Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 819 insertions, 0 deletions

diff --git a/src/basic/hexdecoct.c b/src/basic/hexdecoct.c
new file mode 100644
index 0000000..c0f9640
--- /dev/null
+++ b/src/basic/hexdecoct.c
@@ -0,0 +1,819 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "string-util.h"
+#include "util.h"
+
+char octchar(int x) {
+        return '0' + (x & 7);
+}
+
+int unoctchar(char c) {
+
+        if (c >= '0' && c <= '7')
+                return c - '0';
+
+        return -EINVAL;
+}
+
+char decchar(int x) {
+        return '0' + (x % 10);
+}
+
+int undecchar(char c) {
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        return -EINVAL;
+}
+
+char hexchar(int x) {
+        static const char table[16] = "0123456789abcdef";
+
+        return table[x & 15];
+}
+
+int unhexchar(char c) {
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        if (c >= 'a' && c <= 'f')
+                return c - 'a' + 10;
+
+        if (c >= 'A' && c <= 'F')
+                return c - 'A' + 10;
+
+        return -EINVAL;
+}
+
+char *hexmem(const void *p, size_t l) {
+        const uint8_t *x;
+        char *r, *z;
+
+        z = r = new(char, l * 2 + 1);
+        if (!r)
+                return NULL;
+
+        for (x = p; x < (const uint8_t*) p + l; x++) {
+                *(z++) = hexchar(*x >> 4);
+                *(z++) = hexchar(*x & 15);
+        }
+
+        *z = 0;
+        return r;
+}
+
+static int unhex_next(const char **p, size_t *l) {
+        int r;
+
+        assert(p);
+        assert(l);
+
+        /* Find the next non-whitespace character, and decode it. We
+         * greedily skip all preceding and all following whitespace. */
+
+        for (;;) {
+                if (*l == 0)
+                        return -EPIPE;
+
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip leading whitespace */
+                (*p)++, (*l)--;
+        }
+
+        r = unhexchar(**p);
+        if (r < 0)
+                return r;
+
+        for (;;) {
+                (*p)++, (*l)--;
+
+                if (*l == 0 || !strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip following whitespace */
+        }
+
+        return r;
+}
+
+int unhexmem(const char *p, size_t l, void **ret, size_t *ret_len) {
+        _cleanup_free_ uint8_t *buf = NULL;
+        const char *x;
+        uint8_t *z;
+
+        assert(ret);
+        assert(ret_len);
+        assert(p || l == 0);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* Note that the calculation of memory size is an upper boundary, as we ignore whitespace while decoding */
+        buf = malloc((l + 1) / 2 + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        for (x = p, z = buf;;) {
+                int a, b;
+
+                a = unhex_next(&x, &l);
+                if (a == -EPIPE) /* End of string */
+                        break;
+                if (a < 0)
+                        return a;
+
+                b = unhex_next(&x, &l);
+                if (b < 0)
+                        return b;
+
+                *(z++) = (uint8_t) a << 4 | (uint8_t) b;
+        }
+
+        *z = 0;
+
+        *ret_len = (size_t) (z - buf);
+        *ret = TAKE_PTR(buf);
+
+        return 0;
+}
+
+/* https://tools.ietf.org/html/rfc4648#section-6
+ * Notice that base32hex differs from base32 in the alphabet it uses.
