privcache: New closure for signature key handling

[secnet.git] / rsa.c

diff --git a/rsa.c b/rsa.c
index 49672c2511bb26a5ed38dfb841ba4b4f1ab0b755..1c37ef98acf3abec9e641267d532e720efa74f27 100644 (file)
--- a/rsa.c
+++ b/rsa.c
@@ -41,10 +41,15 @@
 
 #define mpp(s,n) do { char *p = mpz_get_str(NULL,16,n); printf("%s 0x%sL\n", s, p); free(p); } while (0)
 
+struct rsacommon {
+    uint8_t *hashbuf;
+};
+
 struct rsapriv {
     closure_t cl;
     struct sigprivkey_if ops;
     struct cloc loc;
+    struct rsacommon common;
     MP_INT n;
     MP_INT p, dp;
     MP_INT q, dq;
@@ -54,6 +59,7 @@ struct rsapub {
     closure_t cl;
     struct sigpubkey_if ops;
     struct cloc loc;
+    struct rsacommon common;
     MP_INT e;
     MP_INT n;
 };
@@ -67,6 +73,24 @@ struct rsapub {
 
 static const char *hexchars="0123456789abcdef";
 
+static void rsa_sethash(struct rsacommon *c, struct hash_if *hash,
+                       const struct hash_if **in_ops)
+{
+    free(c->hashbuf);
+    c->hashbuf=safe_malloc(hash->hlen, "generate_msg");
+    *in_ops=hash;
+}
+static void rsa_pub_sethash(void *sst, struct hash_if *hash)
+{
+    struct rsapub *st=sst;
+    rsa_sethash(&st->common, hash, &st->ops.hash);
+}
+static void rsa_priv_sethash(void *sst, struct hash_if *hash)
+{
+    struct rsapriv *st=sst;
+    rsa_sethash(&st->common, hash, &st->ops.hash);
+}
+
 static void emsa_pkcs1(MP_INT *n, MP_INT *m,
                       const uint8_t *data, int32_t datalen)
 {
@@ -94,7 +118,7 @@ static void emsa_pkcs1(MP_INT *n, MP_INT *m,
     msize=mpz_sizeinbase(n, 16);
 
     if (datalen*2+6>=msize) {
-       fatal("rsa_sign: message too big");
+       fatal("rsa: message too big");
     }
 
     strcpy(buff,"0001");
@@ -126,8 +150,9 @@ static bool_t rsa_sign(void *sst, uint8_t *data, int32_t datalen,
     mpz_init(&a);
     mpz_init(&b);
 
+    hash_hash(st->ops.hash,data,datalen,st->common.hashbuf);
     /* Construct the message representative. */
-    emsa_pkcs1(&st->n, &a, data, datalen);
+    emsa_pkcs1(&st->n, &a, st->common.hashbuf, st->ops.hash->hlen);
 
     /*
      * Produce an RSA signature (a^d mod n) using the Chinese
@@ -188,9 +213,9 @@ static bool_t rsa_sig_unpick(void *sst, struct buffer_if *msg,
 {
     uint8_t *lp = buf_unprepend(msg, 2);
     if (!lp) return False;
-    sig->siglen = get_uint16(lp);
-    sig->sigstart = buf_unprepend(msg, sig->siglen);
-    if (!sig->sigstart) return False;
+    sig->len = get_uint16(lp);
+    sig->start = buf_unprepend(msg, sig->len);
+    if (!sig->start) return False;
 
     /* In `rsa_sig_check' below, we assume that we can write a nul
      * terminator following the signature.  Make sure there's enough space.
@@ -213,13 +238,14 @@ static bool_t rsa_sig_check(void *sst, uint8_t *data, int32_t datalen,
     mpz_init(&b);
     mpz_init(&c);
 
-    emsa_pkcs1(&st->n, &a, data, datalen);
+    hash_hash(st->ops.hash,data,datalen,st->common.hashbuf);
+    emsa_pkcs1(&st->n, &a, st->common.hashbuf, st->ops.hash->hlen);
 
     /* Terminate signature with a '0' - already checked that this will fit */
-    int save = sig->sigstart[sig->siglen];
-    sig->sigstart[sig->siglen] = 0;
-    mpz_set_str(&b, sig->sigstart, 16);
-    sig->sigstart[sig->siglen] = save;
+    int save = sig->start[sig->len];
+    sig->start[sig->len] = 0;
+    mpz_set_str(&b, sig->start, 16);
+    sig->start[sig->len] = save;
 
     mpz_powm(&c, &b, &st->e, &st->n);
 
@@ -245,8 +271,12 @@ static list_t *rsapub_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->cl.apply=NULL;
     st->cl.interface=&st->ops;
     st->ops.st=st;
+    st->ops.sethash=rsa_pub_sethash;
+    st->common.hashbuf=NULL;
     st->ops.unpick=rsa_sig_unpick;
     st->ops.check=rsa_sig_check;
+    st->ops.hash=0;
+    st->ops.dispose=0; /* xxx */
     st->loc=loc;
 
     i=list_elem(args,0);
@@ -324,7 +354,11 @@ static list_t *rsapriv_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->cl.apply=NULL;
     st->cl.interface=&st->ops;
     st->ops.st=st;
+    st->ops.sethash=rsa_priv_sethash;
+    st->common.hashbuf=NULL;
     st->ops.sign=rsa_sign;
+    st->ops.hash=0;
+    st->ops.dispose=0; /* xxx */
     st->loc=loc;
 
     /* Argument is filename pointing to SSH1 private key file */