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

7 files changed, 730 insertions, 0 deletions

diff --git a/libtomcrypt/src/pk/dsa/dsa_export.c b/libtomcrypt/src/pk/dsa/dsa_export.c
new file mode 100644
index 0000000..5a093d9
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_export.c
@@ -0,0 +1,72 @@
+/* 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 dsa_export.c
+   DSA implementation, export key, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+  Export a DSA key to a binary packet
+  @param out    [out] Where to store the packet
+  @param outlen [in/out] The max size and resulting size of the packet
+  @param type   The type of key to export (PK_PRIVATE or PK_PUBLIC)
+  @param key    The key to export
+  @return CRYPT_OK if successful
+*/
+int dsa_export(unsigned char *out, unsigned long *outlen, int type, dsa_key *key)
+{
+   unsigned char flags[1];
+
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+   LTC_ARGCHK(key    != NULL);
+
+   /* can we store the static header?  */
+   if (type == PK_PRIVATE && key->type != PK_PRIVATE) {
+      return CRYPT_PK_TYPE_MISMATCH;
+   }
+
+   if (type != PK_PUBLIC && type != PK_PRIVATE) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   flags[0] = (type != PK_PUBLIC) ? 1 : 0;
+
+   if (type == PK_PRIVATE) {
+      return der_encode_sequence_multi(out, outlen,
+                                 LTC_ASN1_BIT_STRING,   1UL, flags,
+                                 LTC_ASN1_INTEGER,      1UL, &key->g,
+                                 LTC_ASN1_INTEGER,      1UL, &key->p,
+                                 LTC_ASN1_INTEGER,      1UL, &key->q,
+                                 LTC_ASN1_INTEGER,      1UL, &key->y,
+                                 LTC_ASN1_INTEGER,      1UL, &key->x,
+                                 LTC_ASN1_EOL,          0UL, NULL);
+   } else {
+      return der_encode_sequence_multi(out, outlen,
+                                 LTC_ASN1_BIT_STRING,   1UL, flags,
+                                 LTC_ASN1_INTEGER,      1UL, &key->g,
+                                 LTC_ASN1_INTEGER,      1UL, &key->p,
+                                 LTC_ASN1_INTEGER,      1UL, &key->q,
+                                 LTC_ASN1_INTEGER,      1UL, &key->y,
+                                 LTC_ASN1_EOL,          0UL, NULL);
+   }
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_export.c,v $ */
+/* $Revision: 1.6 $ */
+/* $Date: 2005/06/03 19:24:31 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_free.c b/libtomcrypt/src/pk/dsa/dsa_free.c
new file mode 100644
index 0000000..9157acb
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_free.c
@@ -0,0 +1,34 @@
+/* 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 dsa_free.c
+   DSA implementation, free a DSA key, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+   Free a DSA key
+   @param key   The key to free from memory
+*/
+void dsa_free(dsa_key *key)
+{
+   LTC_ARGCHK(key != NULL);
+   mp_clear_multi(&key->g, &key->q, &key->p, &key->x, &key->y, NULL);
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_free.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:59 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_import.c b/libtomcrypt/src/pk/dsa/dsa_import.c
new file mode 100644
index 0000000..e81bac8
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_import.c
@@ -0,0 +1,89 @@
+/* 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 dsa_import.c
+   DSA implementation, import a DSA key, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+   Import a DSA key 
+   @param in       The binary packet to import from
+   @param inlen    The length of the binary packet
+   @param key      [out] Where to store the imported key
+   @return CRYPT_OK if successful, upon error this function will free all allocated memory
+*/
+int dsa_import(const unsigned char *in, unsigned long inlen, dsa_key *key)
