Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 852 insertions, 0 deletions

diff --git a/security/nss/lib/util/nssb64d.c b/security/nss/lib/util/nssb64d.c
new file mode 100644
index 0000000000..ebfb154f90
--- /dev/null
+++ b/security/nss/lib/util/nssb64d.c
@@ -0,0 +1,852 @@
+/* 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
+
+/* A constant time range check for unsigned chars.
+ * Returns 255 if a <= x <= b and 0 otherwise.
+ */
+static inline unsigned char
+ct_u8_in_range(unsigned char x, unsigned char a, unsigned char b)
+{
+    /*  Let x, a, b be ints in {0, 1, ... 255}.
+     *  The value (a - x - 1) is in {-256, ..., 254}, so the low
+     *  8 bits of
+     *      (a - x - 1) >> 8
+     *  are all 1 if a <= x and all 0 if a > x.
+     *
+     *  Likewise the low 8 bits of
+     *      ((a - x - 1) >> 8) & ((x - c - 1) >> 8)
+     *  are all 1 if a <= x <= c and all 0 otherwise.
+     *
+     *  The same is true if we perform the shift after the AND
+     *      ((a - x - 1) & (x - b - 1)) >> 8.
+     */
+    return (unsigned char)(((a - x - 1) & (x - b - 1)) >> 8);
+}
+
+/* Convert a base64 code [A-Za-z0-9+/] to its value in {1, 2, ..., 64}.
+ * The use of 1-64 instead of 0-63 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
+pl_base64_codetovaluep1(unsigned char code)
+{
+    unsigned char mask;
+    unsigned char res = 0;
+
+    /* The range 'A' to 'Z' is mapped to 1 to 26 */
+    mask = ct_u8_in_range(code, 'A', 'Z');
+    res |= mask & (code - 'A' + 1);
+
+    /* The range 'a' to 'z' is mapped to 27 to 52 */
+    mask = ct_u8_in_range(code, 'a', 'z');
+    res |= mask & (code - 'a' + 27);
+
+    /* The range '0' to '9' is mapped to 53 to 62 */
+    mask = ct_u8_in_range(code, '0', '9');
+    res |= mask & (code - '0' + 53);
+
+    /* The code '+' is mapped to 63 */
+    mask = ct_u8_in_range(code, '+', '+');
+    res |= mask & 63;
+
+    /* The code '/' is mapped to 64 */
+    mask = ct_u8_in_range(code, '/', '/');
+    res |= mask & 64;
+
+    /* All other characters, including '=' are mapped to 0. */
+    return res;
+}
+
+#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 = pl_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 = pl_base64_codetovaluep1(in[0]);
+    bits2 = pl_base64_codetovaluep1(in[1]);
+    bits3 = pl_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 = pl_base64_codetovaluep1(in[0]);
+    bits2 = pl_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 (pl_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((PRUint32)(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 (pl_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 * 0.75;
+}
+
+/*
+ * 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;
+    void *mark = NULL;
+    unsigned char *dummy = NULL;
+
+    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);
+    if (max_out_len == 0) {
+        goto loser;
+    }
+    out_item = SECITEM_AllocItem(arenaOpt, outItemOpt, max_out_len);
+    if (out_item == NULL) {
+        goto loser;
+    }
+
+    dummy = PL_Base64DecodeBuffer(inStr, inLen, out_item->data,
+                                  max_out_len, &out_item->len);
+    if (dummy == NULL) {
+        goto loser;
+    }
+    if (arenaOpt != NULL) {
+        PORT_ArenaUnmark(arenaOpt, mark);
+    }
+    return out_item;
+
+loser:
+    if (arenaOpt != NULL) {
+        PORT_ArenaRelease(arenaOpt, mark);
+        if (outItemOpt != NULL) {
+            outItemOpt->data = NULL;
+            outItemOpt->len = 0;
+        }
+    } else if (dummy == NULL) {
+        SECITEM_FreeItem(out_item, (PRBool)(outItemOpt == NULL));
+    }
+    return NULL;
+}
+
+/*
+ * 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;
+}