X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshdes.c;h=13487fcd79bdb704451eb2f296af77dc6b2f126e;hb=72c3c23ebd2149ea326ad4fe7b71ac7bdefaa514;hp=f926fca3774cbe4bd36fa6ad11460364d714b159;hpb=024781b3ed53a728f5ea331fe429f9e7edd4257d;p=PuTTY.git

diff --git a/sshdes.c b/sshdes.c
index f926fca3..13487fcd 100644
--- a/sshdes.c
+++ b/sshdes.c
@@ -600,7 +600,7 @@ static void des_decipher(word32 * output, word32 L, word32 R,
     output[1] = R;
 }
 
-static void des_cbc_encrypt(unsigned char *dest, const unsigned char *src,
+static void des_cbc_encrypt(unsigned char *blk,
 			    unsigned int len, DESContext * sched)
 {
     word32 out[2], iv0, iv1;
@@ -611,23 +611,20 @@ static void des_cbc_encrypt(unsigned char *dest, const unsigned char *src,
     iv0 = sched->iv0;
     iv1 = sched->iv1;
     for (i = 0; i < len; i += 8) {
-	iv0 ^= GET_32BIT_MSB_FIRST(src);
-	src += 4;
-	iv1 ^= GET_32BIT_MSB_FIRST(src);
-	src += 4;
+	iv0 ^= GET_32BIT_MSB_FIRST(blk);
+	iv1 ^= GET_32BIT_MSB_FIRST(blk + 4);
 	des_encipher(out, iv0, iv1, sched);
 	iv0 = out[0];
 	iv1 = out[1];
-	PUT_32BIT_MSB_FIRST(dest, iv0);
-	dest += 4;
-	PUT_32BIT_MSB_FIRST(dest, iv1);
-	dest += 4;
+	PUT_32BIT_MSB_FIRST(blk, iv0);
+	PUT_32BIT_MSB_FIRST(blk + 4, iv1);
+	blk += 8;
     }
     sched->iv0 = iv0;
     sched->iv1 = iv1;
 }
 
-static void des_cbc_decrypt(unsigned char *dest, const unsigned char *src,
+static void des_cbc_decrypt(unsigned char *blk,
 			    unsigned int len, DESContext * sched)
 {
     word32 out[2], iv0, iv1, xL, xR;
@@ -638,17 +635,14 @@ static void des_cbc_decrypt(unsigned char *dest, const unsigned char *src,
     iv0 = sched->iv0;
     iv1 = sched->iv1;
     for (i = 0; i < len; i += 8) {
-	xL = GET_32BIT_MSB_FIRST(src);
-	src += 4;
-	xR = GET_32BIT_MSB_FIRST(src);
-	src += 4;
+	xL = GET_32BIT_MSB_FIRST(blk);
+	xR = GET_32BIT_MSB_FIRST(blk + 4);
 	des_decipher(out, xL, xR, sched);
 	iv0 ^= out[0];
 	iv1 ^= out[1];
-	PUT_32BIT_MSB_FIRST(dest, iv0);
-	dest += 4;
-	PUT_32BIT_MSB_FIRST(dest, iv1);
-	dest += 4;
+	PUT_32BIT_MSB_FIRST(blk, iv0);
+	PUT_32BIT_MSB_FIRST(blk + 4, iv1);
+	blk += 8;
 	iv0 = xL;
 	iv1 = xR;
     }
@@ -656,15 +650,15 @@ static void des_cbc_decrypt(unsigned char *dest, const unsigned char *src,
     sched->iv1 = iv1;
 }
 
-static void des_3cbc_encrypt(unsigned char *dest, const unsigned char *src,
+static void des_3cbc_encrypt(unsigned char *blk,
 			     unsigned int len, DESContext * scheds)
 {
-    des_cbc_encrypt(dest, src, len, &scheds[0]);
-    des_cbc_decrypt(dest, src, len, &scheds[1]);
-    des_cbc_encrypt(dest, src, len, &scheds[2]);
+    des_cbc_encrypt(blk, len, &scheds[0]);
+    des_cbc_decrypt(blk, len, &scheds[1]);
+    des_cbc_encrypt(blk, len, &scheds[2]);
 }
 
