From 22d3da72492f2b0939d11f1bf0a2b23a4f69ec63 Mon Sep 17 00:00:00 2001 From: John Denker Date: Sat, 2 Jun 2012 17:37:16 -0700 Subject: apply the big auth patch --- base64.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 base64.c (limited to 'base64.c') diff --git a/base64.c b/base64.c new file mode 100644 index 0000000..fbce145 --- /dev/null +++ b/base64.c @@ -0,0 +1,90 @@ +#include "base64.h" +#include "stralloc.h" +#include "substdio.h" +#include "str.h" + +static char *b64alpha = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +#define B64PAD '=' + +/* returns 0 ok, 1 illegal, -1 problem */ + +int b64decode(in,l,out) +const unsigned char *in; +int l; +stralloc *out; /* not null terminated */ +{ + int i, j; + unsigned char a[4]; + unsigned char b[3]; + char *s; + + if (l == 0) + { + if (!stralloc_copys(out,"")) return -1; + return 0; + } + + if (!stralloc_ready(out,l + 2)) return -1; /* XXX generous */ + s = out->s; + + for (i = 0;i < l;i += 4) { + for (j = 0;j < 4;j++) + if ((i + j) < l && in[i + j] != B64PAD) + { + a[j] = str_chr(b64alpha,in[i + j]); + if (a[j] > 63) return 1; + } + else a[j] = 0; + + b[0] = (a[0] << 2) | (a[1] >> 4); + b[1] = (a[1] << 4) | (a[2] >> 2); + b[2] = (a[2] << 6) | (a[3]); + + *s++ = b[0]; + + if (in[i + 1] == B64PAD) break; + *s++ = b[1]; + + if (in[i + 2] == B64PAD) break; + *s++ = b[2]; + } + out->len = s - out->s; + while (out->len && !out->s[out->len - 1]) --out->len; /* XXX avoid? */ + return 0; +} + +int b64encode(in,out) +stralloc *in; +stralloc *out; /* not null terminated */ +{ + unsigned char a, b, c; + int i; + char *s; + + if (in->len == 0) + { + if (!stralloc_copys(out,"")) return -1; + return 0; + } + + if (!stralloc_ready(out,in->len / 3 * 4 + 4)) return -1; + s = out->s; + + for (i = 0;i < in->len;i += 3) { + a = in->s[i]; + b = i + 1 < in->len ? in->s[i + 1] : 0; + c = i + 2 < in->len ? in->s[i + 2] : 0; + + *s++ = b64alpha[a >> 2]; + *s++ = b64alpha[((a & 3 ) << 4) | (b >> 4)]; + + if (i + 1 >= in->len) *s++ = B64PAD; + else *s++ = b64alpha[((b & 15) << 2) | (c >> 6)]; + + if (i + 2 >= in->len) *s++ = B64PAD; + else *s++ = b64alpha[c & 63]; + } + out->len = s - out->s; + return 0; +} -- cgit v1.2.3