ref: 189f67ae9bd7f3ed5c1a6b7b0460646c3f746c54
dir: /libsec/decodepem.c/
#include <u.h> #include <libc.h> #include <mp.h> #include <libsec.h> #define STRLEN(s) (sizeof(s)-1) uchar* decodepem(char *s, char *type, int *len) { uchar *d; char *t, *e, *tt; int n; /* * find the correct section of the file, stripping garbage at the beginning and end. * the data is delimited by -----BEGIN <type>-----\n and -----END <type>-----\n */ n = strlen(type); e = strchr(s, '\0'); for(t = s; t != nil && t < e; ){ tt = t; t = strchr(tt, '\n'); if(t != nil) t++; if(strncmp(tt, "-----BEGIN ", STRLEN("-----BEGIN ")) == 0 && strncmp(&tt[STRLEN("-----BEGIN ")], type, n) == 0 && strncmp(&tt[STRLEN("-----BEGIN ")+n], "-----\n", STRLEN("-----\n")) == 0) break; } for(tt = t; tt != nil && tt < e; tt++){ if(strncmp(tt, "-----END ", STRLEN("-----END ")) == 0 && strncmp(&tt[STRLEN("-----END ")], type, n) == 0 && strncmp(&tt[STRLEN("-----END ")+n], "-----\n", STRLEN("-----\n")) == 0) break; tt = strchr(tt, '\n'); if(tt == nil) break; } if(tt == nil || tt == e){ werrstr("incorrect .pem file format: bad header or trailer"); return nil; } n = ((tt - t) * 6 + 7) / 8; d = malloc(n); if(d == nil){ werrstr("out of memory"); return nil; } n = dec64(d, n, t, tt - t); if(n < 0){ free(d); werrstr("incorrect .pem file format: bad base64 encoded data"); return nil; } *len = n; return d; }