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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
commit | 1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5 (patch) | |
tree | 6cf8220b628ebd2ccfc1375dd6516c6996e9abcc /lib/crypto_backend/argon2/encoding.c | |
parent | Initial commit. (diff) | |
download | cryptsetup-upstream.tar.xz cryptsetup-upstream.zip |
Adding upstream version 2:2.6.1.upstream/2%2.6.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/crypto_backend/argon2/encoding.c | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/lib/crypto_backend/argon2/encoding.c b/lib/crypto_backend/argon2/encoding.c new file mode 100644 index 0000000..a717263 --- /dev/null +++ b/lib/crypto_backend/argon2/encoding.c @@ -0,0 +1,462 @@ +/* + * Argon2 reference source code package - reference C implementations + * + * Copyright 2015 + * Daniel Dinu, Dmitry Khovratovich, Jean-Philippe Aumasson, and Samuel Neves + * + * You may use this work under the terms of a Creative Commons CC0 1.0 + * License/Waiver or the Apache Public License 2.0, at your option. The terms of + * these licenses can be found at: + * + * - CC0 1.0 Universal : https://creativecommons.org/publicdomain/zero/1.0 + * - Apache 2.0 : https://www.apache.org/licenses/LICENSE-2.0 + * + * You should have received a copy of both of these licenses along with this + * software. If not, they may be obtained at the above URLs. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <limits.h> +#include "encoding.h" +#include "core.h" + +/* + * Example code for a decoder and encoder of "hash strings", with Argon2 + * parameters. + * + * This code comprises three sections: + * + * -- The first section contains generic Base64 encoding and decoding + * functions. It is conceptually applicable to any hash function + * implementation that uses Base64 to encode and decode parameters, + * salts and outputs. It could be made into a library, provided that + * the relevant functions are made public (non-static) and be given + * reasonable names to avoid collisions with other functions. + * + * -- The second section is specific to Argon2. It encodes and decodes + * the parameters, salts and outputs. It does not compute the hash + * itself. + * + * The code was originally written by Thomas Pornin <pornin@bolet.org>, + * to whom comments and remarks may be sent. It is released under what + * should amount to Public Domain or its closest equivalent; the + * following mantra is supposed to incarnate that fact with all the + * proper legal rituals: + * + * --------------------------------------------------------------------- + * This file is provided under the terms of Creative Commons CC0 1.0 + * Public Domain Dedication. To the extent possible under law, the + * author (Thomas Pornin) has waived all copyright and related or + * neighboring rights to this file. This work is published from: Canada. + * --------------------------------------------------------------------- + * + * Copyright (c) 2015 Thomas Pornin + */ + +/* ==================================================================== */ +/* + * Common code; could be shared between different hash functions. + * + * Note: the Base64 functions below assume that uppercase letters (resp. + * lowercase letters) have consecutive numerical codes, that fit on 8 + * bits. All modern systems use ASCII-compatible charsets, where these + * properties are true. If you are stuck with a dinosaur of a system + * that still defaults to EBCDIC then you already have much bigger + * interoperability issues to deal with. + */ + +/* + * Some macros for constant-time comparisons. These work over values in + * the 0..255 range. Returned value is 0x00 on "false", 0xFF on "true". + */ +#define EQ(x, y) ((((0U - ((unsigned)(x) ^ (unsigned)(y))) >> 8) & 0xFF) ^ 0xFF) +#define GT(x, y) ((((unsigned)(y) - (unsigned)(x)) >> 8) & 0xFF) +#define GE(x, y) (GT(y, x) ^ 0xFF) +#define LT(x, y) GT(y, x) +#define LE(x, y) GE(y, x) + +/* + * Convert value x (0..63) to corresponding Base64 character. + */ +static int b64_byte_to_char(unsigned x) { + return (LT(x, 26) & (x + 'A')) | + (GE(x, 26) & LT(x, 52) & (x + ('a' - 26))) | + (GE(x, 52) & LT(x, 62) & (x + ('0' - 52))) | (EQ(x, 62) & '+') | + (EQ(x, 63) & '/'); +} + +/* + * Convert character c to the corresponding 6-bit value. If character c + * is not a Base64 character, then 0xFF (255) is returned. + */ +static unsigned b64_char_to_byte(int c) { + unsigned x; + + x = (GE(c, 'A') & LE(c, 'Z') & (c - 'A')) | + (GE(c, 'a') & LE(c, 'z') & (c - ('a' - 26))) | + (GE(c, '0') & LE(c, '9') & (c - ('0' - 52))) | (EQ(c, '+') & 62) | + (EQ(c, '/') & 63); + return x | (EQ(x, 0) & (EQ(c, 'A') ^ 0xFF)); +} + +/* + * Convert some bytes to Base64. 