需要帮助base64 [英] Need Help with base64
问题描述
我目前正在尝试在C中实现base64编码和解码
方案。 Python有一个模块base64，它可以轻松地进行
编码和解码。我知道OpenSSL支持
用于base64编码和解码，但我现在必须在C中实现
而不使用openssl库。
我能够下载代码wrt base 64编码和
解码。我附上下面的代码。
void encodeblock（unsigned char cin [3]，unsigned char cout [4]，int
nlen）
{
cout [0] = cb64 [cin [0]> 2];
cout [1] = cb64 [（ （cin [0]& 0x03）<< 4）| （（cin [1]& 0xf0）> 4）];
cout [2] =（无符号字符）（nlen 1？cb64 [（（cin [1]& 0x0f）< ;< 2）
|（（cin [2]& 0xc0）> 6）]：''=''）;
cout [3] = （unsigned char）（nlen 2？cb64 [cin [2]& 0x3f]：
''=''）;
}
void decodeblock（unsigned char cin [4]，unsigned char cout [3]）
{
cout [0] =（unsigned char）（cin [0]<< 2 | cin [1]> 4）;
cout [1] =（unsigned char）（cin [1]<< 4> cin [2]> 2）;
cout [2] =（unsigned char）（（（cin [2]<<<<<<<<<<<<<<<< 6>& 0xc0）| cin [3]）;
}
int base641_decodestring（char * pcstr，int size，char ** ppcdest）
{
unsigned char cin [4] = {""};
unsigned char cout [3] = {""};
unsigned char cv = 0;
int ni = 0;
int nlen = 0;
char * cptr = pcstr;
* ppcdest = malloc（sizeof（char） * 160）;
if（！* ppcdest）
{
返回1;
}
memset（* ppcdest，0，sizeof（char）* 160）;
char * pcstring = malloc（sizeof（char）* SIZE）;
if（！pcstring）
{
aps_log（" APS_log.txt"，" \ nbae64.c：base64encode：mall oc failed
\ n"）;
返回1;
}
memset（pcstring，''\ 0' '，SIZE）;
for（nlen = 0，ni = 0; ni< 4; ni ++）
{
cv = 0;
而（cv == 0）
{
cv =（unsigned char）* cptr;
cv =（unsigned char）（（cv< 43 || cv 122）？0：
cd64 [cv - 43]）;
if（cv）
{
cv =（unsigned char）（（cv =='' $''）？0：cv - 61）;
}
}
if（cptr ++）
{
nlen ++;
if（cv）
{
cin [ni] =（unsigned char）（ cv - 1）;
}
}
其他
{
cin [ni] = 0;
}
}
if（nlen）
{
decodeblock（cin，cout）;
}
memcpy（* ppcdest，cout，160）;
返回0;
} / * base64_decode结束* /
char * base64_encode（char * pcstr）
{
unsigned char cin [3] = {""};
unsigned char cout [4] = {""};
int ni = 0;
int nlen = 0;
int flag = 1;
char * cptr = pcstr;
char * pcstring = malloc（sizeof（char）* SIZE）;
if（！pcstring）
{
aps_log（" APS_log.txt"，" \ nbae64.c：base64encode：mall oc failed
\ n"）;
return（void *）0;
}
memset（pcstring，''\ 0''，SIZE）;
while（flag）
{
for（ni = 0; ni< 3; ni ++）
{
cin [ni] =（unsigned char）* cptr;
if（* ++ cptr！=''\\ \\ 0''）
nlen ++;
else
{
cin [ni] = 0;
flag = 0;
休息;
}
}
encodeblock（cin， cout，nlen）;
strcat（pcstring，cout）;
}
返回pcstring;
} / * base64_encode结束* /
但是这个代码与
python base64.encodestring相比给出了不同的十六进制值base64.decodestring分别。
我需要一些关于此事的帮助。我需要一些指示
这里是上述文件的错误。
Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having support
for base64 encoding and decoding , but i will have to now implement
both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and
decoding . I am attaching the code below .
