=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/kex.c,v retrieving revision 1.12 retrieving revision 1.12.2.3 diff -u -r1.12 -r1.12.2.3 --- src/usr.bin/ssh/kex.c 2000/10/11 20:27:23 1.12 +++ src/usr.bin/ssh/kex.c 2001/03/21 19:46:25 1.12.2.3 @@ -23,26 +23,26 @@ */ #include "includes.h" -RCSID("$OpenBSD: kex.c,v 1.12 2000/10/11 20:27:23 markus Exp $"); +RCSID("$OpenBSD: kex.c,v 1.12.2.3 2001/03/21 19:46:25 jason Exp $"); -#include "ssh.h" -#include "ssh2.h" -#include "xmalloc.h" -#include "buffer.h" -#include "bufaux.h" -#include "packet.h" -#include "compat.h" - -#include -#include - #include #include #include #include #include +#include "ssh2.h" +#include "xmalloc.h" +#include "buffer.h" +#include "bufaux.h" +#include "packet.h" +#include "compat.h" +#include "cipher.h" #include "kex.h" +#include "key.h" +#include "log.h" +#include "mac.h" +#include "match.h" #define KEX_COOKIE_LEN 16 @@ -50,7 +50,7 @@ kex_init(char *myproposal[PROPOSAL_MAX]) { int first_kex_packet_follows = 0; - unsigned char cookie[KEX_COOKIE_LEN]; + u_char cookie[KEX_COOKIE_LEN]; u_int32_t rand = 0; int i; Buffer *ki = xmalloc(sizeof(*ki)); @@ -81,7 +81,7 @@ debug("send KEXINIT"); packet_start(SSH2_MSG_KEXINIT); - packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit)); + packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit)); packet_send(); packet_write_wait(); debug("done"); @@ -138,18 +138,35 @@ return 0; } -DH * -dh_gen_key(DH *dh) +void +dh_gen_key(DH *dh, int need) { - int tries = 0; + int i, bits_set = 0, tries = 0; + if (dh->p == NULL) + fatal("dh_gen_key: dh->p == NULL"); + if (2*need >= BN_num_bits(dh->p)) + fatal("dh_gen_key: group too small: %d (2*need %d)", + BN_num_bits(dh->p), 2*need); do { + if (dh->priv_key != NULL) + BN_free(dh->priv_key); + dh->priv_key = BN_new(); + if (dh->priv_key == NULL) + fatal("dh_gen_key: BN_new failed"); + /* generate a 2*need bits random private exponent */ + if (!BN_rand(dh->priv_key, 2*need, 0, 0)) + fatal("dh_gen_key: BN_rand failed"); if (DH_generate_key(dh) == 0) fatal("DH_generate_key"); + for (i = 0; i <= BN_num_bits(dh->priv_key); i++) + if (BN_is_bit_set(dh->priv_key, i)) + bits_set++; + debug("dh_gen_key: priv key bits set: %d/%d", + bits_set, BN_num_bits(dh->priv_key)); if (tries++ > 10) - fatal("dh_new_group1: too many bad keys: giving up"); + fatal("dh_gen_key: too many bad keys: giving up"); } while (!dh_pub_is_valid(dh, dh->pub_key)); - return dh; } DH * @@ -167,9 +184,14 @@ if ((ret = BN_hex2bn(&dh->g, gen)) < 0) fatal("BN_hex2bn g"); - return (dh_gen_key(dh)); + return (dh); } +/* + * This just returns the group, we still need to generate the exchange + * value. + */ + DH * dh_new_group(BIGNUM *gen, BIGNUM *modulus) { @@ -181,11 +203,11 @@ dh->p = modulus; dh->g = gen; - return (dh_gen_key(dh)); + return (dh); } DH * -dh_new_group1() +dh_new_group1(void) { static char *gen = "2", *group1 = "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1" @@ -198,8 +220,9 @@ return (dh_new_group_asc(gen, group1)); } +#ifdef DEBUG_KEX void -dump_digest(unsigned char *digest, int len) +dump_digest(u_char *digest, int len) { int i; for (i = 0; i< len; i++){ @@ -209,8 +232,9 @@ } fprintf(stderr, "\n"); } +#endif -unsigned char * +u_char * kex_hash( char *client_version_string, char *server_version_string, @@ -222,7 +246,7 @@ BIGNUM *shared_secret) { Buffer b; - static unsigned char digest[EVP_MAX_MD_SIZE]; + static u_char digest[EVP_MAX_MD_SIZE]; EVP_MD *evp_md = EVP_sha1(); EVP_MD_CTX md; @@ -242,7 +266,7 @@ buffer_put_bignum2(&b, client_dh_pub); buffer_put_bignum2(&b, server_dh_pub); buffer_put_bignum2(&b, shared_secret); - + #ifdef DEBUG_KEX buffer_dump(&b); #endif @@ -259,7 +283,7 @@ return digest; } -unsigned char * +u_char * kex_hash_gex( char *client_version_string, char *server_version_string, @@ -272,7 +296,7 @@ BIGNUM *shared_secret) { Buffer b; - static unsigned char digest[EVP_MAX_MD_SIZE]; + static u_char