diff options
Diffstat (limited to 'dst/dst_api.c')
| -rw-r--r-- | dst/dst_api.c | 1089 |
1 files changed, 1089 insertions, 0 deletions
diff --git a/dst/dst_api.c b/dst/dst_api.c new file mode 100644 index 0000000..8925c66 --- /dev/null +++ b/dst/dst_api.c @@ -0,0 +1,1089 @@ +#ifndef LINT +static const char rcsid[] = "$Header: /proj/cvs/prod/DHCP/dst/dst_api.c,v 1.9 2009-10-29 00:46:48 sar Exp $"; +#endif + +/* + * Portions Copyright (c) 1995-1998 by Trusted Information Systems, Inc. + * Portions Copyright (c) 2007,2009 by Internet Systems Consortium, Inc. ("ISC") + * + * 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 TRUSTED INFORMATION SYSTEMS + * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL + * TRUSTED INFORMATION SYSTEMS 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 THE SOFTWARE. + */ +/* + * This file contains the interface between the DST API and the crypto API. + * This is the only file that needs to be changed if the crypto system is + * changed. Exported functions are: + * void dst_init() Initialize the toolkit + * int dst_check_algorithm() Function to determines if alg is supported. + * int dst_compare_keys() Function to compare two keys for equality. + * int dst_sign_data() Incremental signing routine. + * int dst_verify_data() Incremental verify routine. + * int dst_generate_key() Function to generate new KEY + * DST_KEY *dst_read_key() Function to retrieve private/public KEY. + * void dst_write_key() Function to write out a key. + * DST_KEY *dst_dnskey_to_key() Function to convert DNS KEY RR to a DST + * KEY structure. + * int dst_key_to_dnskey() Function to return a public key in DNS + * format binary + * DST_KEY *dst_buffer_to_key() Convert a data in buffer to KEY + * int *dst_key_to_buffer() Writes out DST_KEY key material in buffer + * void dst_free_key() Releases all memory referenced by key structure + */ + +#include <stdio.h> +#include <errno.h> +#include <fcntl.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <memory.h> +#include <ctype.h> +#include <time.h> +#include <sys/param.h> +#include <sys/stat.h> +#include <sys/socket.h> +#include <netinet/in.h> + +#include "cdefs.h" +#include "osdep.h" +#include "arpa/nameser.h" + +#include "dst_internal.h" + +/* static variables */ +static int done_init = 0; +dst_func *dst_t_func[DST_MAX_ALGS]; +const char *key_file_fmt_str = "Private-key-format: v%s\nAlgorithm: %d (%s)\n"; +const char *dst_path = ""; + +/* internal I/O functions */ +static DST_KEY *dst_s_read_public_key(const char *in_name, + const unsigned in_id, int in_alg); +static int dst_s_read_private_key_file(char *name, DST_KEY *pk_key, + unsigned in_id, int in_alg); +static int dst_s_write_public_key(const DST_KEY *key); +static int dst_s_write_private_key(const DST_KEY *key); + +/* internal function to set up data structure */ +static DST_KEY *dst_s_get_key_struct(const char *name, const int alg, + const u_int32_t flags, const int protocol, + const int bits); + +/* + * dst_init + * This function initializes the Digital Signature Toolkit. + * Right now, it just checks the DSTKEYPATH environment variable. + * Parameters + * none + * Returns + * none + */ +void +dst_init() +{ + char *s; + unsigned len; + + if (done_init != 0) + return; + done_init = 1; + + s = getenv("DSTKEYPATH"); + len = 0; + if (s) { + struct stat statbuf; + + len = strlen(s); + if (len > PATH_MAX) { + EREPORT(("%s is longer than %d characters, ignoring\n", + s, PATH_MAX)); + } else if (stat(s, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) { + EREPORT(("%s is not a valid directory\n", s)); + } else { + char *dp = (char *) malloc(len + 2); + int l; + memcpy(dp, s, len + 1); + l = strlen (dp); + if (dp[l - 1] != '/') { + dp[l + 1] = 0; + dp[l] = '/'; + } + dst_path = dp; + } + } + memset(dst_t_func, 0, sizeof(dst_t_func)); + /* first