Problem - Kevin Tafuro

#include
#include
#include
#include
static char *crypt64_encode(const unsigned char *buf) {
int i;
char *out, *ptr;
unsigned long l;
static char *crypt64_set = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
if (!(out = ptr = (char *)malloc(23))) return 0;
#define CRYPT64_ENCODE(x, y, z) \
for (i = 0, l = (buf[(x)] = 6) *ptr++ = crypt64_set[l & 0x3F]
CRYPT64_ENCODE(0, 6, 12); CRYPT64_ENCODE(1, 7, 13);
CRYPT64_ENCODE(2, 8, 14); CRYPT64_ENCODE(3, 9, 15);
CRYPT64_ENCODE(4, 10, 5);
for (i = 0, l = buf[11]; i++ < 2; l >>= 6) *ptr++ = crypt64_set[l & 0x3F];
*ptr = 0;
#undef CRYPT64_ENCODE
return out;
}
static void compute_hash(unsigned char *hash, const char *key,
const char *salt, size_t salt_length) {
int i, length;
size_t key_length;
MD5_CTX ctx, ctx1;
key_length = strlen(key);
MD5_Init(&ctx);
MD5_Update(&ctx, key, key_length);
MD5_Update(&ctx, salt, salt_length);
MD5_Init(&ctx1);
MD5_Update(&ctx1, key, key_length);
MD5_Update(&ctx1, salt, salt_length);
MD5_Update(&ctx1, key, key_length);
MD5_Final(hash, &ctx1);
for (length = key_length; length > 0; length -= 16)
MD5_Update(&ctx, hash, (length > 16 ? 16 : length));
memset(hash, 0, 16);
for (i = key_length; i; i >>= 1)
if (i & 1) MD5_Update(&ctx, hash, 1);
else MD5_Update(&ctx, key, 1);
MD5_Final(hash, &ctx);
404 | Chapter 8: Authentication and Key Exchange
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