+{
+   unsigned char flags[1];
+   int           err;
+
+   LTC_ARGCHK(in  != NULL);
+   LTC_ARGCHK(key != NULL);
+
+   /* init key */
+   if (mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL) != MP_OKAY) {
+      return CRYPT_MEM;
+   }
+
+   /* get key type */
+   if ((err = der_decode_sequence_multi(in, inlen,
+                                  LTC_ASN1_BIT_STRING, 1UL, flags,
+                                  LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
+      goto error;
+   }
+
+   if (flags[0] == 1) {
+      if ((err = der_decode_sequence_multi(in, inlen,
+                                 LTC_ASN1_BIT_STRING,   1UL, flags,
+                                 LTC_ASN1_INTEGER,      1UL, &key->g,
+                                 LTC_ASN1_INTEGER,      1UL, &key->p,
+                                 LTC_ASN1_INTEGER,      1UL, &key->q,
+                                 LTC_ASN1_INTEGER,      1UL, &key->y,
+                                 LTC_ASN1_INTEGER,      1UL, &key->x,
+                                 LTC_ASN1_EOL,          0UL, NULL)) != CRYPT_OK) {
+         goto error;
+      }
+      key->type = PK_PRIVATE;
+   } else {
+      if ((err = der_decode_sequence_multi(in, inlen,
+                                 LTC_ASN1_BIT_STRING,   1UL, flags,
+                                 LTC_ASN1_INTEGER,      1UL, &key->g,
+                                 LTC_ASN1_INTEGER,      1UL, &key->p,
+                                 LTC_ASN1_INTEGER,      1UL, &key->q,
+                                 LTC_ASN1_INTEGER,      1UL, &key->y,
+                                 LTC_ASN1_EOL,          0UL, NULL)) != CRYPT_OK) {
+         goto error;
+      }
+      key->type = PK_PUBLIC;
+  }
+  key->qord = mp_unsigned_bin_size(&key->q);
+
+  if (key->qord >= MDSA_MAX_GROUP || key->qord <= 15 ||
+      key->qord >= mp_unsigned_bin_size(&key->p) || (mp_unsigned_bin_size(&key->p) - key->qord) >= MDSA_DELTA) {
+      err = CRYPT_INVALID_PACKET;
+      goto error;
+   }
+
+  return CRYPT_OK;
+error: 
+   mp_clear_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
+   return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_import.c,v $ */
+/* $Revision: 1.7 $ */
+/* $Date: 2005/06/08 23:31:17 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_make_key.c b/libtomcrypt/src/pk/dsa/dsa_make_key.c
new file mode 100644
index 0000000..02f69e0
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_make_key.c
@@ -0,0 +1,146 @@
+/* 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 dsa_make_key.c
+   DSA implementation, generate a DSA key, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+  Create a DSA key
+  @param prng          An active PRNG state
+  @param wprng         The index of the PRNG desired
+  @param group_size    Size of the multiplicative group (octets)
+  @param modulus_size  Size of the modulus (octets)
+  @param key           [out] Where to store the created key
+  @return CRYPT_OK if successful, upon error this function will free all allocated memory
+*/
+int dsa_make_key(prng_state *prng, int wprng, int group_size, int modulus_size, dsa_key *key)
+{
+   mp_int         tmp, tmp2;
+   int            err, res;
+   unsigned char *buf;
+
+   LTC_ARGCHK(key  != NULL);
+
+   /* check prng */
+   if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* check size */
+   if (group_size >= MDSA_MAX_GROUP || group_size <= 15 || 
+       group_size >= modulus_size || (modulus_size - group_size) >= MDSA_DELTA) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   /* allocate ram */
+   buf = XMALLOC(MDSA_DELTA);
+   if (buf == NULL) {
+      return CRYPT_MEM;
+   }
+
+   /* init mp_ints  */
+   if ((err = mp_init_multi(&tmp, &tmp2, &key->g, &key->q, &key->p, &key->x, &key->y, NULL)) != MP_OKAY) {
+      err = mpi_to_ltc_error(err);
+      goto LBL_ERR;