one is selected */ +#if 0 + dst_bsafe_init(); + dst_rsaref_init(); +#endif + dst_hmac_md5_init(); +#if 0 + dst_eay_dss_init(); + dst_cylink_init(); +#endif +} + +/* + * dst_check_algorithm + * This function determines if the crypto system for the specified + * algorithm is present. + * Parameters + * alg 1 KEY_RSA + * 3 KEY_DSA + * 157 KEY_HMAC_MD5 + * future algorithms TBD and registered with IANA. + * Returns + * 1 - The algorithm is available. + * 0 - The algorithm is not available. + */ +int +dst_check_algorithm(const int alg) +{ + return (dst_t_func[alg] != NULL); +} + +/* + * dst_s_get_key_struct + * This function allocates key structure and fills in some of the + * fields of the structure. + * Parameters: + * name: the name of the key + * alg: the algorithm number + * flags: the dns flags of the key + * protocol: the dns protocol of the key + * bits: the size of the key + * Returns: + * NULL if error + * valid pointer otherwise + */ +static DST_KEY * +dst_s_get_key_struct(const char *name, const int alg, const u_int32_t flags, + const int protocol, const int bits) +{ + DST_KEY *new_key = NULL; + + if (dst_check_algorithm(alg)) /* make sure alg is available */ + new_key = (DST_KEY *) malloc(sizeof(*new_key)); + if (new_key == NULL) + return (NULL); + + memset(new_key, 0, sizeof(*new_key)); + new_key->dk_key_name = strdup(name); + new_key->dk_alg = alg; + new_key->dk_flags = flags; + new_key->dk_proto = protocol; + new_key->dk_KEY_struct = NULL; + new_key->dk_key_size = bits; + new_key->dk_func = dst_t_func[alg]; + return (new_key); +} + +/* + * dst_compare_keys + * Compares two keys for equality. + * Parameters + * key1, key2 Two keys to be compared. + * Returns + * 0 The keys are equal. + * non-zero The keys are not equal. + */ + +int +dst_compare_keys(const DST_KEY *key1, const DST_KEY *key2) +{ + if (key1 == key2) + return (0); + if (key1 == NULL || key2 == NULL) + return (4); + if (key1->dk_alg != key2->dk_alg) + return (1); + if (key1->dk_key_size != key2->dk_key_size) + return (2); + if (key1->dk_id != key2->dk_id) + return (3); + return (key1->dk_func->compare(key1, key2)); +} + + +/* + * dst_sign_data + * An incremental signing function. Data is signed in steps. + * First the context must be initialized (SIG_MODE_INIT). + * Then data is hashed (SIG_MODE_UPDATE). Finally the signature + * itself is created (SIG_MODE_FINAL). This function can be called + * once with INIT, UPDATE and FINAL modes all set, or it can be + + * called separately with a different mode set for each step. The + * UPDATE step can be repeated. + * Parameters + * mode A bit mask used to specify operation(s) to be performed. + * SIG_MODE_INIT 1 Initialize digest + * SIG_MODE_UPDATE 2 Add data to digest + * SIG_MODE_FINAL 4 Generate signature + * from signature + * SIG_MODE_ALL (SIG_MODE_INIT,SIG_MODE_UPDATE,SIG_MODE_FINAL + * data Data to be signed. + * len The length in bytes of data to be signed. + * in_key Contains a private key to sign with. + * KEY structures should be handled (created, converted, + * compared, stored, freed) by the DST. + * signature + * The location to which the signature will be written. + * sig_len Length of the signature field in bytes. + * Return + * 0 Successful INIT or Update operation + * >0 success FINAL (sign) operation + * <0 failure + */ + +int +dst_sign_data(const int mode, DST_KEY *in_key, void **context, + const u_char *data, const unsigned len, + u_char *signature, const unsigned sig_len) +{ + DUMP(data, mode, len, "dst_sign_data()"); + + if (mode & SIG_MODE_FINAL && + (in_key->dk_KEY_struct == NULL || signature == NULL)) + return (MISSING_KEY_OR_SIGNATURE); + + if (in_key->dk_func && in_key->dk_func->sign) + return (in_key->dk_func->sign(mode, in_key, context, data, len, + signature, sig_len)); + return (UNKNOWN_KEYALG); +} + + +/* + * dst_verify_data + * An incremental verify function. Data is verified in steps. + * First the context must be initialized (SIG_MODE_INIT). + * Then data is hashed (SIG_MODE_UPDATE). Finally the signature + * is verified (SIG_MODE_FINAL). This function can be called + * once with INIT, UPDATE and FINAL modes all set, or it can be + * called separately with a different mode set for each step. The + * UPDATE step can be repeated. + * Parameters + * mode Operations to perform this time. + * SIG_MODE_INIT 1 Initialize digest + * SIG_MODE_UPDATE 2 add data to digest + * SIG_MODE_FINAL 4 verify signature + * SIG_MODE_ALL + * (SIG_MODE_INIT,SIG_MODE_UPDATE,SIG_MODE_FINAL) + * data Data to pass through the hash function. + * len Length of the data in bytes. + * in_key Key for verification. + * signature Location of signature. + * sig_len Length of the signature in bytes. + * Returns + * 0 Verify success + * Non-Zero Verify Failure + */ + +int +dst_verify_data(const int mode, DST_KEY *in_key, void **context, + const u_char *data, const unsigned len, + const u_char *signature, const unsigned sig_len) +{ + DUMP(data, mode, len, "dst_verify_data()"); + if (mode & SIG_MODE_FINAL && + (in_key->dk_KEY_struct == NULL || signature == NULL)) + return (MISSING_KEY_OR_SIGNATURE); + + if (in_key->dk_func == NULL || in_key->dk_func->verify == NULL) + return (UNSUPPORTED_KEYALG); + return (in_key->dk_func->verify(mode, in_key, context, data, len, + signature, sig_len)); +} + + +/* + * dst_read_private_key + * Access a private key. First the list of private keys that have + * already been read in is searched, then the key accessed on disk. + * If the private key can be found, it is returned. If the key cannot + * be found, a null pointer is returned. The options specify required + * key characteristics. If the private key requested does not have + * these characteristics, it will not be read. + * Parameters + * in_keyname The private key name. + * in_id The id of the private key. + * options DST_FORCE_READ Read from disk - don't use a previously + * read key. + * DST_CAN_SIGN The key must be usable for signing. + * DST_NO_AUTHEN The key must be usable for authentication. + * DST_STANDARD Return any key + * Returns + * NULL If there is no key found in the current directory or + * this key has not been loaded before. + * !NULL Success - KEY structure returned. + */ + +DST_KEY * +dst_read_key(const char *in_keyname, const unsigned in_id, + const int in_alg, const int type) +{ + char keyname[PATH_MAX]; + DST_KEY *dg_key = NULL, *pubkey = NULL; + + if (!dst_check_algorithm(in_alg)) { /* make sure alg is available */ + EREPORT(("dst_read_private_key(): Algorithm %d not supported\n", + in_alg)); + return (NULL); + } + if ((type && (DST_PUBLIC | DST_PRIVATE)) == 0) + return (NULL); + if (in_keyname == NULL) { + EREPORT(("dst_read_private_key(): Null key name passed in\n")); + return (NULL); + } else + strcpy(keyname, in_keyname); + + /* before I read in the public key, check if it is allowed to sign */ + if ((pubkey = dst_s_read_public_key(keyname, in_id, in_alg)) == NULL) + return (NULL); + + if (type == DST_PUBLIC) + return pubkey; + + if (!(dg_key = dst_s_get_key_struct(keyname, pubkey->dk_alg, + pubkey->dk_flags, pubkey->dk_proto, + 0))) + return (dg_key); + /* Fill in private key and some fields in the general key structure */ + if (dst_s_read_private_key_file(keyname, dg_key, pubkey->dk_id, + pubkey->dk_alg) == 0) + dg_key = dst_free_key(dg_key); + + pubkey = dst_free_key(pubkey); + return (dg_key); +} + +int +dst_write_key(const DST_KEY *key, const int type) +{ + int pub = 0, priv = 0; + + if (key == NULL) + return (0); + if (!dst_check_algorithm(key->dk_alg)) { /* make sure alg is available */ + EREPORT(("dst_write_key(): Algorithm %d not supported\n", + key->dk_alg)); + return (UNSUPPORTED_KEYALG); + } + if ((type & (DST_PRIVATE|DST_PUBLIC)) == 0) + return (0); + + if (type & DST_PUBLIC) + if ((pub = dst_s_write_public_key(key)) < 0) + return (pub); + if (type & DST_PRIVATE) + if ((priv = dst_s_write_private_key(key)) < 0) + return (priv); + return (priv+pub); +} + +/* + * dst_write_private_key + * Write a private key to disk. The filename will be of the form: + * K<key->dk_name>+<key->dk_alg>+<key->dk_id>.