Resolve PR review comments

1) use `pk_get_rsapubkey` instead of reimplementing the parsing
2) rename the key files, according to their type and key size
3) comment in the data_files/Makefile hoe the keys were generated
4) Fix issue of failure parsing pkcs#1 DER format parsing, missed in previous commit

library/pkparse.c

@@ -649,14 +649,6 @@ static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
 
     p = (unsigned char *) key;
     end = p + keylen;
-    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
-            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
-    {
-        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
-    }
-
-    end = p + len;
-
     if( mode == 0 )
     {
     /*
@@ -675,6 +667,14 @@ static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
      *      otherPrimeInfos   OtherPrimeInfos OPTIONAL
      *  }
      */
+        if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+                MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+        {
+            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+        }
+
+        end = p + len;
+
         if( ( ret = mbedtls_asn1_get_int( &p, end, &rsa->ver ) ) != 0 )
         {
             return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
@@ -715,36 +715,11 @@ static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
     }
     else /* public key*/
     {
-    /*
+        if( ( ret = pk_get_rsapubkey( &p, end, rsa ) ) != 0 )
-     * This function parses the RSAPublicKey (PKCS#1)
-     *
-     *  RSAPublicKey ::= SEQUENCE {
-     *                   modulus           INTEGER,  -- n
-     *                   publicExponent    INTEGER   -- e
-     *                   }
-     */
-        if( ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->N  ) ) != 0 ||
-            ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->E  ) ) != 0 )
         {
             mbedtls_rsa_free( rsa );
-            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+            return( ret );
         }
-
-        rsa->len = mbedtls_mpi_size( &rsa->N );
-
-        if( p != end )
-        {
-             mbedtls_rsa_free( rsa );
-             return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
-                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
-        }
-
-        if( ( ret = mbedtls_rsa_check_pubkey( rsa ) ) != 0 )
-        {
-             mbedtls_rsa_free( rsa );
-             return( ret );
-        }
-
     }
     return( 0 );
 }
@@ -1287,6 +1262,7 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
 #if defined(MBEDTLS_PEM_PARSE_C)
     size_t len;
     mbedtls_pem_context pem;
+    const mbedtls_pk_info_t *pk_info;
 
     mbedtls_pem_init( &pem );
 #if defined(MBEDTLS_RSA_C)
@@ -1301,7 +1277,6 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
 
     if( ret == 0 )
     {
-         const mbedtls_pk_info_t *pk_info;
          if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
               return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
 
@@ -1319,6 +1294,21 @@ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
         mbedtls_pem_free( &pem );
         return( ret );
     }
+
+    if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
+          return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    if( ( ret = mbedtls_pk_setup( ctx, pk_info ) ) != 0 )
+        return( ret );
+
+    ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *ctx ),
+                                  key, keylen, 1 );
+    if ( ret == 0 )
+    {
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    mbedtls_pk_free( ctx );
 #endif /* MBEDTLS_RSA_C */
 
        /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */

tests/data_files/Makefile

@@ -64,7 +64,13 @@ server2-sha256.crt: server2-rsa.csr
 	$(OPENSSL) x509 -req -extfile $(cli_crt_extensions_file) -extensions cli-rsa -CA test-ca-sha256.crt -CAkey $(test_ca_key_file_rsa) -passin "pass:$(test_ca_pwd_rsa)" -set_serial 4 -days 3653 -sha256 -in server2-rsa.csr -out $@
 all_final += server2-sha256.crt
 
+rsa_pkcs1_2048_public.pem: server8.key
+	$(OPENSSL)  rsa -in server8.key -outform PEM -RSAPublicKey_out -out $@
+all_final += rsa_pkcs8_2048_public.pem
 
+rsa_pkcs1_2048_public.der: rsa_pkcs1_2048_public.pem
+	$(OPENSSL) -RSAPublicKey_in -in rsa_pkcs1_2048_public.pem -outform DER -RSAPublicKey_out -out $@
+all_final += rsa_pkcs8_2048_public.der
 
 ################################################################
 #### Meta targets

tests/data_files/public_rsa_key.pem

@@ -1,8 +0,0 @@
------BEGIN RSA PUBLIC KEY-----
-MIIBCgKCAQEA2UFMidUiQFATstnnSR6Q97QThcnPzkATdIM5LQ1HMLLbzmTrLRa1
-mjneNIh9jE+ZpPDEXVcUAwrvgCOb/MQeqetYNxU8FHU1Baw76ZCSe91GPK6xSdIW
-ovsrsPCKnu8qQBYGTV/OQ4Y6KvVL5NvcLsQfxGgOYtFuD6xn6oE25SwScqWD5y4Q
-zB3Rm7u23xBBcLr+zb4fVjBOGS1vIVNnxj7aDYJTB9ZO2i+5MUch0BPHhsd3gf//
-u5ECyItnc+B50apbc/7wziwX1ABMvGVIWbvEMG68Vgst2kX91ojiDPZJej/c2xLR
-gpzage6SGEIQiCDQVIudSMnzZoltyMUmNwIDAQAB
------END RSA PUBLIC KEY-----

tests/data_files/rsa_pkcs1_2048_public.pem

@@ -0,0 +1,8 @@
+-----BEGIN RSA PUBLIC KEY-----
+MIIBCgKCAQEA2xx/LgvNv87RdRCgorjOfariBeB62ERjj7W9wLAZuTe4GUoO8V10
+gGdGhwbeW38GA73BjV4HFdRb9Nzlzz35wREsrmq5ir0dZ2YX6k692xWagofk8HjD
+o4WHsP2fqZlf4zPszOoLtWFe8Ul+P6Mt6gEMzEKadpvE0DfTsRcBYQEWWX4cF8NT
+/dFyy0xgFdp94uqtUO+O4ovUandV1nDZa7vx7jkEOKO94tHgZmvinEeZ6Sjmtvwu
+ymdDhOjVg9admGsBPoHcPHrK+fOc99YoGyd4fMPQ1WOngTSJrSVqvfLq7fpX/OU0
+xsEPcS3SCBAbrURB4P55oGOTirFd6bDubwIDAQAB
+-----END RSA PUBLIC KEY-----

tests/suites/test_suite_pkparse.data

@@ -108,15 +108,15 @@ pk_parse_public_keyfile_rsa:"data_files/format_gen.pub":0
 
 Parse Public RSA Key #1 (PKCS#8 wrapped, DER)
 depends_on:MBEDTLS_MD5_C:MBEDTLS_PEM_PARSE_C
-pk_parse_public_keyfile_rsa:"data_files/format_gen_der.pub":0
+pk_parse_public_keyfile_rsa:"data_files/rsa_pkcs8_1024_public.der":0
 
 Parse Public RSA Key #3 (PKCS#1 wrapped)
 depends_on:MBEDTLS_RSA_C:MBEDTLS_PEM_PARSE_C
-pk_parse_public_keyfile_rsa:"data_files/public_rsa_key.pem":0
+pk_parse_public_keyfile_rsa:"data_files/rsa_pkcs1_2048_public.pem":0
 
 Parse Public RSA Key #4 (PKCS#1 wrapped, DER)
 depends_on:MBEDTLS_RSA_C:MBEDTLS_PEM_PARSE_C
-pk_parse_public_keyfile_rsa:"data_files/public_rsa_key.der":0
+pk_parse_public_keyfile_rsa:"data_files/rsa_pkcs1_2048_public.der":0
 
 Parse Public EC Key #1 (RFC 5480, DER)
 depends_on:MBEDTLS_ECP_C:MBEDTLS_ECP_DP_SECP192R1_ENABLED