+   }
+
+   /* make our prime q */
+   if ((err = rand_prime(&key->q, group_size*8, prng, wprng)) != CRYPT_OK)             { goto LBL_ERR; }
+
+   /* double q  */
+   if ((err = mp_mul_2(&key->q, &tmp)) != MP_OKAY)                                     { goto error; }
+
+   /* now make a random string and multply it against q */
+   if (prng_descriptor[wprng].read(buf+1, modulus_size - group_size, prng) != (unsigned long)(modulus_size - group_size)) {
+      err = CRYPT_ERROR_READPRNG;
+      goto LBL_ERR;
+   }
+
+   /* force magnitude */
+   buf[0] |= 0xC0;
+
+   /* force even */
+   buf[modulus_size - group_size - 1] &= ~1;
+
+   if ((err = mp_read_unsigned_bin(&tmp2, buf, modulus_size - group_size)) != MP_OKAY) { goto error; }
+   if ((err = mp_mul(&key->q, &tmp2, &key->p)) != MP_OKAY)                             { goto error; }
+   if ((err = mp_add_d(&key->p, 1, &key->p)) != MP_OKAY)                               { goto error; }
+
+   /* now loop until p is prime */
+   for (;;) {
+       if ((err = is_prime(&key->p, &res)) != CRYPT_OK)                                { goto LBL_ERR; }
+       if (res == MP_YES) break;
+
+       /* add 2q to p and 2 to tmp2 */
+       if ((err = mp_add(&tmp, &key->p, &key->p)) != MP_OKAY)                          { goto error; }
+       if ((err = mp_add_d(&tmp2, 2, &tmp2)) != MP_OKAY)                               { goto error; }
+   }
+
+   /* now p = (q * tmp2) + 1 is prime, find a value g for which g^tmp2 != 1 */
+   mp_set(&key->g, 1);
+
+   do {
+      if ((err = mp_add_d(&key->g, 1, &key->g)) != MP_OKAY)                            { goto error; }
+      if ((err = mp_exptmod(&key->g, &tmp2, &key->p, &tmp)) != MP_OKAY)                { goto error; }
+   } while (mp_cmp_d(&tmp, 1) == MP_EQ);
+
+   /* at this point tmp generates a group of order q mod p */
+   mp_exch(&tmp, &key->g);
+
+   /* so now we have our DH structure, generator g, order q, modulus p 
+      Now we need a random exponent [mod q] and it's power g^x mod p 
+    */
+   do {
+      if (prng_descriptor[wprng].read(buf, group_size, prng) != (unsigned long)group_size) {
+         err = CRYPT_ERROR_READPRNG;
+         goto LBL_ERR;
+      }
+      if ((err = mp_read_unsigned_bin(&key->x, buf, group_size)) != MP_OKAY)           { goto error; }
+   } while (mp_cmp_d(&key->x, 1) != MP_GT);
+   if ((err = mp_exptmod(&key->g, &key->x, &key->p, &key->y)) != MP_OKAY)              { goto error; }
+   
+   key->type = PK_PRIVATE;
+   key->qord = group_size;
+
+   /* shrink the ram required */
+   if ((err = mp_shrink(&key->g)) != MP_OKAY)                                          { goto error; }
+   if ((err = mp_shrink(&key->p)) != MP_OKAY)                                          { goto error; }
+   if ((err = mp_shrink(&key->q)) != MP_OKAY)                                          { goto error; }
+   if ((err = mp_shrink(&key->x)) != MP_OKAY)                                          { goto error; }
+   if ((err = mp_shrink(&key->y)) != MP_OKAY)                                          { goto error; }
+
+#ifdef LTC_CLEAN_STACK
+   zeromem(buf, MDSA_DELTA);
+#endif
+
+   err = CRYPT_OK;
+   goto done;
+error: 
+    err = mpi_to_ltc_error(err);
+LBL_ERR: 
+    mp_clear_multi(&key->g, &key->q, &key->p, &key->x, &key->y, NULL);
+done: 
+    mp_clear_multi(&tmp, &tmp2, NULL);
+
+    XFREE(buf);
+    return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_make_key.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2005/06/11 05:45:35 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_sign_hash.c b/libtomcrypt/src/pk/dsa/dsa_sign_hash.c
new file mode 100644
index 0000000..48d29a2
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_sign_hash.c
@@ -0,0 +1,159 @@
+/* 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 dsa_sign_hash.c
+   DSA implementation, sign a hash, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+  Sign a hash with DSA
