Fix: Allow empty input/output in simple encrypt/decrypt.

Change-Id: I44663a1ea50982cc641b30df8a3f4959d6ce4c36

diff --git a/api/yaca/yaca_simple.h b/api/yaca/yaca_simple.h
index e1260746d711fa34570d93ce268f000f0dd81673..e4fd2c36125b0ca89d1ea40464e61e305027cb05 100755 (executable)
--- a/api/yaca/yaca_simple.h
+++ b/api/yaca/yaca_simple.h
@@ -24,8 +24,8 @@
  *           Design constraints:
  *           - All operations are single-shot (no streaming possible)
  *           - Context is not used
- *           - For now only digest and symmetric ciphers are supported
- *           - Disabling PKCS#5 padding for ECB and CBC chaining is not supported.
+ *           - Only digest, signatures and symmetric ciphers are supported
+ *           - Disabling PKCS#5 padding for ECB and CBC chaining is not supported
  *           - GCM and CCM chaining is not supported
  *           - All outputs are allocated by the library
  */

diff --git a/src/simple.c b/src/simple.c
index 5fabcc8a8758cd4f299f5048f78c2e7ff2b6d3f5..00d9b3cf5fcc0bdfbde0b1cf862bcb5c0c567f22 100644 (file)
--- a/src/simple.c
+++ b/src/simple.c
@@ -95,9 +95,11 @@ API int yaca_simple_encrypt(yaca_encrypt_algorithm_e algo,
        yaca_context_h ctx;
        int ret;
        char *lciphertext = NULL;
-       size_t out_len, lciphertext_len, written;
+       size_t out_len = 0;
+       size_t lciphertext_len = 0;
+       size_t written = 0;
 
-       if (plaintext == NULL || plaintext_len == 0 ||
+       if ((plaintext == NULL && plaintext_len > 0) || (plaintext != NULL && plaintext_len == 0) ||
            ciphertext == NULL || ciphertext_len == NULL ||
            sym_key == YACA_KEY_NULL ||
            bcm == YACA_BCM_CCM || bcm == YACA_BCM_GCM)
@@ -107,9 +109,11 @@ API int yaca_simple_encrypt(yaca_encrypt_algorithm_e algo,
        if (ret != YACA_ERROR_NONE)
                return ret;
 
-       ret = yaca_context_get_output_length(ctx, plaintext_len, &out_len);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       if (plaintext_len > 0) {
+               ret = yaca_context_get_output_length(ctx, plaintext_len, &out_len);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       }
 
        ret = yaca_context_get_output_length(ctx, 0, &lciphertext_len);
        if (ret != YACA_ERROR_NONE)
@@ -127,9 +131,11 @@ API int yaca_simple_encrypt(yaca_encrypt_algorithm_e algo,
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
-       ret = yaca_encrypt_update(ctx, plaintext, plaintext_len, lciphertext, &out_len);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       if (plaintext_len > 0) {
+               ret = yaca_encrypt_update(ctx, plaintext, plaintext_len, lciphertext, &out_len);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       }
 
        assert(out_len <= lciphertext_len);
        written = out_len;
@@ -139,11 +145,22 @@ API int yaca_simple_encrypt(yaca_encrypt_algorithm_e algo,
                goto exit;
 
        written += out_len;
-       assert(written <= lciphertext_len && written > 0);
+       assert(written <= lciphertext_len);
 
-       ret = yaca_realloc(written, (void**)&lciphertext);
-       if (ret != YACA_ERROR_NONE)
+       if (((bcm == YACA_BCM_CBC || bcm == YACA_BCM_ECB) && written == 0) ||
+           (bcm != YACA_BCM_CBC && bcm != YACA_BCM_ECB && plaintext_len == 0 && written > 0)) {
+               ret = YACA_ERROR_INTERNAL;
                goto exit;
+       }
+
+       if (written > 0) {
+               ret = yaca_realloc(written, (void**)&lciphertext);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       } else {
+               yaca_free(lciphertext);
+               lciphertext = NULL;
+       }
 
        *ciphertext = lciphertext;
        *ciphertext_len = written;
@@ -169,9 +186,12 @@ API int yaca_simple_decrypt(yaca_encrypt_algorithm_e algo,
        yaca_context_h ctx;
        int ret;
        char *lplaintext = NULL;
-       size_t out_len, lplaintext_len, written;
+       size_t out_len = 0;
+       size_t lplaintext_len = 0;
+       size_t written = 0;
 
-       if (ciphertext == NULL || ciphertext_len == 0 ||
+       if ((ciphertext == NULL && ciphertext_len > 0) || (ciphertext != NULL && ciphertext_len == 0) ||
+           ((bcm == YACA_BCM_ECB || bcm == YACA_BCM_CBC) && ciphertext == NULL && ciphertext_len == 0) ||
            plaintext == NULL || plaintext_len == NULL ||
            sym_key == YACA_KEY_NULL ||
            bcm == YACA_BCM_CCM || bcm == YACA_BCM_GCM)
@@ -181,9 +201,11 @@ API int yaca_simple_decrypt(yaca_encrypt_algorithm_e algo,
        if (ret != YACA_ERROR_NONE)
                return ret;
 
-       ret = yaca_context_get_output_length(ctx, ciphertext_len, &out_len);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       if (ciphertext_len > 0) {
+               ret = yaca_context_get_output_length(ctx, ciphertext_len, &out_len);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       }
 
        ret = yaca_context_get_output_length(ctx, 0, &lplaintext_len);
        if (ret != YACA_ERROR_NONE)
@@ -201,9 +223,11 @@ API int yaca_simple_decrypt(yaca_encrypt_algorithm_e algo,
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
-       ret = yaca_decrypt_update(ctx, ciphertext, ciphertext_len, lplaintext, &out_len);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       if (ciphertext_len > 0) {
+               ret = yaca_decrypt_update(ctx, ciphertext, ciphertext_len, lplaintext, &out_len);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       }
 
        assert(out_len <= lplaintext_len);
        written = out_len;
@@ -213,11 +237,21 @@ API int yaca_simple_decrypt(yaca_encrypt_algorithm_e algo,
                goto exit;
 
        written += out_len;
-       assert(written <= lplaintext_len && written > 0);
+       assert(written <= lplaintext_len);
 
-       ret = yaca_realloc(written, (void**)&lplaintext);
-       if (ret != YACA_ERROR_NONE)
+       if (bcm != YACA_BCM_CBC && bcm != YACA_BCM_ECB && ciphertext_len == 0 && written > 0) {
+               ret = YACA_ERROR_INTERNAL;
                goto exit;
+       }
+
+       if (written > 0) {
+               ret = yaca_realloc(written, (void**)&lplaintext);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
+       } else {
+               yaca_free(lplaintext);
+               lplaintext = NULL;
+       }
 
        *plaintext = lplaintext;
        *plaintext_len = written;