serpent, transform: rework GET_32BIT_MSB_FIRST, PUT_...

[secnet.git] / transform.c

diff --git a/transform.c b/transform.c
index 5497711c228b7b4b0e2395739c5b00a0b97886e2..08ddad6e2831dfc844ebf22c16148c99f24f9b8d 100644 (file)
--- a/transform.c
+++ b/transform.c
@@ -19,7 +19,6 @@
 
 struct transform {
     closure_t cl;
-    uint32_t line;
     struct transform_if ops;
     uint32_t max_seq_skew;
 };
@@ -60,21 +59,28 @@ static bool_t transform_setkey(void *sst, uint8_t *key, int32_t keylen)
 
     serpent_makekey(&ti->cryptkey,256,key);
     serpent_makekey(&ti->mackey,256,key+32);
-    ti->cryptiv=GET_32BIT_MSB_FIRST(key+64);
-    ti->maciv=GET_32BIT_MSB_FIRST(key+68);
-    ti->sendseq=GET_32BIT_MSB_FIRST(key+72);
+    ti->cryptiv=get_uint32(key+64);
+    ti->maciv=get_uint32(key+68);
+    ti->sendseq=get_uint32(key+72);
     ti->lastrecvseq=ti->sendseq;
     ti->keyed=True;
 
     return True;
 }
 
+static bool_t transform_valid(void *sst)
+{
+    struct transform_inst *ti=sst;
+
+    return ti->keyed;
+}
+
 static void transform_delkey(void *sst)
 {
     struct transform_inst *ti=sst;
 
-    memset(&ti->cryptkey,0,sizeof(ti->cryptkey));
-    memset(&ti->mackey,0,sizeof(ti->mackey));
+    FILLZERO(ti->cryptkey);
+    FILLZERO(ti->mackey);
     ti->keyed=False;
 }
 
@@ -115,7 +121,7 @@ static uint32_t transform_forward(void *sst, struct buffer_if *buf,
        it we've have to add 16 bytes to each message, not 4, so that the
        message stays a multiple of 16 bytes long.) */
     memset(iv,0,16);
-    PUT_32BIT_MSB_FIRST(iv, ti->maciv);
+    put_uint32(iv, ti->maciv);
     serpent_encrypt(&ti->mackey,iv,macacc);
 
     /* CBCMAC: encrypt in CBC mode. The MAC is the last encrypted
@@ -132,7 +138,7 @@ static uint32_t transform_forward(void *sst, struct buffer_if *buf,
     /* Serpent-CBC. We expand the ID as for CBCMAC, do the encryption,
        and prepend the IV before increasing it. */
     memset(iv,0,16);
-    PUT_32BIT_MSB_FIRST(iv, ti->cryptiv);
+    put_uint32(iv, ti->cryptiv);
     serpent_encrypt(&ti->cryptkey,iv,iv);
 
     /* CBC: each block is XORed with the previous encrypted block (or the IV)
@@ -172,16 +178,21 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
        return 1;
     }
 
+    if (buf->size < 4 + 16 + 16) {
+       *errmsg="msg too short";
+       return 1;
+    }
 
     /* CBC */
     memset(iv,0,16);
     {
        uint32_t ivword = buf_unprepend_uint32(buf);
-       PUT_32BIT_MSB_FIRST(iv, ivword);
+       put_uint32(iv, ivword);
     }
     /* Assert bufsize is multiple of blocksize */
     if (buf->size&0xf) {
        *errmsg="msg not multiple of cipher blocksize";
+       return 1;
     }
     serpent_encrypt(&ti->cryptkey,iv,iv);
     for (n=buf->start; n<buf->start+buf->size; n+=16)
@@ -197,7 +208,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
     /* CBCMAC */
     macexpected=buf_unappend(buf,16);
     memset(iv,0,16);
-    PUT_32BIT_MSB_FIRST(iv, ti->maciv);
+    put_uint32(iv, ti->maciv);
     serpent_encrypt(&ti->mackey,iv,macacc);
 
     /* CBCMAC: encrypt in CBC mode. The MAC is the last encrypted
@@ -209,7 +220,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
        serpent_encrypt(&ti->mackey,macplain,macacc);
     }
     serpent_encrypt(&ti->mackey,macacc,macacc);
-    if (memcmp(macexpected,macacc,16)!=0) {
+    if (!consttime_memeq(macexpected,macacc,16)!=0) {
        *errmsg="invalid MAC";
        return 1;
     }
@@ -223,13 +234,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
        return 1;
     }
 
-    padp=buf_unappend(buf,padlen-1);
-    for (i=0; i<padlen-1; i++) {
-       if (*++padp != padlen) {
-           *errmsg="pkcs5: corrupted padding";
-           return 1;
-       }
-    }
+    buf_unappend(buf,padlen-1);
 
     /* Sequence number must be within max_skew of lastrecvseq; lastrecvseq
        is only allowed to increase. */
@@ -243,7 +248,7 @@ static uint32_t transform_reverse(void *sst, struct buffer_if *buf,
     } else {
        /* Too much skew */
        *errmsg="seqnum: too much skew";
-       return 1;
+       return 2;
     }
     
     return 0;
@@ -253,7 +258,7 @@ static void transform_destroy(void *sst)
 {
     struct transform_inst *st=sst;
 
-    memset(st,0,sizeof(*st)); /* Destroy key material */
+    FILLZERO(*st); /* Destroy key material */
     free(st);
 }
 
@@ -267,6 +272,7 @@ static struct transform_inst_if *transform_create(void *sst)
 
     ti->ops.st=ti;
     ti->ops.setkey=transform_setkey;
+    ti->ops.valid=transform_valid;
     ti->ops.delkey=transform_delkey;
     ti->ops.forwards=transform_forward;
     ti->ops.reverse=transform_reverse;