Add support for old Elgamal v3 key IDs

[onak.git] / keyid.c

diff --git a/keyid.c b/keyid.c
index d114852bd3081b2f44da24fd785ccce3bada8dfe..6920ee478ef4bca7362bca7313047a199b01f02e 100644 (file)
--- a/keyid.c
+++ b/keyid.c
@@ -31,6 +31,7 @@
 
 #ifdef HAVE_NETTLE
 #include <nettle/md5.h>
+#include <nettle/ripemd160.h>
 #include <nettle/sha.h>
 #else
 #include "md5.h"
@@ -130,6 +131,10 @@ onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
        int             i = 0;
        size_t          length = 0;
        unsigned char   buff[20];
+#ifdef NETTLE_WITH_RIPEMD160
+       struct ripemd160_ctx ripemd160_context;
+       uint8_t         data;
+#endif
 
        if (packet == NULL)
                return ONAK_E_INVALID_PARAM;
@@ -137,6 +142,46 @@ onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
        switch (packet->data[0]) {
        case 2:
        case 3:
+               /*
+                * Old versions of GnuPG would put Elgamal keys inside
+                * a V3 key structure, then generate the keyid using
+                * RIPED160.
+                */
+#ifdef NETTLE_WITH_RIPEMD160
+               if (packet->data[7] == 16) {
+                       ripemd160_init(&ripemd160_context);
+                       data = 0x99;
+                       ripemd160_update(&ripemd160_context, 1, &data);
+                       data = packet->length >> 8;
+                       ripemd160_update(&ripemd160_context, 1, &data);
+                       data = packet->length & 0xFF;
+                       ripemd160_update(&ripemd160_context, 1, &data);
+                       ripemd160_update(&ripemd160_context,
+                               packet->length,
+                               packet->data);
+
+                       ripemd160_digest(&ripemd160_context,
+                               RIPEMD160_DIGEST_SIZE,
+                               buff);
+
+                       for (*keyid = 0, i = 12; i < 20; i++) {
+                               *keyid <<= 8;
+                               *keyid += buff[i];
+                       }
+
+                       return ONAK_E_OK;
+               }
+#endif
+               /*
+                * Check for an RSA key; if not return an error.
+                * 1 == RSA
+                * 2 == RSA Encrypt-Only
+                * 3 == RSA Sign-Only
+                */
+               if (packet->data[7] < 1 || packet->data[7] > 3) {
+                       return ONAK_E_INVALID_PKT;
+               }
+
                /*
                 * For a type 2 or 3 key the keyid is the last 64 bits of the
                 * public modulus n, which is stored as an MPI from offset 8
@@ -150,15 +195,6 @@ onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
                        *keyid <<= 8;
                        *keyid += packet->data[offset++];
                }
-               /*
-                * Check for an RSA key; if not return an error.
-                * 1 == RSA
-                * 2 == RSA Encrypt-Only
-                * 3 == RSA Sign-Only
-                */
-               if (packet->data[7] < 1 || packet->data[7] > 3) {
-                       return ONAK_E_INVALID_PKT;
-               }
                break;
        case 4:
                get_fingerprint(packet, buff, &length);