/*
 * Portions Copyright (C) 2004-2012  Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 AND NETWORK ASSOCIATES 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.
 *
 * Portions Copyright (C) 1995-2000 by Network Associates, Inc.
 *
 * Permission to use, copy, modify, and/or 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 AND NETWORK ASSOCIATES 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.
 */

/*%
 * Principal Author: Brian Wellington
 * $Id$
 */

#include <config.h>

#include <isc/base64.h>
#include <isc/dir.h>
#include <isc/fsaccess.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/stdtime.h>
#include <isc/string.h>
#include <isc/util.h>

#include <dns/time.h>

#include "dst_internal.h"
#include "dst_parse.h"
#include "dst/result.h"

#define DST_AS_STR(t) ((t).value.as_textregion.base)

#define PRIVATE_KEY_STR "Private-key-format:"
#define ALGORITHM_STR "Algorithm:"

#define TIMING_NTAGS (DST_MAX_TIMES + 1)
static const char *timetags[TIMING_NTAGS] = {
	"Created:",
	"Publish:",
	"Activate:",
	"Revoke:",
	"Inactive:",
	"Delete:",
	"DSPublish:"
};

#define NUMERIC_NTAGS (DST_MAX_NUMERIC + 1)
static const char *numerictags[NUMERIC_NTAGS] = {
	"Predecessor:",
	"Successor:",
	"MaxTTL:",
	"RollPeriod:"
};

struct parse_map {
	const int value;
	const char *tag;
};

static struct parse_map map[] = {
	{TAG_RSA_MODULUS, "Modulus:"},
	{TAG_RSA_PUBLICEXPONENT, "PublicExponent:"},
	{TAG_RSA_PRIVATEEXPONENT, "PrivateExponent:"},
	{TAG_RSA_PRIME1, "Prime1:"},
	{TAG_RSA_PRIME2, "Prime2:"},
	{TAG_RSA_EXPONENT1, "Exponent1:"},
	{TAG_RSA_EXPONENT2, "Exponent2:"},
	{TAG_RSA_COEFFICIENT, "Coefficient:"},
	{TAG_RSA_ENGINE, "Engine:" },
	{TAG_RSA_LABEL, "Label:" },
	{TAG_RSA_PIN, "PIN:" },

	{TAG_DH_PRIME, "Prime(p):"},
	{TAG_DH_GENERATOR, "Generator(g):"},
	{TAG_DH_PRIVATE, "Private_value(x):"},
	{TAG_DH_PUBLIC, "Public_value(y):"},

	{TAG_DSA_PRIME, "Prime(p):"},
	{TAG_DSA_SUBPRIME, "Subprime(q):"},
	{TAG_DSA_BASE, "Base(g):"},
	{TAG_DSA_PRIVATE, "Private_value(x):"},
	{TAG_DSA_PUBLIC, "Public_value(y):"},

	{TAG_GOST_PRIVASN1, "GostAsn1:"},

	{TAG_HMACMD5_KEY, "Key:"},
	{TAG_HMACMD5_BITS, "Bits:"},

	{TAG_HMACSHA1_KEY, "Key:"},
	{TAG_HMACSHA1_BITS, "Bits:"},

	{TAG_HMACSHA224_KEY, "Key:"},
	{TAG_HMACSHA224_BITS, "Bits:"},

	{TAG_HMACSHA256_KEY, "Key:"},
	{TAG_HMACSHA256_BITS, "Bits:"},

	{TAG_HMACSHA384_KEY, "Key:"},
	{TAG_HMACSHA384_BITS, "Bits:"},

	{TAG_HMACSHA512_KEY, "Key:"},
	{TAG_HMACSHA512_BITS, "Bits:"},

	{0, NULL}
};

static int
find_value(const char *s, const unsigned int alg) {
	int i;

	for (i = 0; map[i].tag != NULL; i++) {
		if (strcasecmp(s, map[i].tag) == 0 &&
		    (TAG_ALG(map[i].value) == alg))
			return (map[i].value);
	}
	return (-1);
}

static const char *
find_tag(const int value) {
	int i;

	for (i = 0; ; i++) {
		if (map[i].tag == NULL)
			return (NULL);
		else if (value == map[i].value)
			return (map[i].tag);
	}
}

