使用 openssl 在 X509 证书中添加 DN 主题备用名称扩展

Question

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的sn-p（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;
}

Answer 1

我所做的几乎和我看到的一样（见下文）。我看到的唯一增量是使用 V_ASN1_IA5STRING 或 V_ASN1_UTF8STRING（如果需要）。

Dw.

+(X509_NAME_ENTRY *) x509nameEntryFromDict:(NSDictionary *)entry {
    X509_NAME_ENTRY * nameEntry = NULL;
    int nid = [self nidFromDict:entry];

    if (nid == NID_undef) {
        NSLog(@"x509nameFromDictArray: Unknown entry - ignored: %@", entry);
        return NULL;
    }

    NSString * val = [entry objectForKey:kOpenSSLNameValueKey];
    const char * buff;
    int valType;

    if ([val dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:NO]) {
        valType = V_ASN1_IA5STRING;
        buff = [val cStringUsingEncoding:NSASCIIStringEncoding];                    
    } else {
        valType = V_ASN1_UTF8STRING;
        buff = [val cStringUsingEncoding:NSUTF8StringEncoding];
    }        
    int len = strlen(buff);

    return X509_NAME_ENTRY_create_by_NID(&nameEntry, nid, valType, (unsigned char*)buff, len);
}