propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)

            to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)

--HG--
extra : convert_revision : dc4809882e1b9f2dcd3f8bbe38c74a0a52c39ce4

3 files changed, 319 insertions, 0 deletions

diff --git a/libtomcrypt/src/pk/asn1/der/integer/der_decode_integer.c b/libtomcrypt/src/pk/asn1/der/integer/der_decode_integer.c
new file mode 100644
index 0000000..e68b2c9
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/integer/der_decode_integer.c
@@ -0,0 +1,110 @@
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_decode_integer.c
+  ASN.1 DER, decode an integer, Tom St Denis
+*/
+
+
+#ifdef LTC_DER
+
+/**
+  Read a mp_int integer
+  @param in       The DER encoded data
+  @param inlen    Size of DER encoded data
+  @param num      The first mp_int to decode
+  @return CRYPT_OK if successful
+*/
+int der_decode_integer(const unsigned char *in, unsigned long inlen, mp_int *num)
+{
+   unsigned long x, y, z;
+   int           err;
+
+   LTC_ARGCHK(num    != NULL);
+   LTC_ARGCHK(in     != NULL);
+
+   /* min DER INTEGER is 0x02 01 00 == 0 */
+   if (inlen < (1 + 1 + 1)) {
+      return CRYPT_INVALID_PACKET;
+   }
+
+   /* ok expect 0x02 when we AND with 0001 1111 [1F] */
+   x = 0;
+   if ((in[x++] & 0x1F) != 0x02) {
+      return CRYPT_INVALID_PACKET;
+   }
+
+   /* now decode the len stuff */
+   z = in[x++];
+
+   if ((z & 0x80) == 0x00) {
+      /* short form */
+
+      /* will it overflow? */
+      if (x + z > inlen) {
+         return CRYPT_INVALID_PACKET;
+      }
+     
+      /* no so read it */
+      if ((err = mpi_to_ltc_error(mp_read_unsigned_bin(num, (unsigned char *)in + x, z))) != CRYPT_OK) {
+         return err;
+      }
+   } else {
+      /* long form */
+      z &= 0x7F;
+      
+      /* will number of length bytes overflow? (or > 4) */
+      if (((x + z) > inlen) || (z > 4) || (z == 0)) {
+         return CRYPT_INVALID_PACKET;
+      }
+
+      /* now read it in */
+      y = 0;
+      while (z--) {
+         y = ((unsigned long)(in[x++])) | (y << 8);
+      }
+
+      /* now will reading y bytes overrun? */
+      if ((x + y) > inlen) {
+         return CRYPT_INVALID_PACKET;
+      }
+
+      /* no so read it */
+      if ((err = mpi_to_ltc_error(mp_read_unsigned_bin(num, (unsigned char *)in + x, y))) != CRYPT_OK) {
+         return err;
+      }
+   }
+
+   /* see if it's negative */
+   if (in[x] & 0x80) {
+      mp_int tmp;
+      if (mp_init(&tmp) != MP_OKAY) {
+         return CRYPT_MEM;
+      }
+
+      if (mp_2expt(&tmp, mp_count_bits(num)) != MP_OKAY || mp_sub(num, &tmp, num) != MP_OKAY) {
+         mp_clear(&tmp);
+         return CRYPT_MEM;
+      }
+      mp_clear(&tmp);
+   } 
+
+   return CRYPT_OK;
+
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_decode_integer.c,v $ */
+/* $Revision: 1.2 $ */
+/* $Date: 2005/06/01 00:06:05 $ */
diff --git a/libtomcrypt/src/pk/asn1/der/integer/der_encode_integer.c b/libtomcrypt/src/pk/asn1/der/integer/der_encode_integer.c
new file mode 100644
index 0000000..f0f41be
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/integer/der_encode_integer.c
@@ -0,0 +1,128 @@
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_encode_integer.c
+  ASN.1 DER, encode an integer, Tom St Denis
+*/
+
+
+#ifdef LTC_DER
+
+/* Exports a positive bignum as DER format (upto 2^32 bytes in size) */
+/**
+  Store a mp_int integer
+  @param num      The first mp_int to encode
+  @param out      [out] The destination for the DER encoded integers
+  @param outlen   [in/out] The max size and resulting size of the DER encoded integers
+  @return CRYPT_OK if successful
+*/
+int der_encode_integer(mp_int *num, unsigned char *out, unsigned long *outlen)
+{  
+   unsigned long tmplen, y;
+   int           err, leading_zero;
+
+   LTC_ARGCHK(num    != NULL);
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+
+   /* find out how big this will be */
+   if ((err = der_length_integer(num, &tmplen)) != CRYPT_OK) {
+      return err;
+   }
+
+   if (*outlen < tmplen) {
