1 files changed, 37 insertions, 146 deletions

diff --git a/src/crypto/ecdsa/ecdsa_asn1.c b/src/crypto/ecdsa/ecdsa_asn1.c
index f2d7c36..f557ca7 100644
--- a/src/crypto/ecdsa/ecdsa_asn1.c
+++ b/src/crypto/ecdsa/ecdsa_asn1.c
@@ -52,33 +52,45 @@
 
 #include <openssl/ecdsa.h>
 
-#include <limits.h>
-#include <string.h>
-
-#include <openssl/bn.h>
-#include <openssl/bytestring.h>
-#include <openssl/err.h>
+#include <openssl/asn1.h>
+#include <openssl/asn1t.h>
 #include <openssl/ec_key.h>
 #include <openssl/mem.h>
 
 #include "../ec/internal.h"
 
 
+DECLARE_ASN1_FUNCTIONS_const(ECDSA_SIG);
+DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECDSA_SIG, ECDSA_SIG);
+
+ASN1_SEQUENCE(ECDSA_SIG) = {
+    ASN1_SIMPLE(ECDSA_SIG, r, CBIGNUM),
+    ASN1_SIMPLE(ECDSA_SIG, s, CBIGNUM),
+} ASN1_SEQUENCE_END(ECDSA_SIG);
+
+IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(ECDSA_SIG, ECDSA_SIG, ECDSA_SIG);
+
 size_t ECDSA_size(const EC_KEY *key) {
-  if (key == NULL) {
-    return 0;
-  }
+  size_t ret, i, group_order_size;
+  ASN1_INTEGER bs;
+  BIGNUM *order = NULL;
+  unsigned char buf[4];
+  const EC_GROUP *group;
 
-  size_t group_order_size;
   if (key->ecdsa_meth && key->ecdsa_meth->group_order_size) {
     group_order_size = key->ecdsa_meth->group_order_size(key);
   } else {
-    const EC_GROUP *group = EC_KEY_get0_group(key);
+    size_t num_bits;
+
+    if (key == NULL) {
+      return 0;
+    }
+    group = EC_KEY_get0_group(key);
     if (group == NULL) {
       return 0;
     }
 
-    BIGNUM *order = BN_new();
+    order = BN_new();
     if (order == NULL) {
       return 0;
     }
@@ -87,11 +99,21 @@ size_t ECDSA_size(const EC_KEY *key) {
       return 0;
     }
 
-    group_order_size = BN_num_bytes(order);
-    BN_clear_free(order);
+    num_bits = BN_num_bits(order);
+    group_order_size = (num_bits + 7) / 8;
   }
 
-  return ECDSA_SIG_max_len(group_order_size);
+  bs.length = group_order_size;
+  bs.data = buf;
+  bs.type = V_ASN1_INTEGER;
+  /* If the top bit is set the ASN.1 encoding is 1 larger. */
+  buf[0] = 0xff;
+
+  i = i2d_ASN1_INTEGER(&bs, NULL);
+  i += i; /* r and s */
+  ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
+  BN_clear_free(order);
+  return ret;
 }
 
 ECDSA_SIG *ECDSA_SIG_new(void) {
@@ -117,134 +139,3 @@ void ECDSA_SIG_free(ECDSA_SIG *sig) {
   BN_free(sig->s);
   OPENSSL_free(sig);
 }
-
-ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs) {
-  ECDSA_SIG *ret = ECDSA_SIG_new();
-  if (ret == NULL) {
-    return NULL;
-  }
-  CBS child;
-  if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
-      !BN_cbs2unsigned(&child, ret->r) ||
-      !BN_cbs2unsigned(&child, ret->s) ||
-      CBS_len(&child) != 0) {
-    OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
-    ECDSA_SIG_free(ret);
-    return NULL;
-  }
-  return ret;
-}
-
-ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in, size_t in_len) {
-  CBS cbs;
-  CBS_init(&cbs, in, in_len);
-  ECDSA_SIG *ret = ECDSA_SIG_parse(&cbs);
-  if (ret == NULL || CBS_len(&cbs) != 0) {
-    OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
-    ECDSA_SIG_free(ret);
-    return NULL;
-  }
-  return ret;
-}
-
-int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig) {
-  CBB child;
-  if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
-      !BN_bn2cbb(&child, sig->r) ||
-      !BN_bn2cbb(&child, sig->s) ||
-      !CBB_flush(cbb)) {
-    OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
-    return 0;
-  }
-  return 1;
-}
-
-int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len,
-                       const ECDSA_SIG *sig) {
-  CBB cbb;
-  CBB_zero(&cbb);
-  if (!CBB_init(&cbb, 0) ||
-      !ECDSA_SIG_marshal(&cbb, sig) ||
-      !CBB_finish(&cbb, out_bytes, out_len)) {
-    OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
-    CBB_cleanup(&cbb);
-    return 0;
-  }
-  return 1;
-}
-
-/* der_len_len returns the number of bytes needed to represent a length of |len|
- * in DER. */
-static size_t der_len_len(size_t len) {
-  if (len < 0x80) {
-    return 1;
-  }
-  size_t ret = 1;
-  while (len > 0) {
-    ret++;
-    len >>= 8;
-  }
-  return ret;
-}
-
-size_t ECDSA_SIG_max_len(size_t order_len) {
-  /* Compute the maximum length of an |order_len| byte integer. Defensively
-   * assume that the leading 0x00 is included. */
-  size_t integer_len = 1 /* tag */ + der_len_len(order_len + 1) + 1 + order_len;
-  if (integer_len < order_len) {
-    return 0;
-  }
-  /* An ECDSA signature is two INTEGERs. */
-  size_t value_len = 2 * integer_len;
-  if (value_len < integer_len) {
-    return 0;
-  }
-  /* Add the header. */
-  size_t ret = 1 /* tag */ + der_len_len(value_len) + value_len;
-  if (ret < value_len) {
-    return 0;
-  }
-  return ret;
-}
-
-ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp, long len) {
-  if (len < 0) {
-    return NULL;
-  }
-  CBS cbs;
-  CBS_init(&cbs, *inp, (size_t)len);
-  ECDSA_SIG *ret = ECDSA_SIG_parse(&cbs);
-  if (ret == NULL) {
-    return NULL;
-  }
-  if (out != NULL) {
-    ECDSA_SIG_free(*out);
-    *out = ret;
-  }
-  *inp += (size_t)len - CBS_len(&cbs);
-  return ret;
-}
-
-int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp) {
-  uint8_t *der;
-  size_t der_len;
-  if (!ECDSA_SIG_to_bytes(&der, &der_len, sig)) {
-    return -1;
-  }
-  if (der_len > INT_MAX) {
-    OPENSSL_PUT_ERROR(ECDSA, ERR_R_OVERFLOW);
-    OPENSSL_free(der);
-    return -1;
-  }
-  if (outp != NULL) {
-    if (*outp == NULL) {
-      *outp = der;
-      der = NULL;
-    } else {
-      memcpy(*outp, der, der_len);
-      *outp += der_len;
-    }
-  }
-  OPENSSL_free(der);
-  return (int)der_len;
-}