+ * The distinction is that the base32hex representation preserves the
+ * order of the underlying data when compared as bytestrings, this is
+ * useful when representing NSEC3 hashes, as one can then verify the
+ * order of hashes directly from their representation. */
+char base32hexchar(int x) {
+        static const char table[32] = "0123456789"
+                                      "ABCDEFGHIJKLMNOPQRSTUV";
+
+        return table[x & 31];
+}
+
+int unbase32hexchar(char c) {
+        unsigned offset;
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        offset = '9' - '0' + 1;
+
+        if (c >= 'A' && c <= 'V')
+                return c - 'A' + offset;
+
+        return -EINVAL;
+}
+
+char *base32hexmem(const void *p, size_t l, bool padding) {
+        char *r, *z;
+        const uint8_t *x;
+        size_t len;
+
+        assert(p || l == 0);
+
+        if (padding)
+                /* five input bytes makes eight output bytes, padding is added so we must round up */
+                len = 8 * (l + 4) / 5;
+        else {
+                /* same, but round down as there is no padding */
+                len = 8 * l / 5;
+
+                switch (l % 5) {
+                case 4:
+                        len += 7;
+                        break;
+                case 3:
+                        len += 5;
+                        break;
+                case 2:
+                        len += 4;
+                        break;
+                case 1:
+                        len += 2;
+                        break;
+                }
+        }
+
+        z = r = malloc(len + 1);
+        if (!r)
+                return NULL;
+
+        for (x = p; x < (const uint8_t*) p + (l / 5) * 5; x += 5) {
+                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ
+                 * x[3] == QQQQQQQQ; x[4] == WWWWWWWW */
+                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);  /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
+                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
+                *(z++) = base32hexchar((x[3] & 3) << 3 | x[4] >> 5);  /* 000QQWWW */
+                *(z++) = base32hexchar((x[4] & 31));                  /* 000WWWWW */
+        }
+
+        switch (l % 5) {
+        case 4:
+                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);   /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
+                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
+                *(z++) = base32hexchar((x[3] & 3) << 3);              /* 000QQ000 */
+                if (padding)
+                        *(z++) = '=';
+
+                break;
+
+        case 3:
+                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4); /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1);            /* 000ZZZZ0 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+
+        case 2:
+                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4);             /* 000Y0000 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+
+        case 1:
+                *(z++) = base32hexchar(x[0] >> 3);       /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2); /* 000XXX00 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+        }
+
+        *z = 0;
+        return r;
+}
+
+int unbase32hexmem(const char *p, size_t l, bool padding, void **mem, size_t *_len) {
+        _cleanup_free_ uint8_t *r = NULL;
+        int a, b, c, d, e, f, g, h;
+        uint8_t *z;
+        const char *x;
+        size_t len;
+        unsigned pad = 0;
+
+        assert(p || l == 0);
+        assert(mem);
+        assert(_len);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* padding ensures any base32hex input has input divisible by 8 */
+        if (padding && l % 8 != 0)
+                return -EINVAL;
+
+        if (padding) {
+                /* strip the padding */
+                while (l > 0 && p[l - 1] == '=' && pad < 7) {
+                        pad++;
+                        l--;
+                }
+        }
+
+        /* a group of eight input bytes needs five output bytes, in case of
+         * padding we need to add some extra bytes */
+        len = (l / 8) * 5;
+
+        switch (l % 8) {
+        case 7:
+                len += 4;
+                break;
+        case 5:
+                len += 3;
+                break;
+        case 4:
+                len += 2;
+                break;
+        case 2:
+                len += 1;
+                break;
+        case 0:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        z = r = malloc(len + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (x = p; x < p + (l / 8) * 8; x += 8) {
+                /* a == 000XXXXX; b == 000YYYYY; c == 000ZZZZZ; d == 000WWWWW
+                 * e == 000SSSSS; f == 000QQQQQ; g == 000VVVVV; h == 000RRRRR */
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                f = unbase32hexchar(x[5]);
+                if (f < 0)
+                        return -EINVAL;
+
+                g = unbase32hexchar(x[6]);
+                if (g < 0)
+                        return -EINVAL;
+
+                h = unbase32hexchar(x[7]);
+                if (h < 0)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */
+                *(z++) = (uint8_t) g << 5 | (uint8_t) h;                         /* VVVRRRRR */
+        }
+
+        switch (l % 8) {
+        case 7:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                f = unbase32hexchar(x[5]);
+                if (f < 0)
+                        return -EINVAL;
+
+                g = unbase32hexchar(x[6]);
+                if (g < 0)
+                        return -EINVAL;
+
+                /* g == 000VV000 */
+                if (g & 7)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */
+
+                break;
+        case 5:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                /* e == 000SSSS0 */
+                if (e & 1)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+
+                break;
+        case 4:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                /* d == 000W0000 */
+                if (d & 15)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+
+                break;
+        case 2:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                /* b == 000YYY00 */
+                if (b & 3)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2; /* XXXXXYYY */
+
+                break;
+        case 0:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        *z = 0;
+
+        *mem = TAKE_PTR(r);
+        *_len = len;
+
+        return 0;
+}
+
+/* https://tools.ietf.org/html/rfc4648#section-4 */
+char base64char(int x) {
+        static const char table[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                      "abcdefghijklmnopqrstuvwxyz"
+                                      "0123456789+/";
+        return table[x & 63];
+}
+
+int unbase64char(char c) {
+        unsigned offset;
+
+        if (c >= 'A' && c <= 'Z')
+                return c - 'A';
+
+        offset = 'Z' - 'A' + 1;
+
+        if (c >= 'a' && c <= 'z')
+                return c - 'a' + offset;
+
+        offset += 'z' - 'a' + 1;
+
+        if (c >= '0' && c <= '9')
+                return c - '0' + offset;
+
+        offset += '9' - '0' + 1;
+
+        if (c == '+')
+                return offset;
+
+        offset++;
+
+        if (c == '/')
+                return offset;
+
+        return -EINVAL;
+}
+
+ssize_t base64mem(const void *p, size_t l, char **out) {
+        char *r, *z;
+        const uint8_t *x;
+
+        assert(p || l == 0);
+        assert(out);
+
+        /* three input bytes makes four output bytes, padding is added so we must round up */
+        z = r = malloc(4 * (l + 2) / 3 + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (x = p; x < (const uint8_t*) p + (l / 3) * 3; x += 3) {
+                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ */
+                *(z++) = base64char(x[0] >> 2);                    /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4);  /* 00XXYYYY */
+                *(z++) = base64char((x[1] & 15) << 2 | x[2] >> 6); /* 00YYYYZZ */
+                *(z++) = base64char(x[2] & 63);                    /* 00ZZZZZZ */
+        }
+
+        switch (l % 3) {
+        case 2:
+                *(z++) = base64char(x[0] >> 2);                   /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4); /* 00XXYYYY */
+                *(z++) = base64char((x[1] & 15) << 2);            /* 00YYYY00 */
+                *(z++) = '=';
+
+                break;
+        case 1:
+                *(z++) = base64char(x[0] >> 2);        /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4);  /* 00XX0000 */
+                *(z++) = '=';
+                *(z++) = '=';
+
+                break;
+        }
+
+        *z = 0;
+        *out = r;
+        return z - r;
+}
+
+static int base64_append_width(
+                char **prefix, int plen,
+                const char *sep, int indent,
+                const void *p, size_t l,
+                int width) {
+
+        _cleanup_free_ char *x = NULL;
+        char *t, *s;
+        ssize_t len, slen, avail, line, lines;
+
+        len = base64mem(p, l, &x);
+        if (len <= 0)
+                return len;
+
+        lines = DIV_ROUND_UP(len, width);
+
+        slen = strlen_ptr(sep);
+        if (lines > (SSIZE_MAX - plen - 1 - slen) / (indent + width + 1))
+                return -ENOMEM;
+
+        t = realloc(*prefix, plen + 1 + slen + (indent + width + 1) * lines);
+        if (!t)
+                return -ENOMEM;
+
+        memcpy_safe(t + plen, sep, slen);
+
+        for (line = 0, s = t + plen + slen, avail = len; line < lines; line++) {
+                int act = MIN(width, avail);
+
+                if (line > 0 || sep) {
+                        memset(s, ' ', indent);
+                        s += indent;
+                }
+
+                memcpy(s, x + width * line, act);
+                s += act;
+                *(s++) = line < lines - 1 ? '\n' : '\0';
+                avail -= act;
+        }
+        assert(avail == 0);
+
+        *prefix = t;
+        return 0;
+}
+
+int base64_append(
+                char **prefix, int plen,
+                const void *p, size_t l,
+                int indent, int width) {
+
+        if (plen > width / 2 || plen + indent > width)
+                /* leave indent on the left, keep last column free */
+                return base64_append_width(prefix, plen, "\n", indent, p, l, width - indent - 1);
+        else
