Use ssh_diffie-hellman, the new SSH diffie hellman code

And add diffie-hellman-group14-sha1 support

5 files changed, 173 insertions, 38 deletions

diff --git a/src/protocol/CMakeLists.txt b/src/protocol/CMakeLists.txt
index 498d351..84fddf4 100644
--- a/src/protocol/CMakeLists.txt
+++ b/src/protocol/CMakeLists.txt
@@ -15,6 +15,8 @@ set(export_SRCS
 set(internal_SRCS
   internal/ssh_pubkey_crypto.h
   internal/ssh_pubkey_crypto.c
+  internal/ssh_diffie-hellman.h
+  internal/ssh_diffie-hellman.c
   internal/crc32.h
   internal/fqterm_serialization.h
   internal/fqterm_ssh_auth.h
diff --git a/src/protocol/internal/fqterm_ssh2_kex.cpp b/src/protocol/internal/fqterm_ssh2_kex.cpp
index 3a8b75a..137a41e 100644
--- a/src/protocol/internal/fqterm_ssh2_kex.cpp
+++ b/src/protocol/internal/fqterm_ssh2_kex.cpp
@@ -33,27 +33,6 @@
 
 namespace FQTerm {
 
-static const int g = 2;
-static const int q = 128;
-static const unsigned char p[q]={
-  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
-  0xC9, 0x0F, 0xDA, 0xA2, 0x21, 0x68, 0xC2, 0x34,
-  0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
-  0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74,
-  0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B, 0x22,
-  0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
-  0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B,
-  0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37,
-  0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
-  0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6,
-  0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B,
-  0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
-  0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5,
-  0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6,
-  0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,
-  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
-};
-
 FQTermSSH2Kex::FQTermSSH2Kex(const char *V_C, const char *V_S) 
     : FQTermSSHKex(V_C, V_S) {
   is_first_kex_ = true;
@@ -66,16 +45,11 @@ FQTermSSH2Kex::FQTermSSH2Kex(const char *V_C, const char *V_S)
 
   bn_x_ = BN_new();
   bn_e_ = BN_new();
-  bn_g_ = BN_new();
-  bn_p_ = BN_new();
   ctx_ = BN_CTX_new();
 
   bn_K_ = BN_new();
   bn_f_ = BN_new();
 
-  BN_set_word(bn_g_, g);
-  BN_bin2bn(p, q, bn_p_);
-
   session_id_ = NULL;
 }
 
@@ -85,8 +59,7 @@ FQTermSSH2Kex::~FQTermSSH2Kex() {
 
   BN_clear_free(bn_x_);
   BN_clear_free(bn_e_);
-  BN_clear_free(bn_g_);
-  BN_clear_free(bn_p_);
+  ssh_dh_free(dh);
   BN_CTX_free(ctx_);
 
   BN_clear_free(bn_K_);
@@ -151,8 +124,20 @@ void FQTermSSH2Kex::negotiateAlgorithms() {
   // 1. Parse server kex init packet
   packet_receiver_->getRawData((char*)cookie_, 16);
 
+  // select KEX algorithm
+  size_t kl_len = packet_receiver_->getInt();
+  char kex_algos[kl_len+1];
+  packet_receiver_->getRawData(kex_algos, kl_len);
+  kex_algos[kl_len] = '\0';
+  NEW_DH dh = search_dh(kex_algos);
+  if (dh==NULL) {
+	  emit kexError(tr("No matching KEX algorithms!"));
+	  return;
+  }
+  this->dh = dh();
+
   std::vector<char> name_lists;
-  for (int i = 0; i < 10; ++i) {
+  for (int i = 1; i < 10; ++i) {
     int name_lists_len = packet_receiver_->getInt();
     if (name_lists_len > 0) {
       name_lists.resize(name_lists_len);
@@ -171,7 +156,7 @@ void FQTermSSH2Kex::negotiateAlgorithms() {
   // 2. compose a kex init packet.
   packet_sender_->startPacket(SSH2_MSG_KEXINIT);
   packet_sender_->putRawData((const char*)cookie_, 16);    // FIXME: generate new cookie_;
-  packet_sender_->putString("diffie-hellman-group1-sha1");
+  packet_sender_->putString(all_dh_list);
   packet_sender_->putString("ssh-rsa");
   packet_sender_->putString("3des-cbc");
   packet_sender_->putString("3des-cbc");
@@ -196,8 +181,8 @@ void FQTermSSH2Kex::negotiateAlgorithms() {
 }
 
