Add VENC functions to encode & decode base64

doc/sphinx/reference/vtla.rst

@@ -45,6 +45,12 @@ VDD
     Varnish (Core) Developer Day -- Quarterly invite-only meeting strictly
     for Varnish core (C) developers, packagers and VMOD hackers.
 
+VENC
+    Varnish ENCoding -- base64 functions
+
+VEND
+    Varnish ENDianess -- functions to marshall data in specified endianess
+
 VEV
     Varnish EVent -- library functions to implement a simple event-dispatcher.
 

include/Makefile.am

@@ -90,6 +90,7 @@ nobase_noinst_HEADERS = \
 	vcs_version.h \
 	vct.h \
 	vcurses.h \
+	venc.h \
 	vend.h \
 	vev.h \
 	vfil.h \

include/venc.h

+/*-
+ * Copyright (c) 2020 Varnish Software AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+struct vsb;
+
+const char *VENC_Decode_Base64(struct vsb *, const char *, const char *);
+
+void VENC_Encode_Base64(struct vsb*, const void *, size_t);

lib/libvarnish/Makefile.am

@@ -21,6 +21,7 @@ libvarnish_la_SOURCES = \
 	vcli_proto.c \
 	vcli_serve.c \
 	vct.c \
+	venc.c \
 	verrno.c \
 	version.c \
 	vev.c \

lib/libvarnish/venc.c

+/*-
+ * Copyright (c) 2020 Varnish Software AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include "config.h"
+
+#include <stdint.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/types.h>
+
+#include "vdef.h"
+#include "vas.h"
+#include "vrt.h"
+#include "venc.h"
+
+#include "vsb.h"
+
+/*
+ * Yes: Cumbersome.  But if "..." syntax is used, C adds a NUL
+ */
+
+static const char base64_enc[64] = {
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'r', 'q', 's', 't', 'u', 'v',
+    'w', 'x', 'y', 'z', '0', '1', '2', '3',
+    '4', '5', '6', '7', '8', '9', '+', '/'
+};
+
+/*
+ * Encode base64 (RFC4648 section 4) into VSB.
+ */
+
+void
+VENC_Encode_Base64(struct vsb *dst, const void *src, size_t len)
+{
+	const uint8_t *p = src;
+	uint32_t u;
+	char w[4];
+
+	AN(dst);
+	AN(src);
+	for (; len >= 3; len -= 3, p += 3) {
+		u = (p[0] << 16) | (p[1] << 8) | p[2];
+		w[3] = base64_enc[u & 0x3f];
+		u >>= 6;
+		w[2] = base64_enc[u & 0x3f];
+		u >>= 6;
+		w[1] = base64_enc[u & 0x3f];
+		u >>= 6;
+		w[0] = base64_enc[u & 0x3f];
+		if (VSB_bcat(dst, w, sizeof w))
+			break;
+	}
+	if (len) {
+		memset(w, '=', sizeof w);
+		u = (p[0] << 16);
+		if (len == 2)
+		    u |= (p[1] << 8);
+		w[0] = base64_enc[(u >> 18) & 0x3f];
+		w[1] = base64_enc[(u >> 12) & 0x3f];
+		if (len == 2)
+			w[2] = base64_enc[(u >> 6) & 0x3f];
+		VSB_bcat(dst, w, sizeof w);
+	}
+}
+
+#define BV 64
+
+static const uint8_t base64_dec[256] = {
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, 62, BV, BV, BV, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, BV, BV, BV,  0, BV, BV,
+    BV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, BV, BV, BV, BV, BV,
+    BV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV
+};
+
+#if 0 // pending #3376 decision
+static const uint8_t base64url_dec[256] = {
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, 62, BV, BV,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, BV, BV, BV,  0, BV, BV,
+    BV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, BV, BV, BV, BV, 63,
+    BV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV,
+    BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV, BV
+};
+#endif
+
+struct venc_state {
+	unsigned		n;
+	unsigned		f;
+	uint8_t			w;
+	struct vsb		*vsb;
+	const uint8_t		*tbl;
+};
+
+static const char *
+venc_decode_base64(struct venc_state *ves, const char *b, const char *e)
+{
+	unsigned i;
+
+	AN(ves);
+	AN(ves->vsb);
+	AN(ves->tbl);
+
+	AN(b);
+	if (e == NULL)
+		e = strchr(b, '\0');
+	assert(e >= b);
+
+	for (; b < e; b++) {
+		i = ves->tbl[*(const uint8_t*)b];
+		if (i == BV)
+			return (b);
+		if (*b == '=' && ves->n < 2)
+			return (b);
+		else if (*b == '=')
+			ves->f++;
+		else if (ves->f)
+			return (b - 1);
+		if (ves->f && ves->w)
+			return (b - 1);
+		switch(++ves->n) {
+		case 1:
+			ves->w = i << 2;
+			break;
+		case 2:
+			ves->w |= i >> 4;
+			VSB_putc(ves->vsb, ves->w);
+			ves->w = i << 4;
+			break;
+		case 3:
+			ves->w |= i >> 2;
+			if (!ves->f)
+				VSB_putc(ves->vsb, ves->w);
+			ves->w = i << 6;
+			break;
+		case 4:
+			ves->w |= i;
+			if (!ves->f)
+				VSB_putc(ves->vsb, ves->w);
+			ves->w = 0;
+			ves->n = 0;
+			break;
+		default:
+			WRONG("Wrong turn in venc_decode_base64()");
+		}
+	}
+	return (NULL);
+}
+
+/*
+ * Decode base64 (RFC4648 section 4) into VSB.
+ *
+ * Returns NULL on success.
+ * Returns pointer to offending input character on failure.
+ */
+
+const char *
+VENC_Decode_Base64(struct vsb *dst, const char *b, const char *e)
+{
+	struct venc_state ves;
+	const char *rv;
+
+	memset(&ves, 0, sizeof ves);
+	ves.vsb = dst;
+	ves.tbl = base64_dec;
+
+	rv = venc_decode_base64(&ves, b, e);
+	if (rv)
+		return (rv);
+	if (ves.n)
+		return (e);
+	return (NULL);
+}