Add support for displaying ECDH/ECDSA key sizes

The key size of an elliptic curve key is given by the OID defining the
curve. Add support for understanding the OIDs listed in RFC6637 (256,
384 + 521 bits).

diff --git a/keyindex.c b/keyindex.c
index 8800d88e84576ab164381962624105cb010755eb..f3c36aafbf3527408894357ce80c1c7f6ecc2bd0 100644 (file)
--- a/keyindex.c
+++ b/keyindex.c
@@ -76,6 +76,68 @@ char pkalgo2char(uint8_t algo)
        return typech;
 }
 
+/*
+ * Given a public key/subkey packet return the key length.
+ */
+unsigned int keylength(struct openpgp_packet *keydata)
+{
+       unsigned int length;
+
+       switch (keydata->data[0]) {
+       case 2:
+       case 3:
+               length = (keydata->data[8] << 8) +
+                               keydata->data[9];
+               break;
+       case 4:
+               switch (keydata->data[5]) {
+               case OPENPGP_PKALGO_EC:
+               case OPENPGP_PKALGO_ECDSA:
+                       /* Elliptic curve key size is based on OID */
+                       if ((keydata->data[6] == 8) &&
+                                       (keydata->data[7] == 0x2A) &&
+                                       (keydata->data[8] == 0x86) &&
+                                       (keydata->data[9] == 0x48) &&
+                                       (keydata->data[10] == 0xCE) &&
+                                       (keydata->data[11] == 0x3D) &&
+                                       (keydata->data[12] == 0x03) &&
+                                       (keydata->data[13] == 0x01) &&
+                                       (keydata->data[14] == 0x07)) {
+                               length = 256;
+                       } else if ((keydata->data[6] == 5) &&
+                                       (keydata->data[7] == 0x2B) &&
+                                       (keydata->data[8] == 0x81) &&
+                                       (keydata->data[9] == 0x04) &&
+                                       (keydata->data[10] == 0x00) &&
+                                       (keydata->data[11] == 0x22)) {
+                               length = 384;
+                       } else if ((keydata->data[6] == 5) &&
+                                       (keydata->data[7] == 0x2B) &&
+                                       (keydata->data[8] == 0x81) &&
+                                       (keydata->data[9] == 0x04) &&
+                                       (keydata->data[10] == 0x00) &&
+                                       (keydata->data[11] == 0x23)) {
+                               length = 521;
+                       } else {
+                               logthing(LOGTHING_ERROR,
+                                       "Unknown elliptic curve size");
+                               length = 0;
+                       }
+                       break;
+               default:
+                       length = (keydata->data[6] << 8) +
+                               keydata->data[7];
+               }
+               break;
+       default:
+               logthing(LOGTHING_ERROR, "Unknown key version: %d",
+                       keydata->data[0]);
+               length = 0;
+       }
+
+       return length;
+}
+
 int list_sigs(struct openpgp_packet_list *sigs, bool html)
 {
        char *uid = NULL;
@@ -183,19 +245,16 @@ int list_subkeys(struct openpgp_signedpacket_list *subkeys, bool verbose,
                        case 2:
                        case 3:
                                type = subkeys->packet->data[7];
-                               length = (subkeys->packet->data[8] << 8) +
-                                       subkeys->packet->data[9];
                                break;
                        case 4:
                                type = subkeys->packet->data[5];
-                               length = (subkeys->packet->data[6] << 8) +
-                                       subkeys->packet->data[7];
                                break;
                        default:
                                logthing(LOGTHING_ERROR,
                                        "Unknown key type: %d",
                                        subkeys->packet->data[0]);
                        }
+                       length = keylength(subkeys->packet);
 
                        if (get_packetid(subkeys->packet,
                                        &keyid) != ONAK_E_OK) {
@@ -304,19 +363,16 @@ int key_index(struct openpgp_publickey *keys, bool verbose, bool fingerprint,
                case 2:
                case 3:
                        type = keys->publickey->data[7];
-                       length = (keys->publickey->data[8] << 8) +
-                                       keys->publickey->data[9];
                        break;
                case 4:
                        type = keys->publickey->data[5];
-                       length = (keys->publickey->data[6] << 8) +
-                                       keys->publickey->data[7];
                        break;
                default:
                        logthing(LOGTHING_ERROR, "Unknown key type: %d",
                                keys->publickey->data[0]);
                }
-               
+               length = keylength(keys->publickey);
+
                if (get_keyid(keys, &keyid) != ONAK_E_OK) {
                        logthing(LOGTHING_ERROR, "Couldn't get keyid.");
                }
@@ -425,8 +481,6 @@ int mrkey_index(struct openpgp_publickey *keys)
                        }
                        printf("%016" PRIX64, keyid);
                        type = keys->publickey->data[7];
-                       length = (keys->publickey->data[8] << 8) +
-                                       keys->publickey->data[9];
                        break;
                case 4:
                        (void) get_fingerprint(keys->publickey, fp, &fplength);
@@ -436,13 +490,12 @@ int mrkey_index(struct openpgp_publickey *keys)
                        }
 
                        type = keys->publickey->data[5];
-                       length = (keys->publickey->data[6] << 8) +
-                                       keys->publickey->data[7];
                        break;
                default:
                        logthing(LOGTHING_ERROR, "Unknown key type: %d",
                                keys->publickey->data[0]);
                }
+               length = keylength(keys->publickey);
 
                printf(":%d:%d:%ld::%s\n",
                        type,