The Tor Browser: security/nss/lib/util/nssb64d.c@b8a032363ba2 (annotated)

security/nss/lib/util/nssb64d.c@b8a032363ba2 (annotated)

security/nss/lib/util/nssb64d.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * Base64 decoding (ascii to binary).
  */
 #include "nssb64.h"
 #include "nspr.h"
 #include "secitem.h"
 #include "secerr.h"
 /*
  * XXX We want this basic support to go into NSPR (the PL part).
  * Until that can happen, the PL interface is going to be kept entirely
  * internal here -- all static functions and opaque data structures.
  * When someone can get it moved over into NSPR, that should be done:
  *    - giving everything names that are accepted by the NSPR module owners
  *	(though I tried to choose ones that would work without modification)
  *    - exporting the functions (remove static declarations and add
  *	to nssutil.def as necessary)
  *    - put prototypes into appropriate header file (probably replacing
  *	the entire current lib/libc/include/plbase64.h in NSPR)
  *	along with a typedef for the context structure (which should be
  *	kept opaque -- definition in the source file only, but typedef
  *	ala "typedef struct PLBase64FooStr PLBase64Foo;" in header file)
  *    - modify anything else as necessary to conform to NSPR required style
  *	(I looked but found no formatting guide to follow)
  *
  * You will want to move over everything from here down to the comment
  * which says "XXX End of base64 decoding code to be moved into NSPR",
  * into a new file in NSPR.
  */
 /*
  **************************************************************
  * XXX Beginning of base64 decoding code to be moved into NSPR.
  */
 /*
  * This typedef would belong in the NSPR header file (i.e. plbase64.h).
  */
 typedef struct PLBase64DecoderStr PLBase64Decoder;
 /*
  * The following implementation of base64 decoding 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 decoding 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 decoder to store state.
  */
 struct PLBase64DecoderStr {
     /* Current token (or portion, if token_size < 4) being decoded. */
     unsigned char token[4];
     int token_size;
     /*
      * Where to write the decoded 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 unsigned char *buf,
 			  PRInt32 size);
     void *output_arg;
     /*
      * Where the decoded 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.
      */
     unsigned 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 an ascii "code" to its corresponding binary value.
  * For ease of use, the binary values in the table are the actual values
  * PLUS ONE.  This is so that the special value of zero can denote an
  * invalid mapping; that was much easier than trying to fill in the other
  * values with some value other than zero, and to check for it.
  * Just remember to SUBTRACT ONE when using the value retrieved.
  */
 static unsigned char base64_codetovaluep1[256] = {
 /*   0: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0,
 /*   8: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0,
 /*  16: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0,
 /*  24: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0,
 /*  32: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0,
 /*  40: */	  0,	  0,	  0,	 63,	  0,	  0,	  0,	 64,
 /*  48: */	 53,	 54,	 55,	 56,	 57,	 58,	 59,	 60,
 /*  56: */	 61,	 62,	  0,	  0,	  0,	  0,	  0,	  0,
 /*  64: */	  0,	  1,	  2,	  3,	  4,	  5,	  6,	  7,
 /*  72: */	  8,	  9,	 10,	 11,	 12,	 13,	 14,	 15,
 /*  80: */	 16,	 17,	 18,	 19,	 20,	 21,	 22,	 23,
 /*  88: */	 24,	 25,	 26,	  0,	  0,	  0,	  0,	  0,
 /*  96: */	  0,	 27,	 28,	 29,	 30,	 31,	 32,	 33,
 /* 104: */	 34,	 35,	 36,	 37,	 38,	 39,	 40,	 41,
 /* 112: */	 42,	 43,	 44,	 45,	 46,	 47,	 48,	 49,
 /* 120: */	 50,	 51,	 52,	  0,	  0,	  0,	  0,	  0,
 /* 128: */	  0,	  0,	  0,	  0,	  0,	  0,	  0,	  0
 /* and rest are all zero as well */
 };
 #define B64_PAD	'='
 /*
  * Reads 4; writes 3 (known, or expected, to have no trailing padding).
  * Returns bytes written; -1 on error (unexpected character).
  */
 static int
 pl_base64_decode_4to3 (const unsigned char *in, unsigned char *out)
 {
     int j;
     PRUint32 num = 0;
     unsigned char bits;
     for (j = 0; j < 4; j++) {
 	bits = base64_codetovaluep1[in[j]];
 	if (bits == 0)
 	    return -1;
 	num = (num << 6) | (bits - 1);
     }
     out[0] = (unsigned char) (num >> 16);
     out[1] = (unsigned char) ((num >> 8) & 0xFF);
     out[2] = (unsigned char) (num & 0xFF);
     return 3;
 }
 /*
  * Reads 3; writes 2 (caller already confirmed EOF or trailing padding).
