Add an apps internal BIO filter for prefixing output lines

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5224)

1 files changed, 176 insertions, 0 deletions

diff --git a/apps/bf_prefix.c b/apps/bf_prefix.c
new file mode 100644
index 0000000000..4d5e3a31c1
--- /dev/null
+++ b/apps/bf_prefix.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <openssl/bio.h>
+#include "apps.h"
+
+static int prefix_write(BIO *b, const char *out, size_t outl,
+                        size_t *numwritten);
+static int prefix_read(BIO *b, char *buf, size_t size, size_t *numread);
+static int prefix_puts(BIO *b, const char *str);
+static int prefix_gets(BIO *b, char *str, int size);
+static long prefix_ctrl(BIO *b, int cmd, long arg1, void *arg2);
+static int prefix_create(BIO *b);
+static int prefix_destroy(BIO *b);
+static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp);
+
+static BIO_METHOD *prefix_meth = NULL;
+
+BIO_METHOD *apps_bf_prefix(void)
+{
+    if (prefix_meth == NULL) {
+        if ((prefix_meth =
+             BIO_meth_new(BIO_TYPE_FILTER, "Prefix filter")) == NULL
+            || !BIO_meth_set_create(prefix_meth, prefix_create)
+            || !BIO_meth_set_destroy(prefix_meth, prefix_destroy)
+            || !BIO_meth_set_write_ex(prefix_meth, prefix_write)
+            || !BIO_meth_set_read_ex(prefix_meth, prefix_read)
+            || !BIO_meth_set_puts(prefix_meth, prefix_puts)
+            || !BIO_meth_set_gets(prefix_meth, prefix_gets)
+            || !BIO_meth_set_ctrl(prefix_meth, prefix_ctrl)
+            || !BIO_meth_set_callback_ctrl(prefix_meth, prefix_callback_ctrl)) {
+            BIO_meth_free(prefix_meth);
+            prefix_meth = NULL;
+        }
+    }
+    return prefix_meth;
+}
+
+typedef struct prefix_ctx_st {
+    char *prefix;
+    int linestart;               /* flag to indicate we're at the line start */
+} PREFIX_CTX;
+
+static int prefix_create(BIO *b)
+{
+    PREFIX_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
+
+    if (ctx == NULL)
+        return 0;
+
+    ctx->prefix = NULL;
+    ctx->linestart = 1;
+    BIO_set_data(b, ctx);
+    BIO_set_init(b, 1);
+    return 1;
+}
+
+static int prefix_destroy(BIO *b)
+{
+    PREFIX_CTX *ctx = BIO_get_data(b);
+
+    OPENSSL_free(ctx->prefix);
+    OPENSSL_free(ctx);
+    return 1;
+}
+
+static int prefix_read(BIO *b, char *in, size_t size, size_t *numread)
+{
+    return BIO_read_ex(BIO_next(b), in, size, numread);
+}
+
+static int prefix_write(BIO *b, const char *out, size_t outl,
+                        size_t *numwritten)
+{
+    PREFIX_CTX *ctx = BIO_get_data(b);
+
+    if (ctx == NULL)
+        return 0;
+
+    /* If no prefix is set or if it's empty, we've got nothing to do here */
+    if (ctx->prefix == NULL || *ctx->prefix == '\0') {
+        /* We do note if what comes next will be a new line, though */
+        if (outl > 0)
+            ctx->linestart = (out[outl-1] == '\n');
+        return BIO_write_ex(BIO_next(b), out, outl, numwritten);
+    }
+
+    *numwritten = 0;
+
+    while (*out != '\0') {
+        size_t i;
+        char c;
+
+        /* If we know that we're at the start of the line, output the prefix */
+        if (ctx->linestart) {
+            size_t dontcare;
+
+            if (!BIO_write_ex(BIO_next(b), ctx->prefix, strlen(ctx->prefix),
+                              &dontcare))
+                return 0;
+            ctx->linestart = 0;
+        }
+
+        /* Now, go look for the next LF, or the end of the string */
+        for (i = 0; (c = out[i]) != '\n' && c != '\0'; i++)
+            continue;
+        if (c == '\n')
+            i++;
+
+        /* Output what we found so far */
+        while (i > 0) {
+            size_t num = 0;
+
+            if (!BIO_write_ex(BIO_next(b), out, i, &num))
+                return 0;
+            out += num;
+            *numwritten += num;
+            i -= num;
+        }
+
+        /* If we found a LF, what follows is a new line, so take note */
+        if (c == '\n')
+            ctx->linestart = 1;
+    }
+
+    return 1;
+}
+
+static long prefix_ctrl(BIO *b, int cmd, long num, void *ptr)
+{
+    long ret = 0;
+
+    switch (cmd) {
+    case PREFIX_CTRL_SET_PREFIX:
+        {
+            PREFIX_CTX *ctx = BIO_get_data(b);
+
+            if (ctx == NULL)
+                break;
+
+            OPENSSL_free(ctx->prefix);
+            ctx->prefix = OPENSSL_strdup((const char *)ptr);
+            ret = ctx->prefix != NULL;
+        }
+        break;
+    default:
+        if (BIO_next(b) != NULL)
+            ret = BIO_ctrl(BIO_next(b), cmd, num, ptr);
+        break;
+    }
+    return ret;
+}
+
+static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
+{
+    return BIO_callback_ctrl(BIO_next(b), cmd, fp);
+}
+
+static int prefix_gets(BIO *b, char *buf, int size)
+{
+    return BIO_gets(BIO_next(b), buf, size);
+}
+
+static int prefix_puts(BIO *b, const char *str)
+{
+    return BIO_write(b, str, strlen(str));
+}