Move base64 implementation to own file.
authorAndre Noll <maan@systemlinux.org>
Tue, 10 Jun 2014 15:52:22 +0000 (17:52 +0200)
committerAndre Noll <maan@tuebingen.mpg.de>
Tue, 23 Aug 2016 14:29:34 +0000 (16:29 +0200)
The base64 decoder is independent of anything else, so it should not
be part of the crypto API. This patch moves the two public functions
uudecode() and base64_decode() to a new file, base64.c, and introduces
base64.h to declare them.

base64.c [new file with mode: 0644]
base64.h [new file with mode: 0644]
configure.ac
crypt.c
crypt_backend.h
crypt_common.c
error.h
gcrypt.c

diff --git a/base64.c b/base64.c
new file mode 100644 (file)
index 0000000..e989224
--- /dev/null
+++ b/base64.c
@@ -0,0 +1,167 @@
+/*
+ * The code in this file was taken from openssh-5.2p1, Copyright (c) 1996 by
+ * Internet Software Consortium.  Portions Copyright (c) 1995 by International
+ * Business Machines, Inc.
+ */
+
+/** \file base64.c Uudecode and base64decode implementation. */
+
+#include <regex.h>
+
+#include "para.h"
+#include "error.h"
+#include "base64.h"
+#include "string.h"
+
+static const char Base64[] =
+       "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static const char Pad64 = '=';
+
+/**
+ * base64-decode a buffer.
+ *
+ * \param src The buffer to decode.
+ * \param target Result is stored here.
+ * \param targsize Number of bytes of \a target.
+ *
+ * Skips all whitespace anywhere. Converts characters, four at a time, starting
+ * at (or after) src from base - 64 numbers into three 8 bit bytes in the
+ * target area.
+ *
+ * \return The number of data bytes stored at the target, -E_BASE64 on errors.
+ */
+int base64_decode(char const *src, unsigned char *target, size_t targsize)
+{
+       unsigned int tarindex, state;
+       int ch;
+       char *pos;
+
+       state = 0;
+       tarindex = 0;
+
+       while ((ch = *src++) != '\0') {
+               if (para_isspace(ch)) /* Skip whitespace anywhere. */
+                       continue;
+
+               if (ch == Pad64)
+                       break;
+
+               pos = strchr(Base64, ch);
+               if (pos == NULL) /* A non-base64 character. */
+                       return -E_BASE64;
+
+               switch (state) {
+               case 0:
+                       if (tarindex >= targsize)
+                               return -E_BASE64;
+                       target[tarindex] = (pos - Base64) << 2;
+                       state = 1;
+                       break;
+               case 1:
+                       if (tarindex + 1 >= targsize)
+                               return -E_BASE64;
+                       target[tarindex] |= (pos - Base64) >> 4;
+                       target[tarindex + 1] = ((pos - Base64) & 0x0f) << 4;
+                       tarindex++;
+                       state = 2;
+                       break;
+               case 2:
+                       if (tarindex + 1 >= targsize)
+                               return -E_BASE64;
+                       target[tarindex] |= (pos - Base64) >> 2;
+                       target[tarindex + 1] = ((pos - Base64) & 0x03) << 6;
+                       tarindex++;
+                       state = 3;
+                       break;
+               case 3:
+                       if (tarindex >= targsize)
+                               return -E_BASE64;
+                       target[tarindex] |= pos - Base64;
+                       tarindex++;
+                       state = 0;
+                       break;
+               }
+       }
+
+       /*
+        * We are done decoding Base-64 chars.  Let's see if we ended
+        * on a byte boundary, and/or with erroneous trailing characters.
+        */
+
+       if (ch == Pad64) {              /* We got a pad char. */
+               ch = *src++;            /* Skip it, get next. */
+               switch (state) {
+               case 0:         /* Invalid = in first position */