  * Returns bytes written; -1 on error (unexpected character).
  */
 static int
 pl_base64_decode_3to2 (const unsigned char *in, unsigned char *out)
 {
     PRUint32 num = 0;
     unsigned char bits1, bits2, bits3;
     bits1 = base64_codetovaluep1[in[0]];
     bits2 = base64_codetovaluep1[in[1]];
     bits3 = base64_codetovaluep1[in[2]];
     if ((bits1 == 0) || (bits2 == 0) || (bits3 == 0))
 	return -1;
     num = ((PRUint32)(bits1 - 1)) << 10;
     num |= ((PRUint32)(bits2 - 1)) << 4;
     num |= ((PRUint32)(bits3 - 1)) >> 2;
     out[0] = (unsigned char) (num >> 8);
     out[1] = (unsigned char) (num & 0xFF);
     return 2;
 }
 /*
  * Reads 2; writes 1 (caller already confirmed EOF or trailing padding).
  * Returns bytes written; -1 on error (unexpected character).
  */
 static int
 pl_base64_decode_2to1 (const unsigned char *in, unsigned char *out)
 {
     PRUint32 num = 0;
     unsigned char bits1, bits2;
     bits1 = base64_codetovaluep1[in[0]];
     bits2 = base64_codetovaluep1[in[1]];
     if ((bits1 == 0) || (bits2 == 0))
 	return -1;
     num = ((PRUint32)(bits1 - 1)) << 2;
     num |= ((PRUint32)(bits2 - 1)) >> 4;
     out[0] = (unsigned char) num;
     return 1;
 }
 /*
  * Reads 4; writes 0-3.  Returns bytes written or -1 on error.
  * (Writes less than 3 only at (presumed) EOF.)
  */
 static int
 pl_base64_decode_token (const unsigned char *in, unsigned char *out)
 {
     if (in[3] != B64_PAD)
 	return pl_base64_decode_4to3 (in, out);
     if (in[2] == B64_PAD)
 	return pl_base64_decode_2to1 (in, out);
     return pl_base64_decode_3to2 (in, out);
 }
 static PRStatus
 pl_base64_decode_buffer (PLBase64Decoder *data, const unsigned char *in,
 			 PRUint32 length)
 {
     unsigned char *out = data->output_buffer;
     unsigned char *token = data->token;
     int i, n = 0;
     i = data->token_size;
     data->token_size = 0;
     while (length > 0) {
 	while (i < 4 && length > 0) {
 	    /*
 	     * XXX Note that the following simply ignores any unexpected
 	     * characters.  This is exactly what the original code in
 	     * libmime did, and I am leaving it.  We certainly want to skip
 	     * over whitespace (we must); this does much more than that.
 	     * I am not confident changing it, and I don't want to slow
 	     * the processing down doing more complicated checking, but
 	     * someone else might have different ideas in the future.
 	     */
 	    if (base64_codetovaluep1[*in] > 0 || *in == B64_PAD)
 		token[i++] = *in;
 	    in++;
 	    length--;
 	}
 	if (i < 4) {
 	    /* Didn't get enough for a complete token. */
 	    data->token_size = i;
 	    break;
 	}
 	i = 0;
 	PR_ASSERT((out - data->output_buffer + 3) <= data->output_buflen);
 	/*
 	 * Assume we are not at the end; the following function only works
 	 * for an internal token (no trailing padding characters) but is
 	 * faster that way.  If it hits an invalid character (padding) it
 	 * will return an error; we break out of the loop and try again
 	 * calling the routine that will handle a final token.
 	 * Note that we intentionally do it this way rather than explicitly
 	 * add a check for padding here (because that would just slow down
 	 * the normal case) nor do we rely on checking whether we have more
 	 * input to process (because that would also slow it down but also
 	 * because we want to allow trailing garbage, especially white space
 	 * and cannot tell that without read-ahead, also a slow proposition).
 	 * Whew.  Understand?
 	 */
 	n = pl_base64_decode_4to3 (token, out);
 	if (n < 0)
 	    break;
 	/* Advance "out" by the number of bytes just written to it. */
 	out += n;
 	n = 0;
     }
     /*
      * See big comment above, before call to pl_base64_decode_4to3.
      * Here we check if we error'd out of loop, and allow for the case
      * that we are processing the last interesting token.  If the routine
      * which should handle padding characters also fails, then we just
      * have bad input and give up.
      */
     if (n < 0) {
 	n = pl_base64_decode_token (token, out);
 	if (n < 0)
 	    return PR_FAILURE;
 	out += n;
     }
     /*
      * As explained above, we can get here with more input remaining, but
      * it should be all characters we do not care about (i.e. would be
      * ignored when transferring from "in" to "token" in loop above,
      * except here we choose to ignore extraneous pad characters, too).
      * Swallow it, performing that check.  If we find more characters that
      * we would expect to decode, something is wrong.
      */
     while (length > 0) {
 	if (base64_codetovaluep1[*in] > 0)
 	    return PR_FAILURE;
 	in++;
 	length--;
     }
     /* Record the length of decoded data we have left in output_buffer. */
     data->output_length = (PRUint32) (out - data->output_buffer);
     return PR_SUCCESS;
 }
 /*
  * Flush any remaining buffered characters.  Given well-formed input,
  * this will have nothing to do.  If the input was missing the padding
  * characters at the end, though, there could be 1-3 characters left
  * behind -- we will tolerate that by adding the padding for them.
  */
 static PRStatus
 pl_base64_decode_flush (PLBase64Decoder *data)
 {
     int count;
     /*
      * If no remaining characters, or all are padding (also not well-formed
      * input, but again, be tolerant), then nothing more to do.  (And, that
      * is considered successful.)
      */
     if (data->token_size == 0 || data->token[0] == B64_PAD)
 	return PR_SUCCESS;
     /*
      * Assume we have all the interesting input except for some expected
      * padding characters.  Add them and decode the resulting token.
      */
     while (data->token_size < 4)
 	data->token[data->token_size++] = B64_PAD;
     data->token_size = 0;	/* so a subsequent flush call is a no-op */
     count = pl_base64_decode_token (data->token,
 				    data->output_buffer + data->output_length);
     if (count < 0)
 	return PR_FAILURE;
     /*
      * If there is an output function, call it with this last bit of data.
      * Otherwise we are doing all buffered output, and the decoded bytes
      * are now there, we just need to reflect that in the length.
      */
     if (data->output_fn != NULL) {
 	PRInt32 output_result;
 	PR_ASSERT(data->output_length == 0);
 	output_result = data->output_fn (data->output_arg,
 					 data->output_buffer,
 					 (PRInt32) count);
 	if (output_result < 0)
 	    return  PR_FAILURE;
     } else {
 	data->output_length += count;
     }
     return PR_SUCCESS;
 }
 /*
  * The maximum space needed to hold the output of the decoder given
  * input data of length "size".
  */
 static PRUint32
 PL_Base64MaxDecodedLength (PRUint32 size)
 {
     return ((size * 3) / 4);
 }
 /*
  * 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.)  If more common initialization
  * of the decoding context needs to be done, it should be done *here*.
  */
 static PLBase64Decoder *
 pl_base64_create_decoder (void)
 {
     return PR_NEWZAP(PLBase64Decoder);
 }
 /*
  * Function to start a base64 decoding context.
  * An "output_fn" is required; the "output_arg" parameter to that is optional.
  */
 static PLBase64Decoder *
 PL_CreateBase64Decoder (PRInt32 (*output_fn) (void *, const unsigned char *,
 					      PRInt32),
 			void *output_arg)
 {
     PLBase64Decoder *data;
     if (output_fn == NULL) {
 	PR_SetError (PR_INVALID_ARGUMENT_ERROR, 0);
 	return NULL;
     }
     data = pl_base64_create_decoder ();
     if (data != NULL) {
 	data->output_fn = output_fn;
 	data->output_arg = output_arg;
     }
     return data;
 }
 /*
  * Push data through the decoder, causing the output_fn (provided to Create)
  * to be called with the decoded data.
  */
 static PRStatus
 PL_UpdateBase64Decoder (PLBase64Decoder *data, const char *buffer,
 			PRUint32 size)
 {
     PRUint32 need_length;
     PRStatus status;
     /* 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;
     }
     /*
      * How much space could this update need for decoding?
      */
     need_length = PL_Base64MaxDecodedLength (size + data->token_size);
     /*
      * Make sure we have at least that much.  If not, (re-)allocate.
      */
     if (need_length > data->output_buflen) {
 	unsigned char *output_buffer = data->output_buffer;
 	if (output_buffer != NULL)
 	    output_buffer = (unsigned char *) PR_Realloc(output_buffer,
 							 need_length);
 	else
 	    output_buffer = (unsigned char *) PR_Malloc(need_length);
 	if (output_buffer == NULL)
 	    return PR_FAILURE;
 	data->output_buffer = output_buffer;
 	data->output_buflen = need_length;
     }
     /* There should not have been any leftover output data in the buffer. */
     PR_ASSERT(data->output_length == 0);
     data->output_length = 0;
     status = pl_base64_decode_buffer (data, (const unsigned char *) buffer,
 				      size);
     /* Now that we have some decoded data, write it. */
     if (status == PR_SUCCESS && data->output_length > 0) {
 	PRInt32 output_result;
 	PR_ASSERT(data->output_fn != NULL);
 	output_result = data->output_fn (data->output_arg,
 					 data->output_buffer,
 					 (PRInt32) data->output_length);
 	if (output_result < 0)
 	    status = PR_FAILURE;
     }
     data->output_length = 0;
     return status;
 }
 /*
  * When you're done decoding, 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_DestroyBase64Decoder (PLBase64Decoder *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_decode_flush (data);
     if (data->output_buffer != NULL)
 	PR_Free(data->output_buffer);
     PR_Free(data);
     return status;
 }
 /*
  * Perform base64 decoding 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 decoded length of output will be returned to you in
  * "output_destlen".
  *
  * Return value is NULL on error, the output buffer (allocated or provided)
  * otherwise.
  */
 static unsigned char *
 PL_Base64DecodeBuffer (const char *src, PRUint32 srclen, unsigned char *dest,
 		       PRUint32 maxdestlen, PRUint32 *output_destlen)
 {
     PRUint32 need_length;
     unsigned char *output_buffer = NULL;
     PLBase64Decoder *data = NULL;
     PRStatus status;
     PR_ASSERT(srclen > 0);
     if (srclen == 0) {
 	PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
 	return NULL;
     }
     /*
      * How much space could we possibly need for decoding this input?
      */
     need_length = PL_Base64MaxDecodedLength (srclen);
     /*
      * Make sure we have at least that much, if output buffer provided.
      * If no output buffer provided, then we allocate that much.
      */
     if (dest != NULL) {
 	PR_ASSERT(maxdestlen >= need_length);
 	if (maxdestlen < need_length) {
 	    PR_SetError(PR_BUFFER_OVERFLOW_ERROR, 0);
 	    goto loser;
 	}
 	output_buffer = dest;
     } else {
 	output_buffer = (unsigned char *) PR_Malloc(need_length);
 	if (output_buffer == NULL)
 	    goto loser;
 	maxdestlen = need_length;
     }
     data = pl_base64_create_decoder();
     if (data == NULL)
 	goto loser;
     data->output_buflen = maxdestlen;
     data->output_buffer = output_buffer;
     status = pl_base64_decode_buffer (data, (const unsigned char *) src,
 				      srclen);
     /*
      * We do not wait for Destroy to flush, because Destroy will also
      * get rid of our decoder context, which we need to look at first!
      */
     if (status == PR_SUCCESS)
 	status = pl_base64_decode_flush (data);
     /* Must clear this or Destroy will free it. */
     data->output_buffer = NULL;
     if (status == PR_SUCCESS) {
 	*output_destlen = data->output_length;
 	status = PL_DestroyBase64Decoder (data, PR_FALSE);
 	data = NULL;
 	if (status == PR_FAILURE)
 	    goto loser;
 	return output_buffer;
     }
 loser:
     if (dest == NULL && output_buffer != NULL)
 	PR_Free(output_buffer);
     if (data != NULL)
 	(void) PL_DestroyBase64Decoder (data, PR_TRUE);
     return NULL;
 }
 /*
  * XXX End of base64 decoding 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 NSSBase64DecoderStr {
     PLBase64Decoder *pl_data;
 };
 PR_END_EXTERN_C
 /*
  * Function to start a base64 decoding context.
  */
 NSSBase64Decoder *
 NSSBase64Decoder_Create (PRInt32 (*output_fn) (void *, const unsigned char *,
 					       PRInt32),
 			 void *output_arg)
 {
     PLBase64Decoder *pl_data;
     NSSBase64Decoder *nss_data;
     nss_data = PORT_ZNew(NSSBase64Decoder);
     if (nss_data == NULL)
 	return NULL;
     pl_data = PL_CreateBase64Decoder (output_fn, output_arg);
     if (pl_data == NULL) {
 	PORT_Free(nss_data);
 	return NULL;
     }
     nss_data->pl_data = pl_data;
     return nss_data;
 }
 /*
  * Push data through the decoder, causing the output_fn (provided to Create)
  * to be called with the decoded data.
