Subversion Repositories planix.SVN

#include "os.h"
#include <libsec.h>

#define STRLEN(s)       (sizeof(s)-1)

uchar*
decodePEM(char *s, char *type, int *len, char **new_s)
{
        uchar *d;
        char *t, *e, *tt;
        int n;

        *len = 0;

        /*
         * 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], "-----", STRLEN("-----")) == 0
                && strchr("\r\n", tt[STRLEN("-----BEGIN ")+n+STRLEN("-----")]) != nil)
                        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], "-----", STRLEN("-----")) == 0
                && strchr("\r\n", tt[STRLEN("-----END ")+n+STRLEN("-----")]) != nil)
                        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;
        }

        if(new_s)
                *new_s = tt+1;
        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;
}

PEMChain*
decodepemchain(char *s, char *type)
{
        PEMChain *first = nil, *last = nil, *chp;
        uchar *d;
        char *e;
        int n;

        e = strchr(s, '\0');
        while (s < e) {
                d = decodePEM(s, type, &n, &s);
                if(d == nil)
                        break;
                chp = malloc(sizeof(PEMChain));
                chp->next = nil;
                chp->pem = d;
                chp->pemlen = n;
                if (first == nil)
                        first = chp;
                else
                        last->next = chp;
                last = chp;
        }
        return first;
}