Add all the missing pieces for sni_policy

 sbearssl_server_init_and_run is yet unchanged, the next step
is to rewrite it using the new primitives.

1 files changed, 162 insertions, 42 deletions

diff --git a/src/sbearssl/sbearssl_sni_policy_vtable.c b/src/sbearssl/sbearssl_sni_policy_vtable.c
index 3b39055..eca198a 100644
--- a/src/sbearssl/sbearssl_sni_policy_vtable.c
+++ b/src/sbearssl/sbearssl_sni_policy_vtable.c
@@ -1,71 +1,191 @@
 /* ISC license. */
 
+#include <stdint.h>
+#include <string.h>
+
 #include <bearssl.h>
 
+#include <skalibs/bytestr.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+#include <skalibs/avltree.h>
+
 #include <s6-networking/sbearssl.h>
+#include "sbearssl-internal.h"
 
-#define INSTANCE(c) ((sbearssl_x509_small_context *)(c))
+#define INSTANCE(c) ((sbearssl_sni_policy_context *)(c))
 
-static void start_chain (br_x509_class const **c, char const *server_name)
-{
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  ctx->minimal.vtable->start_chain(&ctx->minimal.vtable, server_name) ;
+#define COPY(x) do { k.data.rsa.x = m ; memcpy(s + m, t + k.data.rsa.x, k.data.rsa.x##len) ; m += k.data.rsa.x##len ; } while (0)
 
-  ctx->i = 0 ;
+static inline size_t skey_copy (br_skey *key, sbearssl_skey const *l, char *s, char const *t)
+{
+  sbearssl_skey k = *l ;
+  size_t m = 0 ;
+  switch (k.type)
+  {
+    case BR_KEYTYPE_RSA :
+    {
+      COPY(p) ; COPY(q) ; COPY(dp) ; COPY(dq) ; COPY(iq) ;
+      break ;
+    }
+    case BR_KEYTYPE_EC :
+      k.data.ec.x = m ; memcpy(s + m, t + k.data.ec.x, k.data.ec.xlen) ; m += k.data.ec.xlen ;
+      break ;
+  }
+  sbearssl_skey_to(&k, key, s) ;
+  return m ;
 }
 
-static void start_cert (br_x509_class const **c, uint32_t len)
+static size_t cert_copy (br_x509_certificate *newc, sbearssl_cert const *oldc, char *s, char const *t)
 {
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  ctx->minimal.vtable->start_cert(&ctx->minimal.vtable, len) ;
-
-  if (!ctx->i) br_sha256_init(&ctx->hashctx) ;
+  memcpy(s, t + oldc->data, oldc->datalen) ;
+  newc->data = (unsigned char *)s ;
+  newc->data_len = oldc->datalen ;
+  return oldc->datalen ;
 }
 
-static void append (br_x509_class const **c, unsigned char const *s, size_t len)
+static int choose (br_ssl_server_policy_class const **pctx, br_ssl_server_context const *sc, br_ssl_server_choices *choices)
 {
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  ctx->minimal.vtable->append(&ctx->minimal.vtable, s, len) ;
+  sbearssl_sni_policy_context *pol = INSTANCE(pctx) ;
+  sbearssl_sni_policy_node *node ;
+  char const *servername = br_ssl_engine_get_server_name(&sc->eng) ;
 
-  if (!ctx->i) br_sha256_update(&ctx->hashctx, s, len) ;
-}
+ /* Get the node corresponding to the ServerName sent by the client */
+  {
+    uint32_t n ;
+    if (!avltree_search(&pol->map, servername, &n)
+     && (!servername[0] || !avltree_search(&pol->map, "", &n)))
+      return 0 ;
+    avltree_free(&pol->map) ;
+    node = genalloc_s(sbearssl_sni_policy_node, &pol->mapga) + n ;
+  }
 
