[24319] | 1 | /* $Id: protocol.c 3956 2010-01-05 20:56:56Z zacheiss $ |
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[23095] | 2 | * |
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| 3 | * Reg_svr protocol and encryption/decryption routines |
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| 4 | * |
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| 5 | * Copyright (C) 1998 by the Massachusetts Institute of Technology |
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| 6 | * For copying and distribution information, please see the file |
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| 7 | * <mit-copyright.h>. |
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| 8 | * |
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| 9 | */ |
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| 10 | |
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| 11 | #include <mit-copyright.h> |
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| 12 | #include <moira.h> |
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| 13 | #include "reg_svr.h" |
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| 14 | |
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| 15 | #include <sys/stat.h> |
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| 16 | |
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| 17 | #include <fcntl.h> |
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| 18 | #include <stdarg.h> |
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| 19 | #include <stdio.h> |
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| 20 | #include <stdlib.h> |
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| 21 | #include <string.h> |
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| 22 | #include <unistd.h> |
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| 23 | |
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| 24 | #include <com_err.h> |
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| 25 | #include <des.h> |
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| 26 | |
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| 27 | /* RSARef includes */ |
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| 28 | #include "global.h" |
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| 29 | #include "rsaref.h" |
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| 30 | |
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[24319] | 31 | RCSID("$HeadURL: svn+ssh://svn.mit.edu/moira/trunk/moira/reg_svr/protocol.c $ $Id: protocol.c 3956 2010-01-05 20:56:56Z zacheiss $"); |
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[23095] | 32 | |
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| 33 | R_RSA_PRIVATE_KEY *rsa_key; |
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| 34 | char *emsg[NUM_REG_ERRORS], *ename[NUM_REG_ERRORS]; |
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| 35 | extern char *whoami; |
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| 36 | |
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| 37 | struct _handler { |
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| 38 | char *name; |
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| 39 | void (*handler)(reg_client *rc, int argc, char **argv); |
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| 40 | } handlers[] = { |
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| 41 | { "RIFO", RIFO }, |
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| 42 | { "SWRD", SWRD }, |
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| 43 | { "LOGN", LOGN }, |
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| 44 | { "PSWD", PSWD }, |
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| 45 | { "QUIT", QUIT }, |
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| 46 | { "SPIN", SPIN }, |
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| 47 | { "CLGN", CLGN }, |
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| 48 | { NULL, NULL } |
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| 49 | }; |
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| 50 | |
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| 51 | void parse_pdu(reg_client *rc, long len, char *buf); |
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| 52 | void printhex(unsigned char *buf, int len); |
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[24250] | 53 | static unsigned int swap_32(unsigned int val); |
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[23095] | 54 | |
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| 55 | int read_rsa_key(void) |
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| 56 | { |
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| 57 | struct stat statbuf; |
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| 58 | int fd; |
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| 59 | |
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| 60 | if (stat(REG_SVR_RSA_KEY, &statbuf)) |
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| 61 | return 0; |
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| 62 | |
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| 63 | fd = open(REG_SVR_RSA_KEY, O_RDONLY); |
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| 64 | if (!fd) |
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| 65 | return 0; |
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| 66 | |
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| 67 | rsa_key = malloc(statbuf.st_size); |
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| 68 | if (!rsa_key) |
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| 69 | return 0; |
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| 70 | |
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| 71 | if (read(fd, rsa_key, statbuf.st_size) != statbuf.st_size) |
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| 72 | return 0; |
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| 73 | |
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[24250] | 74 | /* Attempt to byteswap the key length if we get something ridiculous. */ |
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| 75 | if (rsa_key->bits > MAX_RSA_MODULUS_BITS) |
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| 76 | rsa_key->bits = swap_32(rsa_key->bits); |
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| 77 | |
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[23095] | 78 | close(fd); |
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| 79 | return 1; |
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| 80 | } |
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| 81 | |
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[24250] | 82 | static unsigned int swap_32(val) |
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| 83 | unsigned int val; |
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| 84 | { |
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| 85 | unsigned char b1 = (val >> 24) & 0xff; |
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| 86 | unsigned char b2 = (val >> 16) & 0xff; |
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| 87 | unsigned char b3 = (val >> 8) & 0xff; |
