Refactor some of the ECC import internals

Signed-off-by: Steffen Jaeckel <[email protected]>

src/headers/tomcrypt_private.h

@@ -382,6 +382,8 @@ int ecc_copy_curve(const ecc_key *srckey, ecc_key *key);
 int ecc_set_curve_by_size(int size, ecc_key *key);
 int ecc_import_subject_public_key_info(const unsigned char *in, unsigned long inlen, ecc_key *key);
 int ecc_import_pkcs8_asn1(ltc_asn1_list *alg_id, ltc_asn1_list *priv_key, ecc_key *key);
+int ecc_import_with_curve(const unsigned char *in, unsigned long inlen, int type, ecc_key *key);
+int ecc_import_with_oid(const unsigned char *in, unsigned long inlen, unsigned long *oid, unsigned long oid_len, int type, ecc_key *key);
 
 #ifdef LTC_SSH
 int ecc_ssh_ecdsa_encode_name(char *buffer, unsigned long *buflen, const ecc_key *key);

src/pk/ecc/ecc_import_openssl.c

@@ -9,9 +9,7 @@ static int s_ecc_import_private_with_oid(const unsigned char *in, unsigned long
 {
    ltc_asn1_list seq_priv[4], custom[2];
    unsigned char bin_xy[2*ECC_MAXSIZE+2], bin_k[ECC_MAXSIZE];
-   unsigned long len, pkver = 0, curveoid[16];
-   char OID[256];
-   const ltc_ecc_curve *curve;
+   unsigned long pkver = 0, curveoid[16];
    int err;
 
    /* ### try to load private key - no curve parameters just curve OID */
@@ -26,26 +24,37 @@ static int s_ecc_import_private_with_oid(const unsigned char *in, unsigned long
 
    /* try to load private key */
    err = der_decode_sequence(in, inlen, seq_priv, 4);
-   if (err == CRYPT_OK) {
-      /* load curve parameters for given curve OID */
-      len = sizeof(OID);
-      if ((err = pk_oid_num_to_str(curveoid, custom[0].size, OID, &len)) != CRYPT_OK) { goto error; }
-      if ((err = ecc_find_curve(OID, &curve)) != CRYPT_OK)                            { goto error; }
-      if ((err = ecc_set_curve(curve, key)) != CRYPT_OK)                              { goto error; }
-      /* load private+public key */
-      err = ecc_set_key(bin_k, seq_priv[1].size, PK_PRIVATE, key);
-   }
+   if (err != CRYPT_OK) { goto error; }
+   err = ecc_import_with_oid(bin_k, seq_priv[1].size, curveoid, custom[0].size, PK_PRIVATE, key);
 error:
    return err;
 }
 
-static int s_ecc_import_private_with_curve(const unsigned char *in, unsigned long inlen, ecc_key *key)
+int ecc_import_with_oid(const unsigned char *in, unsigned long inlen, unsigned long *oid, unsigned long oid_len, int type, ecc_key *key)
+{
+   char OID[256];
+   unsigned long len;
+   const ltc_ecc_curve *curve;
+   int err;
+
+   /* load curve parameters for given curve OID */
+   len = sizeof(OID);
+   if ((err = pk_oid_num_to_str(oid, oid_len, OID, &len)) != CRYPT_OK) { goto error; }
+   if ((err = ecc_find_curve(OID, &curve)) != CRYPT_OK)                { goto error; }
+   if ((err = ecc_set_curve(curve, key)) != CRYPT_OK)                  { goto error; }
+   /* load public key */
+   err = ecc_set_key(in, inlen, type, key);
+error:
+   return err;
+}
+
+int ecc_import_with_curve(const unsigned char *in, unsigned long inlen, int type, ecc_key *key)
 {
    void *prime, *order, *a, *b, *gx, *gy;
    ltc_asn1_list seq_fieldid[2], seq_curve[3], seq_ecparams[6], seq_priv[4], custom[2];
    unsigned char bin_a[ECC_MAXSIZE], bin_b[ECC_MAXSIZE], bin_k[ECC_MAXSIZE];
    unsigned char bin_g[2*ECC_MAXSIZE+1], bin_xy[2*ECC_MAXSIZE+2], bin_seed[128];
-   unsigned long len_a, len_b, len_k, len_g;
+   unsigned long len_a, len_b, len_k, len_g, len_xy, len;
    unsigned long cofactor = 0, ecver = 0, pkver = 0, tmpoid[16];
    int err;
 
