X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshblowf.c;h=353116a6604fdc8334d774f4004999e934f9d321;hb=e3f5f49cc4e8acbb457277487f89ea7972e57632;hp=a4b43decbb8a01b78be0f9e54cef9a5ebd860e64;hpb=3730ada5ce457468441b32d7e84157e481b8ba75;p=PuTTY.git

diff --git a/sshblowf.c b/sshblowf.c
index a4b43dec..353116a6 100644
--- a/sshblowf.c
+++ b/sshblowf.c
@@ -7,39 +7,37 @@
 #include <assert.h>
 #include <stdio.h>
 #include "ssh.h"
+#include "sshblowf.h"
 
-typedef struct {
+struct BlowfishContext {
     word32 S0[256], S1[256], S2[256], S3[256], P[18];
     word32 iv0, iv1;		       /* for CBC mode */
-} BlowfishContext;
-
-#define GET_32BIT_LSB_FIRST(cp) \
-  (((unsigned long)(unsigned char)(cp)[0]) | \
-  ((unsigned long)(unsigned char)(cp)[1] << 8) | \
-  ((unsigned long)(unsigned char)(cp)[2] << 16) | \
-  ((unsigned long)(unsigned char)(cp)[3] << 24))
-
-#define PUT_32BIT_LSB_FIRST(cp, value) do { \
-  (cp)[0] = (value); \
-  (cp)[1] = (value) >> 8; \
-  (cp)[2] = (value) >> 16; \
-  (cp)[3] = (value) >> 24; } while (0)
-
-#define GET_32BIT_MSB_FIRST(cp) \
-  (((unsigned long)(unsigned char)(cp)[0] << 24) | \
-  ((unsigned long)(unsigned char)(cp)[1] << 16) | \
-  ((unsigned long)(unsigned char)(cp)[2] << 8) | \
-  ((unsigned long)(unsigned char)(cp)[3]))
-
-#define PUT_32BIT_MSB_FIRST(cp, value) do { \
-  (cp)[0] = (value) >> 24; \
-  (cp)[1] = (value) >> 16; \
-  (cp)[2] = (value) >> 8; \
-  (cp)[3] = (value); } while (0)
+};
 
 /*
  * The Blowfish init data: hex digits of the fractional part of pi.
  * (ie pi as a hex fraction is 3.243F6A8885A308D3...)
+ *
+ * If you have Simon Tatham's 'spigot' exact real calculator
+ * available, or any other method of generating 8336 fractional hex
+ * digits of pi on standard output, you can regenerate these tables
+ * exactly as below using the following Perl script (adjusting the
+ * first line or two if your pi-generator is not spigot).
+
+open my $spig, "spigot -n -B16 -d8336 pi |";
+read $spig, $ignore, 2; # throw away the leading "3."
+for my $name ("parray", "sbox0".."sbox3") {
+    print "static const word32 ${name}[] = {\n";
+    my $len = $name eq "parray" ? 18 : 256;
+    for my $i (1..$len) {
+        read $spig, $word, 8;
+        printf "%s0x%s,", ($i%6==1 ? "    " : " "), uc $word;
+        print "\n" if ($i == $len || $i%6 == 0);
+    }
+    print "};\n\n";
+}
+close $spig;
+
  */
 static const word32 parray[] = {
     0x243F6A88, 0x85A308D3, 0x13198A2E, 0x03707344, 0xA4093822, 0x299F31D0,
@@ -329,6 +327,24 @@ static void blowfish_lsb_encrypt_cbc(unsigned char *blk, int len,
     ctx->iv1 = iv1;
 }
 
+void blowfish_lsb_encrypt_ecb(unsigned char *blk, int len,
+                              BlowfishContext * ctx)
+{
+    word32 xL, xR, out[2];
+
+    assert((len & 7) == 0);
+
+    while (len > 0) {
+	xL = GET_32BIT_LSB_FIRST(blk);
+	xR = GET_32BIT_LSB_FIRST(blk + 4);
+	blowfish_encrypt(xL, xR, out, ctx);
+	PUT_32BIT_LSB_FIRST(blk, out[0]);
+	PUT_32BIT_LSB_FIRST(blk + 4, out[1]);
+	blk += 8;
+	len -= 8;
+    }
+}
+
 static void blowfish_lsb_decrypt_cbc(unsigned char *blk, int len,
 				     BlowfishContext * ctx)
 {
@@ -413,8 +429,51 @@ static void blowfish_msb_decrypt_cbc(unsigned char *blk, int len,
     ctx->iv1 = iv1;
 }
 
