/*
-
-hostfile.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Thu Jun 29 07:10:56 1995 ylo
-
-Functions for manipulating the known hosts files.
-
-*/
+ *
+ * hostfile.c
+ *
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ *
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ *
+ * Created: Thu Jun 29 07:10:56 1995 ylo
+ *
+ * Functions for manipulating the known hosts files.
+ *
+ */
#include "includes.h"
-RCSID("$Id$");
+RCSID("$OpenBSD: hostfile.c,v 1.11 2000/01/04 00:07:59 markus Exp $");
#include "packet.h"
#include "ssh.h"
-/* Reads a multiple-precision integer in hex from the buffer, and advances the
- pointer. The integer must already be initialized. This function is
- permitted to modify the buffer. This leaves *cpp to point just beyond
- the last processed (and maybe modified) character. Note that this may
- modify the buffer containing the number. */
+/*
+ * Reads a multiple-precision integer in hex from the buffer, and advances
+ * the pointer. The integer must already be initialized. This function is
+ * permitted to modify the buffer. This leaves *cpp to point just beyond the
+ * last processed (and maybe modified) character. Note that this may modify
+ * the buffer containing the number.
+ */
int
-auth_rsa_read_bignum(char **cpp, BIGNUM *value)
+auth_rsa_read_bignum(char **cpp, BIGNUM * value)
{
- char *cp = *cpp;
- int len, old;
+ char *cp = *cpp;
+ int len, old;
- /* Skip any leading whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
+ /* Skip any leading whitespace. */
+ for (; *cp == ' ' || *cp == '\t'; cp++)
+ ;
- /* Check that it begins with a hex digit. */
- if (*cp < '0' || *cp > '9')
- return 0;
+ /* Check that it begins with a hex digit. */
+ if (*cp < '0' || *cp > '9')
+ return 0;
- /* Save starting position. */
- *cpp = cp;
+ /* Save starting position. */
+ *cpp = cp;
- /* Move forward until all hex digits skipped. */
- for (; *cp >= '0' && *cp <= '9'; cp++)
- ;
+ /* Move forward until all hex digits skipped. */
+ for (; *cp >= '0' && *cp <= '9'; cp++)
+ ;
- /* Compute the length of the hex number. */
- len = cp - *cpp;
+ /* Compute the length of the hex number. */
+ len = cp - *cpp;
- /* Save the old terminating character, and replace it by \0. */
- old = *cp;
- *cp = 0;
+ /* Save the old terminating character, and replace it by \0. */
+ old = *cp;
+ *cp = 0;
-
- /* Parse the number. */
- if (BN_dec2bn(&value, *cpp) == 0)
- return 0;
+ /* Parse the number. */
+ if (BN_dec2bn(&value, *cpp) == 0)
+ return 0;
- /* Restore old terminating character. */
- *cp = old;
+ /* Restore old terminating character. */
+ *cp = old;
- /* Move beyond the number and return success. */
- *cpp = cp;
- return 1;
+ /* Move beyond the number and return success. */
+ *cpp = cp;
+ return 1;
}
-/* Parses an RSA key (number of bits, e, n) from a string. Moves the pointer
- over the key. Skips any whitespace at the beginning and at end. */
+/*
+ * Parses an RSA key (number of bits, e, n) from a string. Moves the pointer
+ * over the key. Skips any whitespace at the beginning and at end.
+ */
int
-auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM *e, BIGNUM *n)
+auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM * e, BIGNUM * n)
{
- unsigned int bits;
- char *cp;
-
- /* Skip leading whitespace. */
- for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
- ;
-
- /* Get number of bits. */
- if (*cp < '0' || *cp > '9')
- return 0; /* Bad bit count... */
- for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
- bits = 10 * bits + *cp - '0';
-
- /* Get public exponent. */
- if (!auth_rsa_read_bignum(&cp, e))
- return 0;
-
- /* Get public modulus. */
- if (!auth_rsa_read_bignum(&cp, n))
- return 0;
-
- /* Skip trailing whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
-
- /* Return results. */
- *cpp = cp;
- *bitsp = bits;
- return 1;
+ unsigned int bits;
+ char *cp;
+
+ /* Skip leading whitespace. */
+ for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
+ ;
+
+ /* Get number of bits. */
+ if (*cp < '0' || *cp > '9')
+ return 0; /* Bad bit count... */
+ for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
+ bits = 10 * bits + *cp - '0';
+
+ /* Get public exponent. */
+ if (!auth_rsa_read_bignum(&cp, e))
+ return 0;
+
+ /* Get public modulus. */
+ if (!auth_rsa_read_bignum(&cp, n))
+ return 0;
+
+ /* Skip trailing whitespace. */
+ for (; *cp == ' ' || *cp == '\t'; cp++)
+ ;
+
+ /* Return results. */
+ *cpp = cp;
+ *bitsp = bits;
+ return 1;
}
-/* Tries to match the host name (which must be in all lowercase) against the
- comma-separated sequence of subpatterns (each possibly preceded by ! to
- indicate negation). Returns true if there is a positive match; zero
- otherwise. */
+/*
+ * Tries to match the host name (which must be in all lowercase) against the
+ * comma-separated sequence of subpatterns (each possibly preceded by ! to
+ * indicate negation). Returns true if there is a positive match; zero
+ * otherwise.
+ */
int
match_hostname(const char *host, const char *pattern, unsigned int len)
{
- char sub[1024];
- int negated;
- int got_positive;
- unsigned int i, subi;
-
- got_positive = 0;
- for (i = 0; i < len;)
- {
- /* Check if the subpattern is negated. */
- if (pattern[i] == '!')
- {
- negated = 1;
- i++;
+ char sub[1024];
+ int negated;
+ int got_positive;
+ unsigned int i, subi;
+
+ got_positive = 0;
+ for (i = 0; i < len;) {
+ /* Check if the subpattern is negated. */
+ if (pattern[i] == '!') {
+ negated = 1;
+ i++;
+ } else
+ negated = 0;
+
+ /*
+ * Extract the subpattern up to a comma or end. Convert the
+ * subpattern to lowercase.
+ */
+ for (subi = 0;
+ i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
+ subi++, i++)
+ sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i];
+ /* If subpattern too long, return failure (no match). */
+ if (subi >= sizeof(sub) - 1)
+ return 0;
+
+ /* If the subpattern was terminated by a comma, skip the comma. */
+ if (i < len && pattern[i] == ',')
+ i++;
+
+ /* Null-terminate the subpattern. */
+ sub[subi] = '\0';
+
+ /* Try to match the subpattern against the host name. */
+ if (match_pattern(host, sub)) {
+ if (negated)
+ return 0; /* Fail */
+ else
+ got_positive = 1;
+ }
}
- else
- negated = 0;
-
- /* Extract the subpattern up to a comma or end. Convert the subpattern
- to lowercase. */
- for (subi = 0;
- i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
- subi++, i++)
- sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i];
- /* If subpattern too long, return failure (no match). */
- if (subi >= sizeof(sub) - 1)
- return 0;
-
- /* If the subpattern was terminated by a comma, skip the comma. */
- if (i < len && pattern[i] == ',')
- i++;
-
- /* Null-terminate the subpattern. */
- sub[subi] = '\0';
-
- /* Try to match the subpattern against the host name. */
- if (match_pattern(host, sub)) {
- if (negated)
- return 0; /* Fail if host matches any negated subpattern. */
- else
- got_positive = 1;
- }
- }
-
- /* Return success if got a positive match. If there was a negative match,
- we have already returned zero and never get here. */
- return got_positive;
+
+ /*
+ * Return success if got a positive match. If there was a negative
+ * match, we have already returned zero and never get here.
+ */
+ return got_positive;
}
-/* Checks whether the given host (which must be in all lowercase) is
- already in the list of our known hosts.
- Returns HOST_OK if the host is known and has the specified key,
- HOST_NEW if the host is not known, and HOST_CHANGED if the host is known
- but used to have a different host key. */
+/*
+ * Checks whether the given host (which must be in all lowercase) is already
+ * in the list of our known hosts. Returns HOST_OK if the host is known and
+ * has the specified key, HOST_NEW if the host is not known, and HOST_CHANGED
+ * if the host is known but used to have a different host key.
+ */
HostStatus
-check_host_in_hostfile(const char *filename,
- const char *host, unsigned int bits,
- BIGNUM *e, BIGNUM *n,
- BIGNUM *ke, BIGNUM *kn)
+check_host_in_hostfile(const char *filename, const char *host,
+ BIGNUM * e, BIGNUM * n, BIGNUM * ke, BIGNUM * kn)
{
- FILE *f;
- char line[8192];
- unsigned int kbits, hostlen;
- char *cp, *cp2;
- HostStatus end_return;
- struct stat st;
-
- /* Open the file containing the list of known hosts. */
- f = fopen(filename, "r");
- if (!f)
- {
- if (stat(filename, &st) >= 0)
- {
- packet_send_debug("Could not open %.900s for reading.", filename);
- packet_send_debug("If your home directory is on an NFS volume, it may need to be world-readable.");
- }
- return HOST_NEW;
- }
-
- /* Cache the length of the host name. */
- hostlen = strlen(host);
-
- /* Return value when the loop terminates. This is set to HOST_CHANGED if
- we have seen a different key for the host and have not found the proper
- one. */
- end_return = HOST_NEW;
-
- /* Go trough the file. */
- while (fgets(line, sizeof(line), f))
- {
- cp = line;
-
- /* Skip any leading whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
-
- /* Ignore comment lines and empty lines. */
- if (!*cp || *cp == '#' || *cp == '\n')
- continue;
-
- /* Find the end of the host name portion. */
- for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
- ;
-
- /* Check if the host name matches. */
- if (!match_hostname(host, cp, (unsigned int)(cp2 - cp)))
- continue;
-
- /* Got a match. Skip host name. */
- cp = cp2;
-
- /* Extract the key from the line. This will skip any leading
- whitespace. Ignore badly formatted lines. */
- if (!auth_rsa_read_key(&cp, &kbits, ke, kn))
- continue;
-
- /* Check if the current key is the same as the previous one. */
- if (kbits == bits && BN_cmp(ke, e) == 0 && BN_cmp(kn, n) == 0)
- {
- /* Ok, they match. */
- fclose(f);
- return HOST_OK;
+ FILE *f;
+ char line[8192];
+ int linenum = 0;
+ unsigned int bits, kbits, hostlen;
+ char *cp, *cp2;
+ HostStatus end_return;
+
+ /* Open the file containing the list of known hosts. */
+ f = fopen(filename, "r");
+ if (!f)
+ return HOST_NEW;
+
+ /* Cache the length of the host name. */
+ hostlen = strlen(host);
+
+ /*
+ * Return value when the loop terminates. This is set to
+ * HOST_CHANGED if we have seen a different key for the host and have
+ * not found the proper one.
