Check set_padding has been called in mbedtls_cipher_finish
Check set_padding has been called in mbedtls_cipher_finish
in modes that require padding.
Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/library/cipher.c b/library/cipher.c
index de7f837..995d3d2 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -268,17 +268,6 @@
ctx->cipher_info = cipher_info;
-#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
- /*
- * Ignore possible errors caused by a cipher mode that doesn't use padding
- */
-#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
- (void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_PKCS7);
-#else
- (void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_NONE);
-#endif
-#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
-
return 0;
}
@@ -1027,6 +1016,16 @@
*olen = 0;
+#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
+ /* CBC mode requires padding so we make sure a call to
+ * mbedtls_cipher_set_padding_mode has been done successfully. */
+ if (MBEDTLS_MODE_CBC == ((mbedtls_cipher_mode_t) ctx->cipher_info->mode)) {
+ if (ctx->get_padding == NULL) {
+ return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
+ }
+ }
+#endif
+
if (MBEDTLS_MODE_CFB == ((mbedtls_cipher_mode_t) ctx->cipher_info->mode) ||
MBEDTLS_MODE_OFB == ((mbedtls_cipher_mode_t) ctx->cipher_info->mode) ||
MBEDTLS_MODE_CTR == ((mbedtls_cipher_mode_t) ctx->cipher_info->mode) ||
diff --git a/tests/suites/test_suite_cipher.aes.data b/tests/suites/test_suite_cipher.aes.data
index 134970f..10bb93e 100644
--- a/tests/suites/test_suite_cipher.aes.data
+++ b/tests/suites/test_suite_cipher.aes.data
@@ -2257,3 +2257,7 @@
Cipher Corner Case behaviours
depends_on:MBEDTLS_AES_C
cipher_special_behaviours:
+
+Check set padding
+depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CBC
+check_set_padding:
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index 192e498..4fda4f9 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -2,6 +2,7 @@
#include "mbedtls/cipher.h"
#include "mbedtls/aes.h"
+
#if defined(MBEDTLS_GCM_C)
#include "mbedtls/gcm.h"
#endif
@@ -400,6 +401,16 @@
if (-1 != pad_mode) {
TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, pad_mode));
TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, pad_mode));
+ } else {
+ if (ctx_dec.cipher_info->mode == MBEDTLS_MODE_CBC) {
+#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_PKCS7));
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, MBEDTLS_PADDING_PKCS7));
+#else
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_NONE));
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, MBEDTLS_PADDING_NONE));
+#endif
+ }
}
#else
(void) pad_mode;
@@ -601,6 +612,16 @@
TEST_ASSERT(0 == mbedtls_cipher_reset(&ctx_dec));
+#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
+ if (ctx_dec.cipher_info->mode == MBEDTLS_MODE_CBC) {
+#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_PKCS7));
+#else
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_NONE));
+#endif
+ }
+#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
+
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
int expected = (cipher_info->mode == MBEDTLS_MODE_GCM ||
cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305) ?
@@ -684,6 +705,16 @@
if (-1 != pad_mode) {
TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, pad_mode));
TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, pad_mode));
+ } else {
+ if (ctx_dec.cipher_info->mode == MBEDTLS_MODE_CBC) {
+#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_PKCS7));
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, MBEDTLS_PADDING_PKCS7));
+#else
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_dec, MBEDTLS_PADDING_NONE));
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx_enc, MBEDTLS_PADDING_NONE));
+#endif
+ }
}
#else
(void) pad_mode;
@@ -1198,3 +1229,37 @@
mbedtls_cipher_free(&ctx_enc);
}
/* END_CASE */
+
+/* BEGIN_CASE */
+void check_set_padding()
+{
+ mbedtls_cipher_context_t ctx;
+ unsigned char key[16] = { 0 };
+ unsigned char iv[16] = { 0 };
+ unsigned char input[16] = { 0 };
+ unsigned char output[32] = { 0 };
+ size_t outlen = 0;
+ int result = MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
+ const mbedtls_cipher_info_t *cipher_info;
+
+ cipher_info = mbedtls_cipher_info_from_type(MBEDTLS_CIPHER_AES_128_CBC);
+
+ mbedtls_cipher_init(&ctx);
+
+ TEST_ASSERT(0 == mbedtls_cipher_setup(&ctx, cipher_info));
+
+ TEST_ASSERT(0 == mbedtls_cipher_setkey(&ctx, key, 128, MBEDTLS_ENCRYPT));
+
+ TEST_ASSERT(result == mbedtls_cipher_crypt(&ctx, iv, sizeof(iv), input,
+ sizeof(input), output, &outlen));
+
+#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
+ TEST_ASSERT(0 == mbedtls_cipher_set_padding_mode(&ctx, MBEDTLS_PADDING_NONE));
+ TEST_ASSERT(0 == mbedtls_cipher_crypt(&ctx, iv, sizeof(iv), input,
+ sizeof(input), output, &outlen));
+#endif
+
+exit:
+ mbedtls_cipher_free(&ctx);
+}
+/* END_CASE */