cscvs to tla changeset 75

[onak.git] / keyid.c

diff --git a/keyid.c b/keyid.c
index 6bb2e19d2a893469c7e68012631f0170a286c418..0a61c1f91c926b8f838b42aba0e510b5b2928321 100644 (file)
--- a/keyid.c
+++ b/keyid.c
@@ -10,6 +10,7 @@
 
 #include "keyid.h"
 #include "keystructs.h"
+#include "log.h"
 #include "md5.h"
 #include "sha.h"
 
@@ -24,50 +25,55 @@ uint64_t get_keyid(struct openpgp_publickey *publickey)
 }
 
 /**
- *     get_packetid - Given a PGP packet returns the keyid.
- *     @packet: The packet to calculate the id for.
+ *     get_fingerprint - Given a public key returns the fingerprint.
+ *     @publickey: The key to calculate the id for.
+ *     @fingerprint: The fingerprint (must be at least 20 bytes of space). 
+ *     @len: The length of the returned fingerprint.
+ *
+ *     This function returns the fingerprint for a given public key. As Type 3
+ *     fingerprints are 16 bytes and Type 4 are 20 the len field indicates
+ *     which we've returned.
  */
-uint64_t get_packetid(struct openpgp_packet *packet)
+unsigned char *get_fingerprint(struct openpgp_packet *packet,
+       unsigned char *fingerprint,
+       size_t *len)
 {
        SHA1_CONTEXT sha_ctx;
-       uint64_t keyid = 0;
-       int offset = 0;
-       int i = 0;
+       MD5_CONTEXT md5_ctx;
        unsigned char c;
        unsigned char *buff = NULL;
+       size_t         modlen, explen;
 
-       assert(packet != NULL);
+       assert(fingerprint != NULL);
+       assert(len != NULL);
+
+       *len = 0;
 
        switch (packet->data[0]) {
        case 2:
        case 3:
+               md5_init(&md5_ctx);
+
                /*
-                * 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
-                * onwards.
-                *
-                * We need to ensure it's an RSA key.
+                * MD5 the modulus and exponent.
                 */
-               if (packet->data[7] == 1) {
-                       offset = (packet->data[8] << 8) +
-                               packet->data[9];
-                       offset = ((offset + 7) / 8) + 2;
+               modlen = ((packet->data[8] << 8) +
+                        packet->data[9] + 7) >> 3;
+               md5_write(&md5_ctx, &packet->data[10], modlen);
+
+               explen = ((packet->data[10+modlen] << 8) +
+                        packet->data[11+modlen] + 7) >> 3;
+               md5_write(&md5_ctx, &packet->data[12 + modlen], explen);
+
+               md5_final(&md5_ctx);
+               buff = md5_read(&md5_ctx);
+
+               *len = 16;
+               memcpy(fingerprint, buff, *len);
 
-                       for (keyid = 0, i = 0; i < 8; i++) {
-                               keyid <<= 8;
-                               keyid += packet->data[offset++];
-                       }
-               } else {
-                       fputs("Type 2 or 3 key, but not RSA.\n", stderr);
-               }
                break;
+
        case 4:
-               /*
-                * For a type 4 key the keyid is the last 64 bits of the
-                * fingerprint, which is the 160 bit SHA-1 hash of the packet
-                * tag, 2 octet packet length and the public key packet
-                * including version field.
-                */
                sha1_init(&sha_ctx);
                /*
                 * TODO: Can this be 0x99? Are all public key packets old
@@ -84,7 +90,58 @@ uint64_t get_packetid(struct openpgp_packet *packet)
                sha1_final(&sha_ctx);
                buff = sha1_read(&sha_ctx);
 
-               assert(buff != NULL);
+               *len = 20;
+               memcpy(fingerprint, buff, *len);
+               break;
+       default:
+               logthing(LOGTHING_ERROR, "Unknown key type: %d",
+                               packet->data[0]);
+       }
+
+       return fingerprint;
+}
+
+
+/**
+ *     get_packetid - Given a PGP packet returns the keyid.
+ *     @packet: The packet to calculate the id for.
+ */
+uint64_t get_packetid(struct openpgp_packet *packet)
+{
+       uint64_t        keyid = 0;
+       int             offset = 0;
+       int             i = 0;
+       size_t          length = 0;
+       unsigned char   buff[20];
+
+       assert(packet != NULL);
+
+       switch (packet->data[0]) {
+       case 2:
+       case 3:
+               /*
+                * 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
+                * onwards.
+                *
+                * We need to ensure it's an RSA key.
+                */
+               if (packet->data[7] == 1) {
+                       offset = (packet->data[8] << 8) +
+                               packet->data[9];
+                       offset = ((offset + 7) / 8) + 2;
+
+                       for (keyid = 0, i = 0; i < 8; i++) {
+                               keyid <<= 8;
+                               keyid += packet->data[offset++];
+                       }
+               } else {
+                       logthing(LOGTHING_ERROR,
+                                       "Type 2 or 3 key, but not RSA.");
+               }
+               break;
+       case 4:
+               get_fingerprint(packet, buff, &length);
                
                for (keyid = 0, i = 12; i < 20; i++) {
                        keyid <<= 8;
@@ -93,7 +150,7 @@ uint64_t get_packetid(struct openpgp_packet *packet)
 
                break;
        default:
-               fprintf(stderr, "Unknown key type: %d\n",
+               logthing(LOGTHING_ERROR, "Unknown key type: %d",
                                packet->data[0]);
        }