Merge remote-tracking branch 'asoc/fix/core' into asoc-linus

[linux-2.6-block.git] / crypto / asymmetric_keys / verify_pefile.c

diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index 79175e6ea0b28493f26079d5a17926e0aab63984..2421f46184ce873076fe3cfc0f195a2d7bf4f902 100644 (file)
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -128,6 +128,7 @@ static int pefile_strip_sig_wrapper(const void *pebuf,
 {
        struct win_certificate wrapper;
        const u8 *pkcs7;
+       unsigned len;
 
        if (ctx->sig_len < sizeof(wrapper)) {
                pr_debug("Signature wrapper too short\n");
@@ -154,33 +155,49 @@ static int pefile_strip_sig_wrapper(const void *pebuf,
                return -ENOTSUPP;
        }
 
-       /* Looks like actual pkcs signature length is in wrapper->length.
-        * size obtained from data dir entries lists the total size of
-        * certificate table which is also aligned to octawrod boundary.
-        *
-        * So set signature length field appropriately.
+       /* It looks like the pkcs signature length in wrapper->length and the
+        * size obtained from the data dir entries, which lists the total size
+        * of certificate table, are both aligned to an octaword boundary, so
+        * we may have to deal with some padding.
         */
        ctx->sig_len = wrapper.length;
        ctx->sig_offset += sizeof(wrapper);
        ctx->sig_len -= sizeof(wrapper);
-       if (ctx->sig_len == 0) {
+       if (ctx->sig_len < 4) {
                pr_debug("Signature data missing\n");
                return -EKEYREJECTED;
        }
 
-       /* What's left should a PKCS#7 cert */
+       /* What's left should be a PKCS#7 cert */
        pkcs7 = pebuf + ctx->sig_offset;
-       if (pkcs7[0] == (ASN1_CONS_BIT | ASN1_SEQ)) {
-               if (pkcs7[1] == 0x82 &&
-                   pkcs7[2] == (((ctx->sig_len - 4) >> 8) & 0xff) &&
-                   pkcs7[3] ==  ((ctx->sig_len - 4)       & 0xff))
-                       return 0;
-               if (pkcs7[1] == 0x80)
-                       return 0;
-               if (pkcs7[1] > 0x82)
-                       return -EMSGSIZE;
+       if (pkcs7[0] != (ASN1_CONS_BIT | ASN1_SEQ))
+               goto not_pkcs7;
+
+       switch (pkcs7[1]) {
+       case 0 ... 0x7f:
+               len = pkcs7[1] + 2;
+               goto check_len;
+       case ASN1_INDEFINITE_LENGTH:
+               return 0;
+       case 0x81:
+               len = pkcs7[2] + 3;
+               goto check_len;
+       case 0x82:
+               len = ((pkcs7[2] << 8) | pkcs7[3]) + 4;
+               goto check_len;
+       case 0x83 ... 0xff:
+               return -EMSGSIZE;
+       default:
+               goto not_pkcs7;
        }
 
+check_len:
+       if (len <= ctx->sig_len) {
+               /* There may be padding */
+               ctx->sig_len = len;
+               return 0;
+       }
+not_pkcs7:
        pr_debug("Signature data not PKCS#7\n");
        return -ELIBBAD;
 }