ASN1_TIME 和 TIME_T转换

清疚 2022-04-10 05:17 446阅读 0赞

Openssl 代码中提供了函数 ASN1\_TIME\_set ，把 time\_t 格式的时间转化为 ASN1\_TIME

函数原型为

ASN1\_TIME \*ASN1\_TIME\_set(ASN1\_TIME \*s, time\_t t)

但是没有找到类似 ASN1\_TIME\_get 函数，把 ASN1\_TIME 转化为 time\_t

下面是一个ASN1\_TIME\_get 测试可用

int mypint( const char ** s, int n, int min, int max, int * e)
    {
    	int retval = 0;
    	while (n) {
    		if (**s < '0' || **s > '9') { *e = 1; return 0; }
    		retval *= 10;
    		retval += **s - '0';
    		--n; ++(*s);
    	}
    	if (retval < min || retval > max) *e = 1;
    	return retval;
    }
    
    time_t ASN1_TIME_get ( ASN1_TIME * a, int *err)
    {
    char days[2][12] ={
       { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
    				{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }};
    	int dummy;
    	const char *s;
    	int generalized;
    	struct tm t;
    	int i, year, isleap, offset;
    	time_t retval;
    	if (err == NULL) 
    		err = &dummy;
    	if (a->type == V_ASN1_GENERALIZEDTIME) {
    		generalized = 1;
    	} else if (a->type == V_ASN1_UTCTIME) {
    		generalized = 0;
    	} else {
    		*err = 1;
    		return 0;	
    	}
    	s = (char *)a->data; // Data should be always null terminated
    	if (s == NULL || s[a->length] != '\0') {
    		*err = 1;
    		return 0;
    	}
    	*err = 0;
    	if (generalized) {
    		t.tm_year = mypint(&s, 4, 0, 9999, err) - 1900;
    	} else {
    		t.tm_year = mypint(&s, 2, 0, 99, err);
    	if (t.tm_year < 50) 
    		t.tm_year += 100;
    	}
    	t.tm_mon = mypint(&s, 2, 1, 12, err) - 1;
    	t.tm_mday = mypint(&s, 2, 1, 31, err);
    // NOTE: It's not yet clear, if this implementation is 100% correct
    // for GeneralizedTime... but at least misinterpretation is
    // impossible --- we just throw an exception
    	t.tm_hour = mypint(&s, 2, 0, 23, err);
    	t.tm_min = mypint(&s, 2, 0, 59, err);
    	if (*s >= '0' && *s <= '9') {
    		t.tm_sec = mypint(&s, 2, 0, 59, err);
    	} else {
    		t.tm_sec = 0;
    	}
    	if (*err) 
    		return 0; // Format violation
    	if (generalized) {
    		// skip fractional seconds if any
    		while (*s == '.' || *s == ',' || (*s >= '0' && *s <= '9')) ++s;
    		// special treatment for local time
    		if (*s == 0) {
    			t.tm_isdst = -1;
    			retval = mktime(&t); // Local time is easy :)
    			if (retval == (time_t)-1) {
    				*err = 2;
    				retval = 0;
    			}
    			return retval;
    		}
    	}
    	if (*s == 'Z') {
    		offset = 0;
    		++s;
    	} else if (*s == '-' || *s == '+') {
    		i = (*s++ == '-');
    		offset = mypint(&s, 2, 0, 12, err);
    		offset *= 60;
    		offset += mypint(&s, 2, 0, 59, err);
    		if (*err) return 0; // Format violation
    		if (i) offset = -offset;
    		} else {
    		*err = 1;
    		return 0;
    	}
    	if (*s) {
    		*err = 1;
    		return 0;
    	}
    // And here comes the hard part --- there's no standard function to
    // convert struct tm containing UTC time into time_t without
    // messing global timezone settings (breaks multithreading and may
    // cause other problems) and thus we have to do this "by hand"
    //
    // NOTE: Overflow check does not detect too big overflows, but is
    // sufficient thanks to the fact that year numbers are limited to four
    // digit non-negative values.
    	retval = t.tm_sec;
    	retval += (t.tm_min - offset) * 60;
    	retval += t.tm_hour * 3600;
    	retval += (t.tm_mday - 1) * 86400;
    	year = t.tm_year + 1900;
    	if ( sizeof (time_t) == 4) {
    		// This is just to avoid too big overflows being undetected, finer
    		// overflow detection is done below.
    		if (year < 1900 || year > 2040) *err = 2;
    	}
    // FIXME: Does POSIX really say, that all years divisible by 4 are
    // leap years (for consistency)??? Fortunately, this problem does
    // not exist for 32-bit time_t and we should'nt be worried about
    // this until the year of 2100 :)
    	isleap = ((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0);
    	for (i = t.tm_mon - 1; i >= 0; --i) retval += days[isleap][i] * 86400;
    	retval += (year - 1970) * 31536000;
    	if (year < 1970) {
    		retval -= ((1970 - year + 2) / 4) * 86400;
    		if ( sizeof (time_t) > 4) {
    			for (i = 1900; i >= year; i -= 100) {
    				if (i % 400 == 0) continue ;
    				retval += 86400;
    			}
    		}
    		if (retval >= 0) *err = 2;
    	} else {
    		retval += ((year - 1970 + 1) / 4) * 86400;
    		if ( sizeof (time_t) > 4) {
    			for (i = 2100; i < year; i += 100) {
    				// The following condition is the reason to
    				// start with 2100 instead of 2000
    				if (i % 400 == 0) continue ;
    				retval -= 86400;
    			}
    		}
    		if (retval < 0) *err = 2;
    	}
    	if (*err) retval = 0;
    	return retval;
    }

