QLOG: JSON Encoder: Implementation

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22037)

1 files changed, 722 insertions, 0 deletions

diff --git a/ssl/quic/json_enc.c b/ssl/quic/json_enc.c
new file mode 100644
index 0000000000..80dfdb0265
--- /dev/null
+++ b/ssl/quic/json_enc.c
@@ -0,0 +1,722 @@
+/*
+ * Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "internal/json_enc.h"
+#include "internal/nelem.h"
+#include <string.h>
+#include <math.h>
+
+/*
+ * wbuf
+ * ====
+ */
+static int wbuf_flush(struct json_write_buf *wbuf);
+
+static int wbuf_init(struct json_write_buf *wbuf, BIO *bio, size_t alloc)
+{
+    wbuf->buf = OPENSSL_malloc(alloc);
+    if (wbuf->buf == NULL)
+        return 0;
+
+    wbuf->cur   = 0;
+    wbuf->alloc = alloc;
+    wbuf->bio   = bio;
+    return 1;
+}
+
+static void wbuf_cleanup(struct json_write_buf *wbuf)
+{
+    OPENSSL_free(wbuf->buf);
+    wbuf->buf   = NULL;
+    wbuf->alloc = 0;
+}
+
+static void wbuf_set_bio(struct json_write_buf *wbuf, BIO *bio)
+{
+    wbuf->bio = bio;
+}
+
+/* Empty write buffer. */
+static ossl_inline void wbuf_clean(struct json_write_buf *wbuf)
+{
+    wbuf->cur = 0;
+}
+
+/* Available data remaining in buffer. */
+static ossl_inline size_t wbuf_avail(struct json_write_buf *wbuf)
+{
+    return wbuf->alloc - wbuf->cur;
+}
+
+/* Add character to write buffer, returning 0 on flush failure. */
+static ossl_inline int wbuf_write_char(struct json_write_buf *wbuf, char c)
+{
+    if (wbuf_avail(wbuf) == 0) {
+        if (!wbuf_flush(wbuf))
+            return 0;
+    }
+
+    wbuf->buf[wbuf->cur++] = c;
+    return 1;
+}
+
+/*
+ * Write zero-terminated string to write buffer, returning 0 on flush failure.
+ */
+static int wbuf_write_str(struct json_write_buf *wbuf, const char *s)
+{
+    char c;
+
+    while ((c = *s++) != 0)
+        if (!wbuf_write_char(wbuf, c))
+            return 0;
+
+    return 1;
+}
+
+/* Flush write buffer, returning 0 on I/O failure. */
+static int wbuf_flush(struct json_write_buf *wbuf)
+{
+    size_t written = 0, total_written = 0;
+
+    while (total_written < wbuf->cur) {
+        if (!BIO_write_ex(wbuf->bio,
+                          wbuf->buf + total_written,
+                          wbuf->cur - total_written,
+                          &written)) {
+            memmove(wbuf->buf,
+                    wbuf->buf + total_written,
+                    wbuf->cur - total_written);
+            wbuf->cur = 0;
+            return 0;
+        }
+
+        total_written += written;
+    }
+
+    wbuf->cur = 0;
+    return 1;
+}
+
+/*
+ * JSON_ENC: Stack Management
+ * ==========================
+ */
+
+static int json_ensure_stack_size(JSON_ENC *json, size_t num_bytes)
+{
+    unsigned char *stack;
+
+    if (json->stack_bytes >= num_bytes)
+        return 1;
+
+    if (num_bytes <= OSSL_NELEM(json->stack_small)) {
+        stack = json->stack_small;
+    } else {
+        if (json->stack == json->stack_small)
+            json->stack = NULL;
+
+        stack = OPENSSL_realloc(json->stack, num_bytes);
+        if (stack == NULL)
+            return 0;
+    }
+
+    json->stack         = stack;
+    json->stack_bytes   = num_bytes;
+    return 1;
+}
+
+/* Push one bit onto the stack. Returns 0 on allocation failure. */
+static int json_push(JSON_ENC *json, unsigned int v)
+{
+    if (v > 1)
+        return 0;
+
+    if (json->stack_end_byte >= json->stack_bytes) {
+        size_t new_size
+            = (json->stack_bytes == 0)
+            ? OSSL_NELEM(json->stack_small)
+            : (json->stack_bytes * 2);
+
+        if (!json_ensure_stack_size(json, new_size))
+            return 0;
+
+        json->stack_bytes = new_size;
+    }
+
+    if (v > 0)
+        json->stack[json->stack_end_byte] |= (v << json->stack_end_bit);
+    else
+        json->stack[json->stack_end_byte] &= ~(1U << json->stack_end_bit);
+
+    json->stack_end_bit = (json->stack_end_bit + 1) % CHAR_BIT;
+    if (json->stack_end_bit == 0)
+        ++json->stack_end_byte;
+
+    return 1;
+}
+
+/*
+ * Pop a bit from the stack. Returns 0 if stack is empty. Use json_peek() to get
+ * the value before calling this.
