rsa1: Indirect postreadcheck via the context

[secnet.git] / rsa.c

diff --git a/rsa.c b/rsa.c
index cda8d8924dfac0f4bd68a54d8648d8ec6fa670f6..63816ee232b3638963bacc6b29a97fd477ae5ffa 100644 (file)
--- a/rsa.c
+++ b/rsa.c
@@ -332,6 +332,7 @@ struct rsapriv_load_ctx {
     void (*verror)(struct rsapriv_load_ctx *l,
                   FILE *maybe_f, bool_t unsup,
                   const char *message, va_list args);
+    bool_t (*postreadcheck)(struct rsapriv_load_ctx *l, FILE *f);
     union {
        struct {
            struct cloc loc;
@@ -344,24 +345,27 @@ struct rsapriv_load_ctx {
 #define LDFATAL_FILE(...) ({ load_error(l,f,0,__VA_ARGS__); goto error_out; })
 #define LDUNSUP_FILE(...) ({ load_error(l,f,1,__VA_ARGS__); goto error_out; })
 #define FREE(b)                ({ free((b)); (b)=0; })
+#define KEYFILE_GET(is)   ({                                   \
+       uint##is##_t keyfile_get_tmp=keyfile_get_##is(l,f);     \
+       if (!l->postreadcheck(l,f)) goto error_out;             \
+       keyfile_get_tmp;                                        \
+    })
 
-static uint32_t keyfile_get_int(struct cloc loc, FILE *f)
+static uint32_t keyfile_get_32(struct rsapriv_load_ctx *l, FILE *f)
 {
     uint32_t r;
     r=fgetc(f)<<24;
     r|=fgetc(f)<<16;
     r|=fgetc(f)<<8;
     r|=fgetc(f);
-    cfgfile_postreadcheck(loc,f);
     return r;
 }
 
-static uint16_t keyfile_get_short(struct cloc loc, FILE *f)
+static uint16_t keyfile_get_16(struct rsapriv_load_ctx *l, FILE *f)
 {
     uint16_t r;
     r=fgetc(f)<<8;
     r|=fgetc(f);
-    cfgfile_postreadcheck(loc,f);
     return r;
 }
 
@@ -439,14 +443,14 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     FREE(b);
 
     cipher_type=fgetc(f);
-    keyfile_get_int(loc,f); /* "Reserved data" */
+    KEYFILE_GET(32); /* "Reserved data" */
     if (cipher_type != 0) {
        LDUNSUP("we don't support encrypted keyfiles\n");
     }
 
     /* Read the public key */
-    keyfile_get_int(loc,f); /* Not sure what this is */
-    length=(keyfile_get_short(loc,f)+7)/8;
+    KEYFILE_GET(32); /* Not sure what this is */
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausible length %ld for modulus\n",
                 length);
@@ -457,7 +461,7 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     }
     read_mpbin(&st->n,b,length);
     FREE(b);
-    length=(keyfile_get_short(loc,f)+7)/8;
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausible length %ld for e\n",length);
     }
@@ -468,7 +472,7 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     read_mpbin(&e,b,length);
     FREE(b);
     
-    length=keyfile_get_int(loc,f);
+    length=KEYFILE_GET(32);
     if (length>1024) {
        LDFATAL("implausibly long (%ld) key comment\n",
                 length);
@@ -482,12 +486,12 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     /* Check that the next two pairs of characters are identical - the
        keyfile is not encrypted, so they should be */
 
-    if (keyfile_get_short(loc,f) != keyfile_get_short(loc,f)) {
+    if (KEYFILE_GET(16) != KEYFILE_GET(16)) {
        LDFATAL("corrupt keyfile\n");
     }
 
     /* Read d */
-    length=(keyfile_get_short(loc,f)+7)/8;
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausibly long (%ld) decryption key\n",
                 length);
@@ -499,7 +503,7 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     read_mpbin(&d,b,length);
     FREE(b);
     /* Read iqmp (inverse of q mod p) */
-    length=(keyfile_get_short(loc,f)+7)/8;
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausibly long (%ld)"
                 " iqmp auxiliary value\n", length);
@@ -511,7 +515,7 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     read_mpbin(&iqmp,b,length);
     FREE(b);
     /* Read q (the smaller of the two primes) */
-    length=(keyfile_get_short(loc,f)+7)/8;
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausibly long (%ld) q value\n",
                 length);
@@ -523,7 +527,7 @@ static struct rsapriv *rsa_loadpriv_core(struct rsapriv_load_ctx *l,
     read_mpbin(&st->q,b,length);
     FREE(b);
     /* Read p (the larger of the two primes) */
-    length=(keyfile_get_short(loc,f)+7)/8;
+    length=(KEYFILE_GET(16)+7)/8;
     if (length>RSA_MAX_MODBYTES) {
        LDFATAL("implausibly long (%ld) p value\n",
                 length);
@@ -623,6 +627,12 @@ static void verror_cfgfatal(struct rsapriv_load_ctx *l,
     vcfgfatal_maybefile(maybe_f,l->u.apply.loc,"rsa-private",message,args);
 }
 
+static bool_t postreadcheck_apply(struct rsapriv_load_ctx *l, FILE *f)
+{
+    cfgfile_postreadcheck(l->u.apply.loc,f);
+    return True;
+}
+
 static list_t *rsapriv_apply(closure_t *self, struct cloc loc, dict_t *context,
                             list_t *args)
 {
@@ -633,6 +643,7 @@ static list_t *rsapriv_apply(closure_t *self, struct cloc loc, dict_t *context,
     struct rsapriv_load_ctx l[1];
 
     l->verror=verror_cfgfatal;
+    l->postreadcheck=postreadcheck_apply;
     l->u.apply.loc=loc;
 
     /* Argument is filename pointing to SSH1 private key file */