+  @param in       The hash to sign
+  @param inlen    The length of the hash to sign
+  @param r        The "r" integer of the signature (caller must initialize with mp_init() first)
+  @param s        The "s" integer of the signature (caller must initialize with mp_init() first)
+  @param prng     An active PRNG state
+  @param wprng    The index of the PRNG desired
+  @param key      A private DSA key
+  @return CRYPT_OK if successful
+*/
+int dsa_sign_hash_raw(const unsigned char *in,  unsigned long inlen,
+                                   mp_int *r,   mp_int *s,
+                               prng_state *prng, int wprng, dsa_key *key)
+{
+   mp_int         k, kinv, tmp;
+   unsigned char *buf;
+   int            err;
+
+   LTC_ARGCHK(in  != NULL);
+   LTC_ARGCHK(r   != NULL);
+   LTC_ARGCHK(s   != NULL);
+   LTC_ARGCHK(key != NULL);
+
+   if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
+      return err;
+   }
+   if (key->type != PK_PRIVATE) {
+      return CRYPT_PK_NOT_PRIVATE;
+   }
+
+   /* check group order size  */
+   if (key->qord >= MDSA_MAX_GROUP) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   buf = XMALLOC(MDSA_MAX_GROUP);
+   if (buf == NULL) {
+      return CRYPT_MEM;
+   }
+
+   /* Init our temps */
+   if ((err = mp_init_multi(&k, &kinv, &tmp, NULL)) != MP_OKAY)               { goto error; }
+
+retry:
+
+   do {
+      /* gen random k */
+      if (prng_descriptor[wprng].read(buf, key->qord, prng) != (unsigned long)key->qord) {
+         err = CRYPT_ERROR_READPRNG;
+         goto LBL_ERR;
+      }
+
+      /* read k */
+      if ((err = mp_read_unsigned_bin(&k, buf, key->qord)) != MP_OKAY)                { goto error; }
+
+      /* k > 1 ? */
+      if (mp_cmp_d(&k, 1) != MP_GT)                                                   { goto retry; }
+
+      /* test gcd */
+      if ((err = mp_gcd(&k, &key->q, &tmp)) != MP_OKAY)                               { goto error; }
+   } while (mp_cmp_d(&tmp, 1) != MP_EQ);
+
+   /* now find 1/k mod q */
+   if ((err = mp_invmod(&k, &key->q, &kinv)) != MP_OKAY)                              { goto error; }
+
+   /* now find r = g^k mod p mod q */
+   if ((err = mp_exptmod(&key->g, &k, &key->p, r)) != MP_OKAY)                        { goto error; }
+   if ((err = mp_mod(r, &key->q, r)) != MP_OKAY)                                      { goto error; }
+
+   if (mp_iszero(r) == MP_YES)                                                        { goto retry; }
+
+   /* now find s = (in + xr)/k mod q */
+   if ((err = mp_read_unsigned_bin(&tmp, (unsigned char *)in, inlen)) != MP_OKAY)     { goto error; }
+   if ((err = mp_mul(&key->x, r, s)) != MP_OKAY)                                      { goto error; }
+   if ((err = mp_add(s, &tmp, s)) != MP_OKAY)                                         { goto error; }
+   if ((err = mp_mulmod(s, &kinv, &key->q, s)) != MP_OKAY)                            { goto error; }
+
+   if (mp_iszero(s) == MP_YES)                                                        { goto retry; }
+
+   err = CRYPT_OK;
+   goto LBL_ERR;
+
+error: 
+   err = mpi_to_ltc_error(err);
+LBL_ERR: 
+   mp_clear_multi(&k, &kinv, &tmp, NULL);
+#ifdef LTC_CLEAN_STACK
+   zeromem(buf, MDSA_MAX_GROUP);
+#endif
+   XFREE(buf);
+   return err;
+}
+
+/**
+  Sign a hash with DSA
+  @param in       The hash to sign
+  @param inlen    The length of the hash to sign
+  @param out      [out] Where to store the signature
+  @param outlen   [in/out] The max size and resulting size of the signature
+  @param prng     An active PRNG state
+  @param wprng    The index of the PRNG desired
+  @param key      A private DSA key
+  @return CRYPT_OK if successful
+*/
+int dsa_sign_hash(const unsigned char *in,  unsigned long inlen,
+                        unsigned char *out, unsigned long *outlen,
