diff options
Diffstat (limited to 'libtomcrypt/src/pk/rsa/rsa_import.c')
| -rw-r--r-- | libtomcrypt/src/pk/rsa/rsa_import.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/rsa/rsa_import.c b/libtomcrypt/src/pk/rsa/rsa_import.c new file mode 100644 index 0000000..7b12fd9 --- /dev/null +++ b/libtomcrypt/src/pk/rsa/rsa_import.c @@ -0,0 +1,143 @@ +/* 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.com + */ +#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, only support >= 1024-bit keys, 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) +{ + int err; + void *zero; + unsigned char *tmpbuf; + unsigned long t, x, y, z, tmpoid[16]; + ltc_asn1_list ssl_pubkey_hashoid[2]; + ltc_asn1_list ssl_pubkey[2]; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(ltc_mp.name != 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)) != CRYPT_OK) { + return err; + } + + /* see if the OpenSSL DER format RSA public key will work */ + tmpbuf = XCALLOC(1, MAX_RSA_SIZE*8); + if (tmpbuf == NULL) { + err = CRYPT_MEM; + goto LBL_ERR; + } + + /* this includes the internal hash ID and optional params (NULL in this case) */ + LTC_SET_ASN1(ssl_pubkey_hashoid, 0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid, sizeof(tmpoid)/sizeof(tmpoid[0])); + LTC_SET_ASN1(ssl_pubkey_hashoid, 1, LTC_ASN1_NULL, NULL, 0); + + /* the actual format of the SSL DER key is odd, it stores a RSAPublicKey in a **BIT** string ... so we have to extract it + then proceed to convert bit to octet + */ + LTC_SET_ASN1(ssl_pubkey, 0, LTC_ASN1_SEQUENCE, &ssl_pubkey_hashoid, 2); + LTC_SET_ASN1(ssl_pubkey, 1, LTC_ASN1_BIT_STRING, tmpbuf, MAX_RSA_SIZE*8); + + if (der_decode_sequence(in, inlen, + ssl_pubkey, 2UL) == CRYPT_OK) { + + /* ok now we have to reassemble the BIT STRING to an OCTET STRING. Thanks OpenSSL... */ + for (t = y = z = x = 0; x < ssl_pubkey[1].size; x++) { + y = (y << 1) | tmpbuf[x]; + if (++z == 8) { + tmpbuf[t++] = (unsigned char)y; + y = 0; + z = 0; + } + } + + /* now it should be SEQUENCE { INTEGER, INTEGER } */ + if ((err = der_decode_sequence_multi(tmpbuf, t, + LTC_ASN1_INTEGER, 1UL, key->N, + LTC_ASN1_INTEGER, 1UL, key->e, + LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { + XFREE(tmpbuf); + goto LBL_ERR; + } + XFREE(tmpbuf); + key->type = PK_PUBLIC; + return CRYPT_OK; + } + XFREE(tmpbuf); + + /* not SSL public key, try to match against PKCS #1 standards */ + if ((err = der_decode_sequence_multi(in, inlen, + LTC_ASN1_INTEGER, 1UL, key->N, + LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { + goto LBL_ERR; + } + + if (mp_cmp_d(key->N, 0) == LTC_MP_EQ) { + if ((err = mp_init(&zero)) != CRYPT_OK) { + goto LBL_ERR; + } + /* it's a private key */ + if ((err = der_decode_sequence_multi(in, inlen, + LTC_ASN1_INTEGER, 1UL, zero, + LTC_ASN1_INTEGER, 1UL, key->N, + LTC_ASN1_INTEGER, 1UL, key->e, + LTC_ASN1_INTEGER, 1UL, key->d, + LTC_ASN1_INTEGER, 1UL, key->p, + LTC_ASN1_INTEGER, 1UL, key->q, + LTC_ASN1_INTEGER, 1UL, key->dP, + LTC_ASN1_INTEGER, 1UL, key->dQ, + LTC_ASN1_INTEGER, 1UL, key->qP, + LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { + mp_clear(zero); + goto LBL_ERR; + } + mp_clear(zero); + key->type = PK_PRIVATE; + } else if (mp_cmp_d(key->N, 1) == LTC_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_decode_sequence_multi(in, inlen, + LTC_ASN1_INTEGER, 1UL, key->N, + LTC_ASN1_INTEGER, 1UL, key->e, + LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { + goto LBL_ERR; + } + 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 */ + + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_import.c,v $ */ +/* $Revision: 1.21 $ */ +/* $Date: 2006/12/04 22:23:27 $ */ |