1 files changed, 31 insertions, 349 deletions

diff --git a/cipher.c b/cipher.c
index b5d38747e..e7c3c5411 100644
--- a/cipher.c
+++ b/cipher.c
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: cipher.c,v 1.62 2002/11/21 22:45:31 markus Exp $");
+RCSID("$OpenBSD: cipher.c,v 1.65 2003/05/17 04:27:52 markus Exp $");
 
 #include "xmalloc.h"
 #include "log.h"
@@ -49,11 +49,14 @@ RCSID("$OpenBSD: cipher.c,v 1.62 2002/11/21 22:45:31 markus Exp $");
 #endif
 
 #if OPENSSL_VERSION_NUMBER < 0x00907000L
-#include "rijndael.h"
-static const EVP_CIPHER *evp_rijndael(void);
+extern const EVP_CIPHER *evp_rijndael(void);
+extern void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
 #endif
-static const EVP_CIPHER *evp_ssh1_3des(void);
-static const EVP_CIPHER *evp_ssh1_bf(void);
+extern const EVP_CIPHER *evp_ssh1_bf(void);
+extern const EVP_CIPHER *evp_ssh1_3des(void);
+extern void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
+extern const EVP_CIPHER *evp_aes_128_ctr(void);
+extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
 
 struct Cipher {
         char    *name;
@@ -84,6 +87,9 @@ struct Cipher {
         { "rijndael-cbc@lysator.liu.se",
                                 SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
 #endif
+        { "aes128-ctr",         SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
+        { "aes192-ctr",         SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
+        { "aes256-ctr",         SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
 
         { NULL,                 SSH_CIPHER_ILLEGAL, 0, 0, NULL }
 };
@@ -296,298 +302,6 @@ cipher_set_key_string(CipherContext *cc, Cipher *cipher,
         memset(&md, 0, sizeof(md));
 }
 