digest[EVP_MAX_MD_SIZE]; EVP_MD *evp_md = EVP_sha1(); EVP_MD_CTX md; @@ -295,7 +319,7 @@ buffer_put_bignum2(&b, client_dh_pub); buffer_put_bignum2(&b, server_dh_pub); buffer_put_bignum2(&b, shared_secret); - + #ifdef DEBUG_KEX buffer_dump(&b); #endif @@ -312,8 +336,8 @@ return digest; } -unsigned char * -derive_key(int id, int need, char unsigned *hash, BIGNUM *shared_secret) +u_char * +derive_key(int id, int need, u_char *hash, BIGNUM *shared_secret) { Buffer b; EVP_MD *evp_md = EVP_sha1(); @@ -321,7 +345,7 @@ char c = id; int have; int mdsz = evp_md->md_size; - unsigned char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz); + u_char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz); buffer_init(&b); buffer_put_bignum2(&b, shared_secret); @@ -349,49 +373,10 @@ return digest; } -#define NKEYS 6 - -#define MAX_PROP 20 -#define SEP "," - -char * -get_match(char *client, char *server) -{ - char *sproposals[MAX_PROP]; - char *c, *s, *p, *ret, *cp, *sp; - int i, j, nproposals; - - c = cp = xstrdup(client); - s = sp = xstrdup(server); - - for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0'; - (p = strsep(&sp, SEP)), i++) { - if (i < MAX_PROP) - sproposals[i] = p; - else - break; - } - nproposals = i; - - for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0'; - (p = strsep(&cp, SEP)), i++) { - for (j = 0; j < nproposals; j++) { - if (strcmp(p, sproposals[j]) == 0) { - ret = xstrdup(p); - xfree(c); - xfree(s); - return ret; - } - } - } - xfree(c); - xfree(s); - return NULL; -} void choose_enc(Enc *enc, char *client, char *server) { - char *name = get_match(client, server); + char *name = match_list(client, server, NULL); if (name == NULL) fatal("no matching cipher found: client %s server %s", client, server); enc->cipher = cipher_by_name(name); @@ -405,28 +390,22 @@ void choose_mac(Mac *mac, char *client, char *server) { - char *name = get_match(client, server); + char *name = match_list(client, server, NULL); if (name == NULL) fatal("no matching mac found: client %s server %s", client, server); - if (strcmp(name, "hmac-md5") == 0) { - mac->md = EVP_md5(); - } else if (strcmp(name, "hmac-sha1") == 0) { - mac->md = EVP_sha1(); - } else if (strcmp(name, "hmac-ripemd160@openssh.com") == 0) { - mac->md = EVP_ripemd160(); - } else { + if (mac_init(mac, name) < 0) fatal("unsupported mac %s", name); - } + /* truncate the key */ + if (datafellows & SSH_BUG_HMAC) + mac->key_len = 16; mac->name = name; - mac->mac_len = mac->md->md_size; - mac->key_len = (datafellows & SSH_BUG_HMAC) ? 16 : mac->mac_len; mac->key = NULL; mac->enabled = 0; } void choose_comp(Comp *comp, char *client, char *server) { - char *name = get_match(client, server); + char *name = match_list(client, server, NULL); if (name == NULL) fatal("no matching comp found: client %s server %s", client, server); if (strcmp(name, "zlib") == 0) { @@ -441,7 +420,7 @@ void choose_kex(Kex *k, char *client, char *server) { - k->name = get_match(client, server); + k->name = match_list(client, server, NULL); if (k->name == NULL) fatal("no kex alg"); if (strcmp(k->name, KEX_DH1) == 0) { @@ -454,11 +433,13 @@ void choose_hostkeyalg(Kex *k, char *client, char *server) { - k->hostkeyalg = get_match(client, server); - if (k->hostkeyalg == NULL) + char *hostkeyalg = match_list(client, server, NULL); + if (hostkeyalg == NULL) fatal("no hostkey alg"); - if (strcmp(k->hostkeyalg, KEX_DSS) != 0) - fatal("bad hostkey alg %s", k->hostkeyalg); + k->hostkey_type = key_type_from_name(hostkeyalg); + if (k->hostkey_type == KEY_UNSPEC) + fatal("bad hostkey alg '%s'", hostkeyalg); + xfree(hostkeyalg); } Kex * @@ -505,13 +486,14 @@ return k; } +#define NKEYS 6 int -kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret) +kex_derive_keys(Kex *k, u_char *hash, BIGNUM *shared_secret) { int i; int mode; int ctos; - unsigned char *keys[NKEYS]; + u_char *keys[NKEYS]; for (i = 0; i < NKEYS; i++) keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);