@@ -53,23 +62,6 @@ static int s_ecc_import_private_with_curve(const unsigned char *in, unsigned lon
       return err;
    }
 
-   /* ### try to load private key - curve parameters included */
-
-   /* ECPrivateKey SEQUENCE */
-   LTC_SET_ASN1(custom,   0, LTC_ASN1_SEQUENCE,       seq_ecparams, 6UL);
-   LTC_SET_ASN1(custom,   1, LTC_ASN1_RAW_BIT_STRING, bin_xy,       8UL*sizeof(bin_xy));
-   LTC_SET_ASN1(seq_priv, 0, LTC_ASN1_SHORT_INTEGER,  &pkver,       1UL);
-   LTC_SET_ASN1(seq_priv, 1, LTC_ASN1_OCTET_STRING,   bin_k,        sizeof(bin_k));
-   LTC_SET_ASN1_CUSTOM_CONSTRUCTED(seq_priv, 2, LTC_ASN1_CL_CONTEXT_SPECIFIC, 0, custom);     /* context specific 0 */
-   LTC_SET_ASN1_CUSTOM_CONSTRUCTED(seq_priv, 3, LTC_ASN1_CL_CONTEXT_SPECIFIC, 1, custom + 1); /* context specific 1 */
-   /* ECParameters SEQUENCE */
-   LTC_SET_ASN1(seq_ecparams, 0, LTC_ASN1_SHORT_INTEGER, &ecver,      1UL);
-   LTC_SET_ASN1(seq_ecparams, 1, LTC_ASN1_SEQUENCE,      seq_fieldid, 2UL);
-   LTC_SET_ASN1(seq_ecparams, 2, LTC_ASN1_SEQUENCE,      seq_curve,   3UL);
-   LTC_SET_ASN1(seq_ecparams, 3, LTC_ASN1_OCTET_STRING,  bin_g,       sizeof(bin_g));
-   LTC_SET_ASN1(seq_ecparams, 4, LTC_ASN1_INTEGER,       order,       1UL);
-   LTC_SET_ASN1(seq_ecparams, 5, LTC_ASN1_SHORT_INTEGER, &cofactor,   1UL);
-   seq_ecparams[5].optional = 1;
    /* FieldID SEQUENCE */
    LTC_SET_ASN1(seq_fieldid,  0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid, 16UL);
    LTC_SET_ASN1(seq_fieldid,  1, LTC_ASN1_INTEGER,           prime,  1UL);
@@ -78,10 +70,33 @@ static int s_ecc_import_private_with_curve(const unsigned char *in, unsigned lon
    LTC_SET_ASN1(seq_curve,    1, LTC_ASN1_OCTET_STRING,      bin_b,    sizeof(bin_b));
    LTC_SET_ASN1(seq_curve,    2, LTC_ASN1_RAW_BIT_STRING,    bin_seed, 8UL*sizeof(bin_seed));
    seq_curve[2].optional = 1;
-   /* try to load private key */
-   err = der_decode_sequence(in, inlen, seq_priv, 4);
+   /* ECParameters SEQUENCE */
+   LTC_SET_ASN1(seq_ecparams, 0, LTC_ASN1_SHORT_INTEGER, &ecver,      1UL);
+   LTC_SET_ASN1(seq_ecparams, 1, LTC_ASN1_SEQUENCE,      seq_fieldid, 2UL);
+   LTC_SET_ASN1(seq_ecparams, 2, LTC_ASN1_SEQUENCE,      seq_curve,   3UL);
+   LTC_SET_ASN1(seq_ecparams, 3, LTC_ASN1_OCTET_STRING,  bin_g,       sizeof(bin_g));