-static void des_cbc3_encrypt(unsigned char *dest, const unsigned char *src,
+static void des_cbc3_encrypt(unsigned char *blk,
 			     unsigned int len, DESContext * scheds)
 {
     word32 out[2], iv0, iv1;
@@ -675,33 +669,30 @@ static void des_cbc3_encrypt(unsigned char *dest, const unsigned char *src,
     iv0 = scheds->iv0;
     iv1 = scheds->iv1;
     for (i = 0; i < len; i += 8) {
-	iv0 ^= GET_32BIT_MSB_FIRST(src);
-	src += 4;
-	iv1 ^= GET_32BIT_MSB_FIRST(src);
-	src += 4;
+	iv0 ^= GET_32BIT_MSB_FIRST(blk);
+	iv1 ^= GET_32BIT_MSB_FIRST(blk + 4);
 	des_encipher(out, iv0, iv1, &scheds[0]);
 	des_decipher(out, out[0], out[1], &scheds[1]);
 	des_encipher(out, out[0], out[1], &scheds[2]);
 	iv0 = out[0];
 	iv1 = out[1];
-	PUT_32BIT_MSB_FIRST(dest, iv0);
-	dest += 4;
-	PUT_32BIT_MSB_FIRST(dest, iv1);
-	dest += 4;
+	PUT_32BIT_MSB_FIRST(blk, iv0);
+	PUT_32BIT_MSB_FIRST(blk + 4, iv1);
+	blk += 8;
     }
     scheds->iv0 = iv0;
     scheds->iv1 = iv1;
 }
 
-static void des_3cbc_decrypt(unsigned char *dest, const unsigned char *src,
+static void des_3cbc_decrypt(unsigned char *blk,
 			     unsigned int len, DESContext * scheds)
 {
-    des_cbc_decrypt(dest, src, len, &scheds[2]);
-    des_cbc_encrypt(dest, src, len, &scheds[1]);
-    des_cbc_decrypt(dest, src, len, &scheds[0]);
+    des_cbc_decrypt(blk, len, &scheds[2]);
+    des_cbc_encrypt(blk, len, &scheds[1]);
+    des_cbc_decrypt(blk, len, &scheds[0]);
 }
 
-static void des_cbc3_decrypt(unsigned char *dest, const unsigned char *src,
+static void des_cbc3_decrypt(unsigned char *blk,
 			     unsigned int len, DESContext * scheds)
 {
     word32 out[2], iv0, iv1, xL, xR;
@@ -712,19 +703,16 @@ static void des_cbc3_decrypt(unsigned char *dest, const unsigned char *src,
     iv0 = scheds->iv0;
     iv1 = scheds->iv1;
     for (i = 0; i < len; i += 8) {
-	xL = GET_32BIT_MSB_FIRST(src);
-	src += 4;
-	xR = GET_32BIT_MSB_FIRST(src);
-	src += 4;
+	xL = GET_32BIT_MSB_FIRST(blk);
+	xR = GET_32BIT_MSB_FIRST(blk + 4);
 	des_decipher(out, xL, xR, &scheds[2]);
 	des_encipher(out, out[0], out[1], &scheds[1]);
 	des_decipher(out, out[0], out[1], &scheds[0]);
 	iv0 ^= out[0];
 	iv1 ^= out[1];
-	PUT_32BIT_MSB_FIRST(dest, iv0);
-	dest += 4;
-	PUT_32BIT_MSB_FIRST(dest, iv1);
-	dest += 4;
+	PUT_32BIT_MSB_FIRST(blk, iv0);
+	PUT_32BIT_MSB_FIRST(blk + 4, iv1);
+	blk += 8;
 	iv0 = xL;
 	iv1 = xR;
     }
@@ -732,8 +720,7 @@ static void des_cbc3_decrypt(unsigned char *dest, const unsigned char *src,
     scheds->iv1 = iv1;
 }
 