-static void blowfish_setkey(BlowfishContext * ctx,
-			    const unsigned char *key, short keybytes)
+static void blowfish_msb_sdctr(unsigned char *blk, int len,
+				     BlowfishContext * ctx)
+{
+    word32 b[2], iv0, iv1, tmp;
+
+    assert((len & 7) == 0);
+
+    iv0 = ctx->iv0;
+    iv1 = ctx->iv1;
+
+    while (len > 0) {
+	blowfish_encrypt(iv0, iv1, b, ctx);
+	tmp = GET_32BIT_MSB_FIRST(blk);
+	PUT_32BIT_MSB_FIRST(blk, tmp ^ b[0]);
+	tmp = GET_32BIT_MSB_FIRST(blk + 4);
+	PUT_32BIT_MSB_FIRST(blk + 4, tmp ^ b[1]);
+	if ((iv1 = (iv1 + 1) & 0xffffffff) == 0)
+	    iv0 = (iv0 + 1) & 0xffffffff;
+	blk += 8;
+	len -= 8;
+    }
+
+    ctx->iv0 = iv0;
+    ctx->iv1 = iv1;
+}
+
+void blowfish_initkey(BlowfishContext *ctx)
+{
+    int i;
+
+    for (i = 0; i < 18; i++) {
+	ctx->P[i] = parray[i];
+    }
+
+    for (i = 0; i < 256; i++) {
+	ctx->S0[i] = sbox0[i];
+	ctx->S1[i] = sbox1[i];
+	ctx->S2[i] = sbox2[i];
+	ctx->S3[i] = sbox3[i];
+    }
+}
+
+void blowfish_expandkey(BlowfishContext * ctx,
+                        const unsigned char *key, short keybytes,
+                        const unsigned char *salt, short saltbytes)
 {
     word32 *S0 = ctx->S0;
     word32 *S1 = ctx->S1;
@@ -422,10 +481,18 @@ static void blowfish_setkey(BlowfishContext * ctx,
     word32 *S3 = ctx->S3;
     word32 *P = ctx->P;
     word32 str[2];
-    int i;
+    int i, j;
+    int saltpos;
+    unsigned char dummysalt[1];
+
+    saltpos = 0;
+    if (!salt) {
+        saltbytes = 1;
+        salt = dummysalt;
+        dummysalt[0] = 0;
+    }
 
     for (i = 0; i < 18; i++) {
-	P[i] = parray[i];
 	P[i] ^=
 	    ((word32) (unsigned char) (key[(i * 4 + 0) % keybytes])) << 24;
 	P[i] ^=
@@ -435,118 +502,161 @@ static void blowfish_setkey(BlowfishContext * ctx,
 	P[i] ^= ((word32) (unsigned char) (key[(i * 4 + 3) % keybytes]));
     }
 
-    for (i = 0; i < 256; i++) {
-	S0[i] = sbox0[i];
-	S1[i] = sbox1[i];
-	S2[i] = sbox2[i];
-	S3[i] = sbox3[i];
-    }
-
     str[0] = str[1] = 0;
 
     for (i = 0; i < 18; i += 2) {
+        for (j = 0; j < 8; j++)
+            str[j/4] ^= ((word32)salt[saltpos++ % saltbytes]) << (24-8*(j%4));
+
 	blowfish_encrypt(str[0], str[1], str, ctx);
 	P[i] = str[0];
 	P[i + 1] = str[1];
     }
 
     for (i = 0; i < 256; i += 2) {
+        for (j = 0; j < 8; j++)
+            str[j/4] ^= ((word32)salt[saltpos++ % saltbytes]) << (24-8*(j%4));
 	blowfish_encrypt(str[0], str[1], str, ctx);
 	S0[i] = str[0];
 	S0[i + 1] = str[1];
     }
     for (i = 0; i < 256; i += 2) {
+        for (j = 0; j < 8; j++)
+            str[j/4] ^= ((word32)salt[saltpos++ % saltbytes]) << (24-8*(j%4));
 	blowfish_encrypt(str[0], str[1], str, ctx);
 	S1[i] = str[0];
 	S1[i + 1] = str[1];
     }
     for (i = 0; i < 256; i += 2) {
+        for (j = 0; j < 8; j++)
+            str[j/4] ^= ((word32)salt[saltpos++ % saltbytes]) << (24-8*(j%4));
 	blowfish_encrypt(str[0], str[1], str, ctx);
 	S2[i] = str[0];
 	S2[i + 1] = str[1];
     }
     for (i = 0; i < 256; i += 2) {
+        for (j = 0; j < 8; j++)
+            str[j/4] ^= ((word32)salt[saltpos++ % saltbytes]) << (24-8*(j%4));
 	blowfish_encrypt(str[0], str[1], str, ctx);
 	S3[i] = str[0];
 	S3[i + 1] = str[1];
     }
 }
 
+static void blowfish_setkey(BlowfishContext *ctx,
+                            const unsigned char *key, short keybytes)
+{
+    blowfish_initkey(ctx);
+    blowfish_expandkey(ctx, key, keybytes, NULL, 0);
+}
+
 /* -- Interface with PuTTY -- */
 
 #define SSH_SESSION_KEY_LENGTH	32
-static BlowfishContext ectx, dctx;
 
-static void blowfish_cskey(unsigned char *key)
+void *blowfish_make_context(void)
+{
+    return snew(BlowfishContext);
+}
+
+static void *blowfish_ssh1_make_context(void)
 {
-    blowfish_setkey(&ectx, key, 16);
-    logevent("Initialised Blowfish client->server encryption");
+    /* In SSH-1, need one key for each direction */
+    return snewn(2, BlowfishContext);
 }
 