 void FQTermSSH2Kex::exchangeKey() {
-  BN_rand(bn_x_, q, 0, -1);
-  BN_mod_exp(bn_e_, bn_g_, bn_x_, bn_p_, ctx_);
+  BN_pseudo_rand_range(bn_x_, dh->p);
+  BN_mod_exp(bn_e_, dh->g, bn_x_, dh->p, ctx_);
 
   packet_sender_->startPacket(SSH2_MSG_KEXDH_INIT);
   packet_sender_->putBN2(bn_e_);
@@ -222,7 +207,7 @@ bool FQTermSSH2Kex::verifyKey() {
   int s_len = -1;
   unsigned char *s = (unsigned char *)packet_receiver_->getString(&s_len);
 
-  BN_mod_exp(bn_K_, bn_f_, bn_x_, bn_p_, ctx_);
+  BN_mod_exp(bn_K_, bn_f_, bn_x_, dh->p, ctx_);
 
   FQTermSSHBuffer *buffer = packet_sender_->output_buffer_;
 
@@ -236,11 +221,11 @@ bool FQTermSSH2Kex::verifyKey() {
   buffer->putSSH2BN(bn_f_);
   buffer->putSSH2BN(bn_K_);
 
-  SHA1(buffer->data(), buffer->len(), H_);
+  dh->hash(buffer->data(), buffer->len(), H_);
 
   // Start verify
   unsigned char s_H[SHA_DIGEST_LENGTH];
-  SHA1(H_, SHA_DIGEST_LENGTH, s_H);
+  SHA1(H_, dh->hashlen, s_H);
 
   // Ignore the first 15 bytes of the signature of H sent from server:
   // algorithm_name_length[4], algorithm_name[7]("ssh-rsa") and signature_length[4].
diff --git a/src/protocol/internal/fqterm_ssh2_kex.h b/src/protocol/internal/fqterm_ssh2_kex.h
index 23beba2..59e3330 100644
--- a/src/protocol/internal/fqterm_ssh2_kex.h
+++ b/src/protocol/internal/fqterm_ssh2_kex.h
@@ -24,6 +24,7 @@
 #include <openssl/sha.h>
 
 #include "fqterm_ssh_kex.h"
+#include "ssh_diffie-hellman.h"
 
 namespace FQTerm {
 
@@ -55,16 +56,15 @@ private:
   int I_S_len_;
   char *I_S_;
 
+  SSH_DH *dh;
   BIGNUM *bn_x_;
   BIGNUM *bn_e_;
-  BIGNUM *bn_g_;
-  BIGNUM *bn_p_;
   BN_CTX *ctx_;
 
   BIGNUM *bn_K_;
   BIGNUM *bn_f_;
 
-  unsigned char H_[SHA_DIGEST_LENGTH];
+  unsigned char H_[SHA512_DIGEST_LENGTH];
 
   unsigned char *session_id_;
 
