pbContent = (BYTE*) "Security is our only business";
cbContent = strlen((char *) pbContent)+1;
printf("The original message => %s\n",pbContent);
if(cbEncodedBlob = CryptMsgCalculateEncodedLength(
MY_ENCODING_TYPE, 指定Encode类型，在程序的开头已经预定义了，MY_ENCODING_TYPE 就是 PKCS_7_ASN_ENCODING | X509_ASN_ENCODING
0, // Flags
CMSG_DATA, 定义了数据的类型，这里指定为BYTE型的字符串
NULL,
NULL,
cbContent)) 内容的大小
这里的的函数的作用是计算指定消息Encode所需要的最大的长度，通过计算，为一个BLOB分配内存空间。
{
printf("The length of the data has been calculated. \n");
}
else
{
MyHandleError("Getting cbEncodedBlob length failed");
}
为encode blob分配内存空间
if(pbEncodedBlob = (BYTE *) malloc(cbEncodedBlob))
{
printf("Memory has been allocated for the signed message. \n");
}
else
{
MyHandleError("Memory allocation failed");
}
if(hMsg = CryptMsgOpenToEncode( CryptMsgOpenToEncode为Encode，开一个消息
MY_ENCODING_TYPE, Encode类型，文件开始有说明
0, // Flags
CMSG_DATA, 指定Message的类型，CMSG_DATA说明类型没用到
NULL, 现在没有到，为NULL
NULL, 同上
NULL)) 不是流加密，这个参数为NULL
{
printf("The message to be encoded has been opened. \n");
}
else
{
MyHandleError("OpenToEncode failed");
}
if(CryptMsgUpdate( CryptMsgUpdate将数据加到消息中，可以通过循环，将数据一段段的加得到消息中
hMsg, 一个小心句柄
pbContent, 指向数据的指针
cbContent, 数据的大小
TRUE)) TRUE表明这个是最后一段数据，在开个消息的时候，如果CMSG_DETACHED_FLAG有使用到，这设为FALSE，否则为TRUE。
{
printf("Content has been added to the encoded message. \n");
}
else
{
MyHandleError("MsgUpdate failed");
}
printf("\nThe length of the encoded message is %d.\n\n",
cbEncodedBlob);
if(CryptMsgUpdate(
hMsg, // Handle to the message
pbEncodedBlob, // Pointer to the encoded BLOB
cbEncodedBlob, // Size of the encoded BLOB
TRUE)) // Last call
{
printf("The encoded BLOB has been added to the message. \n");
}
else
{
MyHandleError("Decode MsgUpdate failed");
}
if(CryptMsgGetParam( CryptMsgGetParam的调用和上面有所不同，这里一共是调用两次，第一次的作用主要是得到消息的大小，第二次是得到消息所在的内存地址
hMsg, 消息句柄
CMSG_CONTENT_PARAM, // Parameter type
0,
NULL, // Address for returned
// information
&cbDecoded)) // Size of the returned
// information
{
printf("The decoded message size is %d. \n", cbDecoded);
}
else
{
MyHandleError("Decode CMSG_CONTENT_PARAM failed");
}
if(pbDecoded = (BYTE *) malloc(cbDecoded))
{
printf("Memory has been allocated for the decoded message.\n");
}
else
{
MyHandleError("Decoding memory allocation failed.");
}
if(CryptMsgGetParam(
hMsg, // Handle to the message
CMSG_CONTENT_PARAM, // Parameter type
0, // Index
pbDecoded, // Address for returned
// information
&cbDecoded)) // Size of the returned
// information
{
printf("The message is %s.\n",(LPSTR)pbDecoded);
}
else
{
MyHandleError("Decode CMSG_CONTENT_PARAM #2 failed");
}
if(pbEncodedBlob)
free(pbEncodedBlob);
if(pbDecoded)
free(pbDecoded);
if(hMsg)
CryptMsgClose(hMsg);
printf("This program ran to completion without error. \n");
//--------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
// Declare variables.
