#define subround(f,w,x,y,z,k,s,ti) \
w = x + rol(w + f(x,y,z) + block[k] + ti, s)
-typedef struct {
- uint32 h[4];
-} MD5_Core_State;
-
void MD5_Core_Init(MD5_Core_State *s) {
s->h[0] = 0x67452301;
s->h[1] = 0xefcdab89;
void MD5Final(unsigned char output[16], struct MD5Context *s) {
int i;
- int pad;
+ unsigned pad;
unsigned char c[64];
uint32 lenhi, lenlo;
memset(c, 0, pad);
c[0] = 0x80;
- MD5_Bytes(s, &c, pad);
+ MD5Update(s, c, pad);
c[7] = (lenhi >> 24) & 0xFF;
c[6] = (lenhi >> 16) & 0xFF;
c[1] = (lenlo >> 8) & 0xFF;
c[0] = (lenlo >> 0) & 0xFF;
- MD5_Bytes(s, &c, 8);
+ MD5Update(s, c, 8);
for (i = 0; i < 4; i++) {
output[4*i+3] = (s->core.h[i] >> 24) & 0xFF;
output[4*i+0] = (s->core.h[i] >> 0) & 0xFF;
}
}
+
+/* ----------------------------------------------------------------------
+ * The above is the MD5 algorithm itself. Now we implement the
+ * HMAC wrapper on it.
+ */
+
+static struct MD5Context md5_cs_mac_s1, md5_cs_mac_s2;
+static struct MD5Context md5_sc_mac_s1, md5_sc_mac_s2;
+
+static void md5_key(struct MD5Context *s1, struct MD5Context *s2,
+ unsigned char *key, int len) {
+ unsigned char foo[64];
+ int i;
+
+ memset(foo, 0x36, 64);
+ for (i = 0; i < len && i < 64; i++)
+ foo[i] ^= key[i];
+ MD5Init(s1);
+ MD5Update(s1, foo, 64);
+
+ memset(foo, 0x5C, 64);
+ for (i = 0; i < len && i < 64; i++)
+ foo[i] ^= key[i];
+ MD5Init(s2);
+ MD5Update(s2, foo, 64);
+
+ memset(foo, 0, 64); /* burn the evidence */
+}
+
+static void md5_cskey(unsigned char *key) {
+ md5_key(&md5_cs_mac_s1, &md5_cs_mac_s2, key, 16);
+}
+
+static void md5_sckey(unsigned char *key) {
+ md5_key(&md5_sc_mac_s1, &md5_sc_mac_s2, key, 16);
+}
+
+static void md5_do_hmac(struct MD5Context *s1, struct MD5Context *s2,
+ unsigned char *blk, int len, unsigned long seq,
+ unsigned char *hmac) {
+ struct MD5Context s;
+ unsigned char intermediate[16];
+
+ intermediate[0] = (unsigned char)((seq >> 24) & 0xFF);
+ intermediate[1] = (unsigned char)((seq >> 16) & 0xFF);
+ intermediate[2] = (unsigned char)((seq >> 8) & 0xFF);
+ intermediate[3] = (unsigned char)((seq ) & 0xFF);
+
+ s = *s1; /* structure copy */
+ MD5Update(&s, intermediate, 4);
+ MD5Update(&s, blk, len);
+ MD5Final(intermediate, &s);
+ s = *s2; /* structure copy */
+ MD5Update(&s, intermediate, 16);
+ MD5Final(hmac, &s);
+}
+
+static void md5_generate(unsigned char *blk, int len, unsigned long seq) {
+ md5_do_hmac(&md5_cs_mac_s1, &md5_cs_mac_s2, blk, len, seq, blk+len);
+}
+
+static int md5_verify(unsigned char *blk, int len, unsigned long seq) {
+ unsigned char correct[16];
+ md5_do_hmac(&md5_sc_mac_s1, &md5_sc_mac_s2, blk, len, seq, correct);
+ return !memcmp(correct, blk+len, 16);
+}
+
+struct ssh_mac ssh_md5 = {
+ md5_cskey, md5_sckey,
+ md5_generate,
+ md5_verify,
+ "hmac-md5",
+ 16
+};