diff options
Diffstat (limited to 'wgtpkg-base64.c')
| -rw-r--r-- | wgtpkg-base64.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/wgtpkg-base64.c b/wgtpkg-base64.c new file mode 100644 index 0000000..5cf6f8a --- /dev/null +++ b/wgtpkg-base64.c @@ -0,0 +1,203 @@ +/* + Copyright 2015 IoT.bzh + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + + +#include <stdlib.h> +#include <string.h> +#include <syslog.h> + +#include "wgtpkg.h" + +static char tob64(char x) +{ + if (x < 26) + return 'A' + x; + if (x < 52) + return 'a' + x - 26; + if (x < 62) + return '0' + x - 52; + return x == 62 ? '+' : '/'; +} + +char *base64encw(const char *buffer, int length, int width) +{ + int remain, in, out; + char *result; + + if (width == 0 || width % 4) { + syslog(LOG_ERR, "bad width in base64enc"); + return NULL; + } + result = malloc(2 + 4 * ((length + 2) / 3) + (length / width)); + if (result == NULL) { + syslog(LOG_ERR, "malloc failed in base64enc"); + return NULL; + } + in = out = 0; + remain = length; + while (remain >= 3) { + if (out % (width + 1) == width) + result[out++] = '\n'; + result[out] = tob64((buffer[in] >> 2) & '\x3f'); + result[out+1] = tob64(((buffer[in] << 4) & '\x30') | ((buffer[in+1] >> 4) & '\x0f')); + result[out+2] = tob64(((buffer[in+1] << 2) & '\x3c') | ((buffer[in+2] >> 6) & '\x03')); + result[out+3] = tob64(buffer[in+2] & '\x3f'); + remain -= 3; + in += 3; + out += 4; + } + if (remain != 0) { + if (out % (width + 1) == width) + result[out++] = '\n'; + result[out] = tob64((buffer[in] >> 2) & '\x3f'); + if (remain == 1) { + result[out+1] = tob64((buffer[in] << 4) & '\x30'); + result[out+2] = '='; + } else { + result[out+1] = tob64(((buffer[in] << 4) & '\x30') | ((buffer[in+1] >> 4) & '\x0f')); + result[out+2] = tob64((buffer[in+1] << 2) & '\x3c'); + } + result[out+3] = '='; + out += 4; + } + result[out] = 0; + return result; +} + +char *base64enc(const char *buffer, int length) +{ + return base64encw(buffer, length, 76); +} + +static char fromb64(char x) +{ + if ('A' <= x && x <= 'Z') + return x - 'A'; + if ('a' <= x && x <= 'z') + return x - 'a' + 26; + if ('0' <= x && x <= '9') + return x - '0' + 52; + if (x == '+') + return 62; + if (x == '/') + return 63; + if (x == '=') + return '@'; + return 'E'; +} + +int base64dec(const char *buffer, char **output) +{ + int len, in, out; + char *result; + unsigned char x0, x1, x2, x3; + + len = strlen(buffer); + result = malloc(3 * ((3 + len) / 4)); + if (result == NULL) { + syslog(LOG_ERR, "malloc failed in base64dec"); + return -1; + } + in = out = 0; + while (buffer[in] == '\r' || buffer[in] == '\n') + in++; + while (buffer[in]) { + if (in + 4 > len) { + syslog(LOG_ERR, "unexpected input size in base64dec"); + free(result); + return -1; + } + x0 = (unsigned char)fromb64(buffer[in]); + x1 = (unsigned char)fromb64(buffer[in+1]); + x2 = (unsigned char)fromb64(buffer[in+2]); + x3 = (unsigned char)fromb64(buffer[in+3]); + in += 4; + if (x0 == 'E' || x1 == 'E' || x2 == 'E' || x3 == 'E') { + syslog(LOG_ERR, "unexpected input character in base64dec"); + free(result); + return -1; + } + if (x0 == '@' || x1 == '@' || (x2 == '@' && x3 != '@')) { + syslog(LOG_ERR, "unexpected termination character in base64dec"); + free(result); + return -1; + } + result[out] = (char)((x0 << 2) | (x1 >> 4)); + result[out+1] = (char)((x1 << 4) | ((x2 >> 2) & 15)); + result[out+2] = (char)((x2 << 6) | (x3 & 63)); + while (buffer[in] == '\r' || buffer[in] == '\n') + in++; + if (x3 != '@') + out += 3; + else if (!buffer[in]) + out += 1 + (x2 != '@'); + else { + syslog(LOG_ERR, "unexpected continuation in base64dec"); + free(result); + return -1; + } + } + *output = result; + return out; +} + +int base64eq(const char *buf1, const char *buf2) +{ + for(;;) { + while(*buf1 == '\n' || *buf1 == '\r') + buf1++; + while(*buf2 == '\n' || *buf2 == '\r') + buf2++; + if (*buf1 != *buf2) + return 0; + if (!*buf1) + return 1; + buf1++; + buf2++; + } +} + +#ifdef TESTBASE64 +#include <fcntl.h> +#include <string.h> + +int main(int ac, char **av) +{ + char buffer[32768]; + int fd, l0, l1, l2; + char *p1, *p2; + + while(*++av) { + fd = open(*av, O_RDONLY); + if (fd < 0) continue; + l0 = read(fd, buffer, sizeof buffer); + if (l0 <= 0) continue; + close(fd); + p1 = base64enc(buffer, l0); + if (!p1) continue; + l1 = strlen(p1); + l2 = base64dec(p1, &p2); + if (l2 <= 0) continue; +printf("[[[%.*s]]]\n",l2,p2); + if (l0 != l2) printf("length mismatch\n"); + else if (memcmp(buffer, p2, l0)) printf("content mismatch\n"); + free(p1); + free(p2); + } + return 0; +} + +#endif |