+                        prng_state *prng, int wprng, dsa_key *key)
+{
+   mp_int        r, s;
+   int           err;
+
+   LTC_ARGCHK(in      != NULL);
+   LTC_ARGCHK(out     != NULL);
+   LTC_ARGCHK(outlen  != NULL);
+   LTC_ARGCHK(key     != NULL);
+
+   if (mp_init_multi(&r, &s, NULL) != MP_OKAY) {
+      return CRYPT_MEM;
+   }
+
+   if ((err = dsa_sign_hash_raw(in, inlen, &r, &s, prng, wprng, key)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   err = der_encode_sequence_multi(out, outlen, 
+                             LTC_ASN1_INTEGER, 1UL, &r, 
+                             LTC_ASN1_INTEGER, 1UL, &s, 
+                             LTC_ASN1_EOL,     0UL, NULL);
+
+LBL_ERR:
+   mp_clear_multi(&r, &s, NULL);
+   return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_sign_hash.c,v $ */
+/* $Revision: 1.6 $ */
+/* $Date: 2005/05/15 21:48:59 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_verify_hash.c b/libtomcrypt/src/pk/dsa/dsa_verify_hash.c
new file mode 100644
index 0000000..11e5c33
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_verify_hash.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 dsa_verify_hash.c
+   DSA implementation, verify a signature, Tom St Denis
+*/
+
+
+#ifdef MDSA
+
+/**
+  Verify a DSA signature
+  @param r        DSA "r" parameter
+  @param s        DSA "s" parameter
+  @param hash     The hash that was signed
+  @param hashlen  The length of the hash that was signed
+  @param stat     [out] The result of the signature verification, 1==valid, 0==invalid
+  @param key      The corresponding public DH key
+  @return CRYPT_OK if successful (even if the signature is invalid)
+*/
+int dsa_verify_hash_raw(         mp_int *r,          mp_int *s,
+                    const unsigned char *hash, unsigned long hashlen, 
+                                    int *stat,      dsa_key *key)
+{
+   mp_int        w, v, u1, u2;
+   int           err;
+
+   LTC_ARGCHK(r    != NULL);
+   LTC_ARGCHK(s    != NULL);
+   LTC_ARGCHK(stat != NULL);
+   LTC_ARGCHK(key  != NULL);
+
+   /* default to invalid signature */
+   *stat = 0;
+
+   /* init our variables */
+   if ((err = mp_init_multi(&w, &v, &u1, &u2, NULL)) != MP_OKAY) {
+      return mpi_to_ltc_error(err);
+   }
+
+   /* neither r or s can be null or >q*/
+   if (mp_iszero(r) == MP_YES || mp_iszero(s) == MP_YES || mp_cmp(r, &key->q) != MP_LT || mp_cmp(s, &key->q) != MP_LT) {
+      err = CRYPT_INVALID_PACKET;
+      goto done;
+   }
+   
+   /* w = 1/s mod q */
+   if ((err = mp_invmod(s, &key->q, &w)) != MP_OKAY)                                      { goto error; }
+
+   /* u1 = m * w mod q */
+   if ((err = mp_read_unsigned_bin(&u1, (unsigned char *)hash, hashlen)) != MP_OKAY)       { goto error; }
+   if ((err = mp_mulmod(&u1, &w, &key->q, &u1)) != MP_OKAY)                                { goto error; }
+
+   /* u2 = r*w mod q */
+   if ((err = mp_mulmod(r, &w, &key->q, &u2)) != MP_OKAY)                                 { goto error; } 
+
+   /* v = g^u1 * y^u2 mod p mod q */
+   if ((err = mp_exptmod(&key->g, &u1, &key->p, &u1)) != MP_OKAY)                          { goto error; }
+   if ((err = mp_exptmod(&key->y, &u2, &key->p, &u2)) != MP_OKAY)                          { goto error; }
+   if ((err = mp_mulmod(&u1, &u2, &key->p, &v)) != MP_OKAY)                                { goto error; }
+   if ((err = mp_mod(&v, &key->q, &v)) != MP_OKAY)                                         { goto error; }
+
+   /* if r = v then we're set */
+   if (mp_cmp(r, &v) == MP_EQ) {
+      *stat = 1;
+   }
+
+   err = CRYPT_OK;
+   goto done;
+
+error : err = mpi_to_ltc_error(err);
+done  : mp_clear_multi(&w, &v, &u1, &u2, NULL);
+   return err;
+}
+
+/**
+  Verify a DSA signature
+  @param sig      The signature
+  @param siglen   The length of the signature (octets)
+  @param hash     The hash that was signed