<private key suffix>. + * If there is already a file with this name, an error is returned. + * + * Parameters + * key A DST managed key structure that contains + * all information needed about a key. + * Return + * >= 0 Correct behavior. Returns length of encoded key value + * written to disk. + * < 0 error. + */ + +static int +dst_s_write_private_key(const DST_KEY *key) +{ + u_char encoded_block[RAW_KEY_SIZE]; + char file[PATH_MAX]; + unsigned len; + FILE *fp; + + /* First encode the key into the portable key format */ + if (key == NULL) + return (-1); + if (key->dk_KEY_struct == NULL) + return (0); /* null key has no private key */ + + if (key->dk_func == NULL || key->dk_func->to_file_fmt == NULL) { + EREPORT(("dst_write_private_key(): Unsupported operation %d\n", + key->dk_alg)); + return (-5); + } else if ((len = key->dk_func->to_file_fmt(key, (char *)encoded_block, + sizeof(encoded_block))) <= 0) { + EREPORT(("dst_write_private_key(): Failed encoding private RSA bsafe key %d\n", len)); + return (-8); + } + /* Now I can create the file I want to use */ + dst_s_build_filename(file, key->dk_key_name, key->dk_id, key->dk_alg, + PRIVATE_KEY, PATH_MAX); + + /* Do not overwrite an existing file */ + if ((fp = dst_s_fopen(file, "w", 0600)) != NULL) { + int nn; + if ((nn = fwrite(encoded_block, 1, len, fp)) != len) { + EREPORT(("dst_write_private_key(): Write failure on %s %d != %d errno=%d\n", + file, out_len, nn, errno)); + return (-5); + } + fclose(fp); + } else { + EREPORT(("dst_write_private_key(): Can not create file %s\n" + ,file)); + return (-6); + } + memset(encoded_block, 0, len); + return (len); +} + +/* +* + * dst_read_public_key + * Read a public key from disk and store in a DST key structure. + * Parameters + * in_name K<in_name><in_id>.<public key suffix> is the + * filename of the key file to be read. + * Returns + * NULL If the key does not exist or no name is supplied. + * NON-NULL Initialized key structure if the key exists. + */ + +static DST_KEY * +dst_s_read_public_key(const char *in_name, const unsigned in_id, int in_alg) +{ + unsigned flags, len; + int proto, alg, dlen; + int c; + char name[PATH_MAX], enckey[RAW_KEY_SIZE]; + unsigned char *notspace; + u_char deckey[RAW_KEY_SIZE]; + FILE *fp; + + if (in_name == NULL) { + EREPORT(("dst_read_public_key(): No key name given\n")); + return (NULL); + } + if (dst_s_build_filename(name, in_name, in_id, in_alg, PUBLIC_KEY, + PATH_MAX) == -1) { + EREPORT(("dst_read_public_key(): Cannot make filename from %s, %d, and %s\n", + in_name, in_id, PUBLIC_KEY)); + return (NULL); + } + /* + * Open the file and read it's formatted contents up to key + * File format: + * domain.name [ttl] [IN] KEY <flags> <protocol> <algorithm> <key> + * flags, proto, alg stored as decimal (or hex numbers FIXME). + * (FIXME: handle parentheses for line continuation.) + */ + if ((fp = dst_s_fopen(name, "r", 0)) == NULL) { + EREPORT(("dst_read_public_key(): Public Key not found %s\n", + name)); + return (NULL); + } + /* Skip domain name, which ends at first blank */ + while ((c = getc(fp)) != EOF) + if (isspace(c)) + break; + /* Skip blank to get to next field */ + while ((c = getc(fp)) != EOF) + if (!isspace(c)) + break; + + /* Skip optional TTL -- if initial digit, skip whole word. */ + if (isdigit(c)) { + while ((c = getc(fp)) != EOF) + if (isspace(c)) + break; + while ((c = getc(fp)) != EOF) + if (!isspace(c)) + break; + } + /* Skip optional "IN" */ + if (c == 'I' || c == 'i') { + while ((c = getc(fp)) != EOF) + if (isspace(c)) + break; + while ((c = getc(fp)) != EOF) + if (!isspace(c)) + break; + } + /* Locate and skip "KEY" */ + if (c != 'K' && c != 'k') { + EREPORT(("\"KEY\" doesn't appear in file: %s", name)); + return NULL; + } + while ((c = getc(fp)) != EOF) + if (isspace(c)) + break; + while ((c = getc(fp)) != EOF) + if (!isspace(c)) + break; + ungetc(c, fp); /* return the character to the input field */ + /* Handle hex!! FIXME. */ + + if (fscanf(fp, "%d %d %d", &flags, &proto, &alg) != 3) { + EREPORT(("dst_read_public_key(): Can not read flag/proto/alg field from %s\n" + ,name)); + return (NULL); + } + /* read in the key string */ + if ((fgets(enckey, sizeof(enckey), fp) == NULL) && + (ferror(fp) != 0)) { + EREPORT(("dst_read_public_kety(): Error reading key\n")); + return (NULL); + } + + /* If we aren't at end-of-file, something is wrong. */ + while ((c = getc(fp)) != EOF) + if (!isspace(c)) + break; + if (!feof(fp)) { + EREPORT(("Key too long in file: %s", name)); + return NULL; + } + fclose(fp); + + if ((len = strlen(enckey)) <= 0) + return (NULL); + + /* discard \n */ + enckey[--len] = '\0'; + + /* remove leading spaces */ + for (notspace = (unsigned char *)enckey; isspace(*notspace); len--) + notspace++; + + dlen = b64_pton((char *)notspace, deckey, sizeof(deckey)); + if (dlen < 0) { + EREPORT(("dst_read_public_key: bad return from b64_pton = %d", + dlen)); + return (NULL); + } + /* store key and info in a key structure that is returned */ +/* return dst_store_public_key(in_name, alg, proto, 666, flags, deckey, + dlen);*/ + return dst_buffer_to_key(in_name, alg, + flags, proto, deckey, (unsigned)dlen); +} + + +/* + * dst_write_public_key + * Write a key to disk in DNS format. + * Parameters + * key Pointer to a DST key structure. + * Returns + * 0 Failure + * 1 Success + */ + +static int +dst_s_write_public_key(const DST_KEY *key) +{ + FILE *fp; + char filename[PATH_MAX]; + u_char out_key[RAW_KEY_SIZE]; + char enc_key[RAW_KEY_SIZE]; + int len = 0; + + memset(out_key, 0, sizeof(out_key)); + if (key == NULL) { + EREPORT(("dst_write_public_key(): No key specified \n")); + return (0); + } else if ((len = dst_key_to_dnskey(key, out_key, sizeof(out_key)))< 0) + return (0); + + /* Make the filename */ + if (dst_s_build_filename(filename, key->dk_key_name, key->dk_id, + key->dk_alg, PUBLIC_KEY, PATH_MAX) == -1) { + EREPORT(("dst_write_public_key(): Cannot make filename from %s, %d, and %s\n", + key->dk_key_name, key->dk_id, PUBLIC_KEY)); + return (0); + } + /* create public key file */ + if ((fp = dst_s_fopen(filename, "w+", 0644)) == NULL) { + EREPORT(("DST_write_public_key: open of file:%s failed (errno=%d)\n", + filename, errno)); + return (0); + } + /*write out key first base64 the key data */ + if (key->dk_flags & DST_EXTEND_FLAG) + b64_ntop(&out_key[6], + (unsigned)(len - 6), enc_key, sizeof(enc_key)); + else + b64_ntop(&out_key[4], + (unsigned)(len - 4), enc_key, sizeof(enc_key)); + fprintf(fp, "%s IN KEY %d %d %d %s\n", + key->dk_key_name, + key->dk_flags, key->dk_proto, key->dk_alg, enc_key); + fclose(fp); + return (1); +} + + +/* + * dst_dnskey_to_public_key + * This function converts the contents of a DNS KEY RR into a DST + * key structure. + * Parameters + * len Length of the RDATA of the KEY RR RDATA + * rdata A pointer to the the KEY RR RDATA. + * in_name Key name to be stored in key structure. + * Returns + * NULL Failure + * NON-NULL Success. Pointer to key structure. + * Caller's responsibility to free() it. + */ + +DST_KEY * +dst_dnskey_to_key(const char *in_name, + const u_char *rdata, const unsigned len) +{ + DST_KEY *key_st; + int alg ; + int start = DST_KEY_START; + + if (rdata == NULL || len <= DST_KEY_ALG) /* no