-/* Implementations for other non-EVP ciphers */
-
-/*
- * This is used by SSH1:
- *
- * What kind of triple DES are these 2 routines?
- *
- * Why is there a redundant initialization vector?
- *
- * If only iv3 was used, then, this would till effect have been
- * outer-cbc. However, there is also a private iv1 == iv2 which
- * perhaps makes differential analysis easier. On the other hand, the
- * private iv1 probably makes the CRC-32 attack ineffective. This is a
- * result of that there is no longer any known iv1 to use when
- * choosing the X block.
- */
-struct ssh1_3des_ctx
-{
-        EVP_CIPHER_CTX  k1, k2, k3;
-};
-
-static int
-ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
-    int enc)
-{
-        struct ssh1_3des_ctx *c;
-        u_char *k1, *k2, *k3;
-
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
-                c = xmalloc(sizeof(*c));
-                EVP_CIPHER_CTX_set_app_data(ctx, c);
-        }
-        if (key == NULL)
-                return (1);
-        if (enc == -1)
-                enc = ctx->encrypt;
-        k1 = k2 = k3 = (u_char *) key;
-        k2 += 8;
-        if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
-                if (enc)
-                        k3 += 16;
-                else
-                        k1 += 16;
-        }
-        EVP_CIPHER_CTX_init(&c->k1);
-        EVP_CIPHER_CTX_init(&c->k2);
-        EVP_CIPHER_CTX_init(&c->k3);
-#ifdef SSH_OLD_EVP
-        EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
-        EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
-        EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
-#else
-        if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
-            EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
-            EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
-                memset(c, 0, sizeof(*c));
-                xfree(c);
-                EVP_CIPHER_CTX_set_app_data(ctx, NULL);
-                return (0);
-        }
-#endif
-        return (1);
-}
-
-static int
-ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len)
-{
-        struct ssh1_3des_ctx *c;
-
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
-                error("ssh1_3des_cbc: no context");
-                return (0);
-        }
-#ifdef SSH_OLD_EVP
-        EVP_Cipher(&c->k1, dest, (u_char *)src, len);
-        EVP_Cipher(&c->k2, dest, dest, len);
-        EVP_Cipher(&c->k3, dest, dest, len);
-#else
-        if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
-            EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
-            EVP_Cipher(&c->k3, dest, dest, len) == 0)
-                return (0);
-#endif
-        return (1);
-}
-
-static int
-ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
-{
-        struct ssh1_3des_ctx *c;
-
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
-                memset(c, 0, sizeof(*c));
-                xfree(c);
-                EVP_CIPHER_CTX_set_app_data(ctx, NULL);
-        }
-        return (1);
-}
-
-static const EVP_CIPHER *
-evp_ssh1_3des(void)
-{
-        static EVP_CIPHER ssh1_3des;
-
-        memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
-        ssh1_3des.nid = NID_undef;
-        ssh1_3des.block_size = 8;
-        ssh1_3des.iv_len = 0;
-        ssh1_3des.key_len = 16;
-        ssh1_3des.init = ssh1_3des_init;
-        ssh1_3des.cleanup = ssh1_3des_cleanup;
-        ssh1_3des.do_cipher = ssh1_3des_cbc;
-#ifndef SSH_OLD_EVP
-        ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
-#endif
-        return (&ssh1_3des);
-}
-
-/*
- * SSH1 uses a variation on Blowfish, all bytes must be swapped before
- * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
- */
-static void
-swap_bytes(const u_char *src, u_char *dst, int n)
-{
-        u_char c[4];
-
-        /* Process 4 bytes every lap. */
-        for (n = n / 4; n > 0; n--) {
-                c[3] = *src++;
-                c[2] = *src++;
-                c[1] = *src++;
-                c[0] = *src++;
-
-                *dst++ = c[0];
-                *dst++ = c[1];
-                *dst++ = c[2];
-                *dst++ = c[3];
-        }
-}
-
-#ifdef SSH_OLD_EVP
-static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
-                          const unsigned char *iv, int enc)
-{
-        if (iv != NULL)
-                memcpy (&(ctx->oiv[0]), iv, 8);
-        memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
-        if (key != NULL)
-                BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
-                            key);
-}
-#endif
-static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
-
-static int
-bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
-{
-        int ret;
-
-        swap_bytes(in, out, len);
-        ret = (*orig_bf)(ctx, out, out, len);
-        swap_bytes(out, out, len);
-        return (ret);
-}
-
-static const EVP_CIPHER *
-evp_ssh1_bf(void)
-{
-        static EVP_CIPHER ssh1_bf;
-
-        memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
-        orig_bf = ssh1_bf.do_cipher;
-        ssh1_bf.nid = NID_undef;
-#ifdef SSH_OLD_EVP
-        ssh1_bf.init = bf_ssh1_init;
-#endif
-        ssh1_bf.do_cipher = bf_ssh1_cipher;
-        ssh1_bf.key_len = 32;
-        return (&ssh1_bf);
-}
-
-#if OPENSSL_VERSION_NUMBER < 0x00907000L
-/* RIJNDAEL */
-#define RIJNDAEL_BLOCKSIZE 16
-struct ssh_rijndael_ctx
-{
-        rijndael_ctx    r_ctx;
-        u_char          r_iv[RIJNDAEL_BLOCKSIZE];
-};
-
-static int
-ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
-    int enc)
-{
-        struct ssh_rijndael_ctx *c;
-
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
-                c = xmalloc(sizeof(*c));
-                EVP_CIPHER_CTX_set_app_data(ctx, c);
-        }
-        if (key != NULL) {
-                if (enc == -1)
-                        enc = ctx->encrypt;
-                rijndael_set_key(&c->r_ctx, (u_char *)key,
-                    8*EVP_CIPHER_CTX_key_length(ctx), enc);
-        }
-        if (iv != NULL)
-                memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE);
-        return (1);
-}
-
-static int
-ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
-    u_int len)
-{
-        struct ssh_rijndael_ctx *c;
-        u_char buf[RIJNDAEL_BLOCKSIZE];
-        u_char *cprev, *cnow, *plain, *ivp;
-        int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
-
-        if (len == 0)
-                return (1);
-        if (len % RIJNDAEL_BLOCKSIZE)
-                fatal("ssh_rijndael_cbc: bad len %d", len);
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
-                error("ssh_rijndael_cbc: no context");
-                return (0);
-        }
-        if (ctx->encrypt) {
-                cnow  = dest;
-                plain = (u_char *)src;
-                cprev = c->r_iv;
-                for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
-                    cnow+=RIJNDAEL_BLOCKSIZE) {
-                        for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
-                                buf[j] = plain[j] ^ cprev[j];
-                        rijndael_encrypt(&c->r_ctx, buf, cnow);
-                        cprev = cnow;
-                }
-                memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE);
-        } else {
-                cnow  = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
-                plain = dest+len-RIJNDAEL_BLOCKSIZE;
-
-                memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE);
-                for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
-                    plain-=RIJNDAEL_BLOCKSIZE) {
-                        rijndael_decrypt(&c->r_ctx, cnow, plain);
-                        ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE;
-                        for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
-                                plain[j] ^= ivp[j];
-                }
-                memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE);
-        }
-        return (1);
-}
-
-static int
-ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx)
-{
-        struct ssh_rijndael_ctx *c;
-
-        if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
-                memset(c, 0, sizeof(*c));
-                xfree(c);
-                EVP_CIPHER_CTX_set_app_data(ctx, NULL);
-        }
-        return (1);
-}
-
-static const EVP_CIPHER *
-evp_rijndael(void)
-{
-        static EVP_CIPHER rijndal_cbc;
-
-        memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER));
-        rijndal_cbc.nid = NID_undef;
-        rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE;
-        rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE;
-        rijndal_cbc.key_len = 16;
-        rijndal_cbc.init = ssh_rijndael_init;
-        rijndal_cbc.cleanup = ssh_rijndael_cleanup;
-        rijndal_cbc.do_cipher = ssh_rijndael_cbc;
-#ifndef SSH_OLD_EVP
-        rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH |
-            EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV;
-#endif
-        return (&rijndal_cbc);
-}
-#endif
-
 /*
  * Exports an IV from the CipherContext required to export the key
  * state back from the unprivileged child to the privileged parent
@@ -611,7 +325,6 @@ void
 cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
 {
         Cipher *c = cc->cipher;
-        u_char *civ = NULL;
         int evplen;
 
