X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/32874aeac8dacbca26663777b39a79efc5d8dc4b..f7aa4b367eaf2c1e928f97263bcf4da74680aff3:/sshmd5.c

diff --git a/sshmd5.c b/sshmd5.c
index 0625f768..2fdb5900 100644
--- a/sshmd5.c
+++ b/sshmd5.c
@@ -19,7 +19,7 @@
 #define subround(f,w,x,y,z,k,s,ti) \
        w = x + rol(w + f(x,y,z) + block[k] + ti, s)
 
-void MD5_Core_Init(MD5_Core_State * s)
+static void MD5_Core_Init(MD5_Core_State * s)
 {
     s->h[0] = 0x67452301;
     s->h[1] = 0xefcdab89;
@@ -27,7 +27,7 @@ void MD5_Core_Init(MD5_Core_State * s)
     s->h[3] = 0x10325476;
 }
 
-void MD5_Block(MD5_Core_State * s, uint32 * block)
+static void MD5_Block(MD5_Core_State * s, uint32 * block)
 {
     uint32 a, b, c, d;
 
@@ -203,82 +203,138 @@ void MD5Final(unsigned char output[16], struct MD5Context *s)
     }
 }
 
+void MD5Simple(void const *p, unsigned len, unsigned char output[16])
+{
+    struct MD5Context s;
+
+    MD5Init(&s);
+    MD5Update(&s, (unsigned char const *)p, len);
+    MD5Final(output, &s);
+}
+
 /* ----------------------------------------------------------------------
  * The above is the MD5 algorithm itself. Now we implement the
  * HMAC wrapper on it.
+ * 
+ * Some of these functions are exported directly, because they are
+ * useful elsewhere (SOCKS5 CHAP authentication uses HMAC-MD5).
  */
 
-static struct MD5Context md5_cs_mac_s1, md5_cs_mac_s2;
-static struct MD5Context md5_sc_mac_s1, md5_sc_mac_s2;
+void *hmacmd5_make_context(void)
+{
+    return snewn(3, struct MD5Context);
+}
 
-static void md5_key(struct MD5Context *s1, struct MD5Context *s2,
-		    unsigned char *key, int len)
+void hmacmd5_free_context(void *handle)
 {
+    sfree(handle);
+}
+
+void hmacmd5_key(void *handle, void const *keyv, int len)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
     unsigned char foo[64];
+    unsigned char const *key = (unsigned char const *)keyv;
     int i;
 
     memset(foo, 0x36, 64);
     for (i = 0; i < len && i < 64; i++)
 	foo[i] ^= key[i];
-    MD5Init(s1);
-    MD5Update(s1, foo, 64);
+    MD5Init(&keys[0]);
+    MD5Update(&keys[0], foo, 64);
 
     memset(foo, 0x5C, 64);
     for (i = 0; i < len && i < 64; i++)
 	foo[i] ^= key[i];
-    MD5Init(s2);
-    MD5Update(s2, foo, 64);
+    MD5Init(&keys[1]);
+    MD5Update(&keys[1], foo, 64);
 
-    memset(foo, 0, 64);		       /* burn the evidence */
+    smemclr(foo, 64);		       /* burn the evidence */
 }
 
-static void md5_cskey(unsigned char *key)
+static void hmacmd5_key_16(void *handle, unsigned char *key)
 {
-    md5_key(&md5_cs_mac_s1, &md5_cs_mac_s2, key, 16);
+    hmacmd5_key(handle, key, 16);
 }
 
-static void md5_sckey(unsigned char *key)
+static void hmacmd5_start(void *handle)
 {
-    md5_key(&md5_sc_mac_s1, &md5_sc_mac_s2, key, 16);
+    struct MD5Context *keys = (struct MD5Context *)handle;
+
+    keys[2] = keys[0];		      /* structure copy */
 }
 
-static void md5_do_hmac(struct MD5Context *s1, struct MD5Context *s2,
-			unsigned char *blk, int len, unsigned long seq,
-			unsigned char *hmac)
+static void hmacmd5_bytes(void *handle, unsigned char const *blk, int len)
 {
+    struct MD5Context *keys = (struct MD5Context *)handle;
+    MD5Update(&keys[2], blk, len);
+}
+
+static void hmacmd5_genresult(void *handle, unsigned char *hmac)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
     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);
+    s = keys[2];		       /* structure copy */
     MD5Final(intermediate, &s);
-    s = *s2;			       /* structure copy */
+    s = keys[1];		       /* structure copy */
     MD5Update(&s, intermediate, 16);
     MD5Final(hmac, &s);
 }
 
-static void md5_generate(unsigned char *blk, int len, unsigned long seq)
+static int hmacmd5_verresult(void *handle, unsigned char const *hmac)
+{
+    unsigned char correct[16];
+    hmacmd5_genresult(handle, correct);
+    return !memcmp(correct, hmac, 16);
+}
+
+static void hmacmd5_do_hmac_internal(void *handle,
+				     unsigned char const *blk, int len,
+				     unsigned char const *blk2, int len2,
+				     unsigned char *hmac)
+{
+    hmacmd5_start(handle);
+    hmacmd5_bytes(handle, blk, len);
+    if (blk2) hmacmd5_bytes(handle, blk2, len2);
+    hmacmd5_genresult(handle, hmac);
+}
+
+void hmacmd5_do_hmac(void *handle, unsigned char const *blk, int len,
+		     unsigned char *hmac)
+{
+    hmacmd5_do_hmac_internal(handle, blk, len, NULL, 0, hmac);
+}
+
+static void hmacmd5_do_hmac_ssh(void *handle, unsigned char const *blk, int len,
+				unsigned long seq, unsigned char *hmac)
+{
+    unsigned char seqbuf[16];
+
+    PUT_32BIT_MSB_FIRST(seqbuf, seq);
+    hmacmd5_do_hmac_internal(handle, seqbuf, 4, blk, len, hmac);
+}
+
+static void hmacmd5_generate(void *handle, unsigned char *blk, int len,
+			     unsigned long seq)
 {
-    md5_do_hmac(&md5_cs_mac_s1, &md5_cs_mac_s2, blk, len, seq, blk + len);
+    hmacmd5_do_hmac_ssh(handle, blk, len, seq, blk + len);
 }
 
-static int md5_verify(unsigned char *blk, int len, unsigned long seq)
+static int hmacmd5_verify(void *handle, 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);
+    hmacmd5_do_hmac_ssh(handle, blk, len, seq, correct);
     return !memcmp(correct, blk + len, 16);
 }
 
-const struct ssh_mac ssh_md5 = {
-    md5_cskey, md5_sckey,
-    md5_generate,
-    md5_verify,
+const struct ssh_mac ssh_hmac_md5 = {
+    hmacmd5_make_context, hmacmd5_free_context, hmacmd5_key_16,
+    hmacmd5_generate, hmacmd5_verify,
+    hmacmd5_start, hmacmd5_bytes, hmacmd5_genresult, hmacmd5_verresult,
     "hmac-md5",
-    16
+    16,
+    "HMAC-MD5"
 };