diff options
Diffstat (limited to 'tools/plink/ssharcf.c')
-rw-r--r-- | tools/plink/ssharcf.c | 246 |
1 files changed, 123 insertions, 123 deletions
diff --git a/tools/plink/ssharcf.c b/tools/plink/ssharcf.c index e0b247e51..06f235c5b 100644 --- a/tools/plink/ssharcf.c +++ b/tools/plink/ssharcf.c @@ -1,123 +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
-};
+/* + * 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); + smemclr(junk, 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 +}; |