+               case 1:         /* Invalid = in second position */
+                       return -E_BASE64;
+
+               case 2:         /* Valid, means one byte of info */
+                       /* Skip any number of spaces. */
+                       for (; ch != '\0'; ch = *src++)
+                               if (!isspace(ch))
+                                       break;
+                       /* Make sure there is another trailing = sign. */
+                       if (ch != Pad64)
+                               return -E_BASE64;
+                       ch = *src++;            /* Skip the = */
+                       /* Fall through to "single trailing =" case. */
+                       /* FALLTHROUGH */
+
+               case 3:         /* Valid, means two bytes of info */
+                       /*
+                        * We know this char is an =.  Is there anything but
+                        * whitespace after it?
+                        */
+                       for (; ch != '\0'; ch = *src++)
+                               if (!isspace(ch))
+                                       return -E_BASE64;
+
+                       /*
+                        * Now make sure for cases 2 and 3 that the "extra"
+                        * bits that slopped past the last full byte were
+                        * zeros.  If we don't check them, they become a
+                        * subliminal channel.
+                        */
+                       if (target[tarindex] != 0)
+                               return -E_BASE64;
+               }
+       } else {
+               /*
+                * We ended by seeing the end of the string.  Make sure we
+                * have no partial bytes lying around.
+                */
+               if (state != 0)
+                       return -E_BASE64;
+       }
+       return tarindex;
+}
+
+/**
+ * uudecode a buffer.
+ *
+ * \param src The buffer to decode.
+ * \param target Result buffer.
+ * \param targsize The length of \a target in bytes.
+ *
+ * This is just a simple wrapper for base64_decode() which strips whitespace.
+ *
+ * \return The return value of the underlying call to base64_decode().
+ */
+int uudecode(const char *src, unsigned char *target, size_t targsize)
+{
+       int len;
+       char *encoded, *p;
+
+       /* copy the 'readonly' source */
+       encoded = para_strdup(src);
+       /* skip whitespace and data */
+       for (p = encoded; *p == ' ' || *p == '\t'; p++)
+               ;
+       for (; *p != '\0' && *p != ' ' && *p != '\t'; p++)
+               ;
+       /* and remove trailing whitespace because base64_decode needs this */
+       *p = '\0';
+       len = base64_decode(encoded, target, targsize);
+       free(encoded);
+       return len;
+}
diff --git a/base64.h b/base64.h
new file mode 100644 (file)
index 0000000..a06bf2e
--- /dev/null
+++ b/base64.h
@@ -0,0 +1,2 @@
+int uudecode(const char *src, unsigned char *target, size_t targsize);
+int base64_decode(char const *src, unsigned char *target, size_t targsize);
index f9115fd..8d4ce59 100644 (file)
@@ -418,6 +418,7 @@ if test -n "$CRYPTOLIB" && test $HAVE_OSL = yes; then
                close_on_fork
                mm
                crypt_common
+               base64
                ipc
                dccp_send
                fd
@@ -480,6 +481,7 @@ if test -n "$CRYPTOLIB"; then
                client_common
                buffer_tree
                crypt_common
+               base64
                version
                ggo
        "
@@ -523,6 +525,7 @@ if test -n "$CRYPTOLIB"; then
                stat
                net
                crypt_common
+               base64
                sideband
                time
                grab_client
diff --git a/crypt.c b/crypt.c
index 610d205..222bece 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -23,6 +23,7 @@
 #include "crypt.h"
 #include "fd.h"
 #include "crypt_backend.h"
+#include "base64.h"
 
 struct asymmetric_key {
        RSA *rsa;
index 06c86d7..f9a69d9 100644 (file)
@@ -13,7 +13,5 @@
 
 size_t is_ssh_rsa_key(char *data, size_t size);
 uint32_t read_ssh_u32(const void *vp);
-int uudecode(const char *src, unsigned char *target, size_t targsize);
 int check_ssh_key_header(const unsigned char *blob, int blen);
 int check_key_file(const char *file, bool private_key);
-int base64_decode(char const *src, unsigned char *target, size_t targsize);
index 022692a..b39ee5e 100644 (file)
@@ -45,166 +45,6 @@ size_t is_ssh_rsa_key(char *data, size_t size)
        return cp - data;
 }
 
-/*
- * This base64/uudecode stuff below is taken from openssh-5.2p1, Copyright (c)
- * 1996 by Internet Software Consortium.  Portions Copyright (c) 1995 by
- * International Business Machines, Inc.
- */
-
-static const char Base64[] =
-       "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-static const char Pad64 = '=';
-
-/**
- * base64-decode a buffer.
- *
- * \param src The buffer to decode.
- * \param target Result is stored here.
- * \param targsize Number of bytes of \a target.
- *
- * Skips all whitespace anywhere. Converts characters, four at a time, starting
- * at (or after) src from base - 64 numbers into three 8 bit bytes in the
- * target area.
- *
- * \return The number of data bytes stored at the target, -E_BASE64 on errors.
- */
-int base64_decode(char const *src, unsigned char *target, size_t targsize)
-{
-       unsigned int tarindex, state;
-       int ch;
-       char *pos;
-
-       state = 0;
-       tarindex = 0;
-
-       while ((ch = *src++) != '\0') {
-               if (para_isspace(ch)) /* Skip whitespace anywhere. */
-                       continue;
-
-               if (ch == Pad64)
-                       break;
-
-               pos = strchr(Base64, ch);
-               if (pos == NULL) /* A non-base64 character. */
-                       return -E_BASE64;
-
-               switch (state) {
-               case 0:
-                       if (tarindex >= targsize)
-                               return -E_BASE64;
-                       target[tarindex] = (pos - Base64) << 2;
-                       state = 1;
-                       break;
-               case 1:
-                       if (tarindex + 1 >= targsize)
-                               return -E_BASE64;
-                       target[tarindex] |= (pos - Base64) >> 4;
-                       target[tarindex + 1] = ((pos - Base64) & 0x0f) << 4;
-                       tarindex++;
-                       state = 2;
-                       break;
-               case 2:
-                       if (tarindex + 1 >= targsize)
-                               return -E_BASE64;
-                       target[tarindex] |= (pos - Base64) >> 2;
-                       target[tarindex + 1] = ((pos - Base64) & 0x03) << 6;
-                       tarindex++;
-                       state = 3;
-                       break;
-               case 3:
-                       if (tarindex >= targsize)
-                               return -E_BASE64;
-                       target[tarindex] |= pos - Base64;
-                       tarindex++;
-                       state = 0;
-                       break;
-               }
-       }
-
-       /*
-        * We are done decoding Base-64 chars.  Let's see if we ended
-        * on a byte boundary, and/or with erroneous trailing characters.
-        */
-
-       if (ch == Pad64) {              /* We got a pad char. */
-               ch = *src++;            /* Skip it, get next. */
-               switch (state) {
-               case 0:         /* Invalid = in first position */
-               case 1:         /* Invalid = in second position */
-                       return -E_BASE64;
-
-               case 2:         /* Valid, means one byte of info */
-                       /* Skip any number of spaces. */
-                       for (; ch != '\0'; ch = *src++)
-                               if (!isspace(ch))
-                                       break;
-                       /* Make sure there is another trailing = sign. */
-                       if (ch != Pad64)
-                               return -E_BASE64;
-                       ch = *src++;            /* Skip the = */
-                       /* Fall through to "single trailing =" case. */
-                       /* FALLTHROUGH */
-
-               case 3:         /* Valid, means two bytes of info */
-                       /*
-                        * We know this char is an =.  Is there anything but
-                        * whitespace after it?
-                        */
-                       for (; ch != '\0'; ch = *src++)
-                               if (!isspace(ch))
-                                       return -E_BASE64;
-
-                       /*
-                        * Now make sure for cases 2 and 3 that the "extra"
-                        * bits that slopped past the last full byte were
-                        * zeros.  If we don't check them, they become a
-                        * subliminal channel.
-                        */
-                       if (target[tarindex] != 0)
-                               return -E_BASE64;
-               }
-       } else {
-               /*
-                * We ended by seeing the end of the string.  Make sure we
-                * have no partial bytes lying around.
-                */
-               if (state != 0)
-                       return -E_BASE64;
-       }
-
-       return tarindex;
-}
-
-/**
- * uudecode a buffer.
- *
- * \param src The buffer to decode.
- * \param target Result buffer.
- * \param targsize The length of \a target in bytes.
- *
- * This is just a simple wrapper for base64_decode() which strips whitespace.
- *
- * \return The return value of the underlying call to base64_decode().
- */
-int uudecode(const char *src, unsigned char *target, size_t targsize)
-{
-       int len;
-       char *encoded, *p;
-
-       /* copy the 'readonly' source */
-       encoded = para_strdup(src);
-       /* skip whitespace and data */
-       for (p = encoded; *p == ' ' || *p == '\t'; p++)
-               ;
-       for (; *p != '\0' && *p != ' ' && *p != '\t'; p++)
-               ;
-       /* and remove trailing whitespace because base64_decode needs this */
-       *p = '\0';
-       len = base64_decode(encoded, target, targsize);
-       free(encoded);
-       return len;
-}
-
 /**
  * Read a 4-byte number from a buffer in big-endian format.
  *
diff --git a/error.h b/error.h
index 337160c..ea12469 100644 (file)
--- a/error.h
+++ b/error.h
@@ -440,9 +440,10 @@ extern const char **para_errlist[];
 
 #define CRYPT_COMMON_ERRORS \
        PARA_ERROR(SSH_KEY_HEADER, "ssh key header not found"), \
-       PARA_ERROR(BASE64, "failed to base64-decode ssh public key"), \
        PARA_ERROR(KEY_PERM, "unprotected private key"), \
 
+#define BASE64_ERRORS \
+       PARA_ERROR(BASE64, "base64 decode error"), \
 
 #define CRYPT_ERRORS \
        PARA_ERROR(PRIVATE_KEY, "can not read private key"), \
index 3c6c1ad..8e73b3b 100644 (file)
--- a/gcrypt.c
+++ b/gcrypt.c
@@ -15,6 +15,7 @@
 #include "crypt.h"
 #include "crypt_backend.h"
 #include "fd.h"
+#include "base64.h"
 
 //#define GCRYPT_DEBUG 1