1 #include <u.h> 2 #include <libc.h> 3 #include <mp.h> 4 #include <libsec.h> 5 6 #define STRLEN(s) (sizeof(s)-1) 7 8 uchar* 9 decodepem(char *s, char *type, int *len) 10 { 11 uchar *d; 12 char *t, *e, *tt; 13 int n; 14 15 /* 16 * find the correct section of the file, stripping garbage at the beginning and end. 17 * the data is delimited by -----BEGIN <type>-----\n and -----END <type>-----\n 18 */ 19 n = strlen(type); 20 e = strchr(s, '\0'); 21 for(t = s; t != nil && t < e; ){ 22 tt = t; 23 t = strchr(tt, '\n'); 24 if(t != nil) 25 t++; 26 if(strncmp(tt, "-----BEGIN ", STRLEN("-----BEGIN ")) == 0 27 && strncmp(&tt[STRLEN("-----BEGIN ")], type, n) == 0 28 && strncmp(&tt[STRLEN("-----BEGIN ")+n], "-----\n", STRLEN("-----\n")) == 0) 29 break; 30 } 31 for(tt = t; tt != nil && tt < e; tt++){ 32 if(strncmp(tt, "-----END ", STRLEN("-----END ")) == 0 33 && strncmp(&tt[STRLEN("-----END ")], type, n) == 0 34 && strncmp(&tt[STRLEN("-----END ")+n], "-----\n", STRLEN("-----\n")) == 0) 35 break; 36 tt = strchr(tt, '\n'); 37 if(tt == nil) 38 break; 39 } 40 if(tt == nil || tt == e){ 41 werrstr("incorrect .pem file format: bad header or trailer"); 42 return nil; 43 } 44 45 n = ((tt - t) * 6 + 7) / 8; 46 d = malloc(n); 47 if(d == nil){ 48 werrstr("out of memory"); 49 return nil; 50 } 51 n = dec64(d, n, t, tt - t); 52 if(n < 0){ 53 free(d); 54 werrstr("incorrect .pem file format: bad base64 encoded data"); 55 return nil; 56 } 57 *len = n; 58 return d; 59 } 60