=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/Attic/auth-rsa.c,v retrieving revision 1.32.2.6 retrieving revision 1.33 diff -u -r1.32.2.6 -r1.33 --- src/usr.bin/ssh/Attic/auth-rsa.c 2002/03/08 17:04:41 1.32.2.6 +++ src/usr.bin/ssh/Attic/auth-rsa.c 2000/11/14 23:42:40 1.33 @@ -14,25 +14,22 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth-rsa.c,v 1.32.2.6 2002/03/08 17:04:41 brad Exp $"); +RCSID("$OpenBSD: auth-rsa.c,v 1.33 2000/11/14 23:42:40 markus Exp $"); -#include -#include - #include "rsa.h" #include "packet.h" #include "xmalloc.h" -#include "ssh1.h" +#include "ssh.h" #include "mpaux.h" #include "uidswap.h" #include "match.h" -#include "auth-options.h" -#include "pathnames.h" -#include "log.h" #include "servconf.h" -#include "auth.h" -#include "hostfile.h" +#include "auth-options.h" +#include +#include + + /* import */ extern ServerOptions options; @@ -40,7 +37,7 @@ * Session identifier that is used to bind key exchange and authentication * responses to a particular session. */ -extern u_char session_id[16]; +extern unsigned char session_id[16]; /* * The .ssh/authorized_keys file contains public keys, one per line, in the @@ -63,20 +60,17 @@ { BIGNUM *challenge, *encrypted_challenge; BN_CTX *ctx; - u_char buf[32], mdbuf[16], response[16]; + unsigned char buf[32], mdbuf[16], response[16]; MD5_CTX md; - u_int i; - int len; + unsigned int i; + int plen, len; - if ((encrypted_challenge = BN_new()) == NULL) - fatal("auth_rsa_challenge_dialog: BN_new() failed"); - if ((challenge = BN_new()) == NULL) - fatal("auth_rsa_challenge_dialog: BN_new() failed"); + encrypted_challenge = BN_new(); + challenge = BN_new(); /* Generate a random challenge. */ BN_rand(challenge, 256, 0, 0); - if ((ctx = BN_CTX_new()) == NULL) - fatal("auth_rsa_challenge_dialog: BN_CTX_new() failed"); + ctx = BN_CTX_new(); BN_mod(challenge, challenge, pk->n, ctx); BN_CTX_free(ctx); @@ -91,10 +85,10 @@ packet_write_wait(); /* Wait for a response. */ - packet_read_expect(SSH_CMSG_AUTH_RSA_RESPONSE); + packet_read_expect(&plen, SSH_CMSG_AUTH_RSA_RESPONSE); + packet_integrity_check(plen, 16, SSH_CMSG_AUTH_RSA_RESPONSE); for (i = 0; i < 16; i++) response[i] = packet_get_char(); - packet_check_eom(); /* The response is MD5 of decrypted challenge plus session id. */ len = BN_num_bytes(challenge); @@ -126,31 +120,29 @@ int auth_rsa(struct passwd *pw, BIGNUM *client_n) { - char line[8192], *file; + char line[8192], file[1024]; int authenticated; - u_int bits; + unsigned int bits; FILE *f; - u_long linenum = 0; + unsigned long linenum = 0; struct stat st; - Key *key; - char *fp; + RSA *pk; /* no user given */ if (pw == NULL) return 0; /* Temporarily use the user's uid. */ - temporarily_use_uid(pw); + temporarily_use_uid(pw->pw_uid); /* The authorized keys. */ - file = authorized_keys_file(pw); - debug("trying public RSA key file %s", file); + snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, + SSH_USER_PERMITTED_KEYS); /* Fail quietly if file does not exist */ if (stat(file, &st) < 0) { /* Restore the privileged uid. */ restore_uid(); - xfree(file); return 0; } /* Open the file containing the authorized keys. */ @@ -160,22 +152,50 @@ restore_uid(); packet_send_debug("Could not open %.900s for reading.", file); packet_send_debug("If your home is on an NFS volume, it may need to be world-readable."); - xfree(file); return 0; } - if (options.strict_modes && - secure_filename(f, file, pw, line, sizeof(line)) != 