data */ + return (NULL); + alg = (u_int8_t) rdata[DST_KEY_ALG]; + if (!dst_check_algorithm(alg)) { /* make sure alg is available */ + EREPORT(("dst_dnskey_to_key(): Algorithm %d not supported\n", + alg)); + return (NULL); + } + if ((key_st = dst_s_get_key_struct(in_name, alg, 0, 0, 0)) == NULL) + return (NULL); + + if (in_name == NULL) + return (NULL); + key_st->dk_flags = dst_s_get_int16(rdata); + key_st->dk_proto = (u_int16_t) rdata[DST_KEY_PROT]; + if (key_st->dk_flags & DST_EXTEND_FLAG) { + u_int32_t ext_flags; + ext_flags = (u_int32_t) dst_s_get_int16(&rdata[DST_EXT_FLAG]); + key_st->dk_flags = key_st->dk_flags | (ext_flags << 16); + start += 2; + } + /* + * now point to the beginning of the data representing the encoding + * of the key + */ + if (key_st->dk_func && key_st->dk_func->from_dns_key) { + if (key_st->dk_func->from_dns_key(key_st, &rdata[start], + len - start) > 0) + return (key_st); + } else + EREPORT(("dst_dnskey_to_public_key(): unsupported alg %d\n", + alg)); + + SAFE_FREE(key_st); + return (key_st); +} + + +/* + * dst_public_key_to_dnskey + * Function to encode a public key into DNS KEY wire format + * Parameters + * key Key structure to encode. + * out_storage Location to write the encoded key to. + * out_len Size of the output array. + * Returns + * <0 Failure + * >=0 Number of bytes written to out_storage + */ + +int +dst_key_to_dnskey(const DST_KEY *key, u_char *out_storage, + const unsigned out_len) +{ + u_int16_t val; + int loc = 0; + int enc_len = 0; + if (key == NULL) + return (-1); + + if (!dst_check_algorithm(key->dk_alg)) { /* make sure alg is available */ + EREPORT(("dst_key_to_dnskey(): Algorithm %d not supported\n", + key->dk_alg)); + return (UNSUPPORTED_KEYALG); + } + memset(out_storage, 0, out_len); + val = (u_int16_t)(key->dk_flags & 0xffff); + out_storage[0] = (val >> 8) & 0xff; + out_storage[1] = val & 0xff; + loc += 2; + + out_storage[loc++] = (u_char) key->dk_proto; + out_storage[loc++] = (u_char) key->dk_alg; + + if (key->dk_flags > 0xffff) { /* Extended flags */ + val = (u_int16_t)((key->dk_flags >> 16) & 0xffff); + out_storage[loc] = (val >> 8) & 0xff; + out_storage[loc+1] = val & 0xff; + loc += 2; + } + if (key->dk_KEY_struct == NULL) + return (loc); + if (key->dk_func && key->dk_func->to_dns_key) { + enc_len = key->dk_func->to_dns_key(key, + (u_char *) &out_storage[loc], + out_len - loc); + if (enc_len > 0) + return (enc_len + loc); + else + return (-1); + } else + EREPORT(("dst_key_to_dnskey(): Unsupported ALG %d\n", + key->dk_alg)); + return (-1); +} + + +/* + * dst_buffer_to_key + * Function to encode a string of raw data into a DST key + * Parameters + * alg The algorithm (HMAC only) + * key A pointer to the data + * keylen The length of the data + * Returns + * NULL an error occurred + * NON-NULL the DST key + */ +DST_KEY * +dst_buffer_to_key(const char *key_name, /* name of the key */ + const int alg, /* algorithm */ + const unsigned flags, /* dns flags */ + const int protocol, /* dns protocol */ + const u_char *key_buf, /* key in dns wire fmt */ + const unsigned key_len) /* size of key */ +{ + + DST_KEY *dkey = NULL; + + if (!dst_check_algorithm(alg)) { /* make sure alg is available */ + EREPORT(("dst_buffer_to_key(): Algorithm %d not supported\n", alg)); + return (NULL); + } + + dkey = dst_s_get_key_struct(key_name, alg, flags, protocol, -1); + + if (dkey == NULL) + return (NULL); + if (dkey->dk_func != NULL && + dkey->dk_func->from_dns_key != NULL) { + if (dkey->dk_func->from_dns_key(dkey, key_buf, key_len) < 0) { + EREPORT(("dst_buffer_to_key(): dst_buffer_to_hmac failed\n")); + return (dst_free_key(dkey)); + } + return (dkey); + } + return (NULL); +} + +int +dst_key_to_buffer(DST_KEY *key, u_char *out_buff, unsigned buf_len) +{ + int len; + /* this function will extract the secret of HMAC