Added SILC Thread Queue API
[silc.git] / lib / silcssh / silcssh_pkcs.c
index 900f108be1f963ec9b04f20894f0c56ec37a20d7..d2b2a239c3bfa9c6418a2815aa207f51ebe89bfd 100644 (file)
@@ -706,15 +706,15 @@ SILC_PKCS_EXPORT_PRIVATE_KEY_FILE(silc_pkcs_ssh_export_private_key_file)
     silc_hash_final(md5, enc + 16);
 
     /* Pad */
-    pad_len = 8 - (key_len % 8);
+    pad_len = (-key_len) % 8;
     if (pad_len) {
       keyenc = silc_smalloc(stack, (key_len + pad_len) * sizeof(*keyenc));
-      if (!key)
+      if (!keyenc)
        goto err;
       memset(keyenc + key_len, 'F', pad_len);
       memcpy(keyenc, key, key_len);
     } else {
-      keyenc = silc_memdup(key, key_len);
+      keyenc = silc_smemdup(stack, key, key_len);
       if (!keyenc)
        goto err;
     }
@@ -845,6 +845,7 @@ SILC_PKCS_DECRYPT(silc_pkcs_ssh_decrypt)
 
 /* Sign context */
 typedef struct {
+  SilcStack stack;
   SilcSshPrivateKey privkey;
   SilcPKCSSignCb sign_cb;
   void *context;
@@ -859,31 +860,83 @@ static void silc_pkcs_ssh_sign_cb(SilcBool success,
                                  void *context)
 {
   SilcSshSign sign = context;
+  SilcStack stack = sign->stack;
+  unsigned char rbuf[20], sbuf[20];
   SilcBufferStruct sig;
-  const char *name;
-
-  if (!strcmp(sign->privkey->pkcs->name, "rsa"))
-    name = "ssh-rsa";
-  else
-    name = "ssh-dss";
+  SilcAsn1 asn1;
+  SilcMPInt r, s;
 
   memset(&sig, 0, sizeof(sig));
-  if (silc_buffer_format(&sig,
-                        SILC_STR_UI_INT(strlen(name)),
-                        SILC_STR_UI32_STRING(name),
-                        SILC_STR_UI_INT(signature_len),
-                        SILC_STR_DATA(signature, signature_len),
-                        SILC_STR_END) < 0) {
-    silc_free(sign);
-    sign->sign_cb(FALSE, NULL, 0, sign->context);
+
+  /* Format the signature.  RSA is easy because PKCS#1 is already in
+     correct format.  For DSA the returned signature is in PKIX compliant
+     format and we have to reformat it for SSH2. */
+  if (!strcmp(sign->privkey->pkcs->name, "dsa")) {
+    asn1 = silc_asn1_alloc(stack);
+    if (!asn1) {
+      sign->sign_cb(FALSE, NULL, 0, sign->context);
+      silc_sfree(stack, sign);
+      silc_stack_free(stack);
+      return;
+    }
+
+    /* Decode the signature */
+    silc_buffer_set(&sig, (unsigned char *)signature, signature_len);
+    if (!silc_asn1_decode(asn1, &sig,
+                         SILC_ASN1_SEQUENCE,
+                           SILC_ASN1_INT(&r),
+                           SILC_ASN1_INT(&s),
+                         SILC_ASN1_END, SILC_ASN1_END)) {
+      sign->sign_cb(FALSE, NULL, 0, sign->context);
+      silc_asn1_free(asn1);
+      silc_sfree(stack, sign);
+      silc_stack_free(stack);
+      return;
+    }
+
+    /* Encode the integers */
+    memset(rbuf, 0, sizeof(rbuf));
+    memset(sbuf, 0, sizeof(sbuf));
+    silc_mp_mp2bin_noalloc(&r, rbuf, sizeof(rbuf));
+    silc_mp_mp2bin_noalloc(&s, sbuf, sizeof(sbuf));
+
+    silc_asn1_free(asn1);
+
+    /* Encode SSH2 DSS signature */
+    if (silc_buffer_sformat(stack, &sig,
+                           SILC_STR_UI_INT(7),
+                           SILC_STR_UI32_STRING("ssh-dss"),
+                           SILC_STR_UI_INT(sizeof(rbuf) + sizeof(sbuf)),
+                           SILC_STR_DATA(rbuf, sizeof(rbuf)),
+                           SILC_STR_DATA(sbuf, sizeof(sbuf)),
+                           SILC_STR_END) < 0) {
+      sign->sign_cb(FALSE, NULL, 0, sign->context);
+      silc_sfree(stack, sign);
+      silc_stack_free(stack);
+      return;
+    }
+  } else {
+    /* Encode SSH2 RSA signature */
+    if (silc_buffer_sformat(stack, &sig,
+                           SILC_STR_UI_INT(7),
+                           SILC_STR_UI32_STRING("ssh-rsa"),
+                           SILC_STR_UI_INT(signature_len),
+                           SILC_STR_DATA(signature, signature_len),
+                           SILC_STR_END) < 0) {
+      sign->sign_cb(FALSE, NULL, 0, sign->context);
+      silc_sfree(stack, sign);
+      silc_stack_free(stack);
+      return;
+    }
   }
 