diff --git a/src/protocol/internal/ssh_diffie-hellman.c b/src/protocol/internal/ssh_diffie-hellman.c
new file mode 100644
index 0000000..1866b2f
--- /dev/null
+++ b/src/protocol/internal/ssh_diffie-hellman.c
@@ -0,0 +1,115 @@
+#include "ssh_diffie-hellman.h"
+#include "ssh_crypto_common.h"
+#include <stdlib.h>
+
+static const int g = 2;
+
+static const unsigned char prime_group1[]={
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xC9, 0x0F, 0xDA, 0xA2, 0x21, 0x68, 0xC2, 0x34,
+	0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
+	0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74,
+	0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B, 0x22,
+	0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
+	0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B,
+	0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37,
+	0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
+	0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6,
+	0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B,
+	0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
+	0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5,
+	0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6,
+	0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+};
+
+static const unsigned char prime_group14[] = {
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xC9, 0x0F, 0xDA, 0xA2, 0x21, 0x68, 0xC2, 0x34,
+	0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
+	0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74,
+	0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B, 0x22,
+	0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
+	0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B,
+	0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37,
+	0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
+	0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6,
+	0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B,
+	0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
+	0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5,
+	0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6,
+	0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D,
+	0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05,
+	0x98, 0xDA, 0x48, 0x36, 0x1C, 0x55, 0xD3, 0x9A,
+	0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F,
+	0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96,
+	0x1C, 0x62, 0xF3, 0x56, 0x20, 0x85, 0x52, 0xBB,
+	0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D,
+	0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04,
+	0xF1, 0x74, 0x6C, 0x08, 0xCA, 0x18, 0x21, 0x7C,
+	0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B,
+	0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03,
+	0x9B, 0x27, 0x83, 0xA2, 0xEC, 0x07, 0xA2, 0x8F,
+	0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9,
+	0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18,
+	0x39, 0x95, 0x49, 0x7C, 0xEA, 0x95, 0x6A, 0xE5,
+	0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10,
+	0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+};
+
+void
+ssh_dh_free(SSH_DH *dh)
+{
+	BN_free(dh->g);
+	BN_free(dh->p);
+	free(dh);
+}
+
+SSH_DH *
+ssh_dh_group1_sha1(void)
+{
+	SSH_DH *dh = (SSH_DH*)malloc(sizeof(SSH_DH));
+	dh->g = BN_new();
+	dh->p = BN_new();
+	dh->hash = SHA1;
+	dh->hashlen = SHA_DIGEST_LENGTH;
+	BN_set_word(dh->g, g);
+	BN_bin2bn(prime_group1, 128, dh->p);
+	return dh;
+}
+
+SSH_DH *
+ssh_dh_group14_sha1(void)
+{
+	SSH_DH *dh = (SSH_DH*)malloc(sizeof(SSH_DH));
+	dh->g = BN_new();
+	dh->p = BN_new();
+	dh->hash = SHA1;
+	dh->hashlen = SHA_DIGEST_LENGTH;
+	BN_set_word(dh->g, g);
+	BN_bin2bn(prime_group14, 256, dh->p);
+	return dh;
+}
+
+struct
+{
+	const char *name;
+	NEW_DH f;
+} all_dh[] = {
+	{ "diffie-hellman-group14-sha1", ssh_dh_group14_sha1 },
+	{ "diffie-hellman-group1-sha1", ssh_dh_group1_sha1 },
+	{ NULL, NULL }
+};
+
+NEW_DH
+search_dh(const char *s)
+{
+	int i = search_name((name_sp)all_dh, s);
+	if (i!=-1)
+		return all_dh[i].f;
+	else
+		return NULL;
+}
+
+const char all_dh_list[] = "diffie-hellman-group14-sha1,diffie-hellman-group1-sha1";
diff --git a/src/protocol/internal/ssh_diffie-hellman.h b/src/protocol/internal/ssh_diffie-hellman.h
new file mode 100644
index 0000000..5468fdb
--- /dev/null
+++ b/src/protocol/internal/ssh_diffie-hellman.h
@@ -0,0 +1,33 @@
+#ifndef SSH_DH_H
+#define SSH_DH_H
+
+#include <openssl/bn.h>
+#include <openssl/sha.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+	typedef unsigned char* (*hash_t)(const unsigned char *, size_t, unsigned char *);
+
+	typedef struct ssh_diffie_hellman
+	{
+		BIGNUM *g; // generator
+		BIGNUM *p; // prime
+		hash_t hash; // can be SHA1 or SHA256
+		size_t hashlen;
+	} SSH_DH;
+
+	void ssh_dh_free(SSH_DH*);
+	SSH_DH *ssh_dh_group1_sha1(void);
+	SSH_DH *ssh_dh_group14_sha1(void);
+
+	typedef SSH_DH*(*NEW_DH)(void);
+	extern const char all_dh_list[];
+	NEW_DH search_dh(const char *s);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif