| /* 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. |
| * |
| * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org |
| */ |
| #include "tomcrypt.h" |
| |
| /** |
| @file rsa_import.c |
| Import a PKCS RSA key, Tom St Denis |
| */ |
| |
| #ifdef MRSA |
| |
| /** |
| Import an RSAPublicKey or RSAPrivateKey [two-prime only, defined in PKCS #1 v2.1] |
| @param in The packet to import from |
| @param inlen It's length (octets) |
| @param key [out] Destination for newly imported key |
| @return CRYPT_OK if successful, upon error allocated memory is freed |
| */ |
| int rsa_import(const unsigned char *in, unsigned long inlen, rsa_key *key) |
| { |
| unsigned long x, y; |
| int err; |
| |
| LTC_ARGCHK(in != NULL); |
| LTC_ARGCHK(key != NULL); |
| |
| /* init key */ |
| if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP, &key->qP, |
| &key->p, &key->q, NULL)) != MP_OKAY) { |
| return mpi_to_ltc_error(err); |
| } |
| |
| /* check the header */ |
| if (inlen < 4) { |
| return CRYPT_INVALID_PACKET; |
| } |
| |
| /* should be 0x30 0x8{1|2} LL LL */ |
| if ((in[0] != 0x30) || ((in[1] != 0x81) && (in[1] != 0x82))) { |
| return CRYPT_INVALID_PACKET; |
| } |
| |
| /* ok all the ASN.1 params are fine so far, let's move up */ |
| x = ((unsigned long)in[2]); |
| y = 0; |
| if ((in[1] & ~0x80) == 2) { |
| x = (x << 8) + ((unsigned long)in[3]) + 1; |
| in += 1; |
| y = 1; |
| } |
| in += 3; /* advance input */ |
| x += 3; /* size of packet according to header */ |
| y += 3; /* used input */ |
| |
| if (x != inlen) { |
| return CRYPT_INVALID_PACKET; |
| } |
| |
| /* decrement inlen by the header size */ |
| inlen -= y; |
| |
| /* read first number, it's either N or 0 [0 == private key] */ |
| x = inlen; |
| if ((err = der_get_multi_integer(in, &x, &key->N, NULL)) != CRYPT_OK) { |
| goto LBL_ERR; |
| } |
| |
| /* advance */ |
| inlen -= x; |
| in += x; |
| |
| if (mp_cmp_d(&key->N, 0) == MP_EQ) { |
| /* it's a private key */ |
| if ((err = der_get_multi_integer(in, &inlen, &key->N, &key->e, |
| &key->d, &key->p, &key->q, &key->dP, |
| &key->dQ, &key->qP, NULL)) != CRYPT_OK) { |
| goto LBL_ERR; |
| } |
| |
| key->type = PK_PRIVATE; |
| } else if (mp_cmp_d(&key->N, 1) == MP_EQ) { |
| /* we don't support multi-prime RSA */ |
| err = CRYPT_PK_INVALID_TYPE; |
| goto LBL_ERR; |
| } else { |
| /* it's a public key and we lack e */ |
| if ((err = der_get_multi_integer(in, &inlen, &key->e, NULL)) != CRYPT_OK) { |
| goto LBL_ERR; |
| } |
| |
| /* free up some ram */ |
| mp_clear_multi(&key->p, &key->q, &key->qP, &key->dP, &key->dQ, NULL); |
| |
| key->type = PK_PUBLIC; |
| } |
| return CRYPT_OK; |
| LBL_ERR: |
| mp_clear_multi(&key->d, &key->e, &key->N, &key->dQ, &key->dP, |
| &key->qP, &key->p, &key->q, NULL); |
| return err; |
| } |
| |
| #endif /* MRSA */ |
| |