From: Jeremy Harris Date: Fri, 22 Jan 2016 13:17:34 +0000 (+0000) Subject: PDKIM: Fix use of private-keys having trailing '=' in the base-64. Bug 1781 X-Git-Tag: exim-4_87_RC4~39 X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=commitdiff_plain;h=df3def249f555f5e6cbfa1bf3fb1a20db4f48fcd PDKIM: Fix use of private-keys having trailing '=' in the base-64. Bug 1781 --- diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index c4a2f00ce..1c862b597 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -164,6 +164,9 @@ JH/38 Fix cutthrough bug with body lines having a single dot. The dot was received - but deduplicating mailstores were liable to retain only the initial truncated version. +JH/39 Bug 1781: Fix use of private-keys having trailing '=' in the base-64. + + Exim version 4.86 ----------------- diff --git a/src/src/base64.c b/src/src/base64.c index ca6466bf2..031beb923 100644 --- a/src/src/base64.c +++ b/src/src/base64.c @@ -129,7 +129,7 @@ compact loop is messy and would probably run more slowly. Arguments: code points to the coded string, zero-terminated ptr where to put the pointer to the result, which is in - dynamic store, and zero-terminated + allocated store, and zero-terminated Returns: the number of bytes in the result, or -1 if the input was malformed @@ -163,35 +163,50 @@ quantum this may decode to 1, 2, or 3 output bytes. */ while ((x = *code++) != 0) { if (isspace(x)) continue; + /* debug_printf("b64d: '%c'\n", x); */ if (x > 127 || (x = dec64table[x]) == 255) return -1; while (isspace(y = *code++)) ; + /* debug_printf("b64d: '%c'\n", y); */ if (y == 0 || (y = dec64table[y]) == 255) return -1; *result++ = (x << 2) | (y >> 4); + /* debug_printf("b64d: -> %02x\n", result[-1]); */ while (isspace(x = *code++)) ; - if (x == '=') + /* debug_printf("b64d: '%c'\n", x); */ + if (x == '=') /* endmarker, but there should be another */ { while (isspace(x = *code++)) ; - if (x != '=' || *code != 0) return -1; + /* debug_printf("b64d: '%c'\n", x); */ + if (x != '=') return -1; + while (isspace(y = *code++)) ; + if (y != 0) return -1; + /* debug_printf("b64d: DONE\n"); */ + break; } else { if (x > 127 || (x = dec64table[x]) == 255) return -1; *result++ = (y << 4) | (x >> 2); + /* debug_printf("b64d: -> %02x\n", result[-1]); */ while (isspace(y = *code++)) ; + /* debug_printf("b64d: '%c'\n", y); */ if (y == '=') { - if (*code != 0) return -1; + while (isspace(y = *code++)) ; + if (y != 0) return -1; + /* debug_printf("b64d: DONE\n"); */ + break; } else { if (y > 127 || (y = dec64table[y]) == 255) return -1; *result++ = (x << 6) | y; + /* debug_printf("b64d: -> %02x\n", result[-1]); */ } } } @@ -201,23 +216,6 @@ return result - *ptr; } -/************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - ************************************************* - *************************************************/ - /************************************************* * Encode byte-string in base 64 * *************************************************/ diff --git a/src/src/dkim.c b/src/src/dkim.c index 33d1e9776..36b103e8f 100644 --- a/src/src/dkim.c +++ b/src/src/dkim.c @@ -158,7 +158,8 @@ for (sig = dkim_signatures; sig; sig = sig->next) "overlong public key record]"); break; - case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: + case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: + case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: logmsg = string_append(logmsg, &size, &ptr, 1, "syntax error in public key record]"); break; @@ -395,7 +396,8 @@ switch (what) { case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return US"pubkey_unavailable"; - case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: return US"pubkey_syntax"; + case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:return US"pubkey_dns_syntax"; + case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return US"pubkey_der_syntax"; case PDKIM_VERIFY_FAIL_BODY: return US"bodyhash_mismatch"; case PDKIM_VERIFY_FAIL_MESSAGE: return US"signature_incorrect"; } diff --git a/src/src/pdkim/pdkim.c b/src/src/pdkim/pdkim.c index a47b6940f..6e471a614 100644 --- a/src/src/pdkim/pdkim.c +++ b/src/src/pdkim/pdkim.c @@ -146,7 +146,8 @@ pdkim_verify_ext_status_str(int ext_status) case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE"; case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE"; case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE"; - case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: return "PDKIM_VERIFY_INVALID_PUBKEY_PARSING"; + case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD"; + case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT"; default: return "PDKIM_VERIFY_UNKNOWN"; } } @@ -1881,13 +1882,23 @@ while (sig) if ( !(p = Ustrstr(sig->rsa_privkey, "-----BEGIN RSA PRIVATE KEY-----")) || !(q = Ustrstr(p+=31, "-----END RSA PRIVATE KEY-----")) ) - return PDKIM_ERR_RSA_PRIVKEY; + return PDKIM_SIGN_PRIVKEY_WRAP; *q = '\0'; - if ( (len = b64decode(p, &p)) < 0 - || !(rsa = d2i_RSAPrivateKey(NULL, CUSS &p, len)) - ) - /*XXX todo: get errstring from library */ + if ((len = b64decode(p, &p)) < 0) + { + DEBUG(D_acl) debug_printf("b64decode failed\n"); + return PDKIM_SIGN_PRIVKEY_B64D; + } + if (!(rsa = d2i_RSAPrivateKey(NULL, CUSS &p, len))) + { + DEBUG(D_acl) + { + char ssl_errstring[256]; + ERR_error_string(ERR_get_error(), ssl_errstring); + debug_printf("d2i_RSAPrivateKey: %s\n", ssl_errstring); + } return PDKIM_ERR_RSA_PRIVKEY; + } #elif defined(RSA_GNUTLS) @@ -2013,7 +2024,7 @@ while (sig) if (!(sig->pubkey = pdkim_parse_pubkey_record(ctx, dns_txt_reply))) { sig->verify_status = PDKIM_VERIFY_INVALID; - sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING; + sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD; DEBUG(D_acl) debug_printf( " Error while parsing public key record\n" @@ -2052,7 +2063,7 @@ while (sig) } sig->verify_status = PDKIM_VERIFY_INVALID; - sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING; + sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; goto NEXT_VERIFY; } diff --git a/src/src/pdkim/pdkim.h b/src/src/pdkim/pdkim.h index 97a03eabc..313afd503 100644 --- a/src/src/pdkim/pdkim.h +++ b/src/src/pdkim/pdkim.h @@ -34,6 +34,8 @@ #define PDKIM_ERR_RSA_SIGNING -102 #define PDKIM_ERR_LONG_LINE -103 #define PDKIM_ERR_BUFFER_TOO_SMALL -104 +#define PDKIM_SIGN_PRIVKEY_WRAP -105 +#define PDKIM_SIGN_PRIVKEY_B64D -106 /* -------------------------------------------------------------------------- */ /* Main/Extended verification status */ @@ -46,7 +48,8 @@ #define PDKIM_VERIFY_FAIL_MESSAGE 2 #define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 3 #define PDKIM_VERIFY_INVALID_BUFFER_SIZE 4 -#define PDKIM_VERIFY_INVALID_PUBKEY_PARSING 5 +#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD 5 +#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT 6 /* -------------------------------------------------------------------------- */ /* Some parameter values */