  */
 SECStatus
 NSSBase64Decoder_Update (NSSBase64Decoder *data, const 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_UpdateBase64Decoder (data->pl_data, buffer, size);
     if (pr_status == PR_FAILURE)
 	return SECFailure;
     return SECSuccess;
 }
 /*
  * When you're done decoding, 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
 NSSBase64Decoder_Destroy (NSSBase64Decoder *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_DestroyBase64Decoder (data->pl_data, abort_p);
     PORT_Free(data);
     if (pr_status == PR_FAILURE)
 	return SECFailure;
     return SECSuccess;
 }
 /*
  * Perform base64 decoding from an ascii string "inStr" to an Item.
  * The length of the input must be provided as "inLen".  The Item
  * may be provided (as "outItemOpt"); you can also pass in a NULL
  * and the Item will be allocated for you.
  *
  * In any case, the data within the Item will be allocated for you.
  * All allocation will happen out of the passed-in "arenaOpt", if non-NULL.
  * If "arenaOpt" is NULL, standard allocation (heap) will be used and
  * you will want to free the result via SECITEM_FreeItem.
  *
  * Return value is NULL on error, the Item (allocated or provided) otherwise.
  */
 SECItem *
 NSSBase64_DecodeBuffer (PLArenaPool *arenaOpt, SECItem *outItemOpt,
 			const char *inStr, unsigned int inLen)
 {
     SECItem *out_item = NULL;
     PRUint32 max_out_len = 0;
     PRUint32 out_len;
     void *mark = NULL;
     unsigned char *dummy;
     if ((outItemOpt != NULL && outItemOpt->data != NULL) || inLen == 0) {
 	PORT_SetError (SEC_ERROR_INVALID_ARGS);
 	return NULL;
     }
     if (arenaOpt != NULL)
 	mark = PORT_ArenaMark (arenaOpt);
     max_out_len = PL_Base64MaxDecodedLength (inLen);
     out_item = SECITEM_AllocItem (arenaOpt, outItemOpt, max_out_len);
     if (out_item == NULL) {
 	if (arenaOpt != NULL)
 	    PORT_ArenaRelease (arenaOpt, mark);
 	return NULL;
     }
     dummy = PL_Base64DecodeBuffer (inStr, inLen, out_item->data,
 				   max_out_len, &out_len);
     if (dummy == NULL) {
 	if (arenaOpt != NULL) {
 	    PORT_ArenaRelease (arenaOpt, mark);
 	    if (outItemOpt != NULL) {
 		outItemOpt->data = NULL;
 		outItemOpt->len = 0;
 	    }
 	} else {
 	    SECITEM_FreeItem (out_item,
 			      (outItemOpt == NULL) ? PR_TRUE : PR_FALSE);
 	}
 	return NULL;
     }
     if (arenaOpt != NULL)
 	PORT_ArenaUnmark (arenaOpt, mark);
     out_item->len = out_len;
     return out_item;
 }
 /*
  * XXX Everything below is deprecated.  If you add new stuff, put it
  * *above*, not below.
  */
 /*
  * XXX The following "ATOB" 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 NSSBase64Decoder_
  * 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_DecodeBuffer 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 string which is the base64 decoded version
 ** of the input string; set *lenp to the length of the returned data.
 */
 unsigned char *
 ATOB_AsciiToData(const char *string, unsigned int *lenp)
 {
     SECItem binary_item, *dummy;
     binary_item.data = NULL;
     binary_item.len = 0;
     dummy = NSSBase64_DecodeBuffer (NULL, &binary_item, string,
 				    (PRUint32) PORT_Strlen(string));
     if (dummy == NULL)
 	return NULL;
     PORT_Assert(dummy == &binary_item);
     *lenp = dummy->len;
     return dummy->data;
 }
 /*
 ** Convert from ascii to binary encoding of an item.
 */
 SECStatus
 ATOB_ConvertAsciiToItem(SECItem *binary_item, const char *ascii)
 {
     SECItem *dummy;
     if (binary_item == NULL) {
 	PORT_SetError (SEC_ERROR_INVALID_ARGS);
 	return SECFailure;
     }
     /*
      * XXX Would prefer to assert here if data is non-null (actually,
      * don't need to, just let NSSBase64_DecodeBuffer do it), so as to
      * to catch unintended memory leaks, but callers are not clean in
      * this respect so we need to explicitly clear here to avoid the
      * assert in NSSBase64_DecodeBuffer.
      */
     binary_item->data = NULL;
     binary_item->len = 0;
     dummy = NSSBase64_DecodeBuffer (NULL, binary_item, ascii,
 				    (PRUint32) PORT_Strlen(ascii));
     if (dummy == NULL)
 	return SECFailure;
     return SECSuccess;
 }

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security/nss/lib/util/nssb64d.c@b8a032363ba2 (annotated)

security/nss/lib/util/nssb64d.c