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| 88 | unsigned char b4 = val & 0xff; |
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| 89 | |
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| 90 | return ((b4 << 24) | (b3 << 16) | (b2 << 8) | b1); |
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| 91 | } |
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| 92 | |
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[23095] | 93 | int read_errors(void) |
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| 94 | { |
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| 95 | int i; |
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| 96 | char errbuf[100], *p; |
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| 97 | FILE *errs; |
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| 98 | |
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| 99 | errs = fopen(REG_SVR_ERROR_MESSAGES, "r"); |
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| 100 | if (!errs) |
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| 101 | return 0; |
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| 102 | for (i = 0; i < NUM_REG_ERRORS && !feof(errs); i++) |
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| 103 | { |
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| 104 | if (errbuf[0] != '#' || errbuf[1] != ' ') |
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| 105 | sprintf(errbuf, "# %d", i); |
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| 106 | ename[i] = strdup(errbuf + 2); |
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| 107 | if (ename[i][strlen(ename[i]) - 1] == '\n') |
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| 108 | ename[i][strlen(ename[i]) - 1] = '\0'; |
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| 109 | emsg[i] = strdup(""); |
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| 110 | if (!ename[i] || !emsg[i]) |
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| 111 | return 0; |
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| 112 | while (1) { |
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| 113 | if (!fgets(errbuf, sizeof(errbuf) - 1, errs)) |
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| 114 | break; |
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| 115 | if (*errbuf == '#') |
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| 116 | break; |
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| 117 | |
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| 118 | if ((p = strchr(errbuf, '\n')) > errbuf) |
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| 119 | { |
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| 120 | *p = ' '; |
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| 121 | *(p + 1) = '\0'; |
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| 122 | } |
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| 123 | emsg[i] = realloc(emsg[i], strlen(emsg[i]) + strlen(errbuf) + 1); |
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| 124 | if (!emsg[i]) |
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| 125 | return 0; |
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| 126 | strcat(emsg[i], errbuf); |
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| 127 | } |
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| 128 | } |
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| 129 | fclose(errs); |
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| 130 | |
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| 131 | if (i < NUM_REG_ERRORS) |
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| 132 | { |
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| 133 | com_err(whoami, 0, "Not enough error messages in %s", |
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| 134 | REG_SVR_ERROR_MESSAGES); |
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| 135 | exit(1); |
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| 136 | } |
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| 137 | return 1; |
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| 138 | } |
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| 139 | |
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[24250] | 140 | void parse_packet(reg_client *rc, int type, int len, char *buf, int sleeping) |
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[23095] | 141 | { |
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| 142 | switch (type) |
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| 143 | { |
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| 144 | case REG_RSA_ENCRYPTED_KEY: |
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| 145 | { |
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| 146 | unsigned char key[MAX_ENCRYPTED_KEY_LEN]; |
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| 147 | unsigned int keylen; |
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| 148 | |
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| 149 | if (RSAPrivateDecrypt(key, &keylen, buf, len, rsa_key) || keylen != 8) |
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| 150 | { |
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| 151 | reply(rc, ENCRYPT_KEY, "INIT", "c", NULL); |
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| 152 | return; |
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| 153 | } |
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| 154 | des_key_sched(key, rc->sched); |
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| 155 | rc->encrypted = 1; |
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| 156 | |
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| 157 | if (sleeping) |
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| 158 | reply(rc, DATABASE_CLOSED, "INIT", "c", NULL); |
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| 159 | else |
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| 160 | reply(rc, NO_MESSAGE, "GETN", "c", NULL); |
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| 161 | return; |
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| 162 | } |
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| 163 | |
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| 164 | case REG_ENCRYPTED: |
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| 165 | { |
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| 166 | char *outbuf, iv[8] = {0, 0, 0, 0, 0, 0, 0, 0}; |
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| 167 | |
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| 168 | if (!rc->encrypted) |
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| 169 | { |
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| 170 | reply(rc, INTERNAL_ERROR, "INIT", "c", NULL, |
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| 171 | "Encrypted packet unexpected"); |
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| 172 | return; |
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| 173 | } |
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| 174 | |
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| 175 | outbuf = malloc(len + 7); |
