evp/evp_enc.c: make assert error message more readable

and add EVPerr(PARTIALLY_OVERLAPPED)
Reviewed-by: NStephen Henson <steve@openssl.org>

crypto/evp/evp_enc.c

@@ -285,10 +285,10 @@ static int is_partially_overlapping(const void *ptr1, const void *ptr2,
      * operations are used instead of boolean to minimize number
      * of conditional branches.]
      */
-    int condition = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
-                                               (diff > (0 - (PTRDIFF_T)len)));
-    assert(!condition);
-    return condition;
+    int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
+                                                (diff > (0 - (PTRDIFF_T)len)));
+    assert(!overlapped);
+    return overlapped;
 }
 
 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
@@ -297,8 +297,10 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
     int i, j, bl;
 
     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
-        if (is_partially_overlapping(out, in, inl))
+        if (is_partially_overlapping(out, in, inl)) {
+            EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
             return 0;
+        }
 
         i = ctx->cipher->do_cipher(ctx, out, in, inl);
         if (i < 0)
@@ -312,8 +314,10 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
         *outl = 0;
         return inl == 0;
     }
-    if (is_partially_overlapping(out, in, inl))
+    if (is_partially_overlapping(out, in, inl)) {
+        EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
         return 0;
+    }
 
     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
@@ -338,8 +342,10 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
             memcpy(&(ctx->buf[i]), in, j);
             inl -= j;
             in += j;
-            if (is_partially_overlapping(out, in, bl))
+            if (is_partially_overlapping(out, in, bl)) {
+	        EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
                 return 0;
+            }
             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
                 return 0;
             out += bl;
@@ -417,8 +423,10 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
     unsigned int b;
 
     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
-        if (is_partially_overlapping(out, in, inl))
+        if (is_partially_overlapping(out, in, inl)) {
+            EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
             return 0;
+        }
 
         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
         if (fix_len < 0) {
@@ -443,8 +451,10 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
     if (ctx->final_used) {
         /* see comment about PTRDIFF_T comparison above */
         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
-            || is_partially_overlapping(out, in, b))
+            || is_partially_overlapping(out, in, b)) {
+            EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
             return 0;
+        }
         memcpy(out, ctx->final, b);
         out += b;
         fix_len = 1;

crypto/evp/evp_err.c

@@ -33,8 +33,10 @@ static ERR_STRING_DATA EVP_str_functs[] = {
     {ERR_FUNC(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH),
      "EVP_CIPHER_CTX_set_key_length"},
     {ERR_FUNC(EVP_F_EVP_DECRYPTFINAL_EX), "EVP_DecryptFinal_ex"},
+    {ERR_FUNC(EVP_F_EVP_DECRYPTUPDATE), "EVP_DecryptUpdate"},
     {ERR_FUNC(EVP_F_EVP_DIGESTINIT_EX), "EVP_DigestInit_ex"},
     {ERR_FUNC(EVP_F_EVP_ENCRYPTFINAL_EX), "EVP_EncryptFinal_ex"},
+    {ERR_FUNC(EVP_F_EVP_ENCRYPTUPDATE), "EVP_EncryptUpdate"},
     {ERR_FUNC(EVP_F_EVP_MD_CTX_COPY_EX), "EVP_MD_CTX_copy_ex"},
     {ERR_FUNC(EVP_F_EVP_MD_SIZE), "EVP_MD_size"},
     {ERR_FUNC(EVP_F_EVP_OPENINIT), "EVP_OpenInit"},
@@ -133,6 +135,7 @@ static ERR_STRING_DATA EVP_str_reasons[] = {
     {ERR_REASON(EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE),
      "operation not supported for this keytype"},
     {ERR_REASON(EVP_R_OPERATON_NOT_INITIALIZED), "operaton not initialized"},
+    {ERR_REASON(EVP_R_PARTIALLY_OVERLAPPING), "partially overlapping buffers"},
     {ERR_REASON(EVP_R_PRIVATE_KEY_DECODE_ERROR), "private key decode error"},
     {ERR_REASON(EVP_R_PRIVATE_KEY_ENCODE_ERROR), "private key encode error"},
     {ERR_REASON(EVP_R_PUBLIC_KEY_NOT_RSA), "public key not rsa"},

include/openssl/evp.h

@@ -1459,8 +1459,10 @@ int ERR_load_EVP_strings(void);
 # define EVP_F_EVP_CIPHER_CTX_CTRL                        124
 # define EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH              122
 # define EVP_F_EVP_DECRYPTFINAL_EX                        101
+# define EVP_F_EVP_DECRYPTUPDATE                          166
 # define EVP_F_EVP_DIGESTINIT_EX                          128
 # define EVP_F_EVP_ENCRYPTFINAL_EX                        127
+# define EVP_F_EVP_ENCRYPTUPDATE                          167
 # define EVP_F_EVP_MD_CTX_COPY_EX                         110
 # define EVP_F_EVP_MD_SIZE                                162
 # define EVP_F_EVP_OPENINIT                               102
@@ -1551,6 +1553,7 @@ int ERR_load_EVP_strings(void);
 # define EVP_R_NO_OPERATION_SET                           149
 # define EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE   150
 # define EVP_R_OPERATON_NOT_INITIALIZED                   151
+# define EVP_R_PARTIALLY_OVERLAPPING                      162
 # define EVP_R_PRIVATE_KEY_DECODE_ERROR                   145
 # define EVP_R_PRIVATE_KEY_ENCODE_ERROR                   146
 # define EVP_R_PUBLIC_KEY_NOT_RSA                         106