我一直在使用 openssl API 创建自己的证书实用程序。在主题备用名称扩展中添加专有名称时,我目前面临一个问题。虽然成功创建了扩展,但在查看证书时,扩展的值被错误编码,例如使用 windows 证书实用程序:
Basic Constraints Subject Type=CA, Path...
Subject Alternative Name
74 53 19 00 00 00 38 27 tS....8'
ac 0b 88 ae ac 0b 00 00 ........
00 00 00 00 00 00 6f 72 ......or
20 53 21 00 00 00 02 00 S!.....
00 00 13 00 00 00 d0 d7 ........
ac 0b 00 00 00 00 0a 00 ........
00 00 00 00 00 00 20 00 ...... .
00 00 19 00 00 00 b8 5d .......]
a4 0b
Thumbprint algorithm sha1
以下是关注点的相关源代码片段(可能存在一些语法错误):
GENERAL_NAME * genn = NULL;
STACK_OF(GENERAL_NAME) * sk_genn;
ASN1_OCTET_STRING *asn1OctetStr=NULL;
X509_EXTENSION* tmpEXT;
X509_NAME* tmpDIRNAME;
char* extSAN_str=(char *) "C=CR, O=OU, D=DR";
/*..*/
case DISTINGUISHED_NAME:
// Initialization of ASN.1 structures
genn = GENERAL_NAME_new();
asn1OctetStr = M_ASN1_OCTET_STRING_new();
sk_genn = GENERAL_NAMES_new();
// Create the X509 extension
tmpDIRNAME=CharToX509_NAME(extSAN_str);
// This GeneralName is an directoryName
genn->type=GEN_DIRNAME;
genn->d.directoryName=tmpDIRNAME;
// Using the stack to create a sequence
sk_GENERAL_NAME_push(sk_genn,genn);
ext_len = i2d_GENERAL_NAMES(sk_genn, NULL);
ext_der = OPENSSL_malloc(ext_len); /* allocate that much memory */
i2d_GENERAL_NAMES(sk_genn, &ext_der);
asn1OctetStr->data = ext_der;
/* fill in the value of the SubjectAltName extension */
asn1OctetStr->length = ext_len;
sanNID = OBJ_txt2nid("subjAltName");
if (!(tmpEXT = X509_EXTENSION_create_by_NID(NULL, sanNID, 0, asn1OctetStr)))
{
ERR_error_string(ERR_get_error(), NULL), ERR_get_error());
}
// Adding the certificate to the X509 structure
if(!X509_add_ext(tmpCert, tmpEXT, -1))
{
ERR_error_string(ERR_get_error(), NULL), ERR_get_error());
}
/*..*/
X509_NAME* CharToX509_NAME(char* SubjectName)
{
X509_NAME *tempSubjectName=NULL;
char name[128];
char value[128];
char* equal;
char* comma;
char* field;
memset(name, 0, 128);
memset(value, 0, 128);
if(!(tempSubjectName = X509_NAME_new()))
{
return 0;
}
if (NULL != SubjectName)
{
field = SubjectName;
do
{
equal=strchr(field, '=');
comma=strchr(field, ',');
if(comma == 0)
comma = field + strlen(field);
strncpy(name, field, (unsigned)(equal-field));
name[equal-field]=0;
strncpy(value, equal+1, (unsigned)(comma-equal-1));
value[comma-equal-1]=0;
field=comma+1;
if(!X509_NAME_add_entry_by_txt(tempSubjectName,name, MBSTRING_ASC, value, -1, -1, 0))
return 0;
}while(*comma != 0);
}
return tempSubjectName;
}