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| 176 | if (!outbuf) |
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| 177 | { |
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| 178 | reply(rc, INTERNAL_ERROR, "INIT", "c", NULL, "Out of memory"); |
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| 179 | return; |
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| 180 | } |
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[24250] | 181 | des_cbc_encrypt((des_cblock *)buf, (des_cblock *)outbuf, len, rc->sched, (const des_cblock *)iv, 0); |
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[23095] | 182 | |
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| 183 | /* Undo PKCS#5 padding */ |
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| 184 | len -= outbuf[len - 1]; |
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| 185 | |
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| 186 | parse_pdu(rc, len - 8, outbuf + 8); |
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| 187 | free(outbuf); |
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| 188 | return; |
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| 189 | } |
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| 190 | |
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| 191 | #ifdef ALLOW_UNENCRYPTED |
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| 192 | case REG_UNENCRYPTED: |
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| 193 | parse_pdu(rc, len, buf); |
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| 194 | return; |
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| 195 | #endif |
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| 196 | |
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| 197 | default: |
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| 198 | com_err(whoami, 0, "Bad packet (type %d, len %d)", type, len); |
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| 199 | rc->lastmod = 0; |
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| 200 | } |
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| 201 | } |
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| 202 | |
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| 203 | void parse_pdu(reg_client *rc, long len, char *buf) |
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| 204 | { |
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| 205 | char **argv, *p; |
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| 206 | int argc, i; |
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| 207 | void (*handler)(reg_client *rc, int argc, char **argv) = NULL; |
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| 208 | |
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| 209 | if (len < 8 || strcmp(buf, "v1")) |
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| 210 | { |
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| 211 | com_err(whoami, 0, "Bad packet version number %s", buf); |
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| 212 | reply(rc, PROTOCOL_ERROR, "INIT", "c", NULL); |
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| 213 | return; |
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| 214 | } |
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| 215 | buf += 3; |
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| 216 | len -= 3; |
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| 217 | |
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| 218 | for (i = 0; handlers[i].name; i++) |
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| 219 | { |
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| 220 | if (!strcmp(buf, handlers[i].name)) |
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| 221 | { |
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| 222 | handler = handlers[i].handler; |
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| 223 | break; |
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| 224 | } |
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| 225 | } |
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| 226 | if (!handler) |
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| 227 | { |
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| 228 | com_err(whoami, 0, "Bad packet request %s", buf); |
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| 229 | reply(rc, PROTOCOL_ERROR, "INIT", "c", NULL); |
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| 230 | return; |
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| 231 | } |
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| 232 | buf += 5; |
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| 233 | len -= 5; |
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| 234 | |
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| 235 | for (argc = 0, p = buf; p < buf + len; p++) |
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| 236 | { |
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| 237 | if (!*p) |
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| 238 | argc++; |
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| 239 | } |
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| 240 | |
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| 241 | argv = malloc(argc * sizeof(char *)); |
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| 242 | if (!argv) |
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| 243 | { |
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| 244 | com_err(whoami, 0, "in parse_pdu"); |
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| 245 | reply(rc, INTERNAL_ERROR, "INIT", "c", NULL, "Out of memory"); |
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| 246 | return; |
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| 247 | } |
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| 248 | |
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| 249 | fprintf(stderr, "%s[#%d]: %s", whoami, rc->clientid, handlers[i].name); |
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| 250 | for (argc = 0, p = buf - 1; p < buf + len - 1; p++) |
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| 251 | { |
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| 252 | if (!*p) |
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| 253 | { |
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| 254 | argv[argc++] = p + 1; |
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| 255 | if (strcmp(handlers[i].name, "PSWD") != 0) |
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| 256 | fprintf(stderr, " '%s'", p + 1); |
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| 257 | } |
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| 258 | } |
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| 259 | fprintf(stderr, "\n"); |
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| 260 | fflush(stderr); |
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| 261 | |
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| 262 | for (i = 0; i < argc; i++) |
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| 263 | strtrim(argv[i]); |
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| 264 | handler(rc, argc, argv); |