into a buffer */ + if(key == NULL) + return (0); + if(key->dk_func != NULL && key->dk_func != NULL) { + len = key->dk_func->to_dns_key(key, out_buff, buf_len); + if (len < 0) + return (0); + return (len); + } + return (0); +} + + +/* + * dst_s_read_private_key_file + * Function reads in private key from a file. + * Fills out the KEY structure. + * Parameters + * name Name of the key to be read. + * pk_key Structure that the key is returned in. + * in_id Key identifier (tag) + * Return + * 1 if everything works + * 0 if there is any problem + */ + +static int +dst_s_read_private_key_file(char *name, DST_KEY *pk_key, unsigned in_id, + int in_alg) +{ + int cnt, alg, len, major, minor, file_major, file_minor; + int id; + char filename[PATH_MAX]; + u_char in_buff[RAW_KEY_SIZE]; + char *p; + FILE *fp; + + if (name == NULL || pk_key == NULL) { + EREPORT(("dst_read_private_key_file(): No key name given\n")); + return (0); + } + /* Make the filename */ + if (dst_s_build_filename(filename, name, in_id, in_alg, PRIVATE_KEY, + PATH_MAX) == -1) { + EREPORT(("dst_read_private_key(): Cannot make filename from %s, %d, and %s\n", + name, in_id, PRIVATE_KEY)); + return (0); + } + /* first check if we can find the key file */ + if ((fp = dst_s_fopen(filename, "r", 0)) == NULL) { + EREPORT(("dst_s_read_private_key_file: Could not open file %s in directory %s\n", + filename, dst_path[0] ? dst_path : + (char *) getcwd(NULL, PATH_MAX - 1))); + return (0); + } + /* now read the header info from the file */ + if ((cnt = fread(in_buff, 1, sizeof(in_buff), fp)) < 5) { + fclose(fp); + EREPORT(("dst_s_read_private_key_file: error reading file %s (empty file)\n", + filename)); + return (0); + } + /* decrypt key */ + fclose(fp); + if (memcmp(in_buff, "Private-key-format: v", 20) != 0) + goto fail; + len = cnt; + p = (char *)in_buff; + + if (!dst_s_verify_str((const char **) &p, "Private-key-format: v")) { + EREPORT(("dst_s_read_private_key_file(): Not a Key file/Decrypt failed %s\n", name)); + goto fail; + } + /* read in file format */ + sscanf(p, "%d.%d", &file_major, &file_minor); + sscanf(KEY_FILE_FORMAT, "%d.%d", &major, &minor); + if (file_major < 1) { + EREPORT(("dst_s_read_private_key_file(): Unknown keyfile %d.%d version for %s\n", + file_major, file_minor, name)); + goto fail; + } else if (file_major > major || file_minor > minor) + EREPORT(( + "dst_s_read_private_key_file(): Keyfile %s version higher than mine %d.%d MAY FAIL\n", + name, file_major, file_minor)); + + while (*p++ != '\n') ; /* skip to end of line */ + + if (!dst_s_verify_str((const char **) &p, "Algorithm: ")) + goto fail; + + if (sscanf(p, "%d", &alg) != 1) + goto fail; + while (*p++ != '\n') ; /* skip to end of line */ + + if (pk_key->dk_key_name && !strcmp(pk_key->dk_key_name, name)) + SAFE_FREE2(pk_key->dk_key_name, strlen(pk_key->dk_key_name)); + pk_key->dk_key_name = (char *) strdup(name); + + /* allocate and fill in key structure */ + if (pk_key->dk_func == NULL || pk_key->dk_func->from_file_fmt == NULL) + goto fail; + + id = pk_key->dk_func->from_file_fmt(pk_key, (char *)p, + (unsigned)(&in_buff[len] - (u_char *)p)); + if (id < 0) + goto fail; + + /* Make sure the actual key tag matches the input tag used in the filename + */ + if (id != in_id) { + EREPORT(("dst_s_read_private_key_file(): actual tag of key read %d != input tag used to build filename %d.