学步园

【原创】

const unsigned char Base64Table[64]=<br /> {<br /> 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',<br /> 'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',<br /> 'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',<br /> 'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'<br /> };</p> <p>const unsigned char Base64RTable[128]=<br /> {</p> <p> 0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,<br /> 0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,<br /> 0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0X3E,0XFF,0XFF,0XFF,0X3F,<br /> 0X34,0X35,0X36,0X37,0X38,0X39,0X3A,0X3B,0X3C,0X3D,0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,<br /> 0XFF,0X00,0X01,0X02,0X03,0X04,0X05,0X06,0X07,0X08,0X09,0X0A,0X0B,0X0C,0X0D,0X0E,<br /> 0X0F,0X10,0X11,0X12,0X13,0X14,0X15,0X16,0X17,0X18,0X19,0XFF,0XFF,0XFF,0XFF,0XFF,<br /> 0XFF,0X1A,0X1B,0X1C,0X1D,0X1E,0X1F,0X20,0X21,0X22,0X23,0X24,0X25,0X26,0X27,0X28,<br /> 0X29,0X2A,0X2B,0X2C,0X2D,0X2E,0X2F,0X30,0X31,0X32,0X33,0XFF,0XFF,0XFF,0XFF,0XFF<br /> };</p> <p>unsigned long<br /> Base64Encode(<br /> const unsigned char *psrc,<br /> unsigned long size,<br /> unsigned char *pdest,<br /> unsigned long *psize)<br /> {<br /> if(psrc == NULL || size == 0)<br /> return 0;<br /> if( *psize == 0)<br /> {<br /> if(size % 3 == 0)<br /> {<br /> *psize=(size / 3)*4;<br /> }<br /> else<br /> {<br /> *psize=(size /3)*4 + 4;<br /> }<br /> return 1;<br /> }</p> <p> const unsigned char *ptable=Base64Table;<br /> const unsigned char *ps=psrc;<br /> unsigned char *pd=pdest;<br /> unsigned long mod=size % 3;</p> <p> if(mod == 0)<br /> {<br /> while( (unsigned long)(ps - psrc) < size )<br /> {<br /> *pd=*(ptable + ((*ps >> 2) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*ps << 4) + (*(ps+1) >> 4)) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*(ps+1) << 2) + (*(ps+2) >> 6)) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (*(ps+2) & 0X3F));<br /> pd++;</p> <p> ps += 3;<br /> }<br /> }<br /> else<br /> {<br /> while((unsigned long)(ps - psrc) < size - mod)<br /> {<br /> *pd=*(ptable + ((*ps >> 2) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*ps << 4) + (*(ps+1) >> 4)) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*(ps+1) << 2) + (*(ps+2) >> 6)) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (*(ps+2) & 0X3F));<br /> pd++;</p> <p> ps += 3;<br /> }</p> <p> unsigned char buff[16]={0};<br /> memcpy_s(buff,16,ps,mod);<br /> unsigned char *p=buff;</p> <p> if(mod == 1)<br /> {<br /> *pd=*(ptable + ((*p >> 2) & 0X3F)) ;<br /> pd++;<br /> *pd=*(ptable + (((*p << 4) + (*(p+1) >> 4)) & 0X3F));<br /> pd++;<br /> *pd='=';<br /> *pd++;<br /> *pd='=';<br /> }<br /> else if(mod == 2)<br /> {<br /> *pd=*(ptable + ((*p >> 2) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*p << 4) + (*(p+1) >> 4)) & 0X3F));<br /> pd++;<br /> *pd=*(ptable + (((*(p+1) << 2) + (*(p+2) >> 6)) & 0X3F));<br /> pd++;<br /> *pd='=';<br /> }<br /> }</p> <p> return 1;<br /> }</p> <p>unsigned long<br /> Base64Decode(<br /> const char *psrc,<br /> unsigned long size,<br /> unsigned char *pdest,<br /> unsigned long *psize)<br /> {<br /> if(psrc == NULL || size == 0 || ((size % 4) != 0) )<br /> return 0;</p> <p> if( *psize == 0)<br /> {<br /> *psize=(size/4)*3;<br /> return 1;<br /> }<br /> const unsigned long ul4=4;</p> <p> const unsigned char *ptable=Base64RTable;<br /> const char *ps=psrc;<br /> unsigned char *pd=pdest;<br /> unsigned long realsize=0;<br /> unsigned long mod=0;</p> <p> const char *pequal=NULL;<br /> pequal=strchr(psrc,'=');<br /> if(pequal == NULL)<br /> {<br /> realsize=size;<br /> }<br /> else<br /> {<br /> realsize= (unsigned long)(pequal - psrc);<br /> }<br /> mod=realsize % 4;</p> <p> if(mod == 0)<br /> {<br /> while( (unsigned long)(ps - psrc ) < realsize)<br /> {<br /> *pd= ( *(ptable + *ps) << 2) + (*(ptable + *(ps+1)) >> 4);<br /> pd++;<br /> *pd= (*(ptable + *(ps+1)) << 4) + (*(ptable + *(ps+2)) >> 2);<br /> pd++;<br /> *pd= (*(ptable + *(ps+2)) << 6) + (*(ptable + *(ps+3)));<br /> pd++;</p> <p> ps += 4;<br /> }<br /> }<br /> else<br /> {<br /> while((unsigned long)(ps - psrc) < size - ul4)<br /> {<br /> *pd= ( *(ptable + *ps) << 2) + (*(ptable + *(ps+1)) >> 4);<br /> pd++;<br /> *pd= (*(ptable + *(ps+1)) << 4) + (*(ptable + *(ps+2)) >> 2);<br /> pd++;<br /> *pd= (*(ptable + *(ps+2)) << 6) + (*(ptable + *(ps+3)));<br /> pd++;</p> <p> ps += 4;<br /> }</p> <p> unsigned long uequal=size - realsize;</p> <p> char buff[16]={0};<br /> memcpy_s(buff,16,ps,ul4 - uequal);<br /> char *p=buff;</p> <p> if(uequal == 1)<br /> {<br /> *pd= (*(ptable + *p) << 2) + (*(ptable + *(p+1)) >> 4);<br /> pd++;<br /> *pd=(*(ptable + *(p+1)) << 4) +(*(ptable + *(p+2)) >> 2);</p> <p> }<br /> else if(uequal == 2)<br /> {<br /> *pd=(*(ptable + *p) << 2) + (*(ptable + *(p+1)) >> 4);</p> <p> }<br /> }</p> <p> return 1;<br /> }