+ */
+ end_return = HOST_NEW;
+
+ /* size of modulus 'n' */
+ bits = BN_num_bits(n);
+
+ /* Go trough the file. */
+ while (fgets(line, sizeof(line), f)) {
+ cp = line;
+ linenum++;
+
+ /* Skip any leading whitespace, comments and empty lines. */
+ for (; *cp == ' ' || *cp == '\t'; cp++)
+ ;
+ if (!*cp || *cp == '#' || *cp == '\n')
+ continue;
+
+ /* Find the end of the host name portion. */
+ for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
+ ;
+
+ /* Check if the host name matches. */
+ if (!match_hostname(host, cp, (unsigned int) (cp2 - cp)))
+ continue;
+
+ /* Got a match. Skip host name. */
+ cp = cp2;
+
+ /*
+ * Extract the key from the line. This will skip any leading
+ * whitespace. Ignore badly formatted lines.
+ */
+ if (!auth_rsa_read_key(&cp, &kbits, ke, kn))
+ continue;
+
+ if (kbits != BN_num_bits(kn)) {
+ error("Warning: %s, line %d: keysize mismatch for host %s: "
+ "actual %d vs. announced %d.",
+ filename, linenum, host, BN_num_bits(kn), kbits);
+ error("Warning: replace %d with %d in %s, line %d.",
+ kbits, BN_num_bits(kn), filename, linenum);
+ }
+ /* Check if the current key is the same as the given key. */
+ if (BN_cmp(ke, e) == 0 && BN_cmp(kn, n) == 0) {
+ /* Ok, they match. */
+ fclose(f);
+ return HOST_OK;
+ }
+ /*
+ * They do not match. We will continue to go through the
+ * file; however, we note that we will not return that it is
+ * new.
+ */
+ end_return = HOST_CHANGED;
}
-
- /* They do not match. We will continue to go through the file; however,
- we note that we will not return that it is new. */
- end_return = HOST_CHANGED;
- }
- /* Clear variables and close the file. */
- fclose(f);
-
- /* Return either HOST_NEW or HOST_CHANGED, depending on whether we saw a
- different key for the host. */
- return end_return;
+ /* Clear variables and close the file. */
+ fclose(f);
+
+ /*
+ * Return either HOST_NEW or HOST_CHANGED, depending on whether we
+ * saw a different key for the host.
+ */
+ return end_return;
}
-/* Appends an entry to the host file. Returns false if the entry
- could not be appended. */
+/*
+ * Appends an entry to the host file. Returns false if the entry could not
+ * be appended.
+ */
int
add_host_to_hostfile(const char *filename, const char *host,
- unsigned int bits, BIGNUM *e, BIGNUM *n)
+ BIGNUM * e, BIGNUM * n)
{
- FILE *f;
- char *buf;
-
- /* Open the file for appending. */
- f = fopen(filename, "a");
- if (!f)
- return 0;
-
- /* Print the host name and key to the file. */
- fprintf(f, "%s %u ", host, bits);
- buf = BN_bn2dec(e);
- assert(buf != NULL);
- fprintf(f, "%s ", buf);
- free (buf);
- buf = BN_bn2dec(n);
- assert(buf != NULL);
- fprintf(f, "%s\n", buf);
- free (buf);
-
- /* Close the file. */
- fclose(f);
- return 1;
+ FILE *f;
+ char *buf;
+ unsigned int bits;
+
+ /* Open the file for appending. */
+ f = fopen(filename, "a");
+ if (!f)
+ return 0;
+
+ /* size of modulus 'n' */
+ bits = BN_num_bits(n);
+
+ /* Print the host name and key to the file. */
+ fprintf(f, "%s %u ", host, bits);
+ buf = BN_bn2dec(e);
+ if (buf == NULL) {
+ error("add_host_to_hostfile: BN_bn2dec(e) failed");
+ fclose(f);
+ return 0;
+ }
+ fprintf(f, "%s ", buf);
+ free(buf);
+ buf = BN_bn2dec(n);
+ if (buf == NULL) {
+ error("add_host_to_hostfile: BN_bn2dec(n) failed");
+ fclose(f);
+ return 0;
+ }
+ fprintf(f, "%s\n", buf);
+ free(buf);
+
+ /* Close the file. */
+ fclose(f);
+ return 1;
}
andersk / openssh.git / blobdiff