1 files changed, 70 insertions, 229 deletions

diff --git a/cipher.c b/cipher.c
index 2def333b1..c3cd5dcf4 100644
--- a/cipher.c
+++ b/cipher.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cipher.c,v 1.102 2016/08/03 05:41:57 djm Exp $ */
+/* $OpenBSD: cipher.c,v 1.107 2017/05/07 23:12:57 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -51,11 +51,6 @@
 
 #include "openbsd-compat/openssl-compat.h"
 
-#ifdef WITH_SSH1
-extern const EVP_CIPHER *evp_ssh1_bf(void);
-extern const EVP_CIPHER *evp_ssh1_3des(void);
-extern int ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
-#endif
 
 struct sshcipher_ctx {
         int     plaintext;
@@ -68,17 +63,16 @@ struct sshcipher_ctx {
 
 struct sshcipher {
         char    *name;
-        int     number;         /* for ssh1 only */
         u_int   block_size;
         u_int   key_len;
         u_int   iv_len;         /* defaults to block_size */
         u_int   auth_len;
-        u_int   discard_len;
         u_int   flags;
 #define CFLAG_CBC               (1<<0)
 #define CFLAG_CHACHAPOLY        (1<<1)
 #define CFLAG_AESCTR            (1<<2)
 #define CFLAG_NONE              (1<<3)
+#define CFLAG_INTERNAL          CFLAG_NONE /* Don't use "none" for packets */
 #ifdef WITH_OPENSSL
         const EVP_CIPHER        *(*evptype)(void);
 #else
@@ -87,53 +81,32 @@ struct sshcipher {
 };
 
 static const struct sshcipher ciphers[] = {
-#ifdef WITH_SSH1
-        { "des",        SSH_CIPHER_DES, 8, 8, 0, 0, 0, 1, EVP_des_cbc },
-        { "3des",       SSH_CIPHER_3DES, 8, 16, 0, 0, 0, 1, evp_ssh1_3des },
-# ifndef OPENSSL_NO_BF
-        { "blowfish",   SSH_CIPHER_BLOWFISH, 8, 32, 0, 0, 0, 1, evp_ssh1_bf },
-# endif /* OPENSSL_NO_BF */
-#endif /* WITH_SSH1 */
 #ifdef WITH_OPENSSL
-        { "none",       SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null },
-        { "3des-cbc",   SSH_CIPHER_SSH2, 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc },
-# ifndef OPENSSL_NO_BF
-        { "blowfish-cbc",
-                        SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_bf_cbc },
-# endif /* OPENSSL_NO_BF */
-# ifndef OPENSSL_NO_CAST
-        { "cast128-cbc",
-                        SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_cast5_cbc },
-# endif /* OPENSSL_NO_CAST */
-# ifndef OPENSSL_NO_RC4
-        { "arcfour",    SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 0, EVP_rc4 },
-        { "arcfour128", SSH_CIPHER_SSH2, 8, 16, 0, 0, 1536, 0, EVP_rc4 },
-        { "arcfour256", SSH_CIPHER_SSH2, 8, 32, 0, 0, 1536, 0, EVP_rc4 },
-# endif /* OPENSSL_NO_RC4 */
-        { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc },
-        { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc },
-        { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc },
+        { "3des-cbc",           8, 24, 0, 0, CFLAG_CBC, EVP_des_ede3_cbc },
+        { "aes128-cbc",         16, 16, 0, 0, CFLAG_CBC, EVP_aes_128_cbc },
+        { "aes192-cbc",         16, 24, 0, 0, CFLAG_CBC, EVP_aes_192_cbc },
+        { "aes256-cbc",         16, 32, 0, 0, CFLAG_CBC, EVP_aes_256_cbc },
         { "rijndael-cbc@lysator.liu.se",
-                        SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc },
-        { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr },
-        { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr },
-        { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr },
+                                16, 32, 0, 0, CFLAG_CBC, EVP_aes_256_cbc },
+        { "aes128-ctr",         16, 16, 0, 0, 0, EVP_aes_128_ctr },
+        { "aes192-ctr",         16, 24, 0, 0, 0, EVP_aes_192_ctr },
+        { "aes256-ctr",         16, 32, 0, 0, 0, EVP_aes_256_ctr },
 # ifdef OPENSSL_HAVE_EVPGCM
         { "aes128-gcm@openssh.com",
-                        SSH_CIPHER_SSH2, 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm },
+                                16, 16, 12, 16, 0, EVP_aes_128_gcm },
         { "aes256-gcm@openssh.com",
-                        SSH_CIPHER_SSH2, 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm },
+                                16, 32, 12, 16, 0, EVP_aes_256_gcm },
 # endif /* OPENSSL_HAVE_EVPGCM */
-#else /* WITH_OPENSSL */
-        { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, CFLAG_AESCTR, NULL },
-        { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, CFLAG_AESCTR, NULL },
-        { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, CFLAG_AESCTR, NULL },
-        { "none",       SSH_CIPHER_NONE, 8, 0, 0, 0, 0, CFLAG_NONE, NULL },
-#endif /* WITH_OPENSSL */
+#else
+        { "aes128-ctr",         16, 16, 0, 0, CFLAG_AESCTR, NULL },
+        { "aes192-ctr",         16, 24, 0, 0, CFLAG_AESCTR, NULL },
+        { "aes256-ctr",         16, 32, 0, 0, CFLAG_AESCTR, NULL },
+#endif
         { "chacha20-poly1305@openssh.com",
-                        SSH_CIPHER_SSH2, 8, 64, 0, 16, 0, CFLAG_CHACHAPOLY, NULL },
+                                8, 64, 0, 16, CFLAG_CHACHAPOLY, NULL },
+        { "none",               8, 0, 0, 0, CFLAG_NONE, NULL },
 
