From a6e9807eb9d93458e3bda2360b72a0a1fdec81a7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?P=C3=A1draig=20Brady?= Date: Mon, 15 Sep 2025 21:31:00 +0100 Subject: [PATCH] maint: basenc: refactor overloaded use of ctx->i member * src/basenc.c (base_decode_context): Remove the shared "i" member, instead using per encoding data and access functions for tracking pending data. --- src/basenc.c | 118 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 76 insertions(+), 42 deletions(-) diff --git a/src/basenc.c b/src/basenc.c index 49740a47b1..35168f49b2 100644 --- a/src/basenc.c +++ b/src/basenc.c @@ -281,11 +281,11 @@ struct base58_context struct base2_decode_context { unsigned char octet; + int bit_pos; }; struct base_decode_context { - int i; /* will be updated manually */ union { struct base64_decode_context base64; struct base32_decode_context base32; @@ -323,21 +323,58 @@ no_padding (MAYBE_UNUSED struct base_decode_context *ctx) { return false; } + +static int +no_pending_length (MAYBE_UNUSED struct base_decode_context *ctx) +{ + return 0; +} #endif #if BASE_TYPE == 42 static bool (*has_padding) (struct base_decode_context *ctx); +static int (*get_pending_length) (struct base_decode_context *ctx); static bool base64_ctx_has_padding (struct base_decode_context *ctx) { - return ctx->i && ctx->ctx.base64.buf[ctx->i - 1] == '='; + return ctx->ctx.base64.i && ctx->ctx.base64.buf[ctx->ctx.base64.i - 1] == '='; } static bool base32_ctx_has_padding (struct base_decode_context *ctx) { - return ctx->i && ctx->ctx.base32.buf[ctx->i - 1] == '='; + return ctx->ctx.base32.i && ctx->ctx.base32.buf[ctx->ctx.base32.i - 1] == '='; +} + +static int +base64_ctx_get_pending_length (struct base_decode_context *ctx) +{ + return ctx->ctx.base64.i; +} + +static int +base32_ctx_get_pending_length (struct base_decode_context *ctx) +{ + return ctx->ctx.base32.i; +} + +static int +base16_ctx_get_pending_length (MAYBE_UNUSED struct base_decode_context *ctx) +{ + return 1; /* Always check nibble state. */ +} + +static int +z85_ctx_get_pending_length (struct base_decode_context *ctx) +{ + return ctx->ctx.z85.i; +} + +static int +base2_ctx_get_pending_length (struct base_decode_context *ctx) +{ + return ctx->ctx.base2.bit_pos; } #else static bool @@ -345,6 +382,12 @@ has_padding (struct base_decode_context *ctx) { return ctx->i && ctx->buf[ctx->i - 1] == '='; } + +static int +get_pending_length (struct base_decode_context *ctx) +{ + return ctx->i; +} #endif @@ -355,7 +398,7 @@ static bool decode_ctx_finalize (struct base_decode_context *ctx, char *restrict *out, idx_t *outlen) { - if (ctx->i == 0) + if (get_pending_length (ctx) == 0) { *outlen = 0; return true; @@ -363,7 +406,8 @@ decode_ctx_finalize (struct base_decode_context *ctx, /* Auto-pad input and flush the context */ char padbuf[8] ATTRIBUTE_NONSTRING = "========"; - idx_t auto_padding = REQUIRED_PADDING (ctx->i); + idx_t pending_len = get_pending_length (ctx); + idx_t auto_padding = REQUIRED_PADDING (pending_len); idx_t n = *outlen; bool result; @@ -393,7 +437,6 @@ static void base64_decode_ctx_init_wrapper (struct base_decode_context *ctx) { base64_decode_ctx_init (&ctx->ctx.base64); - ctx->i = 0; } static bool @@ -401,9 +444,7 @@ base64_decode_ctx_wrapper (struct base_decode_context *ctx, char const *restrict in, idx_t inlen, char *restrict out, idx_t *outlen) { - bool b = base64_decode_ctx (&ctx->ctx.base64, in, inlen, out, outlen); - ctx->i = ctx->ctx.base64.i; - return b; + return base64_decode_ctx (&ctx->ctx.base64, in, inlen, out, outlen); } static void @@ -450,7 +491,6 @@ static void base64url_decode_ctx_init_wrapper (struct base_decode_context *ctx) { base64_decode_ctx_init (&ctx->ctx.base64); - ctx->i = 0; init_inbuf (ctx); } @@ -480,11 +520,8 @@ base64url_decode_ctx_wrapper (struct base_decode_context *ctx, ++p; } - bool b = base64_decode_ctx (&ctx->ctx.base64, ctx->inbuf, inlen, - out, outlen); - ctx->i = ctx->ctx.base64.i; - - return b; + return base64_decode_ctx (&ctx->ctx.base64, ctx->inbuf, inlen, + out, outlen); } @@ -499,7 +536,6 @@ static void base32_decode_ctx_init_wrapper (struct base_decode_context *ctx) { base32_decode_ctx_init (&ctx->ctx.base32); - ctx->i = 0; } static bool @@ -507,9 +543,7 @@ base32_decode_ctx_wrapper (struct base_decode_context *ctx, char const *restrict in, idx_t inlen, char *restrict out, idx_t *outlen) { - bool b = base32_decode_ctx (&ctx->ctx.base32, in, inlen, out, outlen); - ctx->i = ctx->ctx.base32.i; - return b; + return base32_decode_ctx (&ctx->ctx.base32, in, inlen, out, outlen); } /* ABCDEFGHIJKLMNOPQRSTUVWXYZ234567 @@ -579,7 +613,6 @@ static void base32hex_decode_ctx_init_wrapper (struct base_decode_context *ctx) { base32_decode_ctx_init (&ctx->ctx.base32); - ctx->i = 0; init_inbuf (ctx); } @@ -603,11 +636,8 @@ base32hex_decode_ctx_wrapper (struct base_decode_context *ctx, ++in; } - bool b = base32_decode_ctx (&ctx->ctx.base32, ctx->inbuf, inlen, - out, outlen); - ctx->i = ctx->ctx.base32.i; - - return b; + return base32_decode_ctx (&ctx->ctx.base32, ctx->inbuf, inlen, + out, outlen); } /* With this approach this file works independent of the charset used (think EBCDIC). However, it does assume that the characters in the @@ -740,7 +770,6 @@ base16_decode_ctx_init (struct base_decode_context *ctx) { init_inbuf (ctx); ctx->ctx.base16.nibble = -1; - ctx->i = 1; } @@ -868,7 +897,6 @@ z85_decode_ctx_init (struct base_decode_context *ctx) { init_inbuf (ctx); ctx->ctx.z85.i = 0; - ctx->i = 1; } @@ -977,7 +1005,6 @@ z85_decode_ctx (struct base_decode_context *ctx, ctx->ctx.z85.i = 0; } } - ctx->i = ctx->ctx.z85.i; return true; } @@ -1037,7 +1064,7 @@ base2_decode_ctx_init (struct base_decode_context *ctx) { init_inbuf (ctx); ctx->ctx.base2.octet = 0; - ctx->i = 0; + ctx->ctx.base2.bit_pos = 0; } @@ -1054,7 +1081,7 @@ base2lsbf_decode_ctx (struct base_decode_context *ctx, if there is a dangling bit - we are missing some bits, so return false - indicating an invalid input. */ if (inlen == 0) - return ctx->i == 0; + return ctx->ctx.base2.bit_pos == 0; while (inlen--) { @@ -1068,15 +1095,15 @@ base2lsbf_decode_ctx (struct base_decode_context *ctx, return false; bool bit = (*in == '1'); - ctx->ctx.base2.octet |= bit << ctx->i; - ++ctx->i; + ctx->ctx.base2.octet |= bit << ctx->ctx.base2.bit_pos; + ++ctx->ctx.base2.bit_pos; - if (ctx->i == 8) + if (ctx->ctx.base2.bit_pos == 8) { *out++ = ctx->ctx.base2.octet; ctx->ctx.base2.octet = 0; ++*outlen; - ctx->i = 0; + ctx->ctx.base2.bit_pos = 0; } ++in; @@ -1098,7 +1125,7 @@ base2msbf_decode_ctx (struct base_decode_context *ctx, if there is a dangling bit - we are missing some bits, so return false - indicating an invalid input. */ if (inlen == 0) - return