+                /* leave plen on the left, keep last column free */
+                return base64_append_width(prefix, plen, NULL, plen, p, l, width - plen - 1);
+}
+
+static int unbase64_next(const char **p, size_t *l) {
+        int ret;
+
+        assert(p);
+        assert(l);
+
+        /* Find the next non-whitespace character, and decode it. If we find padding, we return it as INT_MAX. We
+         * greedily skip all preceding and all following whitespace. */
+
+        for (;;) {
+                if (*l == 0)
+                        return -EPIPE;
+
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip leading whitespace */
+                (*p)++, (*l)--;
+        }
+
+        if (**p == '=')
+                ret = INT_MAX; /* return padding as INT_MAX */
+        else {
+                ret = unbase64char(**p);
+                if (ret < 0)
+                        return ret;
+        }
+
+        for (;;) {
+                (*p)++, (*l)--;
+
+                if (*l == 0)
+                        break;
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip following whitespace */
+        }
+
+        return ret;
+}
+
+int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
+        _cleanup_free_ uint8_t *buf = NULL;
+        const char *x;
+        uint8_t *z;
+        size_t len;
+
+        assert(p || l == 0);
+        assert(ret);
+        assert(ret_size);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* A group of four input bytes needs three output bytes, in case of padding we need to add two or three extra
+         * bytes. Note that this calculation is an upper boundary, as we ignore whitespace while decoding */
+        len = (l / 4) * 3 + (l % 4 != 0 ? (l % 4) - 1 : 0);
+
+        buf = malloc(len + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        for (x = p, z = buf;;) {
+                int a, b, c, d; /* a == 00XXXXXX; b == 00YYYYYY; c == 00ZZZZZZ; d == 00WWWWWW */
+
+                a = unbase64_next(&x, &l);
+                if (a == -EPIPE) /* End of string */
+                        break;
+                if (a < 0)
+                        return a;
+                if (a == INT_MAX) /* Padding is not allowed at the beginning of a 4ch block */
+                        return -EINVAL;
+
+                b = unbase64_next(&x, &l);
+                if (b < 0)
+                        return b;
+                if (b == INT_MAX) /* Padding is not allowed at the second character of a 4ch block either */
+                        return -EINVAL;
+
+                c = unbase64_next(&x, &l);
+                if (c < 0)
+                        return c;
+
+                d = unbase64_next(&x, &l);
+                if (d < 0)
+                        return d;
+
+                if (c == INT_MAX) { /* Padding at the third character */
+
+                        if (d != INT_MAX) /* If the third character is padding, the fourth must be too */
+                                return -EINVAL;
+
+                        /* b == 00YY0000 */
+                        if (b & 15)
+                                return -EINVAL;
+
+                        if (l > 0) /* Trailing rubbish? */
+                                return -ENAMETOOLONG;
+
+                        *(z++) = (uint8_t) a << 2 | (uint8_t) (b >> 4); /* XXXXXXYY */
+                        break;
+                }
+
+                if (d == INT_MAX) {
+                        /* c == 00ZZZZ00 */
+                        if (c & 3)
+                                return -EINVAL;
+
+                        if (l > 0) /* Trailing rubbish? */
+                                return -ENAMETOOLONG;
+
+                        *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
+                        *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
+                        break;
+                }
+
+                *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
+                *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
+                *(z++) = (uint8_t) c << 6 | (uint8_t) d;      /* ZZWWWWWW */
+        }
+
+        *z = 0;
+
+        *ret_size = (size_t) (z - buf);
+        *ret = TAKE_PTR(buf);
+
+        return 0;
+}
+
+void hexdump(FILE *f, const void *p, size_t s) {
+        const uint8_t *b = p;
+        unsigned n = 0;
+
+        assert(b || s == 0);
+
+        if (!f)
+                f = stdout;
+
+        while (s > 0) {
+                size_t i;
+
+                fprintf(f, "%04x  ", n);
+
+                for (i = 0; i < 16; i++) {
+
+                        if (i >= s)
+                                fputs("   ", f);
+                        else
+                                fprintf(f, "%02x ", b[i]);
+
+                        if (i == 7)
+                                fputc(' ', f);
+                }
+
+                fputc(' ', f);
+
+                for (i = 0; i < 16; i++) {
+
+                        if (i >= s)
+                                fputc(' ', f);
+                        else
+                                fputc(isprint(b[i]) ? (char) b[i] : '.', f);
+                }
+
+                fputc('\n', f);
+
+                if (s < 16)
+                        break;
+
+                n += 16;
+                b += 16;
+                s -= 16;
+        }
+}