-static void blowfish_sckey(unsigned char *key)
+void blowfish_free_context(void *handle)
 {
-    blowfish_setkey(&dctx, key, 16);
-    logevent("Initialised Blowfish server->client encryption");
+    sfree(handle);
 }
 
-static void blowfish_csiv(unsigned char *key)
+static void blowfish_key(void *handle, unsigned char *key)
 {
-    ectx.iv0 = GET_32BIT_MSB_FIRST(key);
-    ectx.iv1 = GET_32BIT_MSB_FIRST(key + 4);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_setkey(ctx, key, 16);
 }
 
-static void blowfish_sciv(unsigned char *key)
+static void blowfish256_key(void *handle, unsigned char *key)
 {
-    dctx.iv0 = GET_32BIT_MSB_FIRST(key);
-    dctx.iv1 = GET_32BIT_MSB_FIRST(key + 4);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_setkey(ctx, key, 32);
 }
 
-static void blowfish_sesskey(unsigned char *key)
+static void blowfish_iv(void *handle, unsigned char *key)
 {
-    blowfish_setkey(&ectx, key, SSH_SESSION_KEY_LENGTH);
-    ectx.iv0 = 0;
-    ectx.iv1 = 0;
-    dctx = ectx;
-    logevent("Initialised Blowfish encryption");
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    ctx->iv0 = GET_32BIT_MSB_FIRST(key);
+    ctx->iv1 = GET_32BIT_MSB_FIRST(key + 4);
 }
 
-static void blowfish_ssh1_encrypt_blk(unsigned char *blk, int len)
+static void blowfish_sesskey(void *handle, unsigned char *key)
 {
-    blowfish_lsb_encrypt_cbc(blk, len, &ectx);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_setkey(ctx, key, SSH_SESSION_KEY_LENGTH);
+    ctx->iv0 = 0;
+    ctx->iv1 = 0;
+    ctx[1] = ctx[0];		       /* structure copy */
 }
 
-static void blowfish_ssh1_decrypt_blk(unsigned char *blk, int len)
+static void blowfish_ssh1_encrypt_blk(void *handle, unsigned char *blk,
+				      int len)
 {
-    blowfish_lsb_decrypt_cbc(blk, len, &dctx);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_lsb_encrypt_cbc(blk, len, ctx);
 }
 
-static void blowfish_ssh2_encrypt_blk(unsigned char *blk, int len)
+static void blowfish_ssh1_decrypt_blk(void *handle, unsigned char *blk,
+				      int len)
 {
-    blowfish_msb_encrypt_cbc(blk, len, &ectx);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_lsb_decrypt_cbc(blk, len, ctx+1);
 }
 
-static void blowfish_ssh2_decrypt_blk(unsigned char *blk, int len)
+static void blowfish_ssh2_encrypt_blk(void *handle, unsigned char *blk,
+				      int len)
 {
-    blowfish_msb_decrypt_cbc(blk, len, &dctx);
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_msb_encrypt_cbc(blk, len, ctx);
+}
+
+static void blowfish_ssh2_decrypt_blk(void *handle, unsigned char *blk,
+				      int len)
+{
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_msb_decrypt_cbc(blk, len, ctx);
+}
+
+static void blowfish_ssh2_sdctr(void *handle, unsigned char *blk,
+				      int len)
+{
+    BlowfishContext *ctx = (BlowfishContext *)handle;
+    blowfish_msb_sdctr(blk, len, ctx);
 }
 
 const struct ssh_cipher ssh_blowfish_ssh1 = {
-    blowfish_sesskey,
-    blowfish_ssh1_encrypt_blk,
-    blowfish_ssh1_decrypt_blk,
-    8
+    blowfish_ssh1_make_context, blowfish_free_context, blowfish_sesskey,
+    blowfish_ssh1_encrypt_blk, blowfish_ssh1_decrypt_blk,
+    8, "Blowfish-128 CBC"
 };
 
 static const struct ssh2_cipher ssh_blowfish_ssh2 = {
-    blowfish_csiv, blowfish_cskey,
-    blowfish_sciv, blowfish_sckey,
-    blowfish_ssh2_encrypt_blk,
-    blowfish_ssh2_decrypt_blk,
+    blowfish_make_context, blowfish_free_context, blowfish_iv, blowfish_key,
+    blowfish_ssh2_encrypt_blk, blowfish_ssh2_decrypt_blk, NULL, NULL,
     "blowfish-cbc",
-    8, 128
+    8, 128, 16, SSH_CIPHER_IS_CBC, "Blowfish-128 CBC",
+    NULL
+};
+
+static const struct ssh2_cipher ssh_blowfish_ssh2_ctr = {
+    blowfish_make_context, blowfish_free_context, blowfish_iv, blowfish256_key,
+    blowfish_ssh2_sdctr, blowfish_ssh2_sdctr, NULL, NULL,
+    "blowfish-ctr",
+    8, 256, 32, 0, "Blowfish-256 SDCTR",
+    NULL
 };
 
 static const struct ssh2_cipher *const blowfish_list[] = {
+    &ssh_blowfish_ssh2_ctr,
     &ssh_blowfish_ssh2
 };