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| 265 | free(argv); |
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| 266 | } |
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| 267 | |
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| 268 | void reply(reg_client *rc, int msg, char *state, char *clean, char *data, |
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| 269 | ...) |
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| 270 | { |
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| 271 | /* reply() can't malloc, since it might be returning an "out of memory" |
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| 272 | error. We'll use a static buffer which is much larger than any |
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| 273 | message we'd be returning, and callers have to make sure that any |
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| 274 | user-generated data is length-limited. */ |
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| 275 | static char buf[8192], outbuf[8192]; |
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| 276 | char *p; |
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| 277 | int len, pad, pcount; |
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| 278 | va_list ap; |
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| 279 | long junk; |
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| 280 | unsigned short *nrand; |
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| 281 | |
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| 282 | com_err(whoami, 0, "Reply: %s, go to state %s %s", ename[msg], state, clean); |
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| 283 | |
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| 284 | seed48(rc->random); |
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| 285 | junk = lrand48(); |
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| 286 | memcpy(buf + 3, &junk, 4); |
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| 287 | junk = lrand48(); |
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| 288 | memcpy(buf + 7, &junk, 4); |
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| 289 | nrand = seed48(rc->random); |
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| 290 | memcpy(rc->random, nrand, 6); |
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| 291 | |
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| 292 | memcpy(buf + 11, "v1", 3); |
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| 293 | memcpy(buf + 14, state, len = strlen(state) + 1); |
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| 294 | p = buf + 14 + len; |
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| 295 | va_start(ap, data); |
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| 296 | p += vsprintf(p, emsg[msg], ap); |
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| 297 | va_end(ap); |
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| 298 | *p++ = '\0'; |
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| 299 | memcpy(p, clean, len = strlen(clean) + 1); |
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| 300 | p += len; |
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| 301 | if (data) |
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| 302 | { |
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| 303 | memcpy(p, data, len = strlen(data) + 1); |
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| 304 | p += len; |
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| 305 | } |
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| 306 | |
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| 307 | len = p - (buf + 3); |
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| 308 | pad = 8 - len % 8; |
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| 309 | for (pcount = pad; pcount; pcount--) |
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| 310 | buf[3 + len++] = pad; |
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| 311 | |
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| 312 | if (rc->encrypted) |
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| 313 | { |
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| 314 | char iv[8] = {0, 0, 0, 0, 0, 0, 0, 0}; |
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| 315 | |
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[24250] | 316 | des_cbc_encrypt((des_cblock *)(buf + 3), (des_cblock *)(outbuf + 3), len, |
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| 317 | rc->sched, (const des_cblock *)iv, 1); |
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[23095] | 318 | p = outbuf; |
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| 319 | *p = REG_ENCRYPTED; |
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| 320 | } |
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| 321 | else |
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| 322 | { |
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| 323 | p = buf; |
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| 324 | *p = REG_UNENCRYPTED; |
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| 325 | } |
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| 326 | |
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| 327 | p[1] = len / 256; |
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| 328 | p[2] = len % 256; |
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| 329 | write(rc->fd, p, len + 3); |
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| 330 | |
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| 331 | /* If we're going to INIT, set lastmod to 0 to cause the connection |
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| 332 | to be closed once we return to the main loop */ |
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| 333 | if (!strcmp(state, "INIT")) |
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| 334 | rc->lastmod = 0; |
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| 335 | } |
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| 336 | |
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| 337 | char hexd[] = { '0', '1', '2', '3', '4', '5', '6', '7', |
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| 338 | '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; |
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| 339 | |
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| 340 | void printhex(unsigned char *buf, int len) |
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| 341 | { |
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| 342 | while (len--) |
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| 343 | { |
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| 344 | printf("%c%c", hexd[*buf>>4], hexd[*buf%0x10]); |
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| 345 | buf++; |
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| 346 | } |
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| 347 | printf("\n"); |
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| 348 | } |
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