'dst_len' is the length (in characters) + * of the output buffer 'dst'; if that buffer is not large enough to + * receive the result (including the terminating 0), then (size_t)-1 + * is returned. Otherwise, the zero-terminated Base64 string is written + * in the buffer, and the output length (counted WITHOUT the terminating + * zero) is returned. + */ +static size_t to_base64(char *dst, size_t dst_len, const void *src, + size_t src_len) { + size_t olen; + const unsigned char *buf; + unsigned acc, acc_len; + + olen = (src_len / 3) << 2; + switch (src_len % 3) { + case 2: + olen++; + /* fall through */ + case 1: + olen += 2; + break; + } + if (dst_len <= olen) { + return (size_t)-1; + } + acc = 0; + acc_len = 0; + buf = (const unsigned char *)src; + while (src_len-- > 0) { + acc = (acc << 8) + (*buf++); + acc_len += 8; + while (acc_len >= 6) { + acc_len -= 6; + *dst++ = (char)b64_byte_to_char((acc >> acc_len) & 0x3F); + } + } + if (acc_len > 0) { + *dst++ = (char)b64_byte_to_char((acc << (6 - acc_len)) & 0x3F); + } + *dst++ = 0; + return olen; +} + +/* + * Decode Base64 chars into bytes. The '*dst_len' value must initially + * contain the length of the output buffer '*dst'; when the decoding + * ends, the actual number of decoded bytes is written back in + * '*dst_len'. + * + * Decoding stops when a non-Base64 character is encountered, or when + * the output buffer capacity is exceeded. If an error occurred (output + * buffer is too small, invalid last characters leading to unprocessed + * buffered bits), then NULL is returned; otherwise, the returned value + * points to the first non-Base64 character in the source stream, which + * may be the terminating zero. + */ +static const char *from_base64(void *dst, size_t *dst_len, const char *src) { + size_t len; + unsigned char *buf; + unsigned acc, acc_len; + + buf = (unsigned char *)dst; + len = 0; + acc = 0; + acc_len = 0; + for (;;) { + unsigned d; + + d = b64_char_to_byte(*src); + if (d == 0xFF) { + break; + } + src++; + acc = (acc << 6) + d; + acc_len += 6; + if (acc_len >= 8) { + acc_len -= 8; + if ((len++) >= *dst_len) { + return NULL; + } + *buf++ = (acc >> acc_len) & 0xFF; + } + } + + /* + * If the input length is equal to 1 modulo 4 (which is + * invalid), then there will remain 6 unprocessed bits; + * otherwise, only 0, 2 or 4 bits are buffered. The buffered + * bits must also all be zero. + */ + if (acc_len > 4 || (acc & (((unsigned)1 << acc_len) - 1)) != 0) { + return NULL; + } + *dst_len = len; + return src; +} + +/* + * Decode decimal integer from 'str'; the value is written in '*v'. + * Returned value is a pointer to the next non-decimal character in the + * string. If there is no digit at all, or the value encoding is not + * minimal (extra leading zeros), or the value does not fit in an + * 'unsigned long', then NULL is returned. + */ +static const char *decode_decimal(const char *str, unsigned long *v) { + const char *orig; + unsigned long acc; + + acc = 0; + for (orig = str;; str++) { + int c; + + c = *str; + if (c < '0' || c > '9') { + break; + } + c -= '0'; + if (acc > (ULONG_MAX / 10)) { + return NULL; + } + acc *= 10; + if ((unsigned long)c > (ULONG_MAX - acc)) { + return NULL; + } + acc += (unsigned long)c; + } + if (str == orig || (*orig == '0' && str != (orig + 1))) { + return NULL; + } + *v = acc; + return str; +} + +/* ==================================================================== */ +/* + * Code specific to Argon2. + * + * The code below applies the following format: + * + * $argon2<T>[$v=<num>]$m=<num>,t=<num>,p=<num>$<bin>$<bin> + * + * where <T> is either 'd', 'id', or 'i', <num> is a decimal integer (positive, + * fits in an 'unsigned long'), and <bin> is Base64-encoded data (no '=' padding + * characters, no newline or whitespace). + * + * The last two binary chunks (encoded in Base64) are, in that order, + * the salt and the output. Both are required. The binary salt length and the + * output length must be in the