60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
#include <u.h>
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#include <libc.h>
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#include <mp.h>
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#include <libsec.h>
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#define STRLEN(s) (sizeof(s)-1)
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uchar*
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decodepem(char *s, char *type, int *len)
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{
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uchar *d;
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char *t, *e, *tt;
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int n;
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/*
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* find the correct section of the file, stripping garbage at the beginning and end.
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* the data is delimited by -----BEGIN <type>-----\n and -----END <type>-----\n
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*/
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n = strlen(type);
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e = strchr(s, '\0');
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for(t = s; t != nil && t < e; ){
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tt = t;
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t = strchr(tt, '\n');
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if(t != nil)
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t++;
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if(strncmp(tt, "-----BEGIN ", STRLEN("-----BEGIN ")) == 0
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&& strncmp(&tt[STRLEN("-----BEGIN ")], type, n) == 0
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&& strncmp(&tt[STRLEN("-----BEGIN ")+n], "-----\n", STRLEN("-----\n")) == 0)
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break;
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}
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for(tt = t; tt != nil && tt < e; tt++){
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if(strncmp(tt, "-----END ", STRLEN("-----END ")) == 0
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&& strncmp(&tt[STRLEN("-----END ")], type, n) == 0
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&& strncmp(&tt[STRLEN("-----END ")+n], "-----\n", STRLEN("-----\n")) == 0)
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break;
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tt = strchr(tt, '\n');
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if(tt == nil)
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break;
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}
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if(tt == nil || tt == e){
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werrstr("incorrect .pem file format: bad header or trailer");
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return nil;
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}
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n = ((tt - t) * 6 + 7) / 8;
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d = malloc(n);
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if(d == nil){
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werrstr("out of memory");
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return nil;
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}
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n = dec64(d, n, t, tt - t);
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if(n < 0){
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free(d);
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werrstr("incorrect .pem file format: bad base64 encoded data");
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return nil;
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}
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*len = n;
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return d;
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}
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