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Diffstat (limited to 'security/nss/lib/util/nssb64e.c')
| -rw-r--r-- | security/nss/lib/util/nssb64e.c | 734 |
1 files changed, 734 insertions, 0 deletions
diff --git a/security/nss/lib/util/nssb64e.c b/security/nss/lib/util/nssb64e.c new file mode 100644 index 0000000000..18b01ddacb --- /dev/null +++ b/security/nss/lib/util/nssb64e.c @@ -0,0 +1,734 @@ +/* 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 encoding (binary to ascii). + */ + +#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; + unsigned 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; + + /* This is the maximum length we support. */ + if (size > 0x3fffffff) { + return 0; + } + + 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); + if (need_length == 0) { + PORT_SetError(SEC_ERROR_INVALID_ARGS); + return NULL; + } + + /* + * 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(PLArenaPool *arenaOpt, char *outStrOpt, + unsigned int maxOutLen, SECItem *inItem) +{ + char *out_string = outStrOpt; + PRUint32 max_out_len; + PRUint32 out_len = 0; + 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 (max_out_len == 0) { + PORT_SetError(SEC_ERROR_INVALID_ARGS); + return NULL; + } + + 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); +} |