X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/c677cad690637a1ceaf6e039dcdbd3a267ad3c86..9916cc1e8d26f1caef36fc1ee525819e6ca62f42:/sshsha.c

diff --git a/sshsha.c b/sshsha.c
index 1db5c26d..cbe9d78b 100644
--- a/sshsha.c
+++ b/sshsha.c
@@ -227,7 +227,7 @@ const struct ssh_hash ssh_sha1 = {
 
 static void *sha1_make_context(void)
 {
-    return snewn(2, SHA_State);
+    return snewn(3, SHA_State);
 }
 
 static void sha1_free_context(void *handle)
@@ -266,33 +266,61 @@ 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];
+
+    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);
+
+    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 !memcmp(correct, hmac, 20);
+}
+
 static int sha1_verify(void *handle, unsigned char *blk, int len,
 		       unsigned long seq)
 {
@@ -301,6 +329,13 @@ static int sha1_verify(void *handle, unsigned char *blk, int len,
     return !memcmp(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)
 {
@@ -309,6 +344,13 @@ static void sha1_96_generate(void *handle, unsigned char *blk, int len,
     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 !memcmp(correct, hmac, 12);
+}
+
 static int sha1_96_verify(void *handle, unsigned char *blk, int len,
 		       unsigned long seq)
 {
@@ -333,6 +375,7 @@ void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
 const struct ssh_mac ssh_hmac_sha1 = {
     sha1_make_context, sha1_free_context, sha1_key,
     sha1_generate, sha1_verify,
+    hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
     "hmac-sha1",
     20,
     "HMAC-SHA1"
@@ -341,6 +384,8 @@ const struct ssh_mac ssh_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",
     12,
     "HMAC-SHA1-96"
@@ -349,6 +394,7 @@ const struct ssh_mac ssh_hmac_sha1_96 = {
 const struct ssh_mac ssh_hmac_sha1_buggy = {
     sha1_make_context, sha1_free_context, sha1_key_buggy,
     sha1_generate, sha1_verify,
+    hmacsha1_start, hmacsha1_bytes, hmacsha1_genresult, hmacsha1_verresult,
     "hmac-sha1",
     20,
     "bug-compatible HMAC-SHA1"
@@ -357,6 +403,8 @@ const struct ssh_mac ssh_hmac_sha1_buggy = {
 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",
     12,
     "bug-compatible HMAC-SHA1-96"