static int
find_metadata(const char *s, const char *tags[], int ntags) {
	int i;

	for (i = 0; i < ntags; i++) {
		if (strcasecmp(s, tags[i]) == 0)
			return (i);
	}

	return (-1);
}

static int
find_timedata(const char *s) {
	return (find_metadata(s, timetags, TIMING_NTAGS));
}

static int
find_numericdata(const char *s) {
	return (find_metadata(s, numerictags, NUMERIC_NTAGS));
}

static int
check_rsa(const dst_private_t *priv) {
	int i, j;
	isc_boolean_t have[RSA_NTAGS];
	isc_boolean_t ok;
	unsigned int mask;

	for (i = 0; i < RSA_NTAGS; i++)
		have[i] = ISC_FALSE;
	for (j = 0; j < priv->nelements; j++) {
		for (i = 0; i < RSA_NTAGS; i++)
			if (priv->elements[j].tag == TAG(DST_ALG_RSAMD5, i))
				break;
		if (i == RSA_NTAGS)
			return (-1);
		have[i] = ISC_TRUE;
	}

	mask = ~0;
	mask <<= sizeof(mask) * 8 - TAG_SHIFT;
	mask >>= sizeof(mask) * 8 - TAG_SHIFT;

	if (have[TAG_RSA_ENGINE & mask])
		ok = have[TAG_RSA_MODULUS & mask] &&
		     have[TAG_RSA_PUBLICEXPONENT & mask] &&
		     have[TAG_RSA_LABEL & mask];
	else
		ok = have[TAG_RSA_MODULUS & mask] &&
		     have[TAG_RSA_PUBLICEXPONENT & mask] &&
		     have[TAG_RSA_PRIVATEEXPONENT & mask] &&
		     have[TAG_RSA_PRIME1 & mask] &&
		     have[TAG_RSA_PRIME2 & mask] &&
		     have[TAG_RSA_EXPONENT1 & mask] &&
		     have[TAG_RSA_EXPONENT2 & mask] &&
		     have[TAG_RSA_COEFFICIENT & mask];
	return (ok ? 0 : -1 );
}

static int
check_dh(const dst_private_t *priv) {
	int i, j;
	if (priv->nelements != DH_NTAGS)
		return (-1);
	for (i = 0; i < DH_NTAGS; i++) {
		for (j = 0; j < priv->nelements; j++)
			if (priv->elements[j].tag == TAG(DST_ALG_DH, i))
				break;
		if (j == priv->nelements)
			return (-1);
	}
	return (0);
}

static int
check_dsa(const dst_private_t *priv) {
	int i, j;
	if (priv->nelements != DSA_NTAGS)
		return (-1);
	for (i = 0; i < DSA_NTAGS; i++) {
		for (j = 0; j < priv->nelements; j++)
			if (priv->elements[j].tag == TAG(DST_ALG_DSA, i))
				break;
		if (j == priv->nelements)
			return (-1);
	}
	return (0);
}

static int
check_gost(const dst_private_t *priv) {
	if (priv->nelements != GOST_NTAGS)
		return (-1);
	if (priv->elements[0].tag != TAG(DST_ALG_ECCGOST, 0))
		return (-1);
	return (0);
}

static int
check_hmac_md5(const dst_private_t *priv, isc_boolean_t old) {
	int i, j;

	if (priv->nelements != HMACMD5_NTAGS) {
		/*
		 * If this is a good old format and we are accepting
		 * the old format return success.
		 */
		if (old && priv->nelements == OLD_HMACMD5_NTAGS &&
		    priv->elements[0].tag == TAG_HMACMD5_KEY)
			return (0);
		return (-1);
	}
	/*
	 * We must be new format at this point.
	 */
	for (i = 0; i < HMACMD5_NTAGS; i++) {
		for (j = 0; j < priv->nelements; j++)
			if (priv->elements[j].tag == TAG(DST_ALG_HMACMD5, i))
				break;
		if (j == priv->nelements)
			return (-1);
	}
	return (0);
}

