Mercurial > dropbear
annotate ecc.c @ 757:230666086711 ecc
ecc key import function
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Wed, 27 Mar 2013 23:50:52 +0800 |
| parents | bf9dc2d9c2b1 |
| children | 76fba0856749 |
| rev | line source |
|---|---|
| 756 | 1 #include "includes.h" |
| 2 #include "options.h" | |
| 3 #include "ecc.h" | |
| 4 | |
|
755
b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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5 #ifdef DROPBEAR_ECC |
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b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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6 |
| 757 | 7 // TODO: use raw bytes for the dp rather than the hex strings in libtomcrypt's ecc.c |
| 8 | |
| 756 | 9 #ifdef DROPBEAR_ECC_256 |
| 757 | 10 const struct dropbear_ecc_curve ecc_curve_secp256r1 { |
| 11 .dp = <c_ecc_sets[0], | |
| 756 | 12 .hash_desc = sha256_desc, |
| 13 .name = "secp256r1" | |
| 14 }; | |
| 15 #endif | |
| 16 | |
| 17 | |
| 18 #ifdef DROPBEAR_ECC_384 | |
| 757 | 19 const struct dropbear_ecc_curve ecc_curve_secp384r1 { |
| 20 .dp = <c_ecc_sets[1], | |
| 756 | 21 .hash_desc = sha384_desc, |
| 22 .name = "secp384r1" | |
| 23 }; | |
| 24 #endif | |
| 25 | |
| 757 | 26 #ifdef DROPBEAR_ECC_521 |
| 27 const struct dropbear_ecc_curve ecc_curve_secp521r1 { | |
| 28 .dp = <c_ecc_sets[2], | |
| 29 .hash_desc = sha521_desc, | |
| 30 .name = "secp521r1" | |
| 756 | 31 }; |
| 32 #endif | |
| 33 | |
| 34 | |
| 757 | 35 void buf_put_ecc_pubkey_string(buffer *buf, ecc_key *key) { |
| 756 | 36 // XXX point compression |
|
755
b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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37 int len = key->dp->size*2 + 1; |
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b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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38 buf_putint(len); |
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b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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39 int err = ecc_ansi_x963_export(key, buf_getwriteptr(buf, len), &len); |
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b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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40 if (err != CRYPT_OK) { |
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b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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41 dropbear_exit("ECC error"); |
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b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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42 } |
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b07eb3dc23ec
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Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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43 buf_incrwritepos(buf, len); |
|
b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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44 } |
|
b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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45 |
| 757 | 46 ecc_key * buf_get_ecc_key_string(buffer *buf, const struct dropbear_ecc_curve *curve) { |
| 47 ecc_key *key = NULL; | |
| 48 int ret = DROPBEAR_FAILURE; | |
| 49 const int size = curve->dp->size; | |
| 50 unsigned int len = buf_get_string(buf); | |
| 51 unsigned char first = buf_get_char(buf); | |
| 52 if (first == 2 || first == 3) { | |
| 53 dropbear_log("Dropbear doesn't support ECC point compression"); | |
| 54 return NULL; | |
| 55 } | |
| 56 if (first != 4 || len != 1+2*size) { | |