-        { NULL,         SSH_CIPHER_INVALID, 0, 0, 0, 0, 0, 0, NULL }
+        { NULL,                 0, 0, 0, 0, 0, NULL }
 };
 
 /*--*/
@@ -147,7 +120,7 @@ cipher_alg_list(char sep, int auth_only)
         const struct sshcipher *c;
 
         for (c = ciphers; c->name != NULL; c++) {
-                if (c->number != SSH_CIPHER_SSH2)
+                if ((c->flags & CFLAG_INTERNAL) != 0)
                         continue;
                 if (auth_only && c->auth_len == 0)
                         continue;
@@ -203,12 +176,6 @@ cipher_ivlen(const struct sshcipher *c)
 }
 
 u_int
-cipher_get_number(const struct sshcipher *c)
-{
-        return (c->number);
-}
-
-u_int
 cipher_is_cbc(const struct sshcipher *c)
 {
         return (c->flags & CFLAG_CBC) != 0;
@@ -220,24 +187,6 @@ cipher_ctx_is_plaintext(struct sshcipher_ctx *cc)
         return cc->plaintext;
 }
 
-u_int
-cipher_ctx_get_number(struct sshcipher_ctx *cc)
-{
-        return cc->cipher->number;
-}
-
-u_int
-cipher_mask_ssh1(int client)
-{
-        u_int mask = 0;
-        mask |= 1 << SSH_CIPHER_3DES;           /* Mandatory */
-        mask |= 1 << SSH_CIPHER_BLOWFISH;
-        if (client) {
-                mask |= 1 << SSH_CIPHER_DES;
-        }
-        return mask;
-}
-
 const struct sshcipher *
 cipher_by_name(const char *name)
 {
@@ -248,16 +197,6 @@ cipher_by_name(const char *name)
         return NULL;
 }
 
-const struct sshcipher *
-cipher_by_number(int id)
-{
-        const struct sshcipher *c;
-        for (c = ciphers; c->name != NULL; c++)
-                if (c->number == id)
-                        return c;
-        return NULL;
-}
-
 #define CIPHER_SEP      ","
 int
 ciphers_valid(const char *names)
@@ -273,7 +212,7 @@ ciphers_valid(const char *names)
         for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
             (p = strsep(&cp, CIPHER_SEP))) {
                 c = cipher_by_name(p);
-                if (c == NULL || c->number != SSH_CIPHER_SSH2) {
+                if (c == NULL || (c->flags & CFLAG_INTERNAL) != 0) {
                         free(cipher_list);
                         return 0;
                 }
@@ -282,38 +221,12 @@ ciphers_valid(const char *names)
         return 1;
 }
 
-/*
- * Parses the name of the cipher.  Returns the number of the corresponding
- * cipher, or -1 on error.
- */
-
-int
-cipher_number(const char *name)
-{
-        const struct sshcipher *c;
-        if (name == NULL)
-                return -1;
-        for (c = ciphers; c->name != NULL; c++)
-                if (strcasecmp(c->name, name) == 0)
-                        return c->number;
-        return -1;
-}
-
-char *
-cipher_name(int id)
-{
-        const struct sshcipher *c = cipher_by_number(id);
-        return (c==NULL) ? "<unknown>" : c->name;
-}
-
 const char *
 cipher_warning_message(const struct sshcipher_ctx *cc)
 {
         if (cc == NULL || cc->cipher == NULL)
                 return NULL;
-        if (cc->cipher->number == SSH_CIPHER_DES)
-                return "use of DES is strongly discouraged due to "
-                    "cryptographic weaknesses";
+        /* XXX repurpose for CBC warning */
         return NULL;
 }
 
