25 lines
626 B
C
25 lines
626 B
C
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#include "fmt.h"
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#include "textcode.h"
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#include "haveinline.h"
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size_t fmt_base64url(char* dest,const char* src,size_t len) {
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register const unsigned char* s=(const unsigned char*) src;
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unsigned short bits=0,temp=0;
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size_t written=0,i;
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if (!dest) return (len>((size_t)-1)/2)?(size_t)-1:((len+2)/3)*4;
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for (i=0; i<len; ++i) {
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temp<<=8; temp+=s[i]; bits+=8;
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while (bits>6) {
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dest[written]=base64url[((temp>>(bits-6))&63)];
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++written; bits-=6;
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}
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}
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if (bits) {
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temp<<=(6-bits);
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dest[written]=base64url[temp&63];
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++written;
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}
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/* no padding for base64url */
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return written;
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}
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