1 files changed, 300 insertions, 0 deletions
diff --git a/crypto/openssh/hostfile.c b/crypto/openssh/hostfile.c
new file mode 100644
index 0000000..ea92fa0
--- /dev/null
+++ b/crypto/openssh/hostfile.c
@@ -0,0 +1,300 @@
+/*
+ * 
+ * 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("$OpenBSD: hostfile.c,v 1.13 2000/02/18 10:20:20 markus Exp $");
+
+#include "packet.h"
+#include "ssh.h"
+
+/*
+ * Reads a multiple-precision integer in decimal 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)
+{
+	char *cp = *cpp;
+	int old;
+
+	/* Skip any leading whitespace. */
+	for (; *cp == ' ' || *cp == '\t'; cp++)
+		;
+
+	/* Check that it begins with a decimal digit. */
+	if (*cp < '0' || *cp > '9')
+		return 0;
+
+	/* Save starting position. */
+	*cpp = cp;
+
+	/* Move forward until all decimal digits skipped. */
+	for (; *cp >= '0' && *cp <= '9'; cp++)
+		;
+
+	/* 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;
+
+	/* Restore old terminating character. */
+	*cp = old;
+
+	/* 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.
+ */
+
+int
+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;
+}
+
+/*
+ * 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++;
+		} 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;
+		}
+	}
+
+	/*
+	 * 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.
+ */
+
+HostStatus
+check_host_in_hostfile(const char *filename, const char *host,
+		       BIGNUM * e, BIGNUM * n, BIGNUM * ke, BIGNUM * kn)
+{
+	FILE *f;
+	char line[8192];
+	int linenum = 0;
+	unsigned int 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;
+
+	/* 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;
+	}
+	/* 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.
+ */
+
+int
+add_host_to_hostfile(const char *filename, const char *host,
+		     BIGNUM * e, BIGNUM * n)
+{
+	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;
+}