@@ -327,19 +240,13 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
 #ifdef WITH_OPENSSL
         const EVP_CIPHER *type;
         int klen;
-        u_char *junk, *discard;
 #endif
 
         *ccp = NULL;
         if ((cc = calloc(sizeof(*cc), 1)) == NULL)
                 return SSH_ERR_ALLOC_FAIL;
 
-        if (cipher->number == SSH_CIPHER_DES) {
-                if (keylen > 8)
-                        keylen = 8;
-        }
-
-        cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
+        cc->plaintext = (cipher->flags & CFLAG_NONE) != 0;
         cc->encrypt = do_encrypt;
 
         if (keylen < cipher->key_len ||
@@ -353,6 +260,10 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
                 ret = chachapoly_init(&cc->cp_ctx, key, keylen);
                 goto out;
         }
+        if ((cc->cipher->flags & CFLAG_NONE) != 0) {
+                ret = 0;
+                goto out;
+        }
 #ifndef WITH_OPENSSL
         if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
                 aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
@@ -360,10 +271,6 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
                 ret = 0;
                 goto out;
         }
-        if ((cc->cipher->flags & CFLAG_NONE) != 0) {
-                ret = 0;
-                goto out;
-        }
         ret = SSH_ERR_INVALID_ARGUMENT;
         goto out;
 #else /* WITH_OPENSSL */
@@ -394,23 +301,6 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
                 ret = SSH_ERR_LIBCRYPTO_ERROR;
                 goto out;
         }
-
-        if (cipher->discard_len > 0) {
-                if ((junk = malloc(cipher->discard_len)) == NULL ||
-                    (discard = malloc(cipher->discard_len)) == NULL) {
-                        free(junk);
-                        ret = SSH_ERR_ALLOC_FAIL;
-                        goto out;
-                }
-                ret = EVP_Cipher(cc->evp, discard, junk, cipher->discard_len);
-                explicit_bzero(discard, cipher->discard_len);
-                free(junk);
-                free(discard);
-                if (ret != 1) {
-                        ret = SSH_ERR_LIBCRYPTO_ERROR;
-                        goto out;
-                }
-        }
         ret = 0;
 #endif /* WITH_OPENSSL */
  out:
@@ -448,6 +338,10 @@ cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
                 return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src,
                     len, aadlen, authlen, cc->encrypt);
         }
+        if ((cc->cipher->flags & CFLAG_NONE) != 0) {
+                memcpy(dest, src, aadlen + len);
+                return 0;
+        }
 #ifndef WITH_OPENSSL
         if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
                 if (aadlen)
@@ -456,10 +350,6 @@ cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
                     dest + aadlen, len);
                 return 0;
         }
-        if ((cc->cipher->flags & CFLAG_NONE) != 0) {
-                memcpy(dest, src, aadlen + len);
-                return 0;
-        }
         return SSH_ERR_INVALID_ARGUMENT;
 #else
         if (authlen) {
@@ -536,28 +426,6 @@ cipher_free(struct sshcipher_ctx *cc)
 }
 
 /*
- * Selects the cipher, and keys if by computing the MD5 checksum of the
- * passphrase and using the resulting 16 bytes as the key.
- */
-int
-cipher_set_key_string(struct sshcipher_ctx **ccp,
-    const struct sshcipher *cipher, const char *passphrase, int do_encrypt)
-{
-        u_char digest[16];
-        int r = SSH_ERR_INTERNAL_ERROR;
-
-        if ((r = ssh_digest_memory(SSH_DIGEST_MD5,
-            passphrase, strlen(passphrase),
-            digest, sizeof(digest))) != 0)
-                goto out;
-
-        r = cipher_init(ccp, cipher, digest, 16, NULL, 0, do_encrypt);
- out:
-        explicit_bzero(digest, sizeof(digest));
-        return r;
-}
-
-/*
  * Exports an IV from the sshcipher_ctx required to export the key
  * state back from the unprivileged child to the privileged parent
  * process.
@@ -566,19 +434,16 @@ int
 cipher_get_keyiv_len(const struct sshcipher_ctx *cc)
 {
         const struct sshcipher *c = cc->cipher;
-        int ivlen = 0;
 
