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Diffstat (limited to 'lib/base64.c')
| -rw-r--r-- | lib/base64.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/lib/base64.c b/lib/base64.c new file mode 100644 index 00000000..d5f3ae9b --- /dev/null +++ b/lib/base64.c @@ -0,0 +1,163 @@ +/* + * 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.base64 for more details. + */ + +#include "nest/bird.h" +#include "conf/conf.h" +#include "lib/resource.h" +#include "lib/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. + */ +struct bytestring * base64_encode(linpool *pool, + const unsigned char *src, size_t len, + size_t *out_len) +{ + unsigned char *pos; + struct bytestring *out; + const unsigned char *end, *in; + size_t olen; + int line_len; + + olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */ + olen += olen / 72; /* line feeds */ + olen++; /* nul termination */ + if (olen < len) + return NULL; /* integer overflow */ + out = lp_alloc(pool, sizeof(struct bytestring) + olen); + if (out == NULL) + return NULL; + + end = src + len; + in = src; + pos = out->data; + 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 >= 72) { + *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'; + out->length = pos - out->data; + if (out_len) + *out_len = out->length; + 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. + */ +struct bytestring * base64_decode_bs(linpool *pool, + const unsigned char *src, size_t len, + size_t *out_len) +{ + unsigned char dtable[256], *pos, block[4], tmp; + size_t i, count, olen; + int pad = 0; + struct bytestring *out; + + 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; + out = lp_alloc(pool, sizeof(struct bytestring) + olen); + if (out == NULL) + return NULL; + pos = out->data; + + 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 */ + //os_free(out); + return NULL; + } + break; + } + } + } + + out->length = pos - out->data; + if (out_len) + *out_len = out->length; + return out; +} |