+ */
+static int json_pop(JSON_ENC *json)
+{
+    if (json->stack_end_byte == 0 && json->stack_end_bit == 0)
+        return 0;
+
+    if (json->stack_end_bit == 0) {
+        --json->stack_end_byte;
+        json->stack_end_bit = CHAR_BIT - 1;
+    } else {
+        --json->stack_end_bit;
+    }
+
+    return 1;
+}
+
+/*
+ * Returns the bit on the top of the stack, or -1 if the stack is empty.
+ */
+static int json_peek(JSON_ENC *json)
+{
+    size_t obyte, obit;
+
+    obyte = json->stack_end_byte;
+    obit  = json->stack_end_bit;
+    if (obit == 0) {
+       if (obyte == 0)
+           return -1;
+
+        --obyte;
+        obit = CHAR_BIT - 1;
+    } else {
+        --obit;
+    }
+
+    return (json->stack[obyte] & (1U << obit)) != 0;
+}
+
+/*
+ * JSON_ENC: Initialisation
+ * ========================
+ */
+
+enum {
+    STATE_PRE_KEY,
+    STATE_PRE_ITEM,
+    STATE_PRE_COMMA
+};
+
+static ossl_inline int in_ijson(const JSON_ENC *json)
+{
+    return (json->flags & JSON_FLAG_IJSON) != 0;
+}
+
+static ossl_inline int in_seq(const JSON_ENC *json)
+{
+    return (json->flags & JSON_FLAG_SEQ) != 0;
+}
+
+static ossl_inline int in_pretty(const JSON_ENC *json)
+{
+    return (json->flags & JSON_FLAG_PRETTY) != 0;
+}
+
+int ossl_json_init(JSON_ENC *json, BIO *bio, uint32_t flags)
+{
+    memset(json, 0, sizeof(*json));
+    json->flags     = flags;
+    json->error     = 1;
+    if (!wbuf_init(&json->wbuf, bio, 4096))
+        return 0;
+
+    json->state = STATE_PRE_COMMA;
+    return ossl_json_reset(json);
+}
+
+void ossl_json_cleanup(JSON_ENC *json)
+{
+    wbuf_cleanup(&json->wbuf);
+
+    if (json->stack != json->stack_small)
+        OPENSSL_free(json->stack);
+
+    json->stack = NULL;
+}
+
+int ossl_json_flush_cleanup(JSON_ENC *json)
+{
+    int ok = ossl_json_flush(json);
+
+    ossl_json_cleanup(json);
+    return ok;
+}
+
+int ossl_json_reset(JSON_ENC *json)
+{
+    wbuf_clean(&json->wbuf);
+    json->stack_end_byte    = 0;
+    json->stack_end_bit     = 0;
+    json->error             = 0;
+    return 1;
+}
+
+int ossl_json_flush(JSON_ENC *json)
+{
+    return wbuf_flush(&json->wbuf);
+}
+
+int ossl_json_set_sink(JSON_ENC *json, BIO *bio)
+{
+    wbuf_set_bio(&json->wbuf, bio);
+    return 1;
+}
+
+int ossl_json_in_error(JSON_ENC *json)
+{
+    return json->error;
+}
+
+/*
+ * JSON Builder Calls
+ * ==================
+ */
+
+static void json_write_qstring(JSON_ENC *json, const char *str);
+static void json_indent(JSON_ENC *json);
+
+static ossl_inline int json_in_error(const JSON_ENC *json)
+{
+    return json->error;
+}
+
+static void json_raise_error(JSON_ENC *json)
+{
+    json->error = 1;
+}
+
+static void json_undefer(JSON_ENC *json)
+{
+    if (!json->defer_indent)
+        return;
+
+    json_indent(json);
+}
+
+static void json_write_char(JSON_ENC *json, char ch)
+{
+    if (json_in_error(json))
+        return;
+
+    json_undefer(json);
+    if (!wbuf_write_char(&json->wbuf, ch))
+        json_raise_error(json);
+}
+
+static void json_write_str(JSON_ENC *json, const char *s)
+{
+    if (json_in_error(json))
+        return;
+
+    json_undefer(json);
+    if (!wbuf_write_str(&json->wbuf, s))
+        json_raise_error(json);
+}
+
+static void json_indent(JSON_ENC *json)
+{
+    size_t i, depth;
+
+    json->defer_indent = 0;
+
+    if (!in_pretty(json))
+        return;
+
+    json_write_char(json, '\n');
+
+    depth = json->stack_end_byte * 8 + json->stack_end_bit;
+    for (i = 0; i < depth * 4; ++i)
+        json_write_str(json, "    ");
+}
+
+static int json_pre_item(JSON_ENC *json)
+{
+    int s;
+
+    if (json_in_error(json))
+        return 0;
+
+    switch (json->state) {
+    case STATE_PRE_COMMA:
+        s = json_peek(json);
+
+        if (s == 0) {
+            json_raise_error(json);
+            return 0;
+        }
+
+        if (s == 1) {
+            json_write_char(json, ',');
+            if (json_in_error(json))
+                return 0;
+
+            json_indent(json);
+        }
+
+        if (s < 0 && in_seq(json))
+            json_write_char(json, '\x1E');
+
+        json->state = STATE_PRE_ITEM;
+        break;
+
+    case STATE_PRE_ITEM:
+        break;
+
+    case STATE_PRE_KEY:
+    default:
+        json_raise_error(json);
+        return 0;
+    }
+
+    return 1;
+}
+
+static void json_post_item(JSON_ENC *json)
+{
+    int s = json_peek(json);
+
+    json->state = STATE_PRE_COMMA;
+
+    if (s < 0 && in_seq(json))
+        json_write_char(json, '\n');
+}
+
+/*
+ * Begin a composite structure (object or array).
+ *
+ * type: 0=object, 1=array.
+ */
+static void composite_begin(JSON_ENC *json, int type, char ch)
+{
+    if (!json_pre_item(json)
+        || !json_push(json, type))
+        json_raise_error(json);
+
+    json_write_char(json, ch);
+    json->defer_indent = 1;
+}
+
+/*
+ * End a composite structure (object or array).
+ *
+ * type: 0=object, 1=array. Errors on mismatch.
+ */
+static void composite_end(JSON_ENC *json, int type, char ch)
+{
+    int was_defer = json->defer_indent;
+
+    if (json_in_error(json))
+        return;
+
+    json->defer_indent = 0;
+
+    if (json_peek(json) != type)
+        return;
+
+    if (type == 0 && json->state == STATE_PRE_ITEM) {
+        json_raise_error(json);
+        return;
+    }
+
+    if (!json_pop(json))
+        return;
+
+    if (!was_defer)
+        json_indent(json);
+
+    json_write_char(json, ch);
+    json_post_item(json);
+}
+
+/* Begin a new JSON object. */
+void ossl_json_object_begin(JSON_ENC *json)
+{
+    composite_begin(json, 0, '{');
+    json->state = STATE_PRE_KEY;
+}
+
+/* End a JSON obejct. Must be matched with a call to ossl_json_object_begin(). */
+void ossl_json_object_end(JSON_ENC *json)
+{
+    composite_end(json, 0, '}');
+}
+
+/* Begin a new JSON array. */
+void ossl_json_array_begin(JSON_ENC *json)
+{
+    composite_begin(json, 1, '[');
+    json->state = STATE_PRE_ITEM;
+}
+
+/* End a JSON array. Must be matched with a call to ossl_json_array_end(). */
+void ossl_json_array_end(JSON_ENC *json)
+{
+    composite_end(json, 1, ']');
+}
+
+/*
+ * Encode a JSON key within an object. Pass a zero-terminated string, which can
+ * be freed immediately following the call to this function.
+ */
+void ossl_json_key(JSON_ENC *json, const char *key)
+{
+    if (json_in_error(json))
+        return;
+
+    if (json_peek(json) != 0) {
+        /* Not in object */
+        json_raise_error(json);
+        return;
+    }
+
+    if (json->state == STATE_PRE_COMMA) {
+        json_write_char(json, ',');
+        json->state = STATE_PRE_KEY;
+    }
+
+    json_indent(json);
+    if (json->state != STATE_PRE_KEY) {
+        json_raise_error(json);
+        return;
+    }
+
+    json_write_qstring(json, key);
+    if (json_in_error(json))
+        return;
+
+    json_write_char(json, ':');
+    if (in_pretty(json))
+        json_write_char(json, ' ');
+
+    json->state = STATE_PRE_ITEM;
+}
+
+/* Encode a JSON 'null' value. */
+void ossl_json_null(JSON_ENC *json)
+{
+    if (!json_pre_item(json))
+        return;
+
+    json_write_str(json, "null");
+    json_post_item(json);
+}
+
+void ossl_json_bool(JSON_ENC *json, int v)
+{
+    if (!json_pre_item(json))
+        return;
+
+    json_write_str(json, v > 0 ? "true" : "false");
+    json_post_item(json);
+}
+
+#define POW_53 (((int64_t)1) << 53)
+
+/* Encode a JSON integer from a uint64_t. */
+static void json_u64(JSON_ENC *json, uint64_t v, int noquote)
+{
+    char buf[22], *p = buf + sizeof(buf) - 1;
+    int quote = !noquote && in_ijson(json) && v > (uint64_t)(POW_53 - 1);
+
+    if (!json_pre_item(json))
+        return;
+
+    if (quote)
+        json_write_char(json, '"');
+
+    if (v == 0)
+        p = "0";
+    else
+        for (*p = '\0'; v > 0; v /= 10)
+            *--p = '0' + v % 10;
+
+    json_write_str(json, p);
+
+    if (quote)
+        json_write_char(json, '"');
+
+    json_post_item(json);
+}
+
+void ossl_json_u64(JSON_ENC *json, uint64_t v)
+{
+    json_u64(json, v, 0);
+}
+
+/* Encode a JSON integer from an int64_t. */
+void ossl_json_i64(JSON_ENC *json, int64_t value)
+{
+    uint64_t uv;
+    int quote;
+
+    if (value >= 0) {
+        ossl_json_u64(json, (uint64_t)value);
+        return;
+    }
+
+    if (!json_pre_item(json))
+        return;
+
+    quote = in_ijson(json)
+        && (value > POW_53 - 1 || value < -POW_53 + 1);
+
+    if (quote)
+        json_write_char(json, '"');
+
+    json_write_char(json, '-');
+
+    uv = (value == INT64_MIN)
+        ? ((uint64_t)-(INT64_MIN + 1)) + 1
+        : (uint64_t)-value;
+    json_u64(json, uv, /*noquote=*/1);
+
+    if (quote && !json_in_error(json))
+        json_write_char(json, '"');
+}
+
+/* Encode a JSON number from a 64-bit floating point value. */
+void ossl_json_f64(JSON_ENC *json, double value)
+{
+    char buf[32];
+
+    if (!json_pre_item(json))
+        return;
+
+    if (isnan(value) || isinf(value)) {
+        json_raise_error(json);
+        return;
+    }
+
+    snprintf(buf, sizeof(buf), "%1.17g", value);
+    json_write_str(json, buf);
+    json_post_item(json);
+}
+
+/*
+ * Encode a JSON UTF-8 string from a zero-terminated string. The string passed
+ * can be freed immediately following the call to this function.
+ */
+static ossl_inline int hex_digit(int v)
+{
+    return v >= 10 ? 'a' + (v - 10) : '0' + v;
+}
+
+static ossl_inline void
+json_write_qstring_inner(JSON_ENC *json, const char *str, size_t str_len,
+                         int nul_term)
+{
+    char c, *o, obuf[7];
+    int i;
+    size_t j;
+
+    if (json_in_error(json))
+        return;
+
+    json_write_char(json, '"');
+
+    for (j = 0; (nul_term && *str != '\0')
+                || (!nul_term && j < str_len); ++str, ++j) {
+        c = *str;
+        switch (c) {
+        case '\n': o = "\\n"; break;
+        case '\r': o = "\\r"; break;
+        case '\t': o = "\\t"; break;
+        case '\b': o = "\\b"; break;
+        case '\f': o = "\\f"; break;
+        case '"': o = "\\\""; break;
+        case '\\': o = "\\\\"; break;
+        default:
+            if ((unsigned char)c >= 0x80) {
+                json_raise_error(json);
+                return;
+            }
+            if ((unsigned char)c < 0x20 || (unsigned char)c >= 0x7f) {
+                obuf[0] = '\\';
+                obuf[1] = 'u';
+                for (i = 0; i < 4; ++i)
+                    obuf[2 + i] = hex_digit((c >> ((3 - i) * 4)) & 0xF);
+                obuf[6] = '\0';
+                o = obuf;
+            } else {
+                json_write_char(json, c);
+                continue;
+            }
+            break;
+        }
+
+        json_write_str(json, o);
+    }
+
+    json_write_char(json, '"');
+}
+
+static void
+json_write_qstring(JSON_ENC *json, const char *str)
+{
+    json_write_qstring_inner(json, str, 0, 1);
+}
+
+static void
+json_write_qstring_len(JSON_ENC *json, const char *str, size_t str_len)
+{
+    json_write_qstring_inner(json, str, str_len, 0);
+}
+
+void ossl_json_str(JSON_ENC *json, const char *str)
+{
+    if (!json_pre_item(json))
+        return;
+
+    json_write_qstring(json, str);
+    json_post_item(json);
+}
+
+void ossl_json_str_len(JSON_ENC *json, const char *str, size_t str_len)
+{
+    if (!json_pre_item(json))
+        return;
+
+    json_write_qstring_len(json, str, str_len);
+    json_post_item(json);
+}
+
+/*
+ * Encode binary data as a lowercase hex string. data_len is the data length in
+ * bytes.
+ */
+void ossl_json_str_hex(JSON_ENC *json, const void *data, size_t data_len)
+{
+    const unsigned char *b = data, *end = b + data_len;
+    unsigned char c;
+
+    if (!json_pre_item(json))
+        return;
+
+    json_write_char(json, '"');
+
+    for (; b < end; ++b) {
+        c = *b;
+        json_write_char(json, hex_digit(c >> 4));
+        json_write_char(json, hex_digit(c & 0x0F));
+    }
+
+    json_write_char(json, '"');
+    json_post_item(json);
+}