\n", id, in_id)); + goto fail; + } + pk_key->dk_id = (u_int16_t) id; + pk_key->dk_alg = alg; + memset(in_buff, 0, (unsigned)cnt); + return (1); + + fail: + memset(in_buff, 0, (unsigned)cnt); + return (0); +} + + +/* + * dst_generate_key + * Generate and store a public/private keypair. + * Keys will be stored in formatted files. + * Parameters + * name Name of the new key. Used to create key files + * K<name>+<alg>+<id>.public and K<name>+<alg>+<id>.private. + * bits Size of the new key in bits. + * exp What exponent to use: + * 0 use exponent 3 + * non-zero use Fermant4 + * flags The default value of the DNS Key flags. + * The DNS Key RR Flag field is defined in RFC 2065, + * section 3.3. The field has 16 bits. + * protocol + * Default value of the DNS Key protocol field. + * The DNS Key protocol field is defined in RFC 2065, + * section 3.4. The field has 8 bits. + * alg What algorithm to use. Currently defined: + * KEY_RSA 1 + * KEY_DSA 3 + * KEY_HMAC 157 + * out_id The key tag is returned. + * + * Return + * NULL Failure + * non-NULL the generated key pair + * Caller frees the result, and its dk_name pointer. + */ +DST_KEY * +dst_generate_key(const char *name, const int bits, const int exp, + const unsigned flags, const int protocol, const int alg) +{ + DST_KEY *new_key = NULL; + int res; + if (name == NULL) + return (NULL); + + if (!dst_check_algorithm(alg)) { /* make sure alg is available */ + EREPORT(("dst_generate_key(): Algorithm %d not supported\n", alg)); + return (NULL); + } + + new_key = dst_s_get_key_struct(name, alg, flags, protocol, bits); + if (new_key == NULL) + return (NULL); + if (bits == 0) /* null key we are done */ + return (new_key); + if (new_key->dk_func == NULL || new_key->dk_func->generate == NULL) { + EREPORT(("dst_generate_key_pair():Unsupported algorithm %d\n", + alg)); + return (dst_free_key(new_key)); + } + if ((res = new_key->dk_func->generate(new_key, exp)) <= 0) { + EREPORT(("dst_generate_key_pair(): Key generation failure %s %d %d %d\n", + new_key->dk_key_name, new_key->dk_alg, + new_key->dk_key_size, exp)); + return (dst_free_key(new_key)); + } + return (new_key); +} + + +/* + * dst_free_key + * Release all data structures pointed to by a key structure. + * Parameters + * f_key Key structure to be freed. + */ + +DST_KEY * +dst_free_key(DST_KEY *f_key) +{ + + if (f_key == NULL) + return (f_key); + if (f_key->dk_func && f_key->dk_func->destroy) + f_key->dk_KEY_struct = + f_key->dk_func->destroy(f_key->dk_KEY_struct); + else { + EREPORT(("dst_free_key(): Unknown key alg %d\n", + f_key->dk_alg)); + free(f_key->dk_KEY_struct); /* SHOULD NOT happen */ + } + if (f_key->dk_KEY_struct) { + free(f_key->dk_KEY_struct); + f_key->dk_KEY_struct = NULL; + } + if (f_key->dk_key_name) + SAFE_FREE(f_key->dk_key_name); + SAFE_FREE(f_key); + return (NULL); +} + +/* + * dst_sig_size + * Return the maximum size of signature from the key specified in bytes + * Parameters + * key + * Returns + * bytes + */ +int +dst_sig_size(DST_KEY *key) { + switch (key->dk_alg) { + case KEY_HMAC_MD5: + return (16); + case KEY_HMAC_SHA1: + return (20); + case KEY_RSA: + return (key->dk_key_size + 7) / 8; + case KEY_DSA: + return (40); + default: + EREPORT(("dst_sig_size(): Unknown key alg %d\n", key->dk_alg)); + return -1; + } +} + +/* + * dst_random + * function that multiplexes number of random number generators + * Parameters + * mode: select the random number generator + * wanted is how many bytes of random data are requested + * outran is a buffer of size at least wanted for the output data + * + * Returns + * number of bytes written to outran + */ +int +dst_random(const int mode, unsigned wanted, u_char *outran) +{ + u_int32_t *buff = NULL, *bp = NULL; + int i; + if (wanted <= 0 || outran == NULL) + return (0); + + switch (mode) { + case DST_RAND_SEMI: + bp = buff = (u_int32_t *) malloc(wanted+sizeof(u_int32_t)); + for (i = 0; i < wanted; i+= sizeof(u_int32_t), bp++) { + *bp = dst_s_quick_random(i); + } + memcpy(outran, buff, (unsigned)wanted); + SAFE_FREE(buff); + return (wanted); + case DST_RAND_STD: + return (dst_s_semi_random(outran, wanted)); + case DST_RAND_KEY: + return (dst_s_random(outran, wanted)); + case DST_RAND_DSS: + default: + /* need error case here XXX OG */ + return (0); + } +} + |