         switch (c->number) {
@@ -624,45 +337,28 @@ cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
                 if (evplen != len)
                         fatal("%s: wrong iv length %d != %d", __func__,
                             evplen, len);
-
 #if OPENSSL_VERSION_NUMBER < 0x00907000L
-                if (c->evptype == evp_rijndael) {
-                        struct ssh_rijndael_ctx *aesc;
-
-                        aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-                        if (aesc == NULL)
-                                fatal("%s: no rijndael context", __func__);
-                        civ = aesc->r_iv;
-                } else
+                if (c->evptype == evp_rijndael)
+                        ssh_rijndael_iv(&cc->evp, 0, iv, len);
+                else
 #endif
-                {
-                        civ = cc->evp.iv;
-                }
+                if (c->evptype == evp_aes_128_ctr)
+                        ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
+                else
+                        memcpy(iv, cc->evp.iv, len);
+                break;
+        case SSH_CIPHER_3DES:
+                ssh1_3des_iv(&cc->evp, 0, iv, 24);
                 break;
-        case SSH_CIPHER_3DES: {
-                struct ssh1_3des_ctx *desc;
-                if (len != 24)
-                        fatal("%s: bad 3des iv length: %d", __func__, len);
-                desc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-                if (desc == NULL)
-                        fatal("%s: no 3des context", __func__);
-                debug3("%s: Copying 3DES IV", __func__);
-                memcpy(iv, desc->k1.iv, 8);
-                memcpy(iv + 8, desc->k2.iv, 8);
-                memcpy(iv + 16, desc->k3.iv, 8);
-                return;
-        }
         default:
                 fatal("%s: bad cipher %d", __func__, c->number);
         }
-        memcpy(iv, civ, len);
 }
 
 void
 cipher_set_keyiv(CipherContext *cc, u_char *iv)
 {
         Cipher *c = cc->cipher;
-        u_char *div = NULL;
         int evplen = 0;
 
         switch (c->number) {
@@ -672,36 +368,22 @@ cipher_set_keyiv(CipherContext *cc, u_char *iv)
                 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
                 if (evplen == 0)
                         return;
-
 #if OPENSSL_VERSION_NUMBER < 0x00907000L
-                if (c->evptype == evp_rijndael) {
-                        struct ssh_rijndael_ctx *aesc;
-
-                        aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-                        if (aesc == NULL)
-                                fatal("%s: no rijndael context", __func__);
-                        div = aesc->r_iv;
-                } else
+                if (c->evptype == evp_rijndael)
+                        ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
+                else
 #endif
-                {
-                        div = cc->evp.iv;
-                }
+                if (c->evptype == evp_aes_128_ctr)
+                        ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
+                else
+                        memcpy(cc->evp.iv, iv, evplen);
+                break;
+        case SSH_CIPHER_3DES:
+                ssh1_3des_iv(&cc->evp, 1, iv, 24);
                 break;
-        case SSH_CIPHER_3DES: {
-                struct ssh1_3des_ctx *desc;
-                desc = EVP_CIPHER_CTX_get_app_data(&cc->evp);
-                if (desc == NULL)
-                        fatal("%s: no 3des context", __func__);
-                debug3("%s: Installed 3DES IV", __func__);
-                memcpy(desc->k1.iv, iv, 8);
-                memcpy(desc->k2.iv, iv + 8, 8);
-                memcpy(desc->k3.iv, iv + 16, 8);
-                return;
-        }
         default:
                 fatal("%s: bad cipher %d", __func__, c->number);
         }
-        memcpy(div, iv, evplen);
 }
 
 #if OPENSSL_VERSION_NUMBER < 0x00907000L