X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshmd5.c;h=b39dfd3e52dba4a399706c3769193c05ff738168;hb=a1e622523e48125b7322cf4e53d504b9a6614c15;hp=215b81fddcb63fc916c6c66cbae2f91bdacbfee2;hpb=11d5c791acb6fbc3376ab0843d2040aa0e40e2f2;p=PuTTY.git

diff --git a/sshmd5.c b/sshmd5.c
index 215b81fd..b39dfd3e 100644
--- a/sshmd5.c
+++ b/sshmd5.c
@@ -210,6 +210,7 @@ void MD5Simple(void const *p, unsigned len, unsigned char output[16])
     MD5Init(&s);
     MD5Update(&s, (unsigned char const *)p, len);
     MD5Final(output, &s);
+    smemclr(&s, sizeof(s));
 }
 
 /* ----------------------------------------------------------------------
@@ -220,13 +221,14 @@ void MD5Simple(void const *p, unsigned len, unsigned char output[16])
  * useful elsewhere (SOCKS5 CHAP authentication uses HMAC-MD5).
  */
 
-void *hmacmd5_make_context(void)
+void *hmacmd5_make_context(void *cipher_ctx)
 {
-    return snewn(2, struct MD5Context);
+    return snewn(3, struct MD5Context);
 }
 
 void hmacmd5_free_context(void *handle)
 {
+    smemclr(handle, 3*sizeof(struct MD5Context));
     sfree(handle);
 }
 
@@ -249,7 +251,7 @@ void hmacmd5_key(void *handle, void const *keyv, int len)
     MD5Init(&keys[1]);
     MD5Update(&keys[1], foo, 64);
 
-    memset(foo, 0, 64);		       /* burn the evidence */
+    smemclr(foo, 64);		       /* burn the evidence */
 }
 
 static void hmacmd5_key_16(void *handle, unsigned char *key)
@@ -257,24 +259,50 @@ static void hmacmd5_key_16(void *handle, unsigned char *key)
     hmacmd5_key(handle, key, 16);
 }
 
-static void hmacmd5_do_hmac_internal(void *handle,
-				     unsigned char const *blk, int len,
-				     unsigned char const *blk2, int len2,
-				     unsigned char *hmac)
+static void hmacmd5_start(void *handle)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+
+    keys[2] = keys[0];		      /* structure copy */
+}
+
+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];
 
-    s = keys[0];		       /* structure copy */
-    MD5Update(&s, blk, len);
-    if (blk2) MD5Update(&s, blk2, len2);
+    s = keys[2];		       /* structure copy */
     MD5Final(intermediate, &s);
     s = keys[1];		       /* structure copy */
     MD5Update(&s, intermediate, 16);
     MD5Final(hmac, &s);
 }
 
+static int hmacmd5_verresult(void *handle, unsigned char const *hmac)
+{
+    unsigned char correct[16];
+    hmacmd5_genresult(handle, correct);
+    return smemeq(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)
 {
@@ -286,11 +314,7 @@ static void hmacmd5_do_hmac_ssh(void *handle, unsigned char const *blk, int len,
 {
     unsigned char seqbuf[16];
 
-    seqbuf[0] = (unsigned char) ((seq >> 24) & 0xFF);
-    seqbuf[1] = (unsigned char) ((seq >> 16) & 0xFF);
-    seqbuf[2] = (unsigned char) ((seq >> 8) & 0xFF);
-    seqbuf[3] = (unsigned char) ((seq) & 0xFF);
-
+    PUT_32BIT_MSB_FIRST(seqbuf, seq);
     hmacmd5_do_hmac_internal(handle, seqbuf, 4, blk, len, hmac);
 }
 
@@ -305,13 +329,14 @@ static int hmacmd5_verify(void *handle, unsigned char *blk, int len,
 {
     unsigned char correct[16];
     hmacmd5_do_hmac_ssh(handle, blk, len, seq, correct);
-    return !memcmp(correct, blk + len, 16);
+    return smemeq(correct, blk + len, 16);
 }
 
 const struct ssh_mac ssh_hmac_md5 = {
     hmacmd5_make_context, hmacmd5_free_context, hmacmd5_key_16,
     hmacmd5_generate, hmacmd5_verify,
-    "hmac-md5",
-    16,
+    hmacmd5_start, hmacmd5_bytes, hmacmd5_genresult, hmacmd5_verresult,
+    "hmac-md5", "hmac-md5-etm@openssh.com",
+    16, 16,
     "HMAC-MD5"
 };