Problem - Kevin Tafuro

char *spc_pbkdf2_encrypt(const char *key, const char *salt) {
int error;
char *base64_out, *base64_salt, *result, *salt_end, *tmp_string;
size_t length, result_length, salt_length;
unsigned int iterations, tmp_uint;
unsigned char out[16], *raw_salt;
unsigned long tmp_ulong;
raw_salt = 0;
base64_out = base64_salt = result = 0;
if (!salt) {
if (!(raw_salt = (unsigned char *)malloc((salt_length = 8)))) return 0;
spc_rand(raw_salt, salt_length);
if (!(base64_salt = spc_base64_encode(raw_salt, salt_length, 0))) {
free(raw_salt);
return 0;
}
iterations = 10000;
} else {
if (strncmp(salt, "$10$", 4) != 0) return 0;
if (!(salt_end = strchr(salt + 4, '$'))) return 0;
if (!(base64_salt = (char *)malloc(salt_end - (salt + 4) + 1))) return 0;
memcpy(base64_salt, salt + 4, salt_end - (salt + 4));
base64_salt[salt_end - (salt + 4)] = 0;
tmp_ulong = strtoul(salt_end + 1, &tmp_string, 10);
if ((tmp_ulong = = ULONG_MAX && errno = = ERANGE) || tmp_ulong > UINT_MAX ||
!tmp_string || *tmp_string != '$') {
free(base64_salt);
return 0;
}
iterations = (unsigned int)tmp_ulong;
raw_salt = spc_base64_decode(base64_salt, &salt_length, 1, &error);
if (!raw_salt || error) {
free(base64_salt);
return 0;
}
}
spc_pbkdf2((char *)key, strlen(key), raw_salt, salt_length, iterations,
out, sizeof(out));
if (!(base64_out = spc_base64_encode(out, sizeof(out), 0))) goto done;
for (tmp_uint = iterations, length = 1; tmp_uint; length++) tmp_uint /= 10;
result_length = strlen(base64_out) + strlen(base64_salt) + length + 6;
if (!(result = (char *)malloc(result_length + 1))) goto done;
sprintf(result, "$10$%s$%u$%s", base64_salt, iterations, base64_out);
done:
/* cleanup */
if (raw_salt) free(raw_salt);
if (base64_salt) free(base64_salt);
if (base64_out) free(base64_out);
return result;
}
410 | Chapter 8: Authentication and Key Exchange
This is the Title of the Book, eMatter Edition
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