static int
check_hmac_sha(const dst_private_t *priv, unsigned int ntags,
	       unsigned int alg)
{
	unsigned int i, j;
	if (priv->nelements != ntags)
		return (-1);
	for (i = 0; i < ntags; i++) {
		for (j = 0; j < priv->nelements; j++)
			if (priv->elements[j].tag == TAG(alg, i))
				break;
		if (j == priv->nelements)
			return (-1);
	}
	return (0);
}

static int
check_data(const dst_private_t *priv, const unsigned int alg,
	   isc_boolean_t old)
{
	/* XXXVIX this switch statement is too sparse to gen a jump table. */
	switch (alg) {
	case DST_ALG_RSAMD5:
	case DST_ALG_RSASHA1:
		return (check_rsa(priv));
	case DST_ALG_DH:
		return (check_dh(priv));
	case DST_ALG_DSA:
		return (check_dsa(priv));
	case DST_ALG_ECCGOST:
		return (check_gost(priv));
	case DST_ALG_HMACMD5:
		return (check_hmac_md5(priv, old));
	case DST_ALG_HMACSHA1:
		return (check_hmac_sha(priv, HMACSHA1_NTAGS, alg));
	case DST_ALG_HMACSHA224:
		return (check_hmac_sha(priv, HMACSHA224_NTAGS, alg));
	case DST_ALG_HMACSHA256:
		return (check_hmac_sha(priv, HMACSHA256_NTAGS, alg));
	case DST_ALG_HMACSHA384:
		return (check_hmac_sha(priv, HMACSHA384_NTAGS, alg));
	case DST_ALG_HMACSHA512:
		return (check_hmac_sha(priv, HMACSHA512_NTAGS, alg));
	default:
		return (DST_R_UNSUPPORTEDALG);
	}
}

void
dst__privstruct_free(dst_private_t *priv, isc_mem_t *mctx) {
	int i;

	if (priv == NULL)
		return;
	for (i = 0; i < priv->nelements; i++) {
		if (priv->elements[i].data == NULL)
			continue;
		memset(priv->elements[i].data, 0, MAXFIELDSIZE);
		isc_mem_put(mctx, priv->elements[i].data, MAXFIELDSIZE);
	}
	priv->nelements = 0;
}

isc_result_t
dst__privstruct_parse(dst_key_t *key, unsigned int alg, isc_lex_t *lex,
		      isc_mem_t *mctx, dst_private_t *priv)
{
	int n = 0, major, minor;
	isc_buffer_t b;
	isc_token_t token;
	unsigned char *data = NULL;
	unsigned int opt = ISC_LEXOPT_EOL;
	isc_stdtime_t when;
	isc_result_t ret;

	REQUIRE(priv != NULL);

	priv->nelements = 0;
	memset(priv->elements, 0, sizeof(priv->elements));

#define NEXTTOKEN(lex, opt, token)				\
	do {							\
		ret = isc_lex_gettoken(lex, opt, token);	\
		if (ret != ISC_R_SUCCESS)			\
			goto fail;				\
	} while (0)

#define READLINE(lex, opt, token)				\
	do {							\
		ret = isc_lex_gettoken(lex, opt, token);	\
		if (ret == ISC_R_EOF)				\
			break;					\
		else if (ret != ISC_R_SUCCESS)			\
			goto fail;				\
	} while ((*token).type != isc_tokentype_eol)

	/*
	 * Read the description line.
	 */
	NEXTTOKEN(lex, opt, &token);
	if (token.type != isc_tokentype_string ||
	    strcmp(DST_AS_STR(token), PRIVATE_KEY_STR) != 0)
	{
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}

	NEXTTOKEN(lex, opt, &token);
	if (token.type != isc_tokentype_string ||
	    (DST_AS_STR(token))[0] != 'v')
	{
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}
	if (sscanf(DST_AS_STR(token), "v%d.%d", &major, &minor) != 2)
	{
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}

	if (major > DST_MAJOR_VERSION) {
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}

	/*
	 * Store the private key format version number
	 */
	dst_key_setprivateformat(key, major, minor);

	READLINE(lex, opt, &token);

	/*
	 * Read the algorithm line.
	 */
	NEXTTOKEN(lex, opt, &token);
	if (token.type != isc_tokentype_string ||
	    strcmp(DST_AS_STR(token), ALGORITHM_STR) != 0)
	{
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}

