Switch pkparse to use new mbedtls_pkcs5_pbes2_ext function

Switch pkparse to use new mbedtls_pkcs5_pbes2_ext function
and deprecate mbedtls_pkcs5_pbes2 function.

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>

include/mbedtls/build_info.h

@@ -229,6 +229,14 @@
 #define MBEDTLS_PK_HAVE_ECC_KEYS
 #endif /* MBEDTLS_PK_USE_PSA_EC_DATA || MBEDTLS_ECP_C */
 
+/* Historically pkparse did not check the CBC padding when decrypting
+ * a key. This was a bug, which is now fixed. As a consequence, pkparse
+ * now needs PKCS7 padding support, but existing configurations might not
+ * enable it, so we enable it here. */
+#if defined(MBEDTLS_PK_PARSE_C) && defined(MBEDTLS_PKCS5_C) && defined(MBEDTLS_CIPHER_MODE_CBC)
+#define MBEDTLS_CIPHER_PADDING_PKCS7
+#endif
+
 /* The following blocks make it easier to disable all of TLS,
  * or of TLS 1.2 or 1.3 or DTLS, without having to manually disable all
  * key exchanges, options and extensions related to them. */

include/mbedtls/pkcs5.h

@@ -25,6 +25,7 @@
 #define MBEDTLS_PKCS5_H
 
 #include "mbedtls/build_info.h"
+#include "mbedtls/platform_util.h"
 
 #include "mbedtls/asn1.h"
 #include "mbedtls/md.h"
@@ -50,12 +51,17 @@ extern "C" {
 
 #if defined(MBEDTLS_ASN1_PARSE_C)
 
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
 /**
  * \brief          PKCS#5 PBES2 function
  *
  * \note           When encrypting, #MBEDTLS_CIPHER_PADDING_PKCS7 must
  *                 be enabled at compile time.
  *
+ * \deprecated     This function is deprecated and will be removed in a
+ *                 future version of the library.
+ *                 Please use mbedtls_pkcs5_pbes2_ext() instead.
+ *
  * \warning        When decrypting:
  *                 - if #MBEDTLS_CIPHER_PADDING_PKCS7 is enabled at compile
  *                   time, this function validates the CBC padding and returns
@@ -86,10 +92,11 @@ extern "C" {
  *
  * \returns        0 on success, or a MBEDTLS_ERR_XXX code if verification fails.
  */
-int mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode,
+int MBEDTLS_DEPRECATED mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode,
-                        const unsigned char *pwd,  size_t pwdlen,
+                                           const unsigned char *pwd,  size_t pwdlen,
-                        const unsigned char *data, size_t datalen,
+                                           const unsigned char *data, size_t datalen,
-                        unsigned char *output);
+                                           unsigned char *output);
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
 
 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
 

library/pkcs5.c

@@ -119,6 +119,7 @@ int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,
                             size_t *output_len);
 #endif
 
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
 int mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode,
                         const unsigned char *pwd,  size_t pwdlen,
                         const unsigned char *data, size_t datalen,
@@ -133,6 +134,7 @@ int mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode,
     return mbedtls_pkcs5_pbes2_ext(pbe_params, mode, pwd, pwdlen, data,
                                    datalen, output, SIZE_MAX, &output_len);
 }
+#endif
 
 int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,
                             const unsigned char *pwd,  size_t pwdlen,

library/pkparse.c

@@ -1417,6 +1417,13 @@ static int pk_parse_key_pkcs8_unencrypted_der(
 #endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
     return MBEDTLS_ERR_PK_UNKNOWN_PK_ALG;
 
+#if !defined(MBEDTLS_PKCS12_C)
+    end = p + len;
+    if (end != (key + keylen)) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
+                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
+    }
+#endif
     return 0;
 }
 
@@ -1445,6 +1452,7 @@ static int pk_parse_key_pkcs8_encrypted_der(
     mbedtls_cipher_type_t cipher_alg;
     mbedtls_md_type_t md_alg;
 #endif
+    size_t outlen = 0;
 
     p = key;
     end = p + keylen;
@@ -1499,14 +1507,14 @@ static int pk_parse_key_pkcs8_encrypted_der(
 
             return ret;
         }
-
+        outlen = len;
         decrypted = 1;
     } else
 #endif /* MBEDTLS_PKCS12_C */
 #if defined(MBEDTLS_PKCS5_C)
     if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS5_PBES2, &pbe_alg_oid) == 0) {
-        if ((ret = mbedtls_pkcs5_pbes2(&pbe_params, MBEDTLS_PKCS5_DECRYPT, pwd, pwdlen,
+        if ((ret = mbedtls_pkcs5_pbes2_ext(&pbe_params, MBEDTLS_PKCS5_DECRYPT, pwd, pwdlen,
-                                       p, len, buf)) != 0) {
+                                           p, len, buf, len, &outlen)) != 0) {
             if (ret == MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH) {
                 return MBEDTLS_ERR_PK_PASSWORD_MISMATCH;
             }
@@ -1524,8 +1532,7 @@ static int pk_parse_key_pkcs8_encrypted_der(
     if (decrypted == 0) {
         return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
     }
-
+    return pk_parse_key_pkcs8_unencrypted_der(pk, buf, outlen, f_rng, p_rng);
-    return pk_parse_key_pkcs8_unencrypted_der(pk, buf, len, f_rng, p_rng);
 }
 #endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
 

tests/suites/test_suite_pkcs5.function

@@ -46,6 +46,7 @@ void pbes2_encrypt(int params_tag, data_t *params_hex, data_t *pw,
 
     ASSERT_ALLOC(my_out, outsize);
 
+#if defined(MBEDTLS_TEST_DEPRECATED)
     if (ref_ret != MBEDTLS_ERR_ASN1_BUF_TOO_SMALL) {
         my_ret = mbedtls_pkcs5_pbes2(&params, MBEDTLS_PKCS5_ENCRYPT,
                                      pw->x, pw->len, data->x, data->len, my_out);
@@ -55,6 +56,7 @@ void pbes2_encrypt(int params_tag, data_t *params_hex, data_t *pw,
         ASSERT_COMPARE(my_out, ref_out->len,
                        ref_out->x, ref_out->len);
     }
+#endif
 
 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
     my_ret = mbedtls_pkcs5_pbes2_ext(&params, MBEDTLS_PKCS5_ENCRYPT,
@@ -93,6 +95,7 @@ void pbes2_decrypt(int params_tag, data_t *params_hex, data_t *pw,
 
     ASSERT_ALLOC(my_out, outsize);
 
+#if defined(MBEDTLS_TEST_DEPRECATED)
     if (ref_ret != MBEDTLS_ERR_ASN1_BUF_TOO_SMALL) {
         my_ret = mbedtls_pkcs5_pbes2(&params, MBEDTLS_PKCS5_DECRYPT,
                                      pw->x, pw->len, data->x, data->len, my_out);
@@ -102,6 +105,8 @@ void pbes2_decrypt(int params_tag, data_t *params_hex, data_t *pw,
         ASSERT_COMPARE(my_out, ref_out->len,
                        ref_out->x, ref_out->len);
     }
+#endif
+
 #if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
     my_ret = mbedtls_pkcs5_pbes2_ext(&params, MBEDTLS_PKCS5_DECRYPT,
                                      pw->x, pw->len, data->x, data->len, my_out,