X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshsha.c;h=2b2eead1405059fd23601385a133378e20688efc;hb=c058fc4ea2ef5ef6d6732b9e8fd65cd723088ab7;hp=d8fc56947016181b871b31e03169644fdef2882c;hpb=2d86617f31717540c640c6d60990d23b40798bdf;p=PuTTY.git

diff --git a/sshsha.c b/sshsha.c
index d8fc5694..2b2eead1 100644
--- a/sshsha.c
+++ b/sshsha.c
@@ -1,5 +1,5 @@
 /*
- * SHA1 hash algorithm. Used in SSH2 as a MAC, and the transform is
+ * SHA1 hash algorithm. Used in SSH-2 as a MAC, and the transform is
  * also used as a `stirring' function for the PuTTY random number
  * pool. Implemented directly from the specification by Simon
  * Tatham.
@@ -28,6 +28,21 @@ void SHATransform(word32 * digest, word32 * block)
     word32 a, b, c, d, e;
     int t;
 
+#ifdef RANDOM_DIAGNOSTICS
+    {
+        extern int random_diagnostics;
+        if (random_diagnostics) {
+            int i;
+            printf("SHATransform:");
+            for (i = 0; i < 5; i++)
+                printf(" %08x", digest[i]);
+            printf(" +");
+            for (i = 0; i < 16; i++)
+                printf(" %08x", block[i]);
+        }
+    }
+#endif
+
     for (t = 0; t < 16; t++)
 	w[t] = block[t];
 
@@ -83,6 +98,19 @@ void SHATransform(word32 * digest, word32 * block)
     digest[2] += c;
     digest[3] += d;
     digest[4] += e;
+
+#ifdef RANDOM_DIAGNOSTICS
+    {
+        extern int random_diagnostics;
+        if (random_diagnostics) {
+            int i;
+            printf(" =");
+            for (i = 0; i < 5; i++)
+                printf(" %08x", digest[i]);
+            printf("\n");
+        }
+    }
+#endif
 }
 
 /* ----------------------------------------------------------------------
@@ -98,9 +126,9 @@ void SHA_Init(SHA_State * s)
     s->lenhi = s->lenlo = 0;
 }
 
-void SHA_Bytes(SHA_State * s, void *p, int len)
+void SHA_Bytes(SHA_State * s, const void *p, int len)
 {
-    unsigned char *q = (unsigned char *) p;
+    const unsigned char *q = (const unsigned char *) p;
     uint32 wordblock[16];
     uint32 lenw = len;
     int i;
@@ -179,27 +207,62 @@ void SHA_Final(SHA_State * s, unsigned char *output)
     }
 }
 
-void SHA_Simple(void *p, int len, unsigned char *output)
+void SHA_Simple(const void *p, int len, unsigned char *output)
 {
     SHA_State s;
 
     SHA_Init(&s);
     SHA_Bytes(&s, p, len);
     SHA_Final(&s, output);
+    smemclr(&s, sizeof(s));
 }
 
+/*
+ * Thin abstraction for things where hashes are pluggable.
+ */
+
+static void *sha1_init(void)
+{
+    SHA_State *s;
+
+    s = snew(SHA_State);
+    SHA_Init(s);
+    return s;
+}
+
+static void sha1_bytes(void *handle, const void *p, int len)
+{
+    SHA_State *s = handle;
+
+    SHA_Bytes(s, p, len);
+}
+
+static void sha1_final(void *handle, unsigned char *output)
+{
+    SHA_State *s = handle;
+
+    SHA_Final(s, output);
+    smemclr(s, sizeof(*s));
+    sfree(s);
+}
+
+const struct ssh_hash ssh_sha1 = {
+    sha1_init, sha1_bytes, sha1_final, 20, "SHA-1"
+};
+
 /* ----------------------------------------------------------------------
  * The above is the SHA-1 algorithm itself. Now we implement the
  * HMAC wrapper on it.
  */
 
-static void *sha1_make_context(void)
+static void *sha1_make_context(void *cipher_ctx)
 {
-    return smalloc(2*sizeof(SHA_State));
+    return snewn(3, SHA_State);
 }
 
 static void sha1_free_context(void *handle)
 {
+    smemclr(handle, 3 * sizeof(SHA_State));
     sfree(handle);
 }
 
@@ -221,7 +284,7 @@ static void sha1_key_internal(void *handle, unsigned char *key, int len)
     SHA_Init(&keys[1]);
     SHA_Bytes(&keys[1], foo, 64);
 
-    memset(foo, 0, 64);		       /* burn the evidence */
+    smemclr(foo, 64);		       /* burn the evidence */
 }
 
 static void sha1_key(void *handle, unsigned char *key)
@@ -234,39 +297,93 @@ static void sha1_key_buggy(void *handle, unsigned char *key)
     sha1_key_internal(handle, key, 16);
 }
 
