26 lines
607 B
C
26 lines
607 B
C
#include "asn1.h"
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/* write int in least amount of bytes, return number of bytes */
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/* as used in ASN.1 tags */
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size_t fmt_asn1tag(char* dest,enum asn1_tagclass tc,enum asn1_tagtype tt,unsigned long l) {
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/* encoding is either l%128 or (0x1f,...) */
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size_t needed=(sizeof l)*7/8,i;
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if (l<0x1f) {
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if (dest) *dest=(int)tc+(int)tt+(l&0x1f);
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return 1;
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}
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for (i=1; i<needed; ++i)
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if (!(l>>(i*7)))
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break;
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if (dest) {
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size_t j=i;
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*dest=(int)tc+(int)tt+0x1f; ++dest;
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while (j) {
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--j;
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*dest=((l>>(j*7))&0x7f) + (j?0x80:0);
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++dest;
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}
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}
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return i+1;
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}
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