	NEXTTOKEN(lex, opt | ISC_LEXOPT_NUMBER, &token);
	if (token.type != isc_tokentype_number ||
	    token.value.as_ulong != (unsigned long) dst_key_alg(key))
	{
		ret = DST_R_INVALIDPRIVATEKEY;
		goto fail;
	}

	READLINE(lex, opt, &token);

	/*
	 * Read the key data.
	 */
	for (n = 0; n < MAXFIELDS; n++) {
		int tag;
		isc_region_t r;
		do {
			ret = isc_lex_gettoken(lex, opt, &token);
			if (ret == ISC_R_EOF)
				goto done;
			if (ret != ISC_R_SUCCESS)
				goto fail;
		} while (token.type == isc_tokentype_eol);

		if (token.type != isc_tokentype_string) {
			ret = DST_R_INVALIDPRIVATEKEY;
			goto fail;
		}

		/* Numeric metadata */
		tag = find_numericdata(DST_AS_STR(token));
		if (tag >= 0) {
			INSIST(tag < NUMERIC_NTAGS);

			NEXTTOKEN(lex, opt | ISC_LEXOPT_NUMBER, &token);
			if (token.type != isc_tokentype_number) {
				ret = DST_R_INVALIDPRIVATEKEY;
				goto fail;
			}

			dst_key_setnum(key, tag, token.value.as_ulong);
			goto next;
		}

		/* Timing metadata */
		tag = find_timedata(DST_AS_STR(token));
		if (tag >= 0) {
			INSIST(tag < TIMING_NTAGS);

			NEXTTOKEN(lex, opt, &token);
			if (token.type != isc_tokentype_string) {
				ret = DST_R_INVALIDPRIVATEKEY;
				goto fail;
			}

			ret = dns_time32_fromtext(DST_AS_STR(token), &when);
			if (ret != ISC_R_SUCCESS)
				goto fail;

			dst_key_settime(key, tag, when);

			goto next;
		}

		/* Key data */
		tag = find_value(DST_AS_STR(token), alg);
		if (tag < 0 && minor > DST_MINOR_VERSION)
			goto next;
		else if (tag < 0) {
			ret = DST_R_INVALIDPRIVATEKEY;
			goto fail;
		}

		priv->elements[n].tag = tag;

		data = (unsigned char *) isc_mem_get(mctx, MAXFIELDSIZE);
		if (data == NULL)
			goto fail;

		isc_buffer_init(&b, data, MAXFIELDSIZE);
		ret = isc_base64_tobuffer(lex, &b, -1);
		if (ret != ISC_R_SUCCESS)
			goto fail;

		isc_buffer_usedregion(&b, &r);
		priv->elements[n].length = r.length;
		priv->elements[n].data = r.base;
		priv->nelements++;

	  next:
		READLINE(lex, opt, &token);
		data = NULL;
	}
 done:
	if (check_data(priv, alg, ISC_TRUE) < 0)
		goto fail;

	return (ISC_R_SUCCESS);

fail:
	dst__privstruct_free(priv, mctx);
	if (data != NULL)
		isc_mem_put(mctx, data, MAXFIELDSIZE);

	return (ret);
}

isc_result_t
dst__privstruct_writefile(const dst_key_t *key, const dst_private_t *priv,
			  const char *directory)
{
	FILE *fp;
	int ret, i;
	isc_result_t result;
	char filename[ISC_DIR_NAMEMAX];
	char buffer[MAXFIELDSIZE * 2];
	isc_fsaccess_t access;
	isc_stdtime_t when;
	isc_uint32_t value;
	isc_buffer_t b;
	isc_region_t r;
	int major, minor;

	REQUIRE(priv != NULL);

	if (check_data(priv, dst_key_alg(key), ISC_FALSE) < 0)
		return (DST_R_INVALIDPRIVATEKEY);

	isc_buffer_init(&b, filename, sizeof(filename));
	ret = dst_key_buildfilename(key, DST_TYPE_PRIVATE, directory, &b);
	if (ret != ISC_R_SUCCESS)
		return (ret);

	if ((fp = fopen(filename, "w")) == NULL)
		return (DST_R_WRITEERROR);

	access = 0;
	isc_fsaccess_add(ISC_FSACCESS_OWNER,
			 ISC_FSACCESS_READ | ISC_FSACCESS_WRITE,
			 &access);
	(void)isc_fsaccess_set(filename, access);

	dst_key_getprivateformat(key, &major, &minor);
	if (major == 0 && minor == 0) {
		major = DST_MAJOR_VERSION;
		minor = DST_MINOR_VERSION;
	}