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   if (mp_cmp_d(num, 0) != MP_LT) {
+      /* we only need a leading zero if the msb of the first byte is one */
+      if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == MP_YES) {
+         leading_zero = 1;
+      } else {
+         leading_zero = 0;
+      }
+
+      /* get length of num in bytes (plus 1 since we force the msbyte to zero) */
+      y = mp_unsigned_bin_size(num) + leading_zero;
+   } else {
+      leading_zero = 0;
+      y            = mp_count_bits(num);
+      y            = y + (8 - (y & 7));
+      y            = y >> 3;
+
+   }
+
+   /* now store initial data */
+   *out++ = 0x02;
+   if (y < 128) {
+      /* short form */
+      *out++ = (unsigned char)y;
+   } else if (y < 256) {
+      *out++ = 0x81;
+      *out++ = y;
+   } else if (y < 65536UL) {
+      *out++ = 0x82;
+      *out++ = (y>>8)&255;
+      *out++ = y;
+   } else if (y < 16777216UL) {
+      *out++ = 0x83;
+      *out++ = (y>>16)&255;
+      *out++ = (y>>8)&255;
+      *out++ = y;
+   } else {
+      return CRYPT_INVALID_ARG;
+   }
+
+   /* now store msbyte of zero if num is non-zero */
+   if (leading_zero) {
+      *out++ = 0x00;
+   }
+
+   /* if it's not zero store it as big endian */
+   if (mp_cmp_d(num, 0) == MP_GT) {
+      /* now store the mpint */
+      if ((err = mp_to_unsigned_bin(num, out)) != MP_OKAY) {
+          return mpi_to_ltc_error(err);
+      }
+   } else if (mp_iszero(num) != MP_YES) {
+      mp_int tmp;
+      /* negative */
+      if (mp_init(&tmp) != MP_OKAY) {
+         return CRYPT_MEM;
+      }
+
+      /* 2^roundup and subtract */
+      y = mp_count_bits(num);
+      y = y + (8 - (y & 7));
+      if (mp_2expt(&tmp, y) != MP_OKAY || mp_add(&tmp, num, &tmp) != MP_OKAY) {
+         mp_clear(&tmp);
+         return CRYPT_MEM;
+      }
+
+      if ((err = mp_to_unsigned_bin(&tmp, out)) != MP_OKAY) {
+         mp_clear(&tmp);
+         return mpi_to_ltc_error(err);
+      }
+      mp_clear(&tmp);
+   }
+
+   /* we good */
+   *outlen = tmplen; 
+   return CRYPT_OK;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_encode_integer.c,v $ */
+/* $Revision: 1.1 $ */
+/* $Date: 2005/05/16 15:08:11 $ */
diff --git a/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c b/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c
new file mode 100644
index 0000000..1bfee45
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c
@@ -0,0 +1,81 @@
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_length_integer.c
+  ASN.1 DER, get length of encoding, Tom St Denis
+*/
+
+
+#ifdef LTC_DER
+/**
+  Gets length of DER encoding of num 
+  @param num    The mp_int to get the size of 
+  @param outlen [out] The length of the DER encoding for the given integer
+  @return CRYPT_OK if successful
+*/
+int der_length_integer(mp_int *num, unsigned long *outlen)
+{
+   unsigned long z, len;
+   int           leading_zero;
+
+   LTC_ARGCHK(num     != NULL);
+   LTC_ARGCHK(outlen  != NULL);
+
+   if (mp_cmp_d(num, 0) != MP_LT) {
+      /* positive */
+
+      /* we only need a leading zero if the msb of the first byte is one */
+      if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == MP_YES) {
+         leading_zero = 1;
+      } else {
+         leading_zero = 0;
+      }
+
+      /* size for bignum */
+      z = len = leading_zero + mp_unsigned_bin_size(num);
+   } else {
+      /* it's negative */
+      /* find power of 2 that is a multiple of eight and greater than count bits */
+      leading_zero = 0;
+      z = mp_count_bits(num);
+      z = z + (8 - (z & 7));
+      len = z = z >> 3;
+   }
+
+   /* now we need a length */
+   if (z < 128) {
+      /* short form */
+      ++len;
+   } else {
+      /* long form (relies on z != 0), assumes length bytes < 128 */
+      ++len;
+
+      while (z) {
+         ++len;
+         z >>= 8;
+      }
+   }
+
+   /* we need a 0x02 to indicate it's INTEGER */
+   ++len;
+
+   /* return length */
+   *outlen = len; 
+   return CRYPT_OK;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c,v $ */
+/* $Revision: 1.1 $ */
+/* $Date: 2005/05/16 15:08:11 $ */