0) { - xfree(file); - fclose(f); - log("Authentication refused: %s", line); - packet_send_debug("Authentication refused: %s", line); - restore_uid(); - return 0; + if (options.strict_modes) { + int fail = 0; + char buf[1024]; + /* Check open file in order to avoid open/stat races */ + if (fstat(fileno(f), &st) < 0 || + (st.st_uid != 0 && st.st_uid != pw->pw_uid) || + (st.st_mode & 022) != 0) { + snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: " + "bad ownership or modes for '%s'.", pw->pw_name, file); + fail = 1; + } else { + /* Check path to SSH_USER_PERMITTED_KEYS */ + int i; + static const char *check[] = { + "", SSH_USER_DIR, NULL + }; + for (i = 0; check[i]; i++) { + snprintf(line, sizeof line, "%.500s/%.100s", pw->pw_dir, check[i]); + if (stat(line, &st) < 0 || + (st.st_uid != 0 && st.st_uid != pw->pw_uid) || + (st.st_mode & 022) != 0) { + snprintf(buf, sizeof buf, "RSA authentication refused for %.100s: " + "bad ownership or modes for '%s'.", pw->pw_name, line); + fail = 1; + break; + } + } + } + if (fail) { + fclose(f); + log("%s",buf); + packet_send_debug("%s",buf); + restore_uid(); + return 0; + } } /* Flag indicating whether authentication has succeeded. */ authenticated = 0; - key = key_new(KEY_RSA1); + pk = RSA_new(); + pk->e = BN_new(); + pk->n = BN_new(); /* * Go though the accepted keys, looking for the current key. If @@ -213,41 +233,39 @@ options = NULL; /* Parse the key from the line. */ - if (hostfile_read_key(&cp, &bits, key) == 0) { - debug("%.100s, line %lu: non ssh1 key syntax", - file, linenum); + if (!auth_rsa_read_key(&cp, &bits, pk->e, pk->n)) { + debug("%.100s, line %lu: bad key syntax", + SSH_USER_PERMITTED_KEYS, linenum); + packet_send_debug("%.100s, line %lu: bad key syntax", + SSH_USER_PERMITTED_KEYS, linenum); continue; } /* cp now points to the comment part. */ /* Check if the we have found the desired key (identified by its modulus). */ - if (BN_cmp(key->rsa->n, client_n) != 0) + if (BN_cmp(pk->n, client_n) != 0) continue; /* check the real bits */ - if (bits != BN_num_bits(key->rsa->n)) - log("Warning: %s, line %lu: keysize mismatch: " + if (bits != BN_num_bits(pk->n)) + log("Warning: %s, line %ld: keysize mismatch: " "actual %d vs. announced %d.", - file, linenum, BN_num_bits(key->rsa->n), bits); + file, linenum, BN_num_bits(pk->n), bits); /* We have found the desired key. */ /* * If our options do not allow this key to be used, * do not send challenge. */ - if (!auth_parse_options(pw, options, file, linenum)) + if (!auth_parse_options(pw, options, linenum)) continue; /* Perform the challenge-response dialog for this key. */ - if (!auth_rsa_challenge_dialog(key->rsa)) { + if (!auth_rsa_challenge_dialog(pk)) { /* Wrong response. */ verbose("Wrong response to RSA authentication challenge."); packet_send_debug("Wrong response to RSA authentication challenge."); - /* - * Break out of the loop. Otherwise we might send - * another challenge and break the protocol. - */ - break; + continue; } /* * Correct response. The client has been successfully @@ -258,12 +276,6 @@ * otherwise continue searching. */ authenticated = 1; - - fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); - verbose("Found matching %s key: %s", - key_type(key), fp); - xfree(fp); - break; } @@ -271,10 +283,9 @@ restore_uid(); /* Close the file. */ - xfree(file); fclose(f); - key_free(key); + RSA_free(pk); if (authenticated) packet_send_debug("RSA authentication accepted.");