	/* XXXDCL return value should be checked for full filesystem */
	fprintf(fp, "%s v%d.%d\n", PRIVATE_KEY_STR, major, minor);

	fprintf(fp, "%s %d ", ALGORITHM_STR, dst_key_alg(key));

	/* XXXVIX this switch statement is too sparse to gen a jump table. */
	switch (dst_key_alg(key)) {
	case DST_ALG_RSAMD5:
		fprintf(fp, "(RSA)\n");
		break;
	case DST_ALG_DH:
		fprintf(fp, "(DH)\n");
		break;
	case DST_ALG_DSA:
		fprintf(fp, "(DSA)\n");
		break;
	case DST_ALG_RSASHA1:
		fprintf(fp, "(RSASHA1)\n");
		break;
	case DST_ALG_NSEC3RSASHA1:
		fprintf(fp, "(NSEC3RSASHA1)\n");
		break;
	case DST_ALG_NSEC3DSA:
		fprintf(fp, "(NSEC3DSA)\n");
		break;
	case DST_ALG_RSASHA256:
		fprintf(fp, "(RSASHA256)\n");
		break;
	case DST_ALG_RSASHA512:
		fprintf(fp, "(RSASHA512)\n");
		break;
	case DST_ALG_ECCGOST:
		fprintf(fp, "(ECC-GOST)\n");
		break;
	case DST_ALG_HMACMD5:
		fprintf(fp, "(HMAC_MD5)\n");
		break;
	case DST_ALG_HMACSHA1:
		fprintf(fp, "(HMAC_SHA1)\n");
		break;
	case DST_ALG_HMACSHA224:
		fprintf(fp, "(HMAC_SHA224)\n");
		break;
	case DST_ALG_HMACSHA256:
		fprintf(fp, "(HMAC_SHA256)\n");
		break;
	case DST_ALG_HMACSHA384:
		fprintf(fp, "(HMAC_SHA384)\n");
		break;
	case DST_ALG_HMACSHA512:
		fprintf(fp, "(HMAC_SHA512)\n");
		break;
	default:
		fprintf(fp, "(?)\n");
		break;
	}

	for (i = 0; i < priv->nelements; i++) {
		const char *s;

		s = find_tag(priv->elements[i].tag);

		r.base = priv->elements[i].data;
		r.length = priv->elements[i].length;
		isc_buffer_init(&b, buffer, sizeof(buffer));
		result = isc_base64_totext(&r, sizeof(buffer), "", &b);
		if (result != ISC_R_SUCCESS) {
			fclose(fp);
			return (DST_R_INVALIDPRIVATEKEY);
		}
		isc_buffer_usedregion(&b, &r);

	       fprintf(fp, "%s %.*s\n", s, (int)r.length, r.base);
	}

	/* Add the metadata tags */
	if (major > 1 || (major == 1 && minor >= 3)) {
		for (i = 0; i < NUMERIC_NTAGS; i++) {
			result = dst_key_getnum(key, i, &value);
			if (result != ISC_R_SUCCESS)
				continue;
			fprintf(fp, "%s %u\n", numerictags[i], value);
		}
		for (i = 0; i < TIMING_NTAGS; i++) {
			result = dst_key_gettime(key, i, &when);
			if (result != ISC_R_SUCCESS)
				continue;

			isc_buffer_init(&b, buffer, sizeof(buffer));
			result = dns_time32_totext(when, &b);
		       if (result != ISC_R_SUCCESS) {
			       fclose(fp);
			       return (DST_R_INVALIDPRIVATEKEY);
		       }

			isc_buffer_usedregion(&b, &r);

		       fprintf(fp, "%s %.*s\n", timetags[i], (int)r.length,
				r.base);
		}
	}

	fflush(fp);
	result = ferror(fp) ? DST_R_WRITEERROR : ISC_R_SUCCESS;
	fclose(fp);
	return (result);
}

/*! \file */