-static void sha1_do_hmac(void *handle, unsigned char *blk, int len,
-			 unsigned long seq, unsigned char *hmac)
+static void hmacsha1_start(void *handle)
+{
+    SHA_State *keys = (SHA_State *)handle;
+
+    keys[2] = keys[0];		      /* structure copy */
+}
+
+static void hmacsha1_bytes(void *handle, unsigned char const *blk, int len)
+{
+    SHA_State *keys = (SHA_State *)handle;
+    SHA_Bytes(&keys[2], (void *)blk, len);
+}
+
+static void hmacsha1_genresult(void *handle, unsigned char *hmac)
 {
     SHA_State *keys = (SHA_State *)handle;
     SHA_State s;
     unsigned char intermediate[20];
 
-    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 = keys[0];		       /* structure copy */
-    SHA_Bytes(&s, intermediate, 4);
-    SHA_Bytes(&s, blk, len);
+    s = keys[2];		       /* structure copy */
     SHA_Final(&s, intermediate);
     s = keys[1];		       /* structure copy */
     SHA_Bytes(&s, intermediate, 20);
     SHA_Final(&s, hmac);
 }
 
+static void sha1_do_hmac(void *handle, unsigned char *blk, int len,
+			 unsigned long seq, unsigned char *hmac)
+{
+    unsigned char seqbuf[4];
+
+    PUT_32BIT_MSB_FIRST(seqbuf, seq);
+    hmacsha1_start(handle);
+    hmacsha1_bytes(handle, seqbuf, 4);
+    hmacsha1_bytes(handle, blk, len);
+    hmacsha1_genresult(handle, hmac);
+}
+
 static void sha1_generate(void *handle, unsigned char *blk, int len,
 			  unsigned long seq)
 {
     sha1_do_hmac(handle, blk, len, seq, blk + len);
 }
 
+static int hmacsha1_verresult(void *handle, unsigned char const *hmac)
+{
+    unsigned char correct[20];
+    hmacsha1_genresult(handle, correct);
+    return smemeq(correct, hmac, 20);
+}
+
 static int sha1_verify(void *handle, unsigned char *blk, int len,
 		       unsigned long seq)
 {
     unsigned char correct[20];
     sha1_do_hmac(handle, blk, len, seq, correct);
-    return !memcmp(correct, blk + len, 20);
+    return smemeq(correct, blk + len, 20);
+}
+
+static void hmacsha1_96_genresult(void *handle, unsigned char *hmac)
+{
+    unsigned char full[20];
+    hmacsha1_genresult(handle, full);
+    memcpy(hmac, full, 12);
+}
+
+static void sha1_96_generate(void *handle, unsigned char *blk, int len,
+			     unsigned long seq)
+{
+    unsigned char full[20];
+    sha1_do_hmac(handle, blk, len, seq, full);
+    memcpy(blk + len, full, 12);
+}
+
+static int hmacsha1_96_verresult(void *handle, unsigned char const *hmac)
+{
+    unsigned char correct[20];
+    hmacsha1_genresult(handle, correct);
+    return smemeq(correct, hmac, 12);
+}
+
+static int sha1_96_verify(void *handle, unsigned char *blk, int len,
+		       unsigned long seq)
+{
+    unsigned char correct[20];
+    sha1_do_hmac(handle, blk, len, seq, correct);
+    return smemeq(correct, blk + len, 12);
 }
 
 void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
@@ -282,16 +399,40 @@ void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
     SHA_Final(&states[1], output);
 }
 
-const struct ssh_mac ssh_sha1 = {
+const struct ssh_mac ssh_hmac_sha1 = {
     sha1_make_context, sha1_free_context, sha1_key,
     sha1_generate, sha1_verify,
-    "hmac-sha1",
-    20
+    hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
+    "hmac-sha1", "hmac-sha1-etm@openssh.com",
+    20,
+    "HMAC-SHA1"
+};
+
+const struct ssh_mac ssh_hmac_sha1_96 = {
+    sha1_make_context, sha1_free_context, sha1_key,
+    sha1_96_generate, sha1_96_verify,
+    hmacsha1_start, hmacsha1_bytes,
+    hmacsha1_96_genresult, hmacsha1_96_verresult,
+    "hmac-sha1-96", "hmac-sha1-96-etm@openssh.com",
+    12,
+    "HMAC-SHA1-96"
 };
 
-const struct ssh_mac ssh_sha1_buggy = {
+const struct ssh_mac ssh_hmac_sha1_buggy = {
     sha1_make_context, sha1_free_context, sha1_key_buggy,
     sha1_generate, sha1_verify,
-    "hmac-sha1",
-    20
+    hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
+    "hmac-sha1", NULL,
+    20,
+    "bug-compatible HMAC-SHA1"
+};
+
+const struct ssh_mac ssh_hmac_sha1_96_buggy = {
+    sha1_make_context, sha1_free_context, sha1_key_buggy,
+    sha1_96_generate, sha1_96_verify,
+    hmacsha1_start, hmacsha1_bytes,
+    hmacsha1_96_genresult, hmacsha1_96_verresult,
+    "hmac-sha1-96", NULL,
+    12,
+    "bug-compatible HMAC-SHA1-96"
 };