-#ifdef ENABLE_3DES_SSH2_CTR
-static void des_sdctr3(unsigned char *dest, const unsigned char *src,
+static void des_sdctr3(unsigned char *blk,
 			     unsigned int len, DESContext * scheds)
 {
     word32 b[2], iv0, iv1, tmp;
@@ -747,21 +734,18 @@ static void des_sdctr3(unsigned char *dest, const unsigned char *src,
 	des_encipher(b, iv0, iv1, &scheds[0]);
 	des_decipher(b, b[0], b[1], &scheds[1]);
 	des_encipher(b, b[0], b[1], &scheds[2]);
-	tmp = GET_32BIT_MSB_FIRST(src);
-	PUT_32BIT_MSB_FIRST(dest, tmp ^ b[0]);
-	src += 4;
-	dest += 4;
-	tmp = GET_32BIT_MSB_FIRST(src);
-	PUT_32BIT_MSB_FIRST(dest, tmp ^ b[0]);
-	src += 4;
-	dest += 4;
-	if ((iv0 = (iv0 + 1) & 0xffffffff) == 0)
-	    iv1 = (iv1 + 1) & 0xffffffff;
+	tmp = GET_32BIT_MSB_FIRST(blk);
+	PUT_32BIT_MSB_FIRST(blk, tmp ^ b[0]);
+	blk += 4;
+	tmp = GET_32BIT_MSB_FIRST(blk);
+	PUT_32BIT_MSB_FIRST(blk, tmp ^ b[1]);
+	blk += 4;
+	if ((iv1 = (iv1 + 1) & 0xffffffff) == 0)
+	    iv0 = (iv0 + 1) & 0xffffffff;
     }
     scheds->iv0 = iv0;
     scheds->iv1 = iv1;
 }
-#endif
 
 static void *des3_make_context(void)
 {
@@ -825,45 +809,43 @@ static void des3_sesskey(void *handle, unsigned char *key)
 static void des3_encrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_3cbc_encrypt(blk, blk, len, keys);
+    des_3cbc_encrypt(blk, len, keys);
 }
 
 static void des3_decrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_3cbc_decrypt(blk, blk, len, keys+3);
+    des_3cbc_decrypt(blk, len, keys+3);
 }
 
 static void des3_ssh2_encrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc3_encrypt(blk, blk, len, keys);
+    des_cbc3_encrypt(blk, len, keys);
 }
 
 static void des3_ssh2_decrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc3_decrypt(blk, blk, len, keys);
+    des_cbc3_decrypt(blk, len, keys);
 }
 
-#ifdef ENABLE_3DES_SSH2_CTR
 static void des3_ssh2_sdctr(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_sdctr3(blk, blk, len, keys);
+    des_sdctr3(blk, len, keys);
 }
-#endif
 
 static void des_ssh2_encrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc_encrypt(blk, blk, len, keys);
+    des_cbc_encrypt(blk, len, keys);
 }
 
 static void des_ssh2_decrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc_decrypt(blk, blk, len, keys);
+    des_cbc_decrypt(blk, len, keys);
 }
 
 void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
@@ -875,8 +857,8 @@ void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
 		  GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
     des_key_setup(GET_32BIT_MSB_FIRST(key),
 		  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[2]);
-    des_3cbc_decrypt(blk, blk, len, ourkeys);
-    memset(ourkeys, 0, sizeof(ourkeys));
+    des_3cbc_decrypt(blk, len, ourkeys);
+    smemclr(ourkeys, sizeof(ourkeys));
 }
 
 void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
@@ -888,8 +870,8 @@ void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
 		  GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
     des_key_setup(GET_32BIT_MSB_FIRST(key),
 		  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[2]);
-    des_3cbc_encrypt(blk, blk, len, ourkeys);
-    memset(ourkeys, 0, sizeof(ourkeys));
+    des_3cbc_encrypt(blk, len, ourkeys);
+    smemclr(ourkeys, sizeof(ourkeys));
 }
 