+  @param hashlen  The length of the hash that was signed
+  @param stat     [out] The result of the signature verification, 1==valid, 0==invalid
+  @param key      The corresponding public DH key
+  @return CRYPT_OK if successful (even if the signature is invalid)
+*/
+int dsa_verify_hash(const unsigned char *sig, unsigned long siglen,
+                    const unsigned char *hash, unsigned long hashlen, 
+                    int *stat, dsa_key *key)
+{
+   int    err;
+   mp_int r, s;
+
+   if ((err = mp_init_multi(&r, &s, NULL)) != CRYPT_OK) {
+      return CRYPT_MEM;
+   }
+
+   /* decode the sequence */
+   if ((err = der_decode_sequence_multi(sig, siglen,
+                                  LTC_ASN1_INTEGER, 1UL, &r, 
+                                  LTC_ASN1_INTEGER, 1UL, &s, 
+                                  LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   /* do the op */
+   err = dsa_verify_hash_raw(&r, &s, hash, hashlen, stat, key);
+
+LBL_ERR:
+   mp_clear_multi(&r, &s, NULL);
+   return err;
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_verify_hash.c,v $ */
+/* $Revision: 1.8 $ */
+/* $Date: 2005/05/15 21:48:59 $ */
diff --git a/libtomcrypt/src/pk/dsa/dsa_verify_key.c b/libtomcrypt/src/pk/dsa/dsa_verify_key.c
new file mode 100644
index 0000000..b7be103
--- /dev/null
+++ b/libtomcrypt/src/pk/dsa/dsa_verify_key.c
@@ -0,0 +1,102 @@
+/* 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 dsa_verify_key.c
+   DSA implementation, verify a key, Tom St Denis
+*/
+
+#ifdef MDSA
+
+/**
+   Verify a DSA key for validity
+   @param key   The key to verify
+   @param stat  [out]  Result of test, 1==valid, 0==invalid
+   @return CRYPT_OK if successful
+*/
+int dsa_verify_key(dsa_key *key, int *stat)
+{
+   mp_int tmp, tmp2;
+   int    res, err;
+
+   LTC_ARGCHK(key  != NULL);
+   LTC_ARGCHK(stat != NULL);
+
+   /* default to an invalid key */
+   *stat = 0;
+
+   /* first make sure key->q and key->p are prime */
+   if ((err = is_prime(&key->q, &res)) != CRYPT_OK) {
+      return err;
+   }
+   if (res == 0) {
+      return CRYPT_OK;
+   }
+
+
+   if ((err = is_prime(&key->p, &res)) != CRYPT_OK) {
+      return err;
+   }
+   if (res == 0) {
+      return CRYPT_OK;
+   }
+
+   /* now make sure that g is not -1, 0 or 1 and <p */
+   if (mp_cmp_d(&key->g, 0) == MP_EQ || mp_cmp_d(&key->g, 1) == MP_EQ) {
+      return CRYPT_OK;
+   }
+   if ((err = mp_init_multi(&tmp, &tmp2, NULL)) != MP_OKAY)               { goto error; }
+   if ((err = mp_sub_d(&key->p, 1, &tmp)) != MP_OKAY)                     { goto error; }
+   if (mp_cmp(&tmp, &key->g) == MP_EQ || mp_cmp(&key->g, &key->p) != MP_LT) {
+      err = CRYPT_OK;
+      goto done;
+   }
+
+   /* 1 < y < p-1 */
+   if (!(mp_cmp_d(&key->y, 1) == MP_GT && mp_cmp(&key->y, &tmp) == MP_LT)) {
+      err = CRYPT_OK;
+      goto done;
+   }
+
+   /* now we have to make sure that g^q = 1, and that p-1/q gives 0 remainder */
+   if ((err = mp_div(&tmp, &key->q, &tmp, &tmp2)) != MP_OKAY)             { goto error; }
+   if (mp_iszero(&tmp2) != MP_YES) {
+      err = CRYPT_OK;
+      goto done;
+   }
+
+   if ((err = mp_exptmod(&key->g, &key->q, &key->p, &tmp)) != MP_OKAY)    { goto error; }
+   if (mp_cmp_d(&tmp, 1) != MP_EQ) {
+      err = CRYPT_OK;
+      goto done;
+   }
+
+   /* now we have to make sure that y^q = 1, this makes sure y \in g^x mod p */
+   if ((err = mp_exptmod(&key->y, &key->q, &key->p, &tmp)) != MP_OKAY)       { goto error; }
+   if (mp_cmp_d(&tmp, 1) != MP_EQ) {
+      err = CRYPT_OK;
+      goto done;
+   }
+
+   /* at this point we are out of tests ;-( */
+   err   = CRYPT_OK;
+   *stat = 1;
+   goto done;
+error: err = mpi_to_ltc_error(err);
+done : mp_clear_multi(&tmp, &tmp2, NULL);
+   return err;
+}
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_verify_key.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:59 $ */