-n

make cipher API easier to use, and also fix Lua stack traversal bug in digest and hmac code which prematurely exited loop processing parameters

1 files changed, 58 insertions, 25 deletions

diff --git a/openssl.c b/openssl.c
index 7d01172..660d463 100644
--- a/openssl.c
+++ b/openssl.c
@@ -3374,19 +3374,26 @@ static int md_interpose(lua_State *L) {
 } /* md_interpose() */
 
 
-static int md_update(lua_State *L) {
-        EVP_MD_CTX *ctx = luaL_checkudata(L, 1, DIGEST_CLASS);
-        int i, top = lua_gettop(L);
+static void md_update_(lua_State *L, EVP_MD_CTX *ctx, int from, int to) {
+        int i;
 
-        for (i = 2; i < top; i++) {
+        for (i = from; i <= to; i++) {
                 const void *p;
                 size_t n;
 
                 p = luaL_checklstring(L, i, &n);
 
                 if (!EVP_DigestUpdate(ctx, p, n))
-                        return throwssl(L, "digest:update");
+                        throwssl(L, "digest:update");
         }
+} /* md_update_() */
+
+
+static int md_update(lua_State *L) {
+        EVP_MD_CTX *ctx = luaL_checkudata(L, 1, DIGEST_CLASS);
+        int i, top = lua_gettop(L);
+
+        md_update_(L, ctx, 2, lua_gettop(L));
 
         lua_pushboolean(L, 1);
         
@@ -3399,6 +3406,8 @@ static int md_final(lua_State *L) {
         unsigned char md[EVP_MAX_MD_SIZE];
         unsigned len;
 
+        md_update_(L, ctx, 2, lua_gettop(L));
+
         if (!EVP_DigestFinal_ex(ctx, md, &len))
                 return throwssl(L, "digest:final");
 
@@ -3470,17 +3479,24 @@ static int hmac_interpose(lua_State *L) {
 } /* hmac_interpose() */
 
 
-static int hmac_update(lua_State *L) {
-        HMAC_CTX *ctx = luaL_checkudata(L, 1, HMAC_CLASS);
-        int i, top = lua_gettop(L);
+static void hmac_update_(lua_State *L, HMAC_CTX *ctx, int from, int to) {
+        int i;
 
-        for (i = 2; i < top; i++) {
+        for (i = from; i <= to; i++) {
                 const void *p;
                 size_t n;
 
                 p = luaL_checklstring(L, i, &n);
+
                 HMAC_Update(ctx, p, n);
         }
+} /* hmac_update_() */
+
+
+static int hmac_update(lua_State *L) {
+        HMAC_CTX *ctx = luaL_checkudata(L, 1, HMAC_CLASS);
+
+        hmac_update_(L, ctx, 2, lua_gettop(L));
 
         lua_pushboolean(L, 1);
         
@@ -3493,6 +3509,8 @@ static int hmac_final(lua_State *L) {
         unsigned char hmac[EVP_MAX_MD_SIZE];
         unsigned len;
 
+        hmac_update_(L, ctx, 2, lua_gettop(L));
+
         HMAC_Final(ctx, hmac, &len);
 
         lua_pushlstring(L, (char *)hmac, len);
@@ -3614,34 +3632,46 @@ static int cipher_decrypt(lua_State *L) {
 } /* cipher_decrypt() */
 
 
-static int cipher_update(lua_State *L) {
-        EVP_CIPHER_CTX *ctx = luaL_checkudata(L, 1, CIPHER_CLASS);
+static _Bool cipher_update_(lua_State *L, EVP_CIPHER_CTX *ctx, luaL_Buffer *B, int from, int to) {
         const unsigned char *p, *pe;
-        luaL_Buffer B;
         size_t block, step, n;
+        int i;
 
         block = EVP_CIPHER_CTX_block_size(ctx);
 
         if (LUAL_BUFFERSIZE < block * 2)
-                return luaL_error(L, "cipher:update: LUAL_BUFFERSIZE(%u) < 2 * EVP_CIPHER_CTX_block_size(%u)", (unsigned)LUAL_BUFFERSIZE, (unsigned)block);
+                luaL_error(L, "cipher:update: LUAL_BUFFERSIZE(%u) < 2 * EVP_CIPHER_CTX_block_size(%u)", (unsigned)LUAL_BUFFERSIZE, (unsigned)block);
 
         step = LUAL_BUFFERSIZE - block;
 
-        p = (const unsigned char *)luaL_checklstring(L, 2, &n);
-        pe = p + n;
-
-        luaL_buffinit(L, &B);
+        for (i = from; i <= to; i++) {
+                p = (const unsigned char *)luaL_checklstring(L, i, &n);
+                pe = p + n;
 
-        while (p < pe) {
-                int in = (int)MIN((size_t)(pe - p), step), out;
+                while (p < pe) {
+                        int in = (int)MIN((size_t)(pe - p), step), out;
 
-                if (!EVP_CipherUpdate(ctx, (void *)luaL_prepbuffer(&B), &out, p, in))
-                        goto sslerr;
+                        if (!EVP_CipherUpdate(ctx, (void *)luaL_prepbuffer(B), &out, p, in))
+                                return 0;
 
-                p += in;
-                luaL_addsize(&B, out);
+                        p += in;
+                        luaL_addsize(B, out);
+                }
         }
 
+        return 1;
+} /* cipher_update_() */
+
+
+static int cipher_update(lua_State *L) {
+        EVP_CIPHER_CTX *ctx = luaL_checkudata(L, 1, CIPHER_CLASS);
+        luaL_Buffer B;
+
+        luaL_buffinit(L, &B);
+
+        if (!cipher_update_(L, ctx, &B, 2, lua_gettop(L)))
+                goto sslerr;
+
         luaL_pushresult(&B);
 
         return 1;
@@ -3659,13 +3689,16 @@ static int cipher_final(lua_State *L) {
         size_t block;
         int out;
 
+        luaL_buffinit(L, &B);
+
+        if (!cipher_update_(L, ctx, &B, 2, lua_gettop(L)))
+                goto sslerr;
+
         block = EVP_CIPHER_CTX_block_size(ctx);
 
         if (LUAL_BUFFERSIZE < block)
                 return luaL_error(L, "cipher:update: LUAL_BUFFERSIZE(%u) < EVP_CIPHER_CTX_block_size(%u)", (unsigned)LUAL_BUFFERSIZE, (unsigned)block);
 
-        luaL_buffinit(L, &B);
-
         if (!EVP_CipherFinal(ctx, (void *)luaL_prepbuffer(&B), &out))
                 goto sslerr;