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| author | marha <marha@users.sourceforge.net> | 2010-11-19 10:30:56 +0000 |
|---|---|---|
| committer | marha <marha@users.sourceforge.net> | 2010-11-19 10:30:56 +0000 |
| commit | 20a8b976130e3b2cfff5c3364169e61ec10291f3 (patch) | |
| tree | b2fbea50cfb846049fc690a252baec07397a1acc /tools/plink/ssharcf.c | |
| parent | 0b67cceb98ba4ab7b5cdaf9d6e9583d3c53802ea (diff) | |
| download | vcxsrv-20a8b976130e3b2cfff5c3364169e61ec10291f3.tar.gz vcxsrv-20a8b976130e3b2cfff5c3364169e61ec10291f3.tar.bz2 vcxsrv-20a8b976130e3b2cfff5c3364169e61ec10291f3.zip | |
Copied tools directory from trunk. Here the original versions will be checked in, so that we can update them and merge the changes back in.
Diffstat (limited to 'tools/plink/ssharcf.c')
| -rw-r--r-- | tools/plink/ssharcf.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/tools/plink/ssharcf.c b/tools/plink/ssharcf.c new file mode 100644 index 000000000..e0b247e51 --- /dev/null +++ b/tools/plink/ssharcf.c @@ -0,0 +1,123 @@ +/*
+ * Arcfour (RC4) implementation for PuTTY.
+ *
+ * Coded from Schneier.
+ */
+
+#include <assert.h>
+#include "ssh.h"
+
+typedef struct {
+ unsigned char i, j, s[256];
+} ArcfourContext;
+
+static void arcfour_block(void *handle, unsigned char *blk, int len)
+{
+ ArcfourContext *ctx = (ArcfourContext *)handle;
+ unsigned k;
+ unsigned char tmp, i, j, *s;
+
+ s = ctx->s;
+ i = ctx->i; j = ctx->j;
+ for (k = 0; (int)k < len; k++) {
+ i = (i + 1) & 0xff;
+ j = (j + s[i]) & 0xff;
+ tmp = s[i]; s[i] = s[j]; s[j] = tmp;
+ blk[k] ^= s[(s[i]+s[j]) & 0xff];
+ }
+ ctx->i = i; ctx->j = j;
+}
+
+static void arcfour_setkey(ArcfourContext *ctx, unsigned char const *key,
+ unsigned keybytes)
+{
+ unsigned char tmp, k[256], *s;
+ unsigned i, j;
+
+ s = ctx->s;
+ assert(keybytes <= 256);
+ ctx->i = ctx->j = 0;
+ for (i = 0; i < 256; i++) {
+ s[i] = i;
+ k[i] = key[i % keybytes];
+ }
+ j = 0;
+ for (i = 0; i < 256; i++) {
+ j = (j + s[i] + k[i]) & 0xff;
+ tmp = s[i]; s[i] = s[j]; s[j] = tmp;
+ }
+}
+
+/* -- Interface with PuTTY -- */
+
+/*
+ * We don't implement Arcfour in SSH-1 because it's utterly insecure in
+ * several ways. See CERT Vulnerability Notes VU#25309, VU#665372,
+ * and VU#565052.
+ *
+ * We don't implement the "arcfour" algorithm in SSH-2 because it doesn't
+ * stir the cipher state before emitting keystream, and hence is likely
+ * to leak data about the key.
+ */
+
+static void *arcfour_make_context(void)
+{
+ return snew(ArcfourContext);
+}
+
+static void arcfour_free_context(void *handle)
+{
+ sfree(handle);
+}
+
+static void arcfour_stir(ArcfourContext *ctx)
+{
+ unsigned char *junk = snewn(1536, unsigned char);
+ memset(junk, 0, 1536);
+ arcfour_block(ctx, junk, 1536);
+ memset(junk, 0, 1536);
+ sfree(junk);
+}
+
+static void arcfour128_key(void *handle, unsigned char *key)
+{
+ ArcfourContext *ctx = (ArcfourContext *)handle;
+ arcfour_setkey(ctx, key, 16);
+ arcfour_stir(ctx);
+}
+
+static void arcfour256_key(void *handle, unsigned char *key)
+{
+ ArcfourContext *ctx = (ArcfourContext *)handle;
+ arcfour_setkey(ctx, key, 32);
+ arcfour_stir(ctx);
+}
+
+static void arcfour_iv(void *handle, unsigned char *key)
+{
+
+}
+
+const struct ssh2_cipher ssh_arcfour128_ssh2 = {
+ arcfour_make_context, arcfour_free_context, arcfour_iv, arcfour128_key,
+ arcfour_block, arcfour_block,
+ "arcfour128",
+ 1, 128, 0, "Arcfour-128"
+};
+
+const struct ssh2_cipher ssh_arcfour256_ssh2 = {
+ arcfour_make_context, arcfour_free_context, arcfour_iv, arcfour256_key,
+ arcfour_block, arcfour_block,
+ "arcfour256",
+ 1, 256, 0, "Arcfour-256"
+};
+
+static const struct ssh2_cipher *const arcfour_list[] = {
+ &ssh_arcfour256_ssh2,
+ &ssh_arcfour128_ssh2,
+};
+
+const struct ssh2_ciphers ssh2_arcfour = {
+ sizeof(arcfour_list) / sizeof(*arcfour_list),
+ arcfour_list
+};
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