X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fbit%2Fder_decode_raw_bit_string.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fbit%2Fder_decode_raw_bit_string.c;h=223899b3346a2706c7ff28fd3acff45fa21ed5ef;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c b/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c
new file mode 100644
index 0000000..223899b
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c
@@ -0,0 +1,107 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_decode_bit_string.c
+  ASN.1 DER, encode a BIT STRING, Tom St Denis
+*/
+
+
+#ifdef LTC_DER
+
+#define SETBIT(v, n)    (v=((unsigned char)(v) | (1U << (unsigned char)(n))))
+#define CLRBIT(v, n)    (v=((unsigned char)(v) & ~(1U << (unsigned char)(n))))
+
+/**
+  Store a BIT STRING
+  @param in      The DER encoded BIT STRING
+  @param inlen   The size of the DER BIT STRING
+  @param out     [out] The array of bits stored (8 per char)
+  @param outlen  [in/out] The number of bits stored
+  @return CRYPT_OK if successful
+*/
+int der_decode_raw_bit_string(const unsigned char *in,  unsigned long inlen,
+                                unsigned char *out, unsigned long *outlen)
+{
+   unsigned long dlen, blen, x, y;
+
+   LTC_ARGCHK(in     != NULL);
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+
+   /* packet must be at least 4 bytes */
+   if (inlen < 4) {
+       return CRYPT_INVALID_ARG;
+   }
+
+   /* check for 0x03 */
+   if ((in[0]&0x1F) != 0x03) {
+      return CRYPT_INVALID_PACKET;
+   }
+
+   /* offset in the data */
+   x = 1;
+
+   /* get the length of the data */
+   if (in[x] & 0x80) {
+      /* long format get number of length bytes */
+      y = in[x++] & 0x7F;
+
+      /* invalid if 0 or > 2 */
+      if (y == 0 || y > 2) {
+         return CRYPT_INVALID_PACKET;
+      }
+
+      /* read the data len */
+      dlen = 0;
+      while (y--) {
+         dlen = (dlen << 8) | (unsigned long)in[x++];
+      }
+   } else {
+      /* short format */
+      dlen = in[x++] & 0x7F;
+   }
+
+   /* is the data len too long or too short? */
+   if ((dlen == 0) || (dlen + x > inlen)) {
+       return CRYPT_INVALID_PACKET;
+   }
+
+   /* get padding count */
+   blen = ((dlen - 1) << 3) - (in[x++] & 7);
+
+   /* too many bits? */
+   if (blen > *outlen) {
+      *outlen = blen;
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   /* decode/store the bits */
+   for (y = 0; y < blen; y++) {
+      if (in[x] & (1 << (7 - (y & 7)))) {
+         SETBIT(out[y/8], 7-(y%8));
+      } else {
+         CLRBIT(out[y/8], 7-(y%8));
+      }
+      if ((y & 7) == 7) {
+         ++x;
+      }
+   }
+
+   /* we done */
+   *outlen = blen;
+   return CRYPT_OK;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */