Mercurial > hg > nginx
view src/core/ngx_crypt.c @ 7667:1ece2ac2555a
OCSP: fixed use-after-free on error.
When validating second and further certificates, ssl callback could be called
twice to report the error. After the first call client connection is
terminated and its memory is released. Prior to the second call and in it
released connection memory is accessed.
Errors triggering this behavior:
- failure to create the request
- failure to start resolving OCSP responder name
- failure to start connecting to the OCSP responder
The fix is to rearrange the code to eliminate the second call.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 15 Jun 2020 20:17:16 +0300 |
parents | 1064ea81ed3a |
children |
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/* * Copyright (C) Maxim Dounin */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_crypt.h> #include <ngx_md5.h> #include <ngx_sha1.h> #if (NGX_CRYPT) static ngx_int_t ngx_crypt_apr1(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted); static ngx_int_t ngx_crypt_plain(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted); static ngx_int_t ngx_crypt_ssha(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted); static ngx_int_t ngx_crypt_sha(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted); static u_char *ngx_crypt_to64(u_char *p, uint32_t v, size_t n); ngx_int_t ngx_crypt(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted) { if (ngx_strncmp(salt, "$apr1$", sizeof("$apr1$") - 1) == 0) { return ngx_crypt_apr1(pool, key, salt, encrypted); } else if (ngx_strncmp(salt, "{PLAIN}", sizeof("{PLAIN}") - 1) == 0) { return ngx_crypt_plain(pool, key, salt, encrypted); } else if (ngx_strncmp(salt, "{SSHA}", sizeof("{SSHA}") - 1) == 0) { return ngx_crypt_ssha(pool, key, salt, encrypted); } else if (ngx_strncmp(salt, "{SHA}", sizeof("{SHA}") - 1) == 0) { return ngx_crypt_sha(pool, key, salt, encrypted); } /* fallback to libc crypt() */ return ngx_libc_crypt(pool, key, salt, encrypted); } static ngx_int_t ngx_crypt_apr1(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted) { ngx_int_t n; ngx_uint_t i; u_char *p, *last, final[16]; size_t saltlen, keylen; ngx_md5_t md5, ctx1; /* Apache's apr1 crypt is Poul-Henning Kamp's md5 crypt with $apr1$ magic */ keylen = ngx_strlen(key); /* true salt: no magic, max 8 chars, stop at first $ */ salt += sizeof("$apr1$") - 1; last = salt + 8; for (p = salt; *p && *p != '$' && p < last; p++) { /* void */ } saltlen = p - salt; /* hash key and salt */ ngx_md5_init(&md5); ngx_md5_update(&md5, key, keylen); ngx_md5_update(&md5, (u_char *) "$apr1$", sizeof("$apr1$") - 1); ngx_md5_update(&md5, salt, saltlen); ngx_md5_init(&ctx1); ngx_md5_update(&ctx1, key, keylen); ngx_md5_update(&ctx1, salt, saltlen); ngx_md5_update(&ctx1, key, keylen); ngx_md5_final(final, &ctx1); for (n = keylen; n > 0; n -= 16) { ngx_md5_update(&md5, final, n > 16 ? 16 : n); } ngx_memzero(final, sizeof(final)); for (i = keylen; i; i >>= 1) { if (i & 1) { ngx_md5_update(&md5, final, 1); } else { ngx_md5_update(&md5, key, 1); } } ngx_md5_final(final, &md5); for (i = 0; i < 1000; i++) { ngx_md5_init(&ctx1); if (i & 1) { ngx_md5_update(&ctx1, key, keylen); } else { ngx_md5_update(&ctx1, final, 16); } if (i % 3) { ngx_md5_update(&ctx1, salt, saltlen); } if (i % 7) { ngx_md5_update(&ctx1, key, keylen); } if (i & 1) { ngx_md5_update(&ctx1, final, 16); } else { ngx_md5_update(&ctx1, key, keylen); } ngx_md5_final(final, &ctx1); } /* output */ *encrypted = ngx_pnalloc(pool, sizeof("$apr1$") - 1 + saltlen + 1 + 22 + 1); if (*encrypted == NULL) { return NGX_ERROR; } p = ngx_cpymem(*encrypted, "$apr1$", sizeof("$apr1$") - 1); p = ngx_copy(p, salt, saltlen); *p++ = '$'; p = ngx_crypt_to64(p, (final[ 0]<<16) | (final[ 6]<<8) | final[12], 4); p = ngx_crypt_to64(p, (final[ 1]<<16) | (final[ 7]<<8) | final[13], 4); p = ngx_crypt_to64(p, (final[ 2]<<16) | (final[ 8]<<8) | final[14], 4); p = ngx_crypt_to64(p, (final[ 3]<<16) | (final[ 9]<<8) | final[15], 4); p = ngx_crypt_to64(p, (final[ 4]<<16) | (final[10]<<8) | final[ 5], 4); p = ngx_crypt_to64(p, final[11], 2); *p = '\0'; return NGX_OK; } static u_char * ngx_crypt_to64(u_char *p, uint32_t v, size_t n) { static u_char itoa64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; while (n--) { *p++ = itoa64[v & 0x3f]; v >>= 6; } return p; } static ngx_int_t ngx_crypt_plain(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted) { size_t len; u_char *p; len = ngx_strlen(key); *encrypted = ngx_pnalloc(pool, sizeof("{PLAIN}") - 1 + len + 1); if (*encrypted == NULL) { return NGX_ERROR; } p = ngx_cpymem(*encrypted, "{PLAIN}", sizeof("{PLAIN}") - 1); ngx_memcpy(p, key, len + 1); return NGX_OK; } static ngx_int_t ngx_crypt_ssha(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted) { size_t len; ngx_int_t rc; ngx_str_t encoded, decoded; ngx_sha1_t sha1; /* "{SSHA}" base64(SHA1(key salt) salt) */ /* decode base64 salt to find out true salt */ encoded.data = salt + sizeof("{SSHA}") - 1; encoded.len = ngx_strlen(encoded.data); len = ngx_max(ngx_base64_decoded_length(encoded.len), 20); decoded.data = ngx_pnalloc(pool, len); if (decoded.data == NULL) { return NGX_ERROR; } rc = ngx_decode_base64(&decoded, &encoded); if (rc != NGX_OK || decoded.len < 20) { decoded.len = 20; } /* update SHA1 from key and salt */ ngx_sha1_init(&sha1); ngx_sha1_update(&sha1, key, ngx_strlen(key)); ngx_sha1_update(&sha1, decoded.data + 20, decoded.len - 20); ngx_sha1_final(decoded.data, &sha1); /* encode it back to base64 */ len = sizeof("{SSHA}") - 1 + ngx_base64_encoded_length(decoded.len) + 1; *encrypted = ngx_pnalloc(pool, len); if (*encrypted == NULL) { return NGX_ERROR; } encoded.data = ngx_cpymem(*encrypted, "{SSHA}", sizeof("{SSHA}") - 1); ngx_encode_base64(&encoded, &decoded); encoded.data[encoded.len] = '\0'; return NGX_OK; } static ngx_int_t ngx_crypt_sha(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted) { size_t len; ngx_str_t encoded, decoded; ngx_sha1_t sha1; u_char digest[20]; /* "{SHA}" base64(SHA1(key)) */ decoded.len = sizeof(digest); decoded.data = digest; ngx_sha1_init(&sha1); ngx_sha1_update(&sha1, key, ngx_strlen(key)); ngx_sha1_final(digest, &sha1); len = sizeof("{SHA}") - 1 + ngx_base64_encoded_length(decoded.len) + 1; *encrypted = ngx_pnalloc(pool, len); if (*encrypted == NULL) { return NGX_ERROR; } encoded.data = ngx_cpymem(*encrypted, "{SHA}", sizeof("{SHA}") - 1); ngx_encode_base64(&encoded, &decoded); encoded.data[encoded.len] = '\0'; return NGX_OK; } #endif /* NGX_CRYPT */