-static void end_cert (br_x509_class const **c)
-{
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  ctx->minimal.vtable->end_cert(&ctx->minimal.vtable) ;
+ /* Replace certga and storage with the chosen chain and its data, free all the rest */
+  {
+    stralloc storage = STRALLOC_ZERO ;
+    genalloc certga = GENALLOC_ZERO ;
+    size_t clen = 0 ;
+    size_t m = 0 ;
+    sbearssl_cert const *certstart = genalloc_s(sbearssl_cert, &pol->certga) + node->chainindex ;
+    for (size_t i = 0 ; i < node->chainlen ; i++) clen += certstart[i].datalen ;
+    if (!stralloc_ready_tuned(&storage, sbearssl_skey_storagelen(&node->skey) + clen, 0, 0, 1)) return 0 ;
+    if (!genalloc_ready_tuned(br_x509_certificate, &certga, node->chainlen, 0, 0, 1))
+    {
+      stralloc_free(&storage) ;
+      return 0 ;
+    }
+    m += skey_copy(&pol->skey, &node->skey, storage.s + m, pol->storage.s) ;
+    for (size_t i = 0 ; i < node->chainlen ; i++)
+      m += cert_copy(genalloc_s(br_x509_certificate, &certga) + i, certstart + i, storage.s + m, pol->storage.s) ;
+    genalloc_setlen(br_x509_certificate, &certga, node->chainlen) ;
+    genalloc_free(sbearssl_sni_policy_node, &pol->mapga) ;
+    genalloc_free(sbearssl_cert, &pol->certga) ;
+    byte_zzero(pol->storage.s, pol->storage.len) ;  /* contains skeys, so we wipe it */
+    stralloc_free(&pol->storage) ;
+    pol->certga = certga ;
+    pol->storage = storage ;
+  }
+
+ /* We got our choice of cert chain */
+  choices->chain = genalloc_s(br_x509_certificate, &pol->certga) ;
+  choices->chain_len = genalloc_len(br_x509_certificate, &pol->certga) ;
 
-  if (!ctx->i) br_sha256_out(&ctx->hashctx, ctx->eehash) ;
-  ctx->i++ ;
+ /* Now fill up the rest of the choices structure and gather info for later keyx/sign */
+  switch (pol->skey.type)
+  {
+    case BR_KEYTYPE_RSA :
+      if (!sbearssl_choose_algos_rsa(sc, choices, BR_KEYTYPE_KEYX | BR_KEYTYPE_SIGN)) return 0 ;
+      pol->keyx.rsa = br_rsa_private_get_default() ;
+      pol->sign.rsa = br_rsa_pkcs1_sign_get_default() ;
+      break ;
+    case BR_KEYTYPE_EC :
+    {
+      int kt ;
+      int r = sbearssl_ec_issuer_keytype(&kt, &choices->chain[0]) ;
+      switch (r)
+      {
+        case -2 : strerr_warnw3x("certificate issuer key type not recognized", servername[0] ? " for name " : "", servername[0] ? servername : "") ; return 0 ;
+        case -1 : strerr_warnwu3sys("get certificate issuer key type", servername[0] ? " for name " : "", servername[0] ? servername : "") ; return 0 ;
+        case 0 : break ;
+        default : strerr_warnwu5x("get certificate issuer key type", servername[0] ? " for name " : "", servername[0] ? servername : "", ": ", sbearssl_error_str(r)) ; return 0 ;
+      }
+      if (!sbearssl_choose_algos_ec(sc, choices, BR_KEYTYPE_KEYX | BR_KEYTYPE_SIGN, kt)) return 0 ;
+      pol->keyx.ec = sc->eng.iec ;  /* the br_ssl_engine_get_ec() abstraction lacks a const */
+      pol->sign.ec = br_ecdsa_i31_sign_asn1 ;  /* have to hardcode, no access to BR_LOMUL */
+      pol->mhash = &sc->eng.mhash ;  /* missing an abstraction function there */
+      break ;
+    }
+    default : return 0 ;
+  }
+  return 1 ;
 }
 