 void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
@@ -904,8 +886,8 @@ void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
 		  GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
     ourkeys[0].iv0 = GET_32BIT_MSB_FIRST(iv);
     ourkeys[0].iv1 = GET_32BIT_MSB_FIRST(iv+4);
-    des_cbc3_decrypt(blk, blk, len, ourkeys);
-    memset(ourkeys, 0, sizeof(ourkeys));
+    des_cbc3_decrypt(blk, len, ourkeys);
+    smemclr(ourkeys, sizeof(ourkeys));
 }
 
 void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
@@ -920,11 +902,11 @@ void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
 		  GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
     ourkeys[0].iv0 = GET_32BIT_MSB_FIRST(iv);
     ourkeys[0].iv1 = GET_32BIT_MSB_FIRST(iv+4);
-    des_cbc3_encrypt(blk, blk, len, ourkeys);
-    memset(ourkeys, 0, sizeof(ourkeys));
+    des_cbc3_encrypt(blk, len, ourkeys);
+    smemclr(ourkeys, sizeof(ourkeys));
 }
 
-static void des_keysetup_xdmauth(unsigned char *keydata, DESContext *dc)
+static void des_keysetup_xdmauth(const unsigned char *keydata, DESContext *dc)
 {
     unsigned char key[8];
     int i, nbits, j;
@@ -947,39 +929,41 @@ static void des_keysetup_xdmauth(unsigned char *keydata, DESContext *dc)
     des_key_setup(GET_32BIT_MSB_FIRST(key), GET_32BIT_MSB_FIRST(key + 4), dc);
 }
 
-void des_encrypt_xdmauth(unsigned char *keydata, unsigned char *blk, int len)
+void des_encrypt_xdmauth(const unsigned char *keydata,
+                         unsigned char *blk, int len)
 {
     DESContext dc;
     des_keysetup_xdmauth(keydata, &dc);
-    des_cbc_encrypt(blk, blk, 24, &dc);
+    des_cbc_encrypt(blk, len, &dc);
 }
 
-void des_decrypt_xdmauth(unsigned char *keydata, unsigned char *blk, int len)
+void des_decrypt_xdmauth(const unsigned char *keydata,
+                         unsigned char *blk, int len)
 {
     DESContext dc;
     des_keysetup_xdmauth(keydata, &dc);
-    des_cbc_decrypt(blk, blk, 24, &dc);
+    des_cbc_decrypt(blk, len, &dc);
 }
 
 static const struct ssh2_cipher ssh_3des_ssh2 = {
     des3_make_context, des3_free_context, des3_iv, des3_key,
-    des3_ssh2_encrypt_blk, des3_ssh2_decrypt_blk,
+    des3_ssh2_encrypt_blk, des3_ssh2_decrypt_blk, NULL, NULL,
     "3des-cbc",
-    8, 168, SSH_CIPHER_IS_CBC, "triple-DES CBC"
+    8, 168, 24, SSH_CIPHER_IS_CBC, "triple-DES CBC",
+    NULL
 };
 
-#ifdef ENABLE_3DES_SSH2_CTR
 static const struct ssh2_cipher ssh_3des_ssh2_ctr = {
     des3_make_context, des3_free_context, des3_iv, des3_key,
-    des3_ssh2_sdctr, des3_ssh2_sdctr,
+    des3_ssh2_sdctr, des3_ssh2_sdctr, NULL, NULL,
     "3des-ctr",
-    8, 168, 0, "triple-DES SDCTR"
+    8, 168, 24, 0, "triple-DES SDCTR",
+    NULL
 };
-#endif
 
 /*
  * Single DES in SSH-2. "des-cbc" is marked as HISTORIC in
- * draft-ietf-secsh-assignednumbers-04.txt, referring to
+ * RFC 4250, referring to
  * FIPS-46-3.  ("Single DES (i.e., DES) will be permitted 
  * for legacy systems only.") , but ssh.com support it and 
  * apparently aren't the only people to do so, so we sigh 
@@ -987,28 +971,22 @@ static const struct ssh2_cipher ssh_3des_ssh2_ctr = {
  */
 static const struct ssh2_cipher ssh_des_ssh2 = {
     des_make_context, des3_free_context, des3_iv, des_key,
-    des_ssh2_encrypt_blk, des_ssh2_decrypt_blk,
+    des_ssh2_encrypt_blk, des_ssh2_decrypt_blk, NULL, NULL,
     "des-cbc",
-    8, 56, SSH_CIPHER_IS_CBC, "single-DES CBC"
+    8, 56, 8, SSH_CIPHER_IS_CBC, "single-DES CBC",
+    NULL
 };
 
 static const struct ssh2_cipher ssh_des_sshcom_ssh2 = {
     des_make_context, des3_free_context, des3_iv, des_key,
-    des_ssh2_encrypt_blk, des_ssh2_decrypt_blk,
+    des_ssh2_encrypt_blk, des_ssh2_decrypt_blk, NULL, NULL,
     "des-cbc@ssh.com",
-    8, 56, SSH_CIPHER_IS_CBC, "single-DES CBC"
+    8, 56, 8, SSH_CIPHER_IS_CBC, "single-DES CBC",
+    NULL
 };
 
-/*
- * "3des-ctr" is disabled because it hasn't had any interoperability
- * testing, which is in turn because I couldn't find another implementation
- * to test against.  Once it's been tested, it can be enabled in standard
- * builds.
- */
 static const struct ssh2_cipher *const des3_list[] = {
-#ifdef ENABLE_3DES_SSH2_CTR
     &ssh_3des_ssh2_ctr,
-#endif
     &ssh_3des_ssh2
 };
 
@@ -1043,13 +1021,13 @@ static void des_sesskey(void *handle, unsigned char *key)
 static void des_encrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc_encrypt(blk, blk, len, keys);
+    des_cbc_encrypt(blk, len, keys);
 }
 
 static void des_decrypt_blk(void *handle, unsigned char *blk, int len)
 {
     DESContext *keys = (DESContext *) handle;
-    des_cbc_decrypt(blk, blk, len, keys+1);
+    des_cbc_decrypt(blk, len, keys+1);
 }
 
 const struct ssh_cipher ssh_des = {
@@ -1057,3 +1035,58 @@ const struct ssh_cipher ssh_des = {
     des_encrypt_blk, des_decrypt_blk,
     8, "single-DES CBC"
 };
+
+#ifdef TEST_XDM_AUTH
+
+/*
+ * Small standalone utility which allows encryption and decryption of
+ * single cipher blocks in the XDM-AUTHORIZATION-1 style. Written
+ * during the rework of X authorisation for connection sharing, to
+ * check the corner case when xa1_firstblock matches but the rest of
+ * the authorisation is bogus.
+ *
+ * Just compile this file on its own with the above ifdef symbol
+ * predefined:
+
+gcc -DTEST_XDM_AUTH -o sshdes sshdes.c
+
+ */
+
+#include <stdlib.h>
+void *safemalloc(size_t n, size_t size) { return calloc(n, size); }
+void safefree(void *p) { return free(p); }
+void smemclr(void *p, size_t size) { memset(p, 0, size); }
+int main(int argc, char **argv)
+{
+    unsigned char words[2][8];
+    unsigned char out[8];
+    int i, j;
+
+    memset(words, 0, sizeof(words));
+
+    for (i = 0; i < 2; i++) {
+        for (j = 0; j < 8 && argv[i+1][2*j]; j++) {
+            char x[3];
+            unsigned u;
+            x[0] = argv[i+1][2*j];
+            x[1] = argv[i+1][2*j+1];
+            x[2] = 0;
+            sscanf(x, "%02x", &u);
+            words[i][j] = u;
+        }
+    }
+
+    memcpy(out, words[0], 8);
+    des_decrypt_xdmauth(words[1], out, 8);
+    printf("decrypt(%s,%s) = ", argv[1], argv[2]);
+    for (i = 0; i < 8; i++) printf("%02x", out[i]);
+    printf("\n");
+
+    memcpy(out, words[0], 8);
+    des_encrypt_xdmauth(words[1], out, 8);
+    printf("encrypt(%s,%s) = ", argv[1], argv[2]);
+    for (i = 0; i < 8; i++) printf("%02x", out[i]);
+    printf("\n");
+}
+
+#endif