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add base64url encoding option

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This commit is contained in:
Eric 2025-05-26 23:59:47 +02:00
parent 8991fe1a69
commit a91be306b1
3 changed files with 39 additions and 30 deletions
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54
encode.c
View file

@ -7,32 +7,38 @@ unsigned char b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"0123456789" \ "0123456789" \
"+/"; "+/";
unsigned char b64u[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"abcdefghijklmnopqrstuvwxyz" \
"0123456789" \
"-_";
int int
encode(unsigned char *op, int olen, unsigned char *sp) encode(unsigned char *op, int olen, unsigned char *sp, int url)
{ {
int n; int n;
unsigned char *sb; unsigned char *sb, *enc;
sb = sp; sb = sp;
enc = (!url) ? b64 : b64u;
switch (olen) { switch (olen) {
case 3: case 3:
*sp++ = b64[(*op & ~3) >> 2]; *sp++ = enc[(*op & ~3) >> 2];
n = (*op++ & 3) << 4; n = (*op++ & 3) << 4;
*sp++ = b64[n + ((*op & ~15) >> 4)]; *sp++ = enc[n + ((*op & ~15) >> 4)];
n = (*op++ & 15) << 2; n = (*op++ & 15) << 2;
*sp++ = b64[n + ((*op & 192) >> 6)]; *sp++ = enc[n + ((*op & 192) >> 6)];
*sp = b64[*op & ~192]; *sp = enc[*op & ~192];
break; break;
case 2: case 2:
*sp++ = b64[(*op & ~3) >> 2]; *sp++ = enc[(*op & ~3) >> 2];
n = (*op++ & 3) << 4; n = (*op++ & 3) << 4;
*sp++ = b64[n + ((*op & ~15) >> 4)]; *sp++ = enc[n + ((*op & ~15) >> 4)];
*sp++ = b64[(*op & 15) << 2]; *sp++ = enc[(*op & 15) << 2];
*sp = PADDING; *sp = PADDING;
break; break;
case 1: case 1:
*sp++ = b64[(*op & ~3) >> 2]; *sp++ = enc[(*op & ~3) >> 2];
*sp++ = b64[(*op & 3) << 4]; *sp++ = enc[(*op & 3) << 4];
*sp++ = PADDING; *sp++ = PADDING;
*sp = PADDING; *sp = PADDING;
break; break;
@ -42,42 +48,42 @@ encode(unsigned char *op, int olen, unsigned char *sp)
} }
int int
decode(unsigned char *sp, int slen, unsigned char *op) decode(unsigned char *sp, int slen, unsigned char *op, int url)
{ {
int n, b, atob(int c); int n, b, atob(int c, int url);
unsigned char *ob; unsigned char *ob;
ob = op; ob = op;
switch (slen) { switch (slen) {
case 4: case 4:
n = atob(*sp++) << 2; n = atob(*sp++, url) << 2;
b = atob(*sp++); b = atob(*sp++, url);
*op++ = n + ((b & ~15) >> 4); *op++ = n + ((b & ~15) >> 4);
n = (b & 15) << 4; n = (b & 15) << 4;
b = atob(*sp++); b = atob(*sp++, url);
*op++ = n + ((b & ~3) >> 2); *op++ = n + ((b & ~3) >> 2);
*op = ((b & 3) << 6) + atob(*sp); *op = ((b & 3) << 6) + atob(*sp, url);
break; break;
case 3: case 3:
n = atob(*sp++) << 2; n = atob(*sp++, url) << 2;
b = atob(*sp++); b = atob(*sp++, url);
*op++ = n + ((b & ~15) >> 4); *op++ = n + ((b & ~15) >> 4);
n = (b & 15) << 4; n = (b & 15) << 4;
*op = n + ((atob(*sp) & ~3) >> 2); *op = n + ((atob(*sp, url) & ~3) >> 2);
break; break;
case 2: case 2:
n = atob(*sp++) << 2; n = atob(*sp++, url) << 2;
*op = n + ((atob(*sp) & ~15) >> 4); *op = n + ((atob(*sp, url) & ~15) >> 4);
break; break;
} }
return op-ob+1; return op-ob+1;
} }
int atob(int c) int atob(int c, int url)
{ {
if (c >= 'A' && c <= 'Z') if (c >= 'A' && c <= 'Z')
c -= 'A'; c -= 'A';
@ -85,7 +91,7 @@ int atob(int c)
c = c - 'a' + 26; c = c - 'a' + 26;
else if (c >= '0' && c <= '9') else if (c >= '0' && c <= '9')
c = c - '0' + 26 * 2; c = c - '0' + 26 * 2;
else if (c == '+') else if (c == ((!url) ? '+' : '-'))
c = 62; c = 62;
else else
c = 63; c = 63;

4
encode.h
View file

@ -2,9 +2,9 @@
#define HEADER_ENCODE #define HEADER_ENCODE
int int
encode(unsigned char *op, int olen, unsigned char *sp); encode(unsigned char *op, int olen, unsigned char *sp, int url);
int int
decode(unsigned char *sp, int slen, unsigned char *op); decode(unsigned char *sp, int slen, unsigned char *op, int url);
#endif #endif

11
main.c
View file

@ -12,17 +12,20 @@ unsigned char sbuf[SBUFSIZE];
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
int c, n, dec, hlp; int c, n, dec, url, hlp;
char *prog = *argv; char *prog = *argv;
FILE *in, *out; FILE *in, *out;
dec = hlp = 0; dec = url = hlp = 0;
while (--argc > 0 && (*++argv)[0] == '-') while (--argc > 0 && (*++argv)[0] == '-')
while ((c = *++argv[0])) while ((c = *++argv[0]))
switch (c) { switch (c) {
case 'd': case 'd':
dec = 1; dec = 1;
break; break;
case 'u':
url = 1;
break;
case 'h': case 'h':
hlp = 1; hlp = 1;
break; break;
@ -44,12 +47,12 @@ main(int argc, char *argv[])
} }
if (dec) { if (dec) {
while ((n = getsxts((argc >= 1) ? in : stdin, sbuf, SBUFSIZE))) { while ((n = getsxts((argc >= 1) ? in : stdin, sbuf, SBUFSIZE))) {
n = decode(sbuf, n, obuf); n = decode(sbuf, n, obuf, url);
fwrite(obuf, sizeof(*obuf), n, (argc == 2) ? out : stdout); fwrite(obuf, sizeof(*obuf), n, (argc == 2) ? out : stdout);
} }
} else { } else {
while ((n = getocts((argc >= 1) ? in : stdin, obuf, OBUFSIZE))) { while ((n = getocts((argc >= 1) ? in : stdin, obuf, OBUFSIZE))) {
encode(obuf, n, sbuf); encode(obuf, n, sbuf, url);
fprintf((argc == 2) ? out : stdout, "%s", sbuf); fprintf((argc == 2) ? out : stdout, "%s", sbuf);
} }
} }