X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fdh%2Fdh_set.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fdh%2Fdh_set.c;h=8d0af7d206143b11c7612ef85590c9bbcf940597;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/pk/dh/dh_set.c b/libtomcrypt/src/pk/dh/dh_set.c new file mode 100644 index 0000000..8d0af7d --- /dev/null +++ b/libtomcrypt/src/pk/dh/dh_set.c @@ -0,0 +1,124 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + */ + +#include "tomcrypt.h" + +#ifdef LTC_MDH + +/** + Import DH key parts p and g from raw numbers + + @param p DH's p (prime) + @param plen DH's p's length + @param g DH's g (group) + @param glen DH's g's length + @param key [out] the destination for the imported key + @return CRYPT_OK if successful +*/ +int dh_set_pg(const unsigned char *p, unsigned long plen, + const unsigned char *g, unsigned long glen, + dh_key *key) +{ + int err; + + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(p != NULL); + LTC_ARGCHK(g != NULL); + LTC_ARGCHK(ltc_mp.name != NULL); + + if ((err = mp_init_multi(&key->x, &key->y, &key->base, &key->prime, NULL)) != CRYPT_OK) { + return err; + } + + if ((err = mp_read_unsigned_bin(key->base, (unsigned char*)g, glen)) != CRYPT_OK) { goto LBL_ERR; } + if ((err = mp_read_unsigned_bin(key->prime, (unsigned char*)p, plen)) != CRYPT_OK) { goto LBL_ERR; } + + return CRYPT_OK; + +LBL_ERR: + dh_free(key); + return err; +} + +/** + Import DH key parts p and g from built-in DH groups + + @param groupsize The size of the DH group to use + @param key [out] Where the newly created DH key will be stored + @return CRYPT_OK if successful, note: on error all allocated memory will be freed automatically. +*/ +int dh_set_pg_groupsize(int groupsize, dh_key *key) +{ + int err, i; + + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(ltc_mp.name != NULL); + LTC_ARGCHK(groupsize > 0); + + for (i = 0; (groupsize > ltc_dh_sets[i].size) && (ltc_dh_sets[i].size != 0); i++); + if (ltc_dh_sets[i].size == 0) return CRYPT_INVALID_KEYSIZE; + + if ((err = mp_init_multi(&key->x, &key->y, &key->base, &key->prime, NULL)) != CRYPT_OK) { + return err; + } + if ((err = mp_read_radix(key->base, ltc_dh_sets[i].base, 16)) != CRYPT_OK) { goto LBL_ERR; } + if ((err = mp_read_radix(key->prime, ltc_dh_sets[i].prime, 16)) != CRYPT_OK) { goto LBL_ERR; } + + return CRYPT_OK; + +LBL_ERR: + dh_free(key); + return err; +} + +/** + Import DH public or private key part from raw numbers + + NB: The p & g parts must be set beforehand + + @param in The key-part to import, either public or private. + @param inlen The key-part's length + @param type Which type of key (PK_PRIVATE or PK_PUBLIC) + @param key [out] the destination for the imported key + @return CRYPT_OK if successful +*/ +int dh_set_key(const unsigned char *in, unsigned long inlen, int type, dh_key *key) +{ + int err; + + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(ltc_mp.name != NULL); + + if (type == PK_PRIVATE) { + key->type = PK_PRIVATE; + if ((err = mp_read_unsigned_bin(key->x, (unsigned char*)in, inlen)) != CRYPT_OK) { goto LBL_ERR; } + if ((err = mp_exptmod(key->base, key->x, key->prime, key->y)) != CRYPT_OK) { goto LBL_ERR; } + } + else { + key->type = PK_PUBLIC; + if ((err = mp_read_unsigned_bin(key->y, (unsigned char*)in, inlen)) != CRYPT_OK) { goto LBL_ERR; } + } + + /* check public key */ + if ((err = dh_check_pubkey(key)) != CRYPT_OK) { + goto LBL_ERR; + } + + return CRYPT_OK; + +LBL_ERR: + dh_free(key); + return err; +} + +#endif /* LTC_MDH */ + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */