First cut at replacement for base64 encoder.
authorrepka%netscape.com
Thu, 06 Apr 2000 00:39:49 +0000
changeset 230 d3006d31dd911e77da468221c9771a41b161a4eb
parent 229 fecb2bfafe3cbda21e1c93de1facb37102ee2f9b
child 231 b7703d46da4aeeba6e35e7bb9a168cfdeb161142
push idunknown
push userunknown
push dateunknown
First cut at replacement for base64 encoder.
security/nss/lib/util/nssb64e.c
new file mode 100644
--- /dev/null
+++ b/security/nss/lib/util/nssb64e.c
@@ -0,0 +1,762 @@
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is the Netscape security libraries.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are 
+ * Copyright (C) 1994-2000 Netscape Communications Corporation.  All
+ * Rights Reserved.
+ * 
+ * Contributor(s):
+ * 
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License Version 2 or later (the
+ * "GPL"), in which case the provisions of the GPL are applicable 
+ * instead of those above.  If you wish to allow use of your 
+ * version of this file only under the terms of the GPL and not to
+ * allow others to use your version of this file under the MPL,
+ * indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by
+ * the GPL.  If you do not delete the provisions above, a recipient
+ * may use your version of this file under either the MPL or the
+ * GPL.
+ */
+
+/*
+ * Base64 encoding (binary to ascii).
+ *
+ * $Id$
+ */
+
+#include "nssb64.h"
+#include "nspr.h"
+#include "secitem.h"
+#include "secerr.h"
+
+/*
+ * XXX See the big comment at the top of nssb64d.c about moving the
+ * bulk of this code over into NSPR (the PL part).  It all applies
+ * here but I didn't want to duplicate it, to avoid divergence problems.
+ */ 
+
+/*
+ **************************************************************
+ * XXX Beginning of base64 encoding code to be moved into NSPR.
+ */
+
+
+struct PLBase64EncodeStateStr {
+    unsigned chunks;
+    unsigned saved;
+    unsigned char buf[3];
+};
+
+/*
+ * This typedef would belong in the NSPR header file (i.e. plbase64.h).
+ */
+typedef struct PLBase64EncoderStr PLBase64Encoder;
+
+/*
+ * The following implementation of base64 encoding was based on code
+ * found in libmime (specifically, in mimeenc.c).  It has been adapted to
+ * use PR types and naming as well as to provide other necessary semantics
+ * (like buffer-in/buffer-out in addition to "streaming" without undue
+ * performance hit of extra copying if you made the buffer versions
+ * use the output_fn).  It also incorporates some aspects of the current
+ * NSPR base64 encoding code.  As such, you may find similarities to
+ * both of those implementations.  I tried to use names that reflected
+ * the original code when possible.  For this reason you may find some
+ * inconsistencies -- libmime used lots of "in" and "out" whereas the
+ * NSPR version uses "src" and "dest"; sometimes I changed one to the other
+ * and sometimes I left them when I thought the subroutines were at least
+ * self-consistent.
+ */
+
+PR_BEGIN_EXTERN_C
+
+/*
+ * Opaque object used by the encoder to store state.
+ */
+struct PLBase64EncoderStr {
+    /*
+     * The one or two bytes pending.  (We need 3 to create a "token",
+     * and hold the leftovers here.  in_buffer_count is *only* ever
+     * 0, 1, or 2.
+     */
+    unsigned char in_buffer[2];
+    int in_buffer_count;
+
+    /*
+     * If the caller wants linebreaks added, line_length specifies
+     * where they come out.  It must be a multiple of 4; if the caller
+     * provides one that isn't, we round it down to the nearest
+     * multiple of 4.
+     *
+     * The value of current_column counts how many characters have been
+     * added since the last linebreaks (or since the beginning, on the
+     * first line).  It is also always a multiple of 4; it is unused when
+     * line_length is 0.
+     */ 
+    PRUint32 line_length;
+    PRUint32 current_column;
+
+    /*
+     * Where to write the encoded data (used when streaming, not when
+     * doing all in-memory (buffer) operations).
+     *
+     * Note that this definition is chosen to be compatible with PR_Write.
+     */
+    PRInt32 (*output_fn) (void *output_arg, const char *buf, PRInt32 size);
+    void *output_arg;
+
+    /*
+     * Where the encoded output goes -- either temporarily (in the streaming
+     * case, staged here before it goes to the output function) or what will
+     * be the entire buffered result for users of the buffer version.
+     */
+    char *output_buffer;
+    PRUint32 output_buflen;	/* the total length of allocated buffer */
+    PRUint32 output_length;	/* the length that is currently populated */
+};
+
+PR_END_EXTERN_C
+
+
+/*
+ * Table to convert a binary value to its corresponding ascii "code".
+ */
+static unsigned char base64_valuetocode[64] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+#define B64_PAD	'='
+#define B64_CR	'\r'
+#define B64_LF	'\n'
+
+static PRStatus
+pl_base64_encode_buffer (PLBase64Encoder *data, const unsigned char *in,
+			 PRUint32 size)
+{
+    const unsigned char *end = in + size;
+    char *out = data->output_buffer + data->output_length;
+    int i = data->in_buffer_count;
+    PRUint32 n = 0;
+    int off;
+    PRUint32 output_threshold;
+
+    /* If this input buffer is too small, wait until next time. */
+    if (size < (3 - i)) {
+	data->in_buffer[i++] = in[0];
+	if (size > 1)
+	    data->in_buffer[i++] = in[1];
+	PR_ASSERT(i < 3);
+	data->in_buffer_count = i;
+	return PR_SUCCESS;
+    }
+
+    /* If there are bytes that were put back last time, take them now. */
+    if (i > 0) {
+	n = data->in_buffer[0];
+	if (i > 1)
+	    n = (n << 8) | data->in_buffer[1];
+	data->in_buffer_count = 0;
+    }
+
+    /* If our total is not a multiple of three, put one or two bytes back. */
+    off = (size + i) % 3;
+    if (off > 0) {
+	size -= off;
+	data->in_buffer[0] = in[size];
+	if (off > 1)
+	    data->in_buffer[1] = in[size + 1];
+	data->in_buffer_count = off;
+	end -= off;
+    }
+
+    output_threshold = data->output_buflen - 3;
+
+    /*
+     * Populate the output buffer with base64 data, one line (or buffer)
+     * at a time.
+     */
+    while (in < end) {
+	int j, k;
+
+	while (i < 3) {
+	    n = (n << 8) | *in++;
+	    i++;
+	}
+	i = 0;
+
+	if (data->line_length > 0) {
+	    if (data->current_column >= data->line_length) {
+		data->current_column = 0;
+		*out++ = B64_CR;
+		*out++ = B64_LF;
+		data->output_length += 2;
+	    }
+	    data->current_column += 4;	/* the bytes we are about to add */
+	}
+
+	for (j = 18; j >= 0; j -= 6) {
+	    k = (n >> j) & 0x3F;
+	    *out++ = base64_valuetocode[k];
+	}
+	n = 0;
+	data->output_length += 4;
+
+	if (data->output_length >= output_threshold) {
+	    PR_ASSERT(data->output_length <= data->output_buflen);
+	    if (data->output_fn != NULL) {
+		PRInt32 output_result;
+
+		output_result = data->output_fn (data->output_arg,
+						 data->output_buffer,
+						 (PRInt32) data->output_length);
+		if (output_result < 0)
+		    return PR_FAILURE;
+
+		out = data->output_buffer;
+		data->output_length = 0;
+	    } else {
+		/*
+		 * Check that we are about to exit the loop.  (Since we
+		 * are over the threshold, there isn't enough room in the
+		 * output buffer for another trip around.)
+		 */
+		PR_ASSERT(in == end);
+		if (in < end) {
+		    PR_SetError (PR_BUFFER_OVERFLOW_ERROR, 0);
+		    return PR_FAILURE;
+		}
+	    }
+	}
+    }
+
+    return PR_SUCCESS;
+}
+
+static PRStatus
+pl_base64_encode_flush (PLBase64Encoder *data)
+{
+    int i = data->in_buffer_count;
+
+    if (i == 0 && data->output_length == 0)
+	return PR_SUCCESS;
+
+    if (i > 0) {
+	char *out = data->output_buffer + data->output_length;
+	PRUint32 n;
+	int j, k;
+
+	n = ((PRUint32) data->in_buffer[0]) << 16;
+	if (i > 1)
+	    n |= ((PRUint32) data->in_buffer[1] << 8);
+
+	data->in_buffer_count = 0;
+
+	if (data->line_length > 0) {
+	    if (data->current_column >= data->line_length) {
+		data->current_column = 0;
+		*out++ = B64_CR;
+		*out++ = B64_LF;
+		data->output_length += 2;
+	    }
+	}
+
+	/*
+	 * This will fill in more than we really have data for, but the
+	 * valid parts will end up in the correct position and the extras
+	 * will be over-written with pad characters below.
+	 */
+	for (j = 18; j >= 0; j -= 6) {
+	    k = (n >> j) & 0x3F;
+	    *out++ = base64_valuetocode[k];
+	}
+
+	/* Pad with equal-signs. */
+	if (i == 1)
+	    out[-2] = B64_PAD;
+	out[-1] = B64_PAD;
+
+	data->output_length += 4;
+    }
+
+    if (data->output_fn != NULL) {
+	PRInt32 output_result;
+
+	output_result = data->output_fn (data->output_arg, data->output_buffer,
+					 (PRInt32) data->output_length);
+	data->output_length = 0;
+
+	if (output_result < 0)
+	    return PR_FAILURE;
+    }
+
+    return PR_SUCCESS;
+}
+
+
+/*
+ * The maximum space needed to hold the output of the encoder given input
+ * data of length "size", and allowing for CRLF added at least every
+ * line_length bytes (we will add it at nearest lower multiple of 4).
+ * There is no trailing CRLF.
+ */
+static PRUint32
+PL_Base64MaxEncodedLength (PRUint32 size, PRUint32 line_length)
+{
+    PRUint32 tokens, tokens_per_line, full_lines, line_break_chars, remainder;
+
+    tokens = (size + 2) / 3;
+
+    if (line_length == 0)
+	return tokens * 4;
+
+    if (line_length < 4)	/* too small! */
+	line_length = 4;
+
+    tokens_per_line = line_length / 4;
+    full_lines = tokens / tokens_per_line;
+    remainder = (tokens - (full_lines * tokens_per_line)) * 4;
+    line_break_chars = full_lines * 2;
+    if (remainder == 0)
+	line_break_chars -= 2;
+
+    return (full_lines * tokens_per_line * 4) + line_break_chars + remainder;
+}
+
+
+/*
+ * A distinct internal creation function for the buffer version to use.
+ * (It does not want to specify an output_fn, and we want the normal
+ * Create function to require that.)  All common initialization of the
+ * encoding context should be done *here*.
+ *
+ * Save "line_length", rounded down to nearest multiple of 4 (if not
+ * already even multiple).  Allocate output_buffer, if not provided --
+ * based on given size if specified, otherwise based on line_length.
+ */
+static PLBase64Encoder *
+pl_base64_create_encoder (PRUint32 line_length, char *output_buffer,
+			  PRUint32 output_buflen)
+{
+    PLBase64Encoder *data;
+    PRUint32 line_tokens;
+
+    data = PR_NEWZAP(PLBase64Encoder);
+    if (data == NULL)
+	return NULL;
+
+    if (line_length > 0 && line_length < 4)	/* too small! */
+	line_length = 4;
+
+    line_tokens = line_length / 4;
+    data->line_length = line_tokens * 4;
+
+    if (output_buffer == NULL) {
+	if (output_buflen == 0) {
+	    if (data->line_length > 0)	/* need to include room for CRLF */
+		output_buflen = data->line_length + 2;
+	    else
+		output_buflen = 64;		/* XXX what is a good size? */
+	}
+
+	output_buffer = (char *) PR_Malloc(output_buflen);
+	if (output_buffer == NULL) {
+	    PR_Free(data);
+	    return NULL;
+	}
+    }
+
+    data->output_buffer = output_buffer;
+    data->output_buflen = output_buflen;
+    return data;
+}
+
+/*
+ * Function to start a base64 encoding context.
+ * An "output_fn" is required; the "output_arg" parameter to that is optional.
+ * If linebreaks in the encoded output are desired, "line_length" specifies
+ * where to place them -- it will be rounded down to the nearest multiple of 4
+ * (if it is not already an even multiple of 4).  If it is zero, no linebreaks
+ * will be added.  (FYI, a linebreak is CRLF -- two characters.)
+ */
+static PLBase64Encoder *
+PL_CreateBase64Encoder (PRInt32 (*output_fn) (void *, const char *, PRInt32),
+			void *output_arg, PRUint32 line_length)
+{
+    PLBase64Encoder *data;
+
+    if (output_fn == NULL) {
+	PR_SetError (PR_INVALID_ARGUMENT_ERROR, 0);
+	return NULL;
+    }
+
+    data = pl_base64_create_encoder (line_length, NULL, 0);
+    if (data == NULL)
+	return NULL;
+
+    data->output_fn = output_fn;
+    data->output_arg = output_arg;
+
+    return data;
+}
+
+
+/*
+ * Push data through the encoder, causing the output_fn (provided to Create)
+ * to be called with the encoded data.
+ */
+static PRStatus
+PL_UpdateBase64Encoder (PLBase64Encoder *data, const unsigned char *buffer,
+			PRUint32 size)
+{
+    /* XXX Should we do argument checking only in debug build? */
+    if (data == NULL || buffer == NULL || size == 0) {
+	PR_SetError (PR_INVALID_ARGUMENT_ERROR, 0);
+	return PR_FAILURE;
+    }
+
+    return pl_base64_encode_buffer (data, buffer, size);
+}
+
+
+/*
+ * When you're done encoding, call this to free the data.  If "abort_p"
+ * is false, then calling this may cause the output_fn to be called
+ * one last time (as the last buffered data is flushed out).
+ */
+static PRStatus
+PL_DestroyBase64Encoder (PLBase64Encoder *data, PRBool abort_p)
+{
+    PRStatus status = PR_SUCCESS;
+
+    /* XXX Should we do argument checking only in debug build? */
+    if (data == NULL) {
+	PR_SetError (PR_INVALID_ARGUMENT_ERROR, 0);
+	return PR_FAILURE;
+    }
+
+    /* Flush out the last few buffered characters. */
+    if (!abort_p)
+	status = pl_base64_encode_flush (data);
+
+    if (data->output_buffer != NULL)
+	PR_Free(data->output_buffer);
+    PR_Free(data);
+
+    return status;
+}
+
+
+/*
+ * Perform base64 encoding from an input buffer to an output buffer.
+ * The output buffer can be provided (as "dest"); you can also pass in
+ * a NULL and this function will allocate a buffer large enough for you,
+ * and return it.  If you do provide the output buffer, you must also
+ * provide the maximum length of that buffer (as "maxdestlen").
+ * The actual encoded length of output will be returned to you in
+ * "output_destlen".
+ *
+ * If linebreaks in the encoded output are desired, "line_length" specifies
+ * where to place them -- it will be rounded down to the nearest multiple of 4
+ * (if it is not already an even multiple of 4).  If it is zero, no linebreaks
+ * will be added.  (FYI, a linebreak is CRLF -- two characters.)
+ *
+ * Return value is NULL on error, the output buffer (allocated or provided)
+ * otherwise.
+ */
+static char *
+PL_Base64EncodeBuffer (const unsigned char *src, PRUint32 srclen,
+		       PRUint32 line_length, char *dest, PRUint32 maxdestlen,
+		       PRUint32 *output_destlen)
+{
+    PRUint32 need_length;
+    PLBase64Encoder *data = NULL;
+    PRStatus status;
+
+    PR_ASSERT(srclen > 0);
+    if (srclen == 0)
+	return dest;
+
+    /*
+     * How much space could we possibly need for encoding this input?
+     */
+    need_length = PL_Base64MaxEncodedLength (srclen, line_length);
+
+    /*
+     * Make sure we have at least that much, if output buffer provided.
+     */
+    if (dest != NULL) {
+	PR_ASSERT(maxdestlen >= need_length);
+	if (maxdestlen < need_length) {
+	    PR_SetError(PR_BUFFER_OVERFLOW_ERROR, 0);
+	    return NULL;
+	}
+    } else {
+	maxdestlen = need_length;
+    }
+
+    data = pl_base64_create_encoder(line_length, dest, maxdestlen);
+    if (data == NULL)
+	return NULL;
+
+    status = pl_base64_encode_buffer (data, src, srclen);
+
+    /*
+     * We do not wait for Destroy to flush, because Destroy will also
+     * get rid of our encoder context, which we need to look at first!
+     */
+    if (status == PR_SUCCESS)
+	status = pl_base64_encode_flush (data);
+
+    if (status != PR_SUCCESS) {
+	(void) PL_DestroyBase64Encoder (data, PR_TRUE);
+	return NULL;
+    }
+
+    dest = data->output_buffer;
+
+    /* Must clear this or Destroy will free it. */
+    data->output_buffer = NULL;
+
+    *output_destlen = data->output_length;
+    status = PL_DestroyBase64Encoder (data, PR_FALSE);
+    if (status == PR_FAILURE) {
+	PR_Free(dest);
+	return NULL;
+    }
+
+    return dest;
+}
+
+/*
+ * XXX End of base64 encoding code to be moved into NSPR.
+ ********************************************************
+ */
+
+/*
+ * This is the beginning of the NSS cover functions.  These will
+ * provide the interface we want to expose as NSS-ish.  For example,
+ * they will operate on our Items, do any special handling or checking
+ * we want to do, etc.
+ */
+
+
+PR_BEGIN_EXTERN_C
+
+/*
+ * A boring cover structure for now.  Perhaps someday it will include
+ * some more interesting fields.
+ */
+struct NSSBase64EncoderStr {
+    PLBase64Encoder *pl_data;
+};
+
+PR_END_EXTERN_C
+
+
+/*
+ * Function to start a base64 encoding context.
+ */
+NSSBase64Encoder *
+NSSBase64Encoder_Create (PRInt32 (*output_fn) (void *, const char *, PRInt32),
+			 void *output_arg)
+{
+    PLBase64Encoder *pl_data;
+    NSSBase64Encoder *nss_data;
+
+    nss_data = PORT_ZNew(NSSBase64Encoder);
+    if (nss_data == NULL)
+	return NULL;
+
+    pl_data = PL_CreateBase64Encoder (output_fn, output_arg, 64);
+    if (pl_data == NULL) {
+	PORT_Free(nss_data);
+	return NULL;
+    }
+
+    nss_data->pl_data = pl_data;
+    return nss_data;
+}
+
+
+/*
+ * Push data through the encoder, causing the output_fn (provided to Create)
+ * to be called with the encoded data.
+ */
+SECStatus
+NSSBase64Encoder_Update (NSSBase64Encoder *data, const unsigned char *buffer,
+			 PRUint32 size)
+{
+    PRStatus pr_status;
+
+    /* XXX Should we do argument checking only in debug build? */
+    if (data == NULL) {
+	PORT_SetError (SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+
+    pr_status = PL_UpdateBase64Encoder (data->pl_data, buffer, size);
+    if (pr_status == PR_FAILURE)
+	return SECFailure;
+
+    return SECSuccess;
+}
+
+
+/*
+ * When you're done encoding, call this to free the data.  If "abort_p"
+ * is false, then calling this may cause the output_fn to be called
+ * one last time (as the last buffered data is flushed out).
+ */
+SECStatus
+NSSBase64Encoder_Destroy (NSSBase64Encoder *data, PRBool abort_p)
+{
+    PRStatus pr_status;
+
+    /* XXX Should we do argument checking only in debug build? */
+    if (data == NULL) {
+	PORT_SetError (SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+
+    pr_status = PL_DestroyBase64Encoder (data->pl_data, abort_p);
+
+    PORT_Free(data);
+
+    if (pr_status == PR_FAILURE)
+	return SECFailure;
+
+    return SECSuccess;
+}
+
+
+/*
+ * Perform base64 encoding of binary data "inItem" to an ascii string.
