs； /* MD used *// summary algorithm
STACK _ OF(X509)* certificate; /*[0]*// Signing certificate
STACK _ OF(X509 _ CRL)* CRL； /*[ 1]*// certificate revocation list
STACK _ OF(pkcs 7 _ SIGNER _ INFO)* SIGNER _ INFO； Signature information
Struct pkcs7 _ st * content;
} PKCS7 _ SIGNED》