From 9153da3e762aef723d54111acc3f42b9f563f8c7 Mon Sep 17 00:00:00 2001
From: Jeff Connelly <shellreef+git@gmail.com>
Date: Thu, 15 May 2008 11:52:19 -0700
Subject: [PATCH] Lookup pads when unpackaging messages.

---
 libotp.c | 37 +++++++++++++++++++++++++++++++------
 libotp.h | 18 ++++++++++--------
 try.c    |  7 -------
 3 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/libotp.c b/libotp.c
index 9d5e7c8..fe81fee 100644
--- a/libotp.c
+++ b/libotp.c
@@ -143,6 +143,23 @@ void load_pad(char *local_filename)
     }
 }
 
+/** Find pad with given name. */
+PAD *find_pad(char *pad_name)
+{
+    PAD *p;
+
+    /* Null or blank pad = default (first) pad. */
+    if (!pad_name || !strcmp(pad_name, ""))
+        return pads;
+
+    for (p = pads; p; p = p->next) {
+        if (!strcmp(p->name, pad_name))
+            return p;
+    }
+
+    return NULL;
+}
+
 /** Close all pads and free allocated memory. */
 void free_pads()
 {
@@ -169,8 +186,9 @@ void free_message(MESSAGE *msg)
 MESSAGE *unpackage(char *input)
 {
     MESSAGE *msg;
-    unsigned int at, raw_ct_len, i;
-    char *s, *end, *raw_ct, *b64_ct;
+    unsigned int at, i;
+    char *s, *end, *b64_ct;
+    char pad_name[PAD_NAME_LENGTH];
 
     msg = malloc(sizeof(MESSAGE));
     if (!msg) {
@@ -220,7 +238,7 @@ MESSAGE *unpackage(char *input)
     }
     ++s;
     
-    memset(msg->pad_name, 0, PAD_NAME_LENGTH);
+    memset(pad_name, 0, PAD_NAME_LENGTH);
     
     /* Includes pad name? */
     if (s[0] != '\n' && s[0] != '\r') {
@@ -229,7 +247,7 @@ MESSAGE *unpackage(char *input)
         i = 0;
         /* v0.7+ message, includes pad name */
         while(s[0] != '\n' && s[0] != '\r' && s[0] != ',' && s < end) {
-            msg->pad_name[i] = s[0];
+            pad_name[i] = s[0];
             ++s;
             ++i;
             if (i > PAD_NAME_LENGTH) {
@@ -240,7 +258,13 @@ MESSAGE *unpackage(char *input)
         }
     }
 
-    printf("Pad name: |%s|\n", msg->pad_name);
+    printf("Pad name: |%s|\n", pad_name);
+
+    msg->pad = find_pad(pad_name);
+    if (!msg->pad) {
+        fprintf(stderr, "No such pad by name '%s'\n", pad_name);
+        exit(EX_DATAERR);
+    }
 
     /* Go to next line */
     while((s[0] == '\n' || s[0] == '\r' || s[0] == ',') && (s < end))
@@ -254,11 +278,12 @@ MESSAGE *unpackage(char *input)
 
     printf("b64_data=<%s>\n", b64_ct);
 
+    /* Decode base64 */
     msg->cipher_text = malloc(strlen(b64_ct));
     msg->length = base64_decode(b64_ct, msg->cipher_text);
     free(b64_ct);
 
-    printf("decoded to %d bytes\n", msg->length);
+    printf("decoded to %ld bytes\n", msg->length);
 
     for (i = 0; i < msg->length; ++i)
         printf("%c", msg->cipher_text[i]);
diff --git a/libotp.h b/libotp.h
index 3569c2d..7bda80f 100644
--- a/libotp.h
+++ b/libotp.h
@@ -13,14 +13,7 @@
 
 #define PAD_NAME_LENGTH         4
 
-/** Packaged up encrypted message, ready for transport. */
-typedef struct _MESSAGE {
-    unsigned long offset;
-    char pad_name[PAD_NAME_LENGTH];
-    unsigned long length;
-    char *cipher_text;
-} MESSAGE;
-
+/* One-time pad. */
 typedef struct _PAD {
     char *local_filename;
     char *name;
@@ -29,6 +22,15 @@ typedef struct _PAD {
     /* Use read_offset() and write_offset() to access offset. */
 } PAD;
 
+
+/** Packaged up encrypted message, ready for transport. */
+typedef struct _MESSAGE {
+    unsigned long offset;
+    PAD *pad;
+    unsigned long length;
+    char *cipher_text;
+} MESSAGE;
+
 void show_pads();
 FILE *open_offset_file(PAD *p, char *mode);
 unsigned long read_offset(PAD *p);
diff --git a/try.c b/try.c
index a046299..3c89d34 100644
--- a/try.c
+++ b/try.c
@@ -21,13 +21,6 @@ int main()
     write_offset(pads, 1213475);
     printf("offset=%ld\n", read_offset(pads));
 
-    m = unpackage("--EMOTP_BEGIN--0,\n"
-            "aGVsbG8gd29ybGQ=\n"
-            "--EMOTP_END--\n");
-
-    free_message(m);
-
-
     m = unpackage("--EMOTP_BEGIN--1213434,\n"
             "gK1O22FPbxLmxrROfFHDCsM1LTsOAjjbRlHVM1p+WG+s6yslYVfzvtc=\n"
             "--EMOTP_END--\n");
-- 
2.11.4.GIT