-        if (c->number == SSH_CIPHER_3DES)
-                ivlen = 24;
-        else if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
-                ivlen = 0;
-        else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
-                ivlen = sizeof(cc->ac_ctx.ctr);
+        if ((c->flags & CFLAG_CHACHAPOLY) != 0)
+                return 0;
+        else if ((c->flags & CFLAG_AESCTR) != 0)
+                return sizeof(cc->ac_ctx.ctr);
 #ifdef WITH_OPENSSL
-        else
-                ivlen = EVP_CIPHER_CTX_iv_length(cc->evp);
-#endif /* WITH_OPENSSL */
-        return (ivlen);
+        return EVP_CIPHER_CTX_iv_length(cc->evp);
+#else
+        return 0;
+#endif
 }
 
 int
@@ -603,38 +468,26 @@ cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len)
         if ((cc->cipher->flags & CFLAG_NONE) != 0)
                 return 0;
 
-        switch (c->number) {
 #ifdef WITH_OPENSSL
-        case SSH_CIPHER_SSH2:
-        case SSH_CIPHER_DES:
-        case SSH_CIPHER_BLOWFISH:
-                evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
-                if (evplen == 0)
-                        return 0;
-                else if (evplen < 0)
-                        return SSH_ERR_LIBCRYPTO_ERROR;
-                if ((u_int)evplen != len)
-                        return SSH_ERR_INVALID_ARGUMENT;
+        evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
+        if (evplen == 0)
+                return 0;
+        else if (evplen < 0)
+                return SSH_ERR_LIBCRYPTO_ERROR;
+        if ((u_int)evplen != len)
+                return SSH_ERR_INVALID_ARGUMENT;
 #ifndef OPENSSL_HAVE_EVPCTR
-                if (c->evptype == evp_aes_128_ctr)
-                        ssh_aes_ctr_iv(cc->evp, 0, iv, len);
-                else
-#endif
-                if (cipher_authlen(c)) {
-                        if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
-                           len, iv))
-                               return SSH_ERR_LIBCRYPTO_ERROR;
-                } else
-                        memcpy(iv, cc->evp->iv, len);
-                break;
+        if (c->evptype == evp_aes_128_ctr)
+                ssh_aes_ctr_iv(cc->evp, 0, iv, len);
+        else
 #endif
-#ifdef WITH_SSH1
-        case SSH_CIPHER_3DES:
-                return ssh1_3des_iv(cc->evp, 0, iv, 24);
+        if (cipher_authlen(c)) {
+                if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
+                   len, iv))
+                       return SSH_ERR_LIBCRYPTO_ERROR;
+        } else
+                memcpy(iv, cc->evp->iv, len);
 #endif
-        default:
-                return SSH_ERR_INVALID_ARGUMENT;
-        }
         return 0;
 }
 
@@ -651,36 +504,24 @@ cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv)
         if ((cc->cipher->flags & CFLAG_NONE) != 0)
                 return 0;
 
-        switch (c->number) {
 #ifdef WITH_OPENSSL
-        case SSH_CIPHER_SSH2:
-        case SSH_CIPHER_DES:
-        case SSH_CIPHER_BLOWFISH:
-                evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
-                if (evplen <= 0)
-                        return SSH_ERR_LIBCRYPTO_ERROR;
+        evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
+        if (evplen <= 0)
+                return SSH_ERR_LIBCRYPTO_ERROR;
 #ifndef OPENSSL_HAVE_EVPCTR
-                /* XXX iv arg is const, but ssh_aes_ctr_iv isn't */
-                if (c->evptype == evp_aes_128_ctr)
-                        ssh_aes_ctr_iv(cc->evp, 1, (u_char *)iv, evplen);
-                else
-#endif
-                if (cipher_authlen(c)) {
-                        /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
-                        if (!EVP_CIPHER_CTX_ctrl(cc->evp,
-                            EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv))
-                                return SSH_ERR_LIBCRYPTO_ERROR;
-                } else
-                        memcpy(cc->evp->iv, iv, evplen);
-                break;
+        /* XXX iv arg is const, but ssh_aes_ctr_iv isn't */
+        if (c->evptype == evp_aes_128_ctr)
+                ssh_aes_ctr_iv(cc->evp, 1, (u_char *)iv, evplen);
+        else
 #endif
-#ifdef WITH_SSH1
-        case SSH_CIPHER_3DES:
-                return ssh1_3des_iv(cc->evp, 1, (u_char *)iv, 24);
+        if (cipher_authlen(c)) {
+                /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
+                if (!EVP_CIPHER_CTX_ctrl(cc->evp,
+                    EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv))
+                        return SSH_ERR_LIBCRYPTO_ERROR;
+        } else
+                memcpy(cc->evp->iv, iv, evplen);
 #endif
-        default:
-                return SSH_ERR_INVALID_ARGUMENT;
-        }
         return 0;
 }