| 57 return NULL; | |
| 58 } | |
| 59 | |
| 60 key = m_malloc(sizeof(*key)); | |
| 61 m_mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL); | |
| 62 | |
| 63 if (mp_read_unsigned_bin(&key->pubkey.x, buf_getptr(buf, size), size) != MP_OKAY) { | |
| 64 goto out; | |
| 65 } | |
| 66 buf_incrpos(buf, size); | |
| 67 | |
| 68 if (mp_read_unsigned_bin(&key->pubkey.y, buf_getptr(buf, size), size) != MP_OKAY) { | |
| 69 goto out; | |
| 70 } | |
| 71 buf_incrpos(buf, size); | |
| 72 | |
| 73 if (mp_set(key->pubkey.z, 1) != MP_OKAY) { | |
| 74 goto out; | |
| 75 } | |
| 76 | |
| 77 if (is_point(key) != CRYPT_OK) { | |
| 78 goto out; | |
| 79 } | |
| 80 | |
| 81 // SEC1 3.2.3.1 Check that Q != 0 | |
| 82 if (mp_cmp_d(key->pubkey.x, 0) == LTC_MP_EQ) { | |
| 83 goto out; | |
| 84 } | |
| 85 if (mp_cmp_d(key->pubkey.y, 0) == LTC_MP_EQ) { | |
| 86 goto out; | |
| 87 } | |
| 88 | |
| 89 ret = DROPBEAR_SUCCESS; | |
| 90 | |
| 91 out: | |
| 92 if (ret == DROPBEAR_FAILURE) { | |
| 93 if (key) { | |
| 94 mp_free_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL); | |
| 95 m_free(key); | |
| 96 key = NULL; | |
| 97 } | |
| 98 } | |
| 99 | |
| 100 return key; | |
| 101 | |
|
755
b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
102 } |
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b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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103 |
| 756 | 104 // a modified version of libtomcrypt's "ecc_shared_secret" to output |
| 105 // a mp_int instead. | |
| 106 mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, ecc_key *private_key) | |
| 107 { | |
| 108 ecc_point *result = NULL | |
| 109 mp_int *prime = NULL, *shared_secret = NULL; | |
| 110 int ret = DROPBEAR_FAILURE; | |
| 111 | |
| 112 /* type valid? */ | |
| 113 if (private_key->type != PK_PRIVATE) { | |
| 114 goto done; | |
| 115 } | |
| 116 | |
| 117 if (private_key->dp != public_key->dp) { | |
| 118 goto done; | |
| 119 } | |
| 120 | |
| 121 #if 0 | |
| 122 // XXX - possibly not neccessary tests? | |
| 123 if (ltc_ecc_is_valid_idx(private_key->idx) == 0 || ltc_ecc_is_valid_idx(public_key->idx) == 0) { | |
| 124 goto done; | |
| 125 } | |
| 126 | |
| 127 if (XSTRCMP(private_key->dp->name, public_key->dp->name) != 0) { | |
| 128 goto done; | |
| 129 } | |
| 130 #endif | |
| 131 | |
| 132 /* make new point */ | |
| 133 result = ltc_ecc_new_point(); | |
| 134 if (result == NULL) { | |
| 135 goto done; | |
| 136 } | |
| 137 | |
| 138 prime = m_malloc(sizeof(*prime)); | |
| 139 m_mp_init(prime); | |
| 140 | |
| 141 if (mp_read_radix(prime, (char *)private_key->dp->prime, 16) != CRYPT_OK) { | |
| 142 goto done; | |
| 143 } | |
| 144 if (ltc_mp.ecc_ptmul(private_key->k, &public_key->pubkey, result, prime, 1) != CRYPT_OK) { | |
| 145 goto done; | |
| 146 } | |
| 147 | |
| 148 err = DROPBEAR_SUCCESS; | |
| 149 done: | |
| 150 if (err == DROPBEAR_SUCCESS) { | |
| 151 shared_secret = prime; | |
| 152 prime = NULL; | |
| 153 } | |
| 154 | |
| 155 if (prime) { | |
| 156 mp_clear(prime); | |
| 157 m_free(prime); | |
| 158 } | |
| 159 ltc_ecc_del_point(result); | |
| 160 | |
| 161 if (err == DROPBEAR_FAILURE) { | |
| 162 dropbear_exit("ECC error"); | |
| 163 } | |
| 164 | |
| 165 return shared_secret; | |
| 166 return err; | |
| 167 } | |
| 168 | |
| 169 } | |
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755
b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
170 |
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b07eb3dc23ec
refactor kexdh code a bit, start working on ecdh etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
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171 #endif |