+   LTC_SET_ASN1(seq_ecparams, 4, LTC_ASN1_INTEGER,       order,       1UL);
+   LTC_SET_ASN1(seq_ecparams, 5, LTC_ASN1_SHORT_INTEGER, &cofactor,   1UL);
+   seq_ecparams[5].optional = 1;
+   if (type == PK_PRIVATE) {
+      /* ECPrivateKey SEQUENCE */
+      LTC_SET_ASN1(custom,   0, LTC_ASN1_SEQUENCE,       seq_ecparams, 6UL);
+      LTC_SET_ASN1(custom,   1, LTC_ASN1_RAW_BIT_STRING, bin_xy,       8UL*sizeof(bin_xy));
+      LTC_SET_ASN1(seq_priv, 0, LTC_ASN1_SHORT_INTEGER,  &pkver,       1UL);
+      LTC_SET_ASN1(seq_priv, 1, LTC_ASN1_OCTET_STRING,   bin_k,        sizeof(bin_k));
+      LTC_SET_ASN1_CUSTOM_CONSTRUCTED(seq_priv, 2, LTC_ASN1_CL_CONTEXT_SPECIFIC, 0, custom);     /* context specific 0 */
+      LTC_SET_ASN1_CUSTOM_CONSTRUCTED(seq_priv, 3, LTC_ASN1_CL_CONTEXT_SPECIFIC, 1, custom + 1); /* context specific 1 */
+      /* try to load private key */
+      err = der_decode_sequence(in, inlen, seq_priv, 4);
+   } else if (type == PK_PUBLIC) {
+      /* try to load public key */
+      len_xy = sizeof(bin_xy);
+      len = 6;
+      err = x509_decode_subject_public_key_info(in, inlen, LTC_OID_EC, bin_xy, &len_xy, LTC_ASN1_SEQUENCE, seq_ecparams, &len);
+   } else {
+      err = CRYPT_PK_INVALID_TYPE;
+   }
    if (err == CRYPT_OK) {
-      len_k  = seq_priv[1].size;
       len_a  = seq_curve[0].size;
       len_b  = seq_curve[1].size;
       len_g  = seq_ecparams[3].size;
@@ -91,8 +106,15 @@ static int s_ecc_import_private_with_curve(const unsigned char *in, unsigned lon
       if ((err = ltc_ecc_import_point(bin_g, len_g, prime, a, b, gx, gy)) != CRYPT_OK)         { goto error; }
       /* load curve parameters */
       if ((err = ecc_set_curve_from_mpis(a, b, prime, order, gx, gy, cofactor, key)) != CRYPT_OK) { goto error; }
-      /* load private+public key */
-      err = ecc_set_key(bin_k, len_k, PK_PRIVATE, key);
+
+      if (type == PK_PRIVATE) {
+         len_k  = seq_priv[1].size;
+         /* load private+public key */
+         err = ecc_set_key(bin_k, len_k, PK_PRIVATE, key);
+      } else {
+         /* load public key */
+         err = ecc_set_key(bin_xy, len_xy, PK_PUBLIC, key);
+      }
    }
 error:
    mp_clear_multi(prime, order, a, b, gx, gy, LTC_NULL);
@@ -111,7 +133,7 @@ int ecc_import_openssl(const unsigned char *in, unsigned long inlen, ecc_key *ke
       goto success;
    }
 