+ * The output buffer may be provided (as "outStrOpt"); you can also pass
+ * in a NULL and the buffer will be allocated for you.  The result will
+ * be null-terminated, and if the buffer is provided, "maxOutLen" must
+ * specify the maximum length of the buffer and will be checked to
+ * supply sufficient space space for the encoded result.  (If "outStrOpt"
+ * is NULL, "maxOutLen" is ignored.)
+ *
+ * If "outStrOpt" is NULL, allocation will happen out of the passed-in
+ * "arenaOpt", if *it* is non-NULL, otherwise standard allocation (heap)
+ * will be used.
+ *
+ * Return value is NULL on error, the output buffer (allocated or provided)
+ * otherwise.
+ */
+char *
+NSSBase64_EncodeItem (PRArenaPool *arenaOpt, char *outStrOpt,
+		      unsigned int maxOutLen, SECItem *inItem)
+{
+    char *out_string = outStrOpt;
+    PRUint32 max_out_len;
+    PRUint32 out_len;
+    void *mark = NULL;
+    char *dummy;
+
+    PORT_Assert(inItem != NULL && inItem->data != NULL && inItem->len != 0);
+    if (inItem == NULL || inItem->data == NULL || inItem->len == 0) {
+	PORT_SetError (SEC_ERROR_INVALID_ARGS);
+	return NULL;
+    }
+
+    max_out_len = PL_Base64MaxEncodedLength (inItem->len, 64);
+
+    if (arenaOpt != NULL)
+	mark = PORT_ArenaMark (arenaOpt);
+
+    if (out_string == NULL) {
+	if (arenaOpt != NULL)
+	    out_string = PORT_ArenaAlloc (arenaOpt, max_out_len + 1);
+	else
+	    out_string = PORT_Alloc (max_out_len + 1);
+
+	if (out_string == NULL) {
+	    if (arenaOpt != NULL)
+		PORT_ArenaRelease (arenaOpt, mark);
+	    return NULL;
+	}
+    } else {
+	if ((max_out_len + 1) > maxOutLen) {
+	    PORT_SetError (SEC_ERROR_OUTPUT_LEN);
+	    return NULL;
+	}
+	max_out_len = maxOutLen;
+    }
+
+
+    dummy = PL_Base64EncodeBuffer (inItem->data, inItem->len, 64,
+				   out_string, max_out_len, &out_len);
+    if (dummy == NULL) {
+	if (arenaOpt != NULL) {
+	    PORT_ArenaRelease (arenaOpt, mark);
+	} else {
+	    PORT_Free (out_string);
+	}
+	return NULL;
+    }
+
+    if (arenaOpt != NULL)
+	PORT_ArenaUnmark (arenaOpt, mark);
+
+    out_string[out_len] = '\0';
+    return out_string;
+}
+
+
+/*
+ * XXX Everything below is deprecated.  If you add new stuff, put it
+ * *above*, not below.
+ */
+
+/*
+ * XXX The following "BTOA" functions are provided for backward compatibility
+ * with current code.  They should be considered strongly deprecated.
+ * When we can convert all our code over to using the new NSSBase64Encoder_
+ * functions defined above, we should get rid of these altogether.  (Remove
+ * protoypes from base64.h as well -- actually, remove that file completely).
+ * If someone thinks either of these functions provides such a very useful
+ * interface (though, as shown, the same functionality can already be
+ * obtained by calling NSSBase64_EncodeItem directly), fine -- but then
+ * that API should be provided with a nice new NSSFoo name and using
+ * appropriate types, etc.
+ */
+
+#include "base64.h"
+
+/*
+** Return an PORT_Alloc'd ascii string which is the base64 encoded
+** version of the input string.
+*/
+char *
+BTOA_DataToAscii(const unsigned char *data, unsigned int len)
+{
+    SECItem binary_item;
+
+    binary_item.data = (unsigned char *)data;
+    binary_item.len = len;
+
+    return NSSBase64_EncodeItem (NULL, NULL, 0, &binary_item);
+}
+
+/*
+** Convert from binary encoding of an item to ascii.
+*/
+char *
+BTOA_ConvertItemToAscii (SECItem *binary_item)
+{
+    return NSSBase64_EncodeItem (NULL, NULL, 0, binary_item);
+}