   /* Deliver result */
   sign->sign_cb(TRUE, silc_buffer_data(&sig), silc_buffer_len(&sig),
                sign->context);
 
-  silc_buffer_purge(&sig);
-  silc_free(sign);
+  silc_buffer_spurge(stack, &sig);
+  silc_sfree(stack, sign);
+  silc_stack_free(stack);
 }
 
 /* Sign */
@@ -891,6 +944,7 @@ static void silc_pkcs_ssh_sign_cb(SilcBool success,
 SILC_PKCS_SIGN(silc_pkcs_ssh_sign)
 {
   SilcSshPrivateKey privkey = private_key;
+  SilcStack stack;
   SilcSshSign sign;
 
   if (!privkey->pkcs->sign) {
@@ -898,12 +952,16 @@ SILC_PKCS_SIGN(silc_pkcs_ssh_sign)
     return NULL;
   }
 
-  sign = silc_calloc(1, sizeof(*sign));
+  stack = silc_stack_alloc(0, silc_crypto_stack());
+
+  sign = silc_scalloc(stack, 1, sizeof(*sign));
   if (!sign) {
     sign_cb(FALSE, NULL, 0, context);
+    silc_stack_free(stack);
     return NULL;
   }
 
+  sign->stack = stack;
   sign->privkey = privkey;
   sign->sign_cb = sign_cb;
   sign->context = context;
@@ -920,29 +978,81 @@ SILC_PKCS_SIGN(silc_pkcs_ssh_sign)
 SILC_PKCS_VERIFY(silc_pkcs_ssh_verify)
 {
   SilcSshPublicKey pubkey = public_key;
-  SilcBufferStruct sig;
+  SilcAsyncOperation op;
+  SilcBufferStruct sig, r, s;
+  unsigned char *signame;
+  SilcStack stack = NULL;
+  SilcAsn1 asn1;
 
   if (!pubkey->pkcs->verify) {
     verify_cb(FALSE, context);
     return NULL;
   }
 
-  /* Decode the SSH2 protocol style signature encoding.  Ignore the
-     algorithm name.  We know the algorithm. */
+  /* Decode the SSH2 protocol style signature encoding. */
   silc_buffer_set(&sig, signature, signature_len);
   if (silc_buffer_unformat(&sig,
-                          SILC_STR_UI32_NSTRING(NULL, NULL),
+                          SILC_STR_UI32_STRING_ALLOC(&signame),
                           SILC_STR_UI32_NSTRING(&signature, &signature_len),
                           SILC_STR_END) < 0) {
     verify_cb(FALSE, context);
     return NULL;
   }
+  memset(&sig, 0, sizeof(sig));
+
+  /* DSS signature must be formatted to PKIX compliant format since our
+     implementation expects that. */
+  if (!strcmp(signame, "ssh-dss")) {
+    /* The integers must be 160 bits each */
+    if (signature_len != 40) {
+      verify_cb(FALSE, context);
+      silc_free(signame);
+      return NULL;
+    }
+
+    silc_buffer_set(&r, signature, 20);
+    silc_buffer_set(&s, signature + 20, 20);
+
+    stack = silc_stack_alloc(0, silc_crypto_stack());
+
+    asn1 = silc_asn1_alloc(stack);
+    if (!asn1) {
+      verify_cb(FALSE, context);
+      silc_free(signame);
+      silc_stack_free(stack);
+      return NULL;
+    }
+
+    /* Encode signature to PKIX compliant format. */
+    if (!silc_asn1_encode(asn1, &sig,
+                         SILC_ASN1_OPTS(SILC_ASN1_ALLOC),
+                         SILC_ASN1_SEQUENCE,
+                           SILC_ASN1_ANY_PRIMITIVE(SILC_ASN1_TAG_INTEGER, &r),
+                           SILC_ASN1_ANY_PRIMITIVE(SILC_ASN1_TAG_INTEGER, &s),
+                         SILC_ASN1_END, SILC_ASN1_END)) {
+      verify_cb(FALSE, context);
+      silc_free(signame);
+      silc_asn1_free(asn1);
+      silc_stack_free(stack);
+      return NULL;
+    }
+
+    signature = silc_buffer_steal(&sig, &signature_len);
+
+    silc_asn1_free(asn1);
+  }
 
   /* Verify */
-  return pubkey->pkcs->verify(pubkey->pkcs, pubkey->public_key,
-                             signature, signature_len,
-                             data, data_len, hash, rng,
-                             verify_cb, context);
+  op = pubkey->pkcs->verify(pubkey->pkcs, pubkey->public_key,
+                           signature, signature_len,
+                           data, data_len, hash, rng,
+                           verify_cb, context);
+
+  silc_free(signame);
+  silc_buffer_spurge(stack, &sig);
+  silc_stack_free(stack);
+
+  return op;
 }
 
 /************************** SSH2 PKCS RSA Alg API ***************************/