-   err = s_ecc_import_private_with_curve(in, inlen, key);
+   err = ecc_import_with_curve(in, inlen, PK_PRIVATE, key);
 
 success:
    return err;

src/pk/ecc/ecc_import_x509.c

@@ -8,78 +8,16 @@ static int s_ecc_import_x509_with_oid(const unsigned char *in, unsigned long inl
 {
    unsigned char bin_xy[2*ECC_MAXSIZE+2];
    unsigned long curveoid[16];
-   unsigned long len_xy, len_oid, len;
-   char OID[256];
-   const ltc_ecc_curve *curve;
+   unsigned long len_xy, len_oid;
    int err;
 
    len_xy = sizeof(bin_xy);
    len_oid = 16;
    err = x509_decode_subject_public_key_info(in, inlen, LTC_OID_EC, bin_xy, &len_xy,
                                              LTC_ASN1_OBJECT_IDENTIFIER, (void *)curveoid, &len_oid);
-   if (err == CRYPT_OK) {
-      /* load curve parameters for given curve OID */
-      len = sizeof(OID);
-      if ((err = pk_oid_num_to_str(curveoid, len_oid, OID, &len)) != CRYPT_OK) { goto error; }
-      if ((err = ecc_find_curve(OID, &curve)) != CRYPT_OK)                     { goto error; }
-      if ((err = ecc_set_curve(curve, key)) != CRYPT_OK)                       { goto error; }
-      /* load public key */
-      err = ecc_set_key(bin_xy, len_xy, PK_PUBLIC, key);
-   }
-error:
-   return err;
-}
-
-static int s_ecc_import_x509_with_curve(const unsigned char *in, unsigned long inlen, ecc_key *key)
-{
-   void *prime, *order, *a, *b, *gx, *gy;
-   ltc_asn1_list seq_fieldid[2], seq_curve[3], seq_ecparams[6];
-   unsigned char bin_a[ECC_MAXSIZE], bin_b[ECC_MAXSIZE];
-   unsigned char bin_g[2*ECC_MAXSIZE+1], bin_xy[2*ECC_MAXSIZE+2], bin_seed[128];
-   unsigned long len_a, len_b, len_g, len_xy, len;
-   unsigned long cofactor = 0, ecver = 0, tmpoid[16];
-   int err;
-
-   if ((err = mp_init_multi(&prime, &order, &a, &b, &gx, &gy, LTC_NULL)) != CRYPT_OK) {
-      return err;
-   }
-
-   /* ECParameters SEQUENCE */
-   LTC_SET_ASN1(seq_ecparams, 0, LTC_ASN1_SHORT_INTEGER,     &ecver,      1UL);
-   LTC_SET_ASN1(seq_ecparams, 1, LTC_ASN1_SEQUENCE,          seq_fieldid, 2UL);
-   LTC_SET_ASN1(seq_ecparams, 2, LTC_ASN1_SEQUENCE,          seq_curve,   3UL);
-   LTC_SET_ASN1(seq_ecparams, 3, LTC_ASN1_OCTET_STRING,      bin_g,       sizeof(bin_g));
-   LTC_SET_ASN1(seq_ecparams, 4, LTC_ASN1_INTEGER,           order,       1UL);
-   LTC_SET_ASN1(seq_ecparams, 5, LTC_ASN1_SHORT_INTEGER,     &cofactor,   1UL);
-   seq_ecparams[5].optional = 1;
-   /* FieldID SEQUENCE */
-   LTC_SET_ASN1(seq_fieldid,  0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid,      16UL);
-   LTC_SET_ASN1(seq_fieldid,  1, LTC_ASN1_INTEGER,           prime,       1UL);
-   /* Curve SEQUENCE */
-   LTC_SET_ASN1(seq_curve,    0, LTC_ASN1_OCTET_STRING,      bin_a,       sizeof(bin_a));
-   LTC_SET_ASN1(seq_curve,    1, LTC_ASN1_OCTET_STRING,      bin_b,       sizeof(bin_b));
-   LTC_SET_ASN1(seq_curve,    2, LTC_ASN1_RAW_BIT_STRING,    bin_seed,    8u*sizeof(bin_seed));
-   seq_curve[2].optional = 1;
-   /* try to load public key */
-   len_xy = sizeof(bin_xy);
-   len = 6;
-   err = x509_decode_subject_public_key_info(in, inlen, LTC_OID_EC, bin_xy, &len_xy, LTC_ASN1_SEQUENCE, seq_ecparams, &len);
-
-   if (err == CRYPT_OK) {
-      len_a = seq_curve[0].size;
-      len_b = seq_curve[1].size;
-      len_g = seq_ecparams[3].size;
-      /* create bignums */
-      if ((err = mp_read_unsigned_bin(a, bin_a, len_a)) != CRYPT_OK)                           { goto error; }
-      if ((err = mp_read_unsigned_bin(b, bin_b, len_b)) != CRYPT_OK)                           { goto error; }
-      if ((err = ltc_ecc_import_point(bin_g, len_g, prime, a, b, gx, gy)) != CRYPT_OK)         { goto error; }
-      /* load curve parameters */
-      if ((err = ecc_set_curve_from_mpis(a, b, prime, order, gx, gy, cofactor, key)) != CRYPT_OK) { goto error; }
-      /* load public key */
-      err = ecc_set_key(bin_xy, len_xy, PK_PUBLIC, key);
-   }
+   if (err != CRYPT_OK) { goto error; }
+   err = ecc_import_with_oid(bin_xy, len_xy, curveoid, len_oid, PK_PUBLIC, key);
 error:
-   mp_clear_multi(prime, order, a, b, gx, gy, LTC_NULL);
    return err;
 }
 
@@ -91,7 +29,7 @@ int ecc_import_subject_public_key_info(const unsigned char *in, unsigned long in
       goto success;
    }
 
-   err = s_ecc_import_x509_with_curve(in, inlen, key);
+   err = ecc_import_with_curve(in, inlen, PK_PUBLIC, key);
 
 success:
    return err;