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Diffstat (limited to 'src/base64.c')
| -rw-r--r-- | src/base64.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/src/base64.c b/src/base64.c new file mode 100644 index 0000000..d07ea60 --- /dev/null +++ b/src/base64.c @@ -0,0 +1,253 @@ +/* + * Base64 encoding/decoding (RFC1341) + * Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi> + * + * This software may be distributed under the terms of the BSD license. + * See README for more details. + */ + +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include "base64.h" + +static const unsigned char base64_table[65] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +/** + * base64_encode - Base64 encode + * @src: Data to be encoded + * @len: Length of the data to be encoded + * @out_len: Pointer to output length variable, or %NULL if not used + * Returns: Allocated buffer of out_len bytes of encoded data, + * or %NULL on failure + * + * Caller is responsible for freeing the returned buffer. Returned buffer is + * nul terminated to make it easier to use as a C string. The nul terminator is + * not included in out_len. + */ +unsigned char * base64_encode(const unsigned char *src, size_t len, + size_t *out_len) +{ + unsigned char *out, *pos; + const unsigned char *end, *in; + size_t olen; + int line_len; + + olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */ + olen += olen / 76; /* line feeds */ + olen++; /* nul termination */ + if (olen < len) + return NULL; /* integer overflow */ + out = malloc(olen); + if (out == NULL) + return NULL; + + end = src + len; + in = src; + pos = out; + line_len = 0; + while (end - in >= 3) { + *pos++ = base64_table[in[0] >> 2]; + *pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)]; + *pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)]; + *pos++ = base64_table[in[2] & 0x3f]; + in += 3; + line_len += 4; + if (line_len >= 76) { + *pos++ = '\n'; + line_len = 0; + } + } + + if (end - in) { + *pos++ = base64_table[in[0] >> 2]; + if (end - in == 1) { + *pos++ = base64_table[(in[0] & 0x03) << 4]; + *pos++ = '='; + } else { + *pos++ = base64_table[((in[0] & 0x03) << 4) | + (in[1] >> 4)]; + *pos++ = base64_table[(in[1] & 0x0f) << 2]; + } + *pos++ = '='; + line_len += 4; + } + + if (line_len) + *pos++ = '\n'; + + *pos = '\0'; + if (out_len) + *out_len = pos - out; + return out; +} + + +/** + * base64_decode - Base64 decode + * @src: Data to be decoded + * @len: Length of the data to be decoded + * @out_len: Pointer to output length variable + * Returns: Allocated buffer of out_len bytes of decoded data, + * or %NULL on failure + * + * Caller is responsible for freeing the returned buffer. + */ +unsigned char * base64_decode(const unsigned char *src, size_t len, + size_t *out_len) +{ + unsigned char dtable[256], *out, *pos, block[4], tmp; + size_t i, count, olen; + int pad = 0; + + memset(dtable, 0x80, 256); + for (i = 0; i < sizeof(base64_table) - 1; i++) + dtable[base64_table[i]] = (unsigned char) i; + dtable['='] = 0; + + count = 0; + for (i = 0; i < len; i++) { + if (dtable[src[i]] != 0x80) + count++; + } + + if (count == 0 || count % 4) + return NULL; + + olen = count / 4 * 3; + pos = out = malloc(olen); + if (out == NULL) + return NULL; + + count = 0; + for (i = 0; i < len; i++) { + tmp = dtable[src[i]]; + if (tmp == 0x80) + continue; + + if (src[i] == '=') + pad++; + block[count] = tmp; + count++; + if (count == 4) { + *pos++ = (block[0] << 2) | (block[1] >> 4); + *pos++ = (block[1] << 4) | (block[2] >> 2); + *pos++ = (block[2] << 6) | block[3]; + count = 0; + if (pad) { + if (pad == 1) + pos--; + else if (pad == 2) + pos -= 2; + else { + /* Invalid padding */ + free(out); + return NULL; + } + break; + } + } + } + + *out_len = pos - out; + return out; +} + +unsigned char * b64t_encode(const unsigned char *src, size_t len, + size_t *out_len) +{ + // allocate new buffer + unsigned char *out = malloc(len); + if (out == NULL) + return NULL; + memset(out, 0, len); + + // remove new line + size_t index = 0; + size_t new_index = 0; + for (index =0; index < len; index++) + { + if(src[index] != '\n' && + src[index] != '\r' && + src[index] != '=' && + src[index] >= '+' && + src[index] <= 'z' ) { + out[new_index] = src[index]; + new_index ++; + } + } + out[new_index] = 0; + *out_len = new_index; + + for (size_t i=0; i < *out_len; i++) { + if(out[i] == '+') { + out[i] = '-'; + } + } + for (size_t i=0; i < *out_len; i++) { + if(out[i] == '/') { + out[i] = '_'; + } + } + return out; +} + +unsigned char * b64t_decode(const unsigned char *src, size_t len, + size_t *out_len) +{ + size_t index = 0; + size_t nb_encoding_chars = 0; + for (index=0; index < len; index++) { + if(src[index] == '\n' || + src[index] == '\r' || + src[index] == '=') { + nb_encoding_chars++; + } + } + + size_t new_len = len - nb_encoding_chars; + size_t nb_newlines = new_len / 76; + size_t padding_len = 0; + if (new_len % 4 != 0) { + padding_len = 4 - new_len % 4; + } + *out_len = new_len + nb_newlines + padding_len + 1; + + // allocate new buffer + unsigned char *out = malloc(*out_len); + if (out == NULL) + return NULL; + memset(out, 0, len); + + size_t index_out = 0; + size_t index_data = 0; + for(index = 0; index < len; index++) { + if(src[index] != '\n' && + src[index] != '\r' && + src[index] != '=') { + if(index_data != 0 && index_data % 76 == 0) { + out[index_out] = '\n'; + index_out++; + } + if (src[index] == '-') { + out[index_out] = '+'; + } + else if (src[index] == '_') { + out[index_out] = '/'; + } + else { + out[index_out] = src[index]; + } + index_out++; + index_data++; + } + } + for(index = 0; index < padding_len; index ++) { + out[index_out] = '='; + index_out++; + } + out[index_out] = '\n'; + + return out; +} |