ctx->i == 0; + return ctx->ctx.base2.bit_pos == 0; while (inlen--) { @@ -1112,17 +1139,16 @@ base2msbf_decode_ctx (struct base_decode_context *ctx, return false; bool bit = (*in == '1'); - if (ctx->i == 0) - ctx->i = 8; - --ctx->i; - ctx->ctx.base2.octet |= bit << ctx->i; + if (ctx->ctx.base2.bit_pos == 0) + ctx->ctx.base2.bit_pos = 8; + --ctx->ctx.base2.bit_pos; + ctx->ctx.base2.octet |= bit << ctx->ctx.base2.bit_pos; - if (ctx->i == 0) + if (ctx->ctx.base2.bit_pos == 0) { *out++ = ctx->ctx.base2.octet; ctx->ctx.base2.octet = 0; ++*outlen; - ctx->i = 0; } ++in; @@ -1279,7 +1305,6 @@ base58_decode_ctx_init (struct base_decode_context *ctx) ctx->ctx.base58.size = 0; ctx->ctx.base58.capacity = 0; ctx->ctx.base58.buf = nullptr; - ctx->i = 0; } static bool @@ -1652,6 +1677,7 @@ main (int argc, char **argv) #if BASE_TYPE == 42 required_padding = no_required_padding; has_padding = no_padding; + get_pending_length = no_pending_length; base_decode_ctx_finalize = decode_ctx_finalize; switch (base_type) @@ -1660,6 +1686,7 @@ main (int argc, char **argv) base_length = base64_length_wrapper; required_padding = base64_required_padding; has_padding = base64_ctx_has_padding; + get_pending_length = base64_ctx_get_pending_length; isubase = isubase64; base_encode = base64_encode; base_decode_ctx_init = base64_decode_ctx_init_wrapper; @@ -1670,6 +1697,7 @@ main (int argc, char **argv) base_length = base64_length_wrapper; required_padding = base64_required_padding; has_padding = base64_ctx_has_padding; + get_pending_length = base64_ctx_get_pending_length; isubase = isubase64url; base_encode = base64url_encode; base_decode_ctx_init = base64url_decode_ctx_init_wrapper; @@ -1680,6 +1708,7 @@ main (int argc, char **argv) base_length = base32_length_wrapper; required_padding = base32_required_padding; has_padding = base32_ctx_has_padding; + get_pending_length = base32_ctx_get_pending_length; isubase = isubase32; base_encode = base32_encode; base_decode_ctx_init = base32_decode_ctx_init_wrapper; @@ -1690,6 +1719,7 @@ main (int argc, char **argv) base_length = base32_length_wrapper; required_padding = base32_required_padding; has_padding = base32_ctx_has_padding; + get_pending_length = base32_ctx_get_pending_length; isubase = isubase32hex; base_encode = base32hex_encode; base_decode_ctx_init = base32hex_decode_ctx_init_wrapper; @@ -1698,6 +1728,7 @@ main (int argc, char **argv) case BASE16_OPTION: base_length = base16_length; + get_pending_length = base16_ctx_get_pending_length; isubase = isubase16; base_encode = base16_encode; base_decode_ctx_init = base16_decode_ctx_init; @@ -1706,6 +1737,7 @@ main (int argc, char **argv) case BASE2MSBF_OPTION: base_length = base2_length; + get_pending_length = base2_ctx_get_pending_length; isubase = isubase2; base_encode = base2msbf_encode; base_decode_ctx_init = base2_decode_ctx_init; @@ -1714,6 +1746,7 @@ main (int argc, char **argv) case BASE2LSBF_OPTION: base_length = base2_length; + get_pending_length = base2_ctx_get_pending_length; isubase = isubase2; base_encode = base2lsbf_encode; base_decode_ctx_init = base2_decode_ctx_init; @@ -1722,6 +1755,7 @@ main (int argc, char **argv) case Z85_OPTION: base_length = z85_length; + get_pending_length = z85_ctx_get_pending_length; isubase = isuz85; base_encode = z85_encode; base_decode_ctx_init = z85_decode_ctx_init; -- 2.47.3