头文件大概需要这些：

\#include <time.h>  
\#include <stdlib.h>

\#include <openssl/pem.h>  
\#include <openssl/conf.h>  
\#include <openssl/x509v3.h>

2） %d-%d-%d %d:%d:%d 格式时间转unix时间戳

time_t strTime2unix(string& timeStamp)  
    {  
        struct tm tm;  
        memset(&tm, 0, sizeof(tm));  
          
        sscanf(timeStamp.c_str(), "%d-%d-%d %d:%d:%d",   
               &tm.tm_year, &tm.tm_mon, &tm.tm_mday,  
               &tm.tm_hour, &tm.tm_min, &tm.tm_sec);  
      
        tm.tm_year -= 1900;  
        tm.tm_mon--;  
      
        return mktime(&tm);  
    }

参考链接：

[http://blog.csdn.net/nanhaizhixin/article/details/8349668][http_blog.csdn.net_nanhaizhixin_article_details_8349668]

[http://www.eefocus.com/xuefu2009/blog/10-03/187348\_f456a.html][http_www.eefocus.com_xuefu2009_blog_10-03_187348_f456a.html]

[http://www.blogjava.net/Archangelsy/articles/112830.html][http_www.blogjava.net_Archangelsy_articles_112830.html]

[http://zhidao.baidu.com/link?url=65o1q3T71ulItE3-aED6wnoRBtJKd\_qe8NGr25t9F0wfSuyjBVV8ERP6Nril7jaE-Zx8EXVsuiLlwmmFz3wCiK][http_zhidao.baidu.com_link_url_65o1q3T71ulItE3-aED6wnoRBtJKd_qe8NGr25t9F0wfSuyjBVV8ERP6Nril7jaE-Zx8EXVsuiLlwmmFz3wCiK]

[http_blog.csdn.net_nanhaizhixin_article_details_8349668]: http://blog.csdn.net/nanhaizhixin/article/details/8349668
[http_www.eefocus.com_xuefu2009_blog_10-03_187348_f456a.html]: http://www.eefocus.com/xuefu2009/blog/10-03/187348_f456a.html
[http_www.blogjava.net_Archangelsy_articles_112830.html]: http://www.blogjava.net/Archangelsy/articles/112830.html
[http_zhidao.baidu.com_link_url_65o1q3T71ulItE3-aED6wnoRBtJKd_qe8NGr25t9F0wfSuyjBVV8ERP6Nril7jaE-Zx8EXVsuiLlwmmFz3wCiK]: http://zhidao.baidu.com/link?url=65o1q3T71ulItE3-aED6wnoRBtJKd_qe8NGr25t9F0wfSuyjBVV8ERP6Nril7jaE-Zx8EXVsuiLlwmmFz3wCiK