Problem - Kevin Tafuro

spc_wordlist_file = f;
spc_wordlist_offsets = offsets;
spc_wordlist_count = count;
spc_wordlist_shortest = shortest - 1; /* shortest includes NULL terminator */
return 1;
}
static int get_wordlist_word(unsigned int num, char *buf, size_t bufsz) {
size_t end, length;
if (num >= spc_wordlist_count) return -1;
if (num = = spc_wordlist_count - 1) {
fseek(spc_wordlist_file, 0, SEEK_END);
end = ftell(spc_wordlist_file);
} else end = spc_wordlist_offsets[num + 1];
length = end - spc_wordlist_offsets[num]; /* includes NULL terminator */
if (length > bufsz) return 0;
if (fseek(spc_wordlist_file, spc_wordlist_offsets[num], SEEK_SET) = = -1)
return -1;
fread(buf, length, 1, spc_wordlist_file);
buf[length - 1] = 0;
return 1;
}
char *spc_generate_passphrase(char *buf, size_t bufsz) {
int attempts = 0, rc;
char *outp;
size_t left, len;
unsigned int idx;
if (!spc_wordlist_file && !load_wordlist( )) return 0;
outp = buf;
left = bufsz - 1;
while (left > spc_wordlist_shortest) {
idx = spc_rand_range(0, spc_wordlist_count - 1);
rc = get_wordlist_word(idx, outp, left + 1);
if (rc = = -1) return 0;
else if (!rc && ++attempts < 10) continue;
else if (!rc) break;
len = strlen(outp) + 1;
*(outp + len - 1) = ' ';
outp += len;
left -= len;
}
*(outp - 1) = 0;
return buf;
}
When spc_generate_passphrase( ) is called, it opens the data file containing the
words to choose from and leaves it open. In addition, depending on the size of the
390 | Chapter 8: Authentication and Key Exchange
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