allowed ranges defined in argon2.h. + * + * The ctx struct must contain buffers large enough to hold the salt and pwd + * when it is fed into decode_string. + */ + +int decode_string(argon2_context *ctx, const char *str, argon2_type type) { + +/* check for prefix */ +#define CC(prefix) \ + do { \ + size_t cc_len = strlen(prefix); \ + if (strncmp(str, prefix, cc_len) != 0) { \ + return ARGON2_DECODING_FAIL; \ + } \ + str += cc_len; \ + } while ((void)0, 0) + +/* optional prefix checking with supplied code */ +#define CC_opt(prefix, code) \ + do { \ + size_t cc_len = strlen(prefix); \ + if (strncmp(str, prefix, cc_len) == 0) { \ + str += cc_len; \ + { code; } \ + } \ + } while ((void)0, 0) + +/* Decoding prefix into decimal */ +#define DECIMAL(x) \ + do { \ + unsigned long dec_x; \ + str = decode_decimal(str, &dec_x); \ + if (str == NULL) { \ + return ARGON2_DECODING_FAIL; \ + } \ + (x) = dec_x; \ + } while ((void)0, 0) + + +/* Decoding prefix into uint32_t decimal */ +#define DECIMAL_U32(x) \ + do { \ + unsigned long dec_x; \ + str = decode_decimal(str, &dec_x); \ + if (str == NULL || dec_x > UINT32_MAX) { \ + return ARGON2_DECODING_FAIL; \ + } \ + (x) = (uint32_t)dec_x; \ + } while ((void)0, 0) + + +/* Decoding base64 into a binary buffer */ +#define BIN(buf, max_len, len) \ + do { \ + size_t bin_len = (max_len); \ + str = from_base64(buf, &bin_len, str); \ + if (str == NULL || bin_len > UINT32_MAX) { \ + return ARGON2_DECODING_FAIL; \ + } \ + (len) = (uint32_t)bin_len; \ + } while ((void)0, 0) + + size_t maxsaltlen = ctx->saltlen; + size_t maxoutlen = ctx->outlen; + int validation_result; + const char* type_string; + + /* We should start with the argon2_type we are using */ + type_string = argon2_type2string(type, 0); + if (!type_string) { + return ARGON2_INCORRECT_TYPE; + } + + CC("$"); + CC(type_string); + + /* Reading the version number if the default is suppressed */ + ctx->version = ARGON2_VERSION_10; + CC_opt("$v=", DECIMAL_U32(ctx->version)); + + CC("$m="); + DECIMAL_U32(ctx->m_cost); + CC(",t="); + DECIMAL_U32(ctx->t_cost); + CC(",p="); + DECIMAL_U32(ctx->lanes); + ctx->threads = ctx->lanes; + + CC("$"); + BIN(ctx->salt, maxsaltlen, ctx->saltlen); + CC("$"); + BIN(ctx->out, maxoutlen, ctx->outlen); + + /* The rest of the fields get the default values */ + ctx->secret = NULL; + ctx->secretlen = 0; + ctx->ad = NULL; + ctx->adlen = 0; + ctx->allocate_cbk = NULL; + ctx->free_cbk = NULL; + ctx->flags = ARGON2_DEFAULT_FLAGS; + + /* On return, must have valid context */ + validation_result = validate_inputs(ctx); + if (validation_result != ARGON2_OK) { + return validation_result; + } + + /* Can't have any additional characters */ + if (*str == 0) { + return ARGON2_OK; + } else { + return ARGON2_DECODING_FAIL; + } +#undef CC +#undef CC_opt +#undef DECIMAL +#undef BIN +} + +int encode_string(char *dst, size_t dst_len, argon2_context *ctx, + argon2_type type) { +#define SS(str) \ + do { \ + size_t pp_len = strlen(str); \ + if (pp_len >= dst_len) { \ + return ARGON2_ENCODING_FAIL; \ + } \ + memcpy(dst, str, pp_len + 1); \ + dst += pp_len; \ + dst_len -= pp_len; \ + } while ((void)0, 0) + +#define SX(x) \ + do { \ + char tmp[30]; \ + sprintf(tmp, "%lu", (unsigned long)(x)); \ + SS(tmp); \ + } while ((void)0, 0) + +#define SB(buf, len) \ + do { \ + size_t sb_len = to_base64(dst, dst_len, buf, len); \ + if (sb_len == (size_t)-1) { \ + return ARGON2_ENCODING_FAIL; \ + } \ + dst += sb_len; \ + dst_len -= sb_len; \ + } while ((void)0, 0) + + const char* type_string = argon2_type2string(type, 0); + int validation_result = validate_inputs(ctx); + + if (!type_string) { + return ARGON2_ENCODING_FAIL; + } + + if (validation_result != ARGON2_OK) { + return validation_result; + } + + + SS("$"); + SS(type_string); + + SS("$v="); + SX(ctx->version); + + SS("$m="); + SX(ctx->m_cost); + SS(",t="); + SX(ctx->t_cost); + SS(",p="); + SX(ctx->lanes); + + SS("$"); + SB(ctx->salt, ctx->saltlen); + + SS("$"); + SB(ctx->out, ctx->outlen); + return ARGON2_OK; + +#undef SS +#undef SX +#undef SB +} + +size_t b64len(uint32_t len) { + size_t olen = ((size_t)len / 3) << 2; + + switch (len % 3) { + case 2: + olen++; + /* fall through */ + case 1: + olen += 2; + break; + } + + return olen; +} + +size_t numlen(uint32_t num) { + size_t len = 1; + while (num >= 10) { + ++len; + num = num / 10; + } + return len; +} |