void encodeblock( unsigned char cin[3], unsigned char cout[4], int
nlen )
{
cout[0] = cb64[ cin[0] >2 ];
cout[1] = cb64[ ((cin[0] & 0x03) << 4) | ((cin[1] & 0xf0) >4) ];
cout[2] = (unsigned char) (nlen 1 ? cb64[ ((cin[1] & 0x0f) << 2)
| ((cin[2] & 0xc0) >6) ] : ''='');
cout[3] = (unsigned char) (nlen 2 ? cb64[ cin[2] & 0x3f ] :
''='');
}
void decodeblock( unsigned char cin[4], unsigned char cout[3] )
{
cout[ 0 ] = (unsigned char ) (cin[0] << 2 | cin[1] >4);
cout[ 1 ] = (unsigned char ) (cin[1] << 4 | cin[2] >2);
cout[ 2 ] = (unsigned char ) (((cin[2] << 6) & 0xc0) | cin[3]);
}
int base641_decodestring(char* pcstr,int size,char** ppcdest)
{
unsigned char cin[4] = {""};
unsigned char cout[3] = {""};
unsigned char cv = 0;
int ni = 0;
int nlen = 0;
char* cptr = pcstr;
*ppcdest = malloc(sizeof(char)*160);
if (!*ppcdest)
{
return 1;
}
memset(*ppcdest,0,sizeof(char)*160);
char* pcstring = malloc( sizeof(char) * SIZE);
if (!pcstring)
{
aps_log("APS_log.txt","\nbae64.c:base64encode:mall oc failed
\n");
return 1;
}
memset(pcstring,''\0'',SIZE);
for( nlen = 0, ni = 0; ni < 4; ni++ )
{
cv = 0;
while( cv == 0 )
{
cv = (unsigned char) *cptr;
cv = (unsigned char) ((cv < 43 || cv 122) ? 0 :
cd64[ cv - 43 ]);
if( cv )
{
cv = (unsigned char) ((cv == ''$'') ? 0 : cv - 61);
}
}
if( cptr++ )
{
nlen++;
if( cv )
{
cin[ ni ] = (unsigned char) (cv - 1);
}
}
else
{
cin[ni] = 0;
}
}
if( nlen )
{
decodeblock( cin, cout );
}
memcpy(*ppcdest,cout,160);
return 0;
}/*end of base64_decode */
char* base64_encode(char* pcstr)
{
unsigned char cin[3] = {""};
unsigned char cout[4] = {""};
int ni = 0;
int nlen = 0;
int flag = 1;
char* cptr = pcstr;
char* pcstring = malloc( sizeof(char) * SIZE);
if (!pcstring)
{
aps_log("APS_log.txt","\nbae64.c:base64encode:mall oc failed
\n");
return (void*)0;
}
memset(pcstring,''\0'',SIZE);
while( flag )
{
for( ni = 0; ni < 3; ni++ )
{
cin[ni] = (unsigned char)*cptr;
if( *++cptr != ''\0'' )
nlen++;
else
{
cin[ni] = 0;
flag = 0;
break;
}
}
encodeblock(cin, cout,nlen);
strcat(pcstring,cout);
}
return pcstring;
}/* end of base64_encode */
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
推荐答案
''） ？ 0：cv - 61）;
}
}
if（cptr ++）
{
nlen ++;
if（cv）
{
cin [ni] =（unsigned char）（cv - 1）;
}
}
其他
{
cin [ni] = 0 ;
}
}
if（nlen）
{
decodeblock（ cin，cout）;
}
memcpy（* ppcdest，cout，160）;
返回0;
} / * base64_decode结束* /
char * base64_encode（char * pcstr）
{
unsigned char cin [3] = {""};
unsigned char cout [4] = {""};
int ni = 0;
int nlen = 0;
int flag = 1;
char * cptr = pcstr;
char * pcstring = malloc（sizeof（char）* SIZE）;
if（！pcstring）
{
aps_log（" APS_log .txt"，" \ nbae64.c：base64encode：mall oc failed
\ n"）;
return（void *）0;
}
memset（pcstring，''\''，SIZE）;
while（flag）
{
for（ni = 0; ni< 3; ni ++）
{
cin [ni] =（unsigned char）* cptr;
if（* ++ cptr！=''\\ \\ 0''）
nlen ++;
else
{
cin [ni] = 0;
flag = 0;
休息;
}
}
encodeblock（cin， cout，nlen）;
strcat（pcstring，cout）;
}
返回pcstring;
} / * base64_encode结束* /
但是这个代码与
python base64.encodestring相比给出了不同的十六进制值base64.decodestring分别。
我需要一些关于此事的帮助。我需要一些指示
这是上述文件的错误。
'') ? 0 : cv - 61);
}
}
if( cptr++ )
{
nlen++;
if( cv )
{
cin[ ni ] = (unsigned char) (cv - 1);
}
}
else
{
cin[ni] = 0;
}
}
if( nlen )
{
decodeblock( cin, cout );
}
memcpy(*ppcdest,cout,160);
return 0;
}/*end of base64_decode */
char* base64_encode(char* pcstr)
{
unsigned char cin[3] = {""};
unsigned char cout[4] = {""};
int ni = 0;
int nlen = 0;
int flag = 1;
char* cptr = pcstr;
char* pcstring = malloc( sizeof(char) * SIZE);
if (!pcstring)
{
aps_log("APS_log.txt","\nbae64.c:base64encode:mall oc failed
\n");
return (void*)0;
}
memset(pcstring,''\0'',SIZE);
while( flag )
{
for( ni = 0; ni < 3; ni++ )
{
cin[ni] = (unsigned char)*cptr;
if( *++cptr != ''\0'' )
nlen++;
else
{
cin[ni] = 0;
flag = 0;
break;
}
}
encodeblock(cin, cout,nlen);
strcat(pcstring,cout);
}
return pcstring;
}/* end of base64_encode */
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
On Mon，2007年7月23日05:37 ：40 -0700，pycraze写道：
On Mon, 23 Jul 2007 05:37:40 -0700, pycraze wrote:
但是这个代码分别给出了与
python base64.encodestring和base64.decodestring相比的不同十六进制值。 br />
我需要一些帮助。我需要一些指示
上面文件的错误在哪里。
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
重新使用现有代码通常比从头实现（和
调试）更容易。几个Base64实现是可用的，例如
，例如 http://www.synesis.com.au/software/b64。 HTML
-
Roland Pibinger
最好的软件简单，优雅，充满戏剧性 - Grady Booch
It''s usually easier to re-use existing code than to implement (and
debug) something from scratch. Several Base64 implementations are
available, e.g. http://www.synesis.com.au/software/b64.html
--
Roland Pibinger
"The best software is simple, elegant, and full of drama" - Grady Booch
pycraze写道：
pycraze wrote:
我目前正在尝试在C中实现base64编码和解码
方案。 Python有一个模块base64，它可以轻松地进行
编码和解码。我知道OpenSSL支持
用于base64编码和解码，但我现在必须在C中实现
而不使用openssl库。
我能够下载代码wrt base 64编码和
解码。我附上下面的代码。
Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having support
for base64 encoding and decoding , but i will have to now implement
both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and
decoding . I am attaching the code below .
[Snip]
[Snip]
但是这段代码给出了不同的十六进制值分别与
python base64.encodestring和base64.decodestring进行比较。
我需要一些帮助来解决这个问题。我需要一些指示
这里是上述文件的错误。
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
在一个简短的测试中，你的代码似乎与捆绑到的代码兼容我必须提供的Java环境中的
MIME支持。也许Python
支持基于不同的标准/ RFC？你可能希望在Python主题的地方查询
。
On a brief test your code seemed compatible with that bundled into the
MIME support in a Java environment I had to hand. Perhaps the Python
support is based on a different standard/RFC? You might wish to enquire
somewhere where Python is on topic.
这篇关于需要帮助base64的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