-static unsigned int end_chain (br_x509_class const **c)
+static uint32_t do_keyx (br_ssl_server_policy_class const **pctx, unsigned char *data, size_t *len)
 {
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  unsigned int r = ctx->minimal.vtable->end_chain(&ctx->minimal.vtable) ;
-  if (!r)
+  sbearssl_sni_policy_context *pol = INSTANCE(pctx) ;
+  switch (pol->skey.type)
   {
-    uint8_t mask = 1 ;
-    for (unsigned int i = 0 ; i < 6 ; i++, mask <<= 1)
-      if (ctx->elts[i].status)
-        *ctx->eltstatus |= ctx->elts[i].status < 0 ? 128 : mask ;
+    case BR_KEYTYPE_RSA :
+      return br_rsa_ssl_decrypt(pol->keyx.rsa, &pol->skey.data.rsa, data, *len) ;
+    case BR_KEYTYPE_EC :
+    {
+      size_t xlen ;
+      uint32_t r = pol->keyx.ec->mul(data, *len, pol->skey.data.ec.x, pol->skey.data.ec.xlen, pol->skey.data.ec.curve) ;
+      size_t xoff = pol->keyx.ec->xoff(pol->skey.data.ec.curve, &xlen) ;
+      memmove(data, data + xoff, xlen) ;
+      *len = xlen ;
+      return r ;
+    }
+    default : return 0 ;
   }
-  return r ;
 }
 
-static br_x509_pkey const *get_pkey(br_x509_class const *const *c, unsigned int *usages)
+static size_t sign_rsa (sbearssl_sni_policy_context *pol, unsigned int algo_id, unsigned char *data, size_t hv_len, size_t len)
+{
+  static unsigned char const HASH_OID_SHA1[] = { 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A } ;
+  static unsigned char const HASH_OID_SHA224[] = { 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04 } ;
+  static unsigned char const HASH_OID_SHA256[] = { 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01 } ;
+  static unsigned char const HASH_OID_SHA384[] = { 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02 } ;
+  static unsigned char const HASH_OID_SHA512[] = { 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03 } ;
+  static unsigned char const *HASH_OID[] = { HASH_OID_SHA1, HASH_OID_SHA224, HASH_OID_SHA256, HASH_OID_SHA384, HASH_OID_SHA512 } ;
+  unsigned char const *hash_oid = 0 ;
+  size_t sig_len ;
+  unsigned char hv[64] ;
+  memcpy(hv, data, hv_len) ;
+  algo_id &= 0xff ;
+  if (algo_id >= 2 && algo_id <= 6) hash_oid = HASH_OID[algo_id - 2] ;
+  else if (algo_id) return 0 ;
+  sig_len = (pol->skey.data.rsa.n_bitlen + 7) >> 3 ;
+  if (len < sig_len) return 0 ;
+  return pol->sign.rsa(hash_oid, hv, hv_len, &pol->skey.data.rsa, data) ? sig_len : 0 ;
+}
+
+static size_t sign_ec (sbearssl_sni_policy_context *pol, unsigned int algo_id, unsigned char *data, size_t hv_len, size_t len)
+{
+  unsigned char hv[64] ;
+  br_hash_class const *hc = br_multihash_getimpl(pol->mhash, algo_id) ;
+  if (!hc) return 0 ;
+  memcpy(hv, data, hv_len) ;
+  if (len < 139) return 0 ;
+  return pol->sign.ec(pol->keyx.ec, hc, hv, &pol->skey.data.ec, data) ;
+}
+
+static size_t do_sign (br_ssl_server_policy_class const **pctx, unsigned int algo_id, unsigned char *data, size_t hv_len, size_t len)
 {
-  sbearssl_x509_small_context *ctx = INSTANCE(c) ;
-  return ctx->minimal.vtable->get_pkey(&ctx->minimal.vtable, usages) ;
+  sbearssl_sni_policy_context *pol = INSTANCE(pctx) ;
+  switch (pol->skey.type)
+  {
+    case BR_KEYTYPE_RSA : return sign_rsa(pol, algo_id, data, hv_len, len) ;
+    case BR_KEYTYPE_EC : return sign_ec(pol, algo_id, data, hv_len, len) ;
+    default : return 0 ;
+  }
 }
 
-br_x509_class const sbearssl_x509_small_vtable =
+br_ssl_server_policy_class const sbearssl_sni_policy_vtable =
 {
-  .context_size = sizeof(sbearssl_x509_small_context),
-  .start_chain = &start_chain,
-  .start_cert = &start_cert,
-  .append = &append,
-  .end_cert = &end_cert,
-  .end_chain = &end_chain,
-  .get_pkey = &get_pkey,
+  .context_size = sizeof(sbearssl_sni_policy_context),
+  .choose = &choose,
+  .do_keyx = &do_keyx,
+  .do_sign = &do_sign
 } ;