Merge remote-tracking branch 'spi/fix/grant' into spi-linus

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / asymmetric_keys / x509_cert_parser.c

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 7fabc4c01993bd92e3fc159ba05ae92b1732f231..facbf26bc6bbbc91eb879b0a5cdf40d01e8f2b05 100644 (file)
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -373,6 +373,9 @@ int rsa_extract_mpi(void *context, size_t hdrlen,
        return 0;
 }
 
+/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
+#define SEQ_TAG_KEYID (ASN1_CONT << 6)
+
 /*
  * Process certificate extensions that are used to qualify the certificate.
  */
@@ -407,21 +410,57 @@ int x509_process_extension(void *context, size_t hdrlen,
        }
 
        if (ctx->last_oid == OID_authorityKeyIdentifier) {
+               size_t key_len;
+
                /* Get hold of the CA key fingerprint */
                if (vlen < 5)
                        return -EBADMSG;
-               if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)) ||
-                   v[1] != vlen - 2 ||
-                   v[2] != (ASN1_CONT << 6) ||
-                   v[3] != vlen - 4)
+
+               /* Authority Key Identifier must be a Constructed SEQUENCE */
+               if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
                        return -EBADMSG;
-               v += 4;
-               vlen -= 4;
 
-               f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
+               /* Authority Key Identifier is not indefinite length */
+               if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
+                       return -EBADMSG;
+
+               if (vlen < ASN1_INDEFINITE_LENGTH) {
+                       /* Short Form length */
+                       if (v[1] != vlen - 2 ||
+                           v[2] != SEQ_TAG_KEYID ||
+                           v[3] > vlen - 4)
+                               return -EBADMSG;
+
+                       key_len = v[3];
+                       v += 4;
+               } else {
+                       /* Long Form length */
+                       size_t seq_len = 0;
+                       size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
+
+                       if (sub > 2)
+                               return -EBADMSG;
+
+                       /* calculate the length from subsequent octets */
+                       v += 2;
+                       for (i = 0; i < sub; i++) {
+                               seq_len <<= 8;
+                               seq_len |= v[i];
+                       }
+
+                       if (seq_len != vlen - 2 - sub ||
+                           v[sub] != SEQ_TAG_KEYID ||
+                           v[sub + 1] > vlen - 4 - sub)
+                               return -EBADMSG;
+
+                       key_len = v[sub + 1];
+                       v += (sub + 2);
+               }
+
+               f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
                if (!f)
                        return -ENOMEM;
-               for (i = 0; i < vlen; i++)
+               for (i = 0; i < key_len; i++)
                        sprintf(f + i * 2, "%02x", v[i]);
                pr_debug("authority   %s\n", f);
                ctx->cert->authority = f;