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Diffstat (limited to '')
| -rw-r--r-- | auth.c | 497 |
1 files changed, 497 insertions, 0 deletions
@@ -0,0 +1,497 @@ +/* $KAME: auth.c,v 1.4 2004/09/07 05:03:02 jinmei Exp $ */ + +/* + * Copyright (C) 2004 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 2000, 2001 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ +#include <sys/param.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/queue.h> +#if TIME_WITH_SYS_TIME +# include <sys/time.h> +# include <time.h> +#else +# if HAVE_SYS_TIME_H +# include <sys/time.h> +# else +# include <time.h> +# endif +#endif + +#include <netinet/in.h> + +#include <syslog.h> +#include <string.h> +#include <errno.h> + +#include <dhcp6.h> +#include <config.h> +#include <common.h> +#include <auth.h> + +#define PADLEN 64 +#define IPAD 0x36 +#define OPAD 0x5C + +#define HMACMD5_KEYLENGTH 64 + +typedef struct { + u_int32_t buf[4]; + u_int32_t bytes[2]; + u_int32_t in[16]; +} md5_t; + +typedef struct { + md5_t md5ctx; + unsigned char key[HMACMD5_KEYLENGTH]; +} hmacmd5_t; + +static void hmacmd5_init __P((hmacmd5_t *, const unsigned char *, + unsigned int)); +static void hmacmd5_invalidate __P((hmacmd5_t *)); +static void hmacmd5_update __P((hmacmd5_t *, const unsigned char *, + unsigned int)); +static void hmacmd5_sign __P((hmacmd5_t *, unsigned char *)); +static int hmacmd5_verify __P((hmacmd5_t *, unsigned char *)); + +static void md5_init __P((md5_t *)); +static void md5_invalidate __P((md5_t *)); +static void md5_final __P((md5_t *, unsigned char *)); +static void md5_update __P((md5_t *, const unsigned char *, unsigned int)); + +int +dhcp6_validate_key(key) + struct keyinfo *key; +{ + time_t now; + + if (key->expire == 0) /* never expire */ + return (0); + + if (time(&now) == -1) + return (-1); /* treat it as expiration (XXX) */ + + if (now > key->expire) + return (-1); + + return (0); +} + +int +dhcp6_calc_mac(buf, len, proto, alg, off, key) + char *buf; + size_t len, off; + int proto, alg; + struct keyinfo *key; +{ + hmacmd5_t ctx; + unsigned char digest[MD5_DIGESTLENGTH]; + + /* right now, we don't care about the protocol */ + + if (alg != DHCP6_AUTHALG_HMACMD5) + return (-1); + + if (off + MD5_DIGESTLENGTH > len) { + /* + * this should be assured by the caller, but check it here + * for safety. + */ + return (-1); + } + + hmacmd5_init(&ctx, key->secret, key->secretlen); + hmacmd5_update(&ctx, buf, len); + hmacmd5_sign(&ctx, digest); + + memcpy(buf + off, digest, MD5_DIGESTLENGTH); + + return (0); +} + +int +dhcp6_verify_mac(buf, len, proto, alg, off, key) + char *buf; + ssize_t len; + int proto, alg; + size_t off; + struct keyinfo *key; +{ + hmacmd5_t ctx; + unsigned char digest[MD5_DIGESTLENGTH]; + int result; + + /* right now, we don't care about the protocol */ + + if (alg != DHCP6_AUTHALG_HMACMD5) + return (-1); + + if (off + MD5_DIGESTLENGTH > len) + return (-1); + + /* + * Copy the MAC value and clear the field. + * XXX: should we make a local working copy? + */ + memcpy(digest, buf + off, sizeof(digest)); + memset(buf + off, 0, sizeof(digest)); + + hmacmd5_init(&ctx, key->secret, key->secretlen); + hmacmd5_update(&ctx, buf, len); + result = hmacmd5_verify(&ctx, digest); + + /* copy back the digest value (XXX) */ + memcpy(buf + off, digest, sizeof(digest)); + + return (result); +} + +/* + * This code implements the HMAC-MD5 keyed hash algorithm + * described in RFC 2104. + */ +/* + * Start HMAC-MD5 process. Initialize an md5 context and digest the key. + */ +static void +hmacmd5_init(hmacmd5_t *ctx, const unsigned char *key, unsigned int len) +{ + unsigned char ipad[PADLEN]; + int i; + + memset(ctx->key, 0, sizeof(ctx->key)); + if (len > sizeof(ctx->key)) { + md5_t md5ctx; + md5_init(&md5ctx); + md5_update(&md5ctx, key, len); + md5_final(&md5ctx, ctx->key); + } else + memcpy(ctx->key, key, len); + + md5_init(&ctx->md5ctx); + memset(ipad, IPAD, sizeof(ipad)); + for (i = 0; i < PADLEN; i++) + ipad[i] ^= ctx->key[i]; + md5_update(&ctx->md5ctx, ipad, sizeof(ipad)); +} + +static void +hmacmd5_invalidate(hmacmd5_t *ctx) +{ + md5_invalidate(&ctx->md5ctx); + memset(ctx->key, 0, sizeof(ctx->key)); + memset(ctx, 0, sizeof(ctx)); +} + +/* + * Update context to reflect the concatenation of another buffer full + * of bytes. + */ +static void +hmacmd5_update(hmacmd5_t *ctx, const unsigned char *buf, unsigned int len) +{ + md5_update(&ctx->md5ctx, buf, len); +} + +/* + * Compute signature - finalize MD5 operation and reapply MD5. + */ +static void +hmacmd5_sign(hmacmd5_t *ctx, unsigned char *digest) +{ + unsigned char opad[PADLEN]; + int i; + + md5_final(&ctx->md5ctx, digest); + + memset(opad, OPAD, sizeof(opad)); + for (i = 0; i < PADLEN; i++) + opad[i] ^= ctx->key[i]; + + md5_init(&ctx->md5ctx); + md5_update(&ctx->md5ctx, opad, sizeof(opad)); + md5_update(&ctx->md5ctx, digest, MD5_DIGESTLENGTH); + md5_final(&ctx->md5ctx, digest); + hmacmd5_invalidate(ctx); +} + +/* + * Verify signature - finalize MD5 operation and reapply MD5, then + * compare to the supplied digest. + */ +static int +hmacmd5_verify(hmacmd5_t *ctx, unsigned char *digest) { + unsigned char newdigest[MD5_DIGESTLENGTH]; + + hmacmd5_sign(ctx, newdigest); + return (memcmp(digest, newdigest, MD5_DIGESTLENGTH)); +} + +/* + * This code implements the MD5 message-digest algorithm. + * The algorithm is due to Ron Rivest. This code was + * written by Colin Plumb in 1993, no copyright is claimed. + * This code is in the public domain; do with it what you wish. + * + * Equivalent code is available from RSA Data Security, Inc. + * This code has been tested against that, and is equivalent, + * except that you don't need to include two pages of legalese + * with every copy. + * + * To compute the message digest of a chunk of bytes, declare an + * MD5Context structure, pass it to MD5Init, call MD5Update as + * needed on buffers full of bytes, and then call MD5Final, which + * will fill a supplied 16-byte array with the digest. + */ + +static void +byteSwap(u_int32_t *buf, unsigned words) +{ + unsigned char *p = (unsigned char *)buf; + + do { + *buf++ = (u_int32_t)((unsigned)p[3] << 8 | p[2]) << 16 | + ((unsigned)p[1] << 8 | p[0]); + p += 4; + } while (--words); +} + +/* + * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious + * initialization constants. + */ +static void +md5_init(md5_t *ctx) +{ + ctx->buf[0] = 0x67452301; + ctx->buf[1] = 0xefcdab89; + ctx->buf[2] = 0x98badcfe; + ctx->buf[3] = 0x10325476; + + ctx->bytes[0] = 0; + ctx->bytes[1] = 0; +} + +static void +md5_invalidate(md5_t *ctx) +{ + memset(ctx, 0, sizeof(md5_t)); +} + +/* The four core functions - F1 is optimized somewhat */ + +/* #define F1(x, y, z) (x & y | ~x & z) */ +#define F1(x, y, z) (z ^ (x & (y ^ z))) +#define F2(x, y, z) F1(z, x, y) +#define F3(x, y, z) (x ^ y ^ z) +#define F4(x, y, z) (y ^ (x | ~z)) + +/* This is the central step in the MD5 algorithm. */ +#define MD5STEP(f,w,x,y,z,in,s) \ + (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x) + +/* + * The core of the MD5 algorithm, this alters an existing MD5 hash to + * reflect the addition of 16 longwords of new data. MD5Update blocks + * the data and converts bytes into longwords for this routine. + */ +static void +transform(u_int32_t buf[4], u_int32_t const in[16]) { + register u_int32_t a, b, c, d; + + a = buf[0]; + b = buf[1]; + c = buf[2]; + d = buf[3]; + + MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); + MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); + MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); + MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); + MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); + MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); + MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); + MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); + MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); + MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); + MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); + MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); + MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); + MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); + MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); + MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); + + MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); + MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); + MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); + MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); + MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); + MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); + MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); + MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); + MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); + MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); + MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); + MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); + MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); + MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); + MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); + MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); + + MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); + MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); + MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); + MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); + MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); + MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); + MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); + MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); + MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); + MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); + MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); + MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); + MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); + MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); + MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); + MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); + + MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); + MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); + MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); + MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); + MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); + MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); + MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); + MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); + MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); + MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); + MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); + MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); + MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); + MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); + MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); + MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); + + buf[0] += a; + buf[1] += b; + buf[2] += c; + buf[3] += d; +} + +/* + * Update context to reflect the concatenation of another buffer full + * of bytes. + */ +static void +md5_update(md5_t *ctx, const unsigned char *buf, unsigned int len) +{ + u_int32_t t; + + /* Update byte count */ + + t = ctx->bytes[0]; + if ((ctx->bytes[0] = t + len) < t) + ctx->bytes[1]++; /* Carry from low to high */ + + t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */ + if (t > len) { + memcpy((unsigned char *)ctx->in + 64 - t, buf, len); + return; + } + /* First chunk is an odd size */ + memcpy((unsigned char *)ctx->in + 64 - t, buf, t); + byteSwap(ctx->in, 16); + transform(ctx->buf, ctx->in); + buf += t; + len -= t; + + /* Process data in 64-byte chunks */ + while (len >= 64) { + memcpy(ctx->in, buf, 64); + byteSwap(ctx->in, 16); + transform(ctx->buf, ctx->in); + buf += 64; + len -= 64; + } + + /* Handle any remaining bytes of data. */ + memcpy(ctx->in, buf, len); +} + +/* + * Final wrapup - pad to 64-byte boundary with the bit pattern + * 1 0* (64-bit count of bits processed, MSB-first) + */ +static void +md5_final(md5_t *ctx, unsigned char *digest) +{ + int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */ + unsigned char *p = (unsigned char *)ctx->in + count; + + /* Set the first char of padding to 0x80. There is always room. */ + *p++ = 0x80; + + /* Bytes of padding needed to make 56 bytes (-8..55) */ + count = 56 - 1 - count; + + if (count < 0) { /* Padding forces an extra block */ + memset(p, 0, count + 8); + byteSwap(ctx->in, 16); + transform(ctx->buf, ctx->in); + p = (unsigned char *)ctx->in; + count = 56; + } + memset(p, 0, count); + byteSwap(ctx->in, 14); + + /* Append length in bits and transform */ + ctx->in[14] = ctx->bytes[0] << 3; + ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29; + transform(ctx->buf, ctx->in); + + byteSwap(ctx->buf, 4); + memcpy(digest, ctx->buf, 16